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Sample records for deep-sea demersal fish

  1. The importance of deep-sea vulnerable marine ecosystems for demersal fish in the Azores

    NASA Astrophysics Data System (ADS)

    Pham, Christopher K.; Vandeperre, Frederic; Menezes, Gui; Porteiro, Filipe; Isidro, Eduardo; Morato, Telmo

    2015-02-01

    Cold-water corals and sponges aggregations are important features of the deep sea, recently classified as vulnerable marine ecosystems (VMEs). VMEs increase habitat complexity, believed to act as feeding, reproductive, nursery and refuge areas for a high number of invertebrates and fish species. In the Azores archipelago (NE Atlantic), VMEs are prevalent but their ecological role has not received much attention. The objective of this study was to investigate the importance of VMEs in influencing the distribution of demersal fish in the Azores. With data collected during experimental longline surveys , we modeled the catch of six demersal fish species of commercial value (Helicolenus dactylopterus, Pagellus bogaraveo, Mora moro, Conger conger, Phycis phycis, Pontinus kuhlii) in relation to the presence of VMEs and other environmental factors using General Additive Models (GAMs). Our study demonstrated that total fish catch was higher inside VMEs but the relationship between fish and VMEs varied among fish species. Species specific models showed that catch was strongly influenced by environmental factors, mainly depth, whilst the presence of VMEs was only important for two rockfish species; juvenile and adult P. kuhlii and juvenile H. dactylopterus. Although the association between deep-sea demersal fish and VMEs may be an exception to the rule, we suggest that VMEs act as an important habitat for two commercially important species in the Azores.

  2. A continuum of life histories in deep-sea demersal fishes

    NASA Astrophysics Data System (ADS)

    Drazen, Jeffrey C.; Haedrich, Richard L.

    2012-03-01

    It is generally perceived that all deep-sea fishes have great longevity, slow growth, and low reproductive output in comparison to shelf dwelling species. However, such a dichotomy is too simplistic because some fishes living on continental slopes are relatively fecund and fast growing, important considerations in respect to the management of expanding deep-sea fisheries. We tested two hypotheses that might explain variation in life history attributes of commercially exploited demersal fishes: (1) phylogeny best explains the differences because deep-sea species are often in different families from shelf dwelling ones and, alternatively, (2) environmental factors affecting individual life history attributes that change with depth account for the observed variation. Our analysis was based on 40 species from 9 orders, including all major commercially exploited deep-sea fishes and several phylogenetically related shelf species. Depth of occurrence correlated significantly with age at 50% maturity increasing linearly with depth (r2=0.46), while the von Bertalanffy growth coefficient, maximum fecundity and potential rate of population increase declined significantly and exponentially with depth (r2=0.41, 0.25 and 0.53, respectively). These trends were still significant when phylogenetically independent contrasts were applied. The trends were also consistent with similar slopes amongst members of the order Gadiformes and the order Scorpaeniformes. Reduced temperatures, predation pressure, food availability, or metabolic rates may all contribute to such changes with depth. Regardless of the mechanisms, by analyzing a suite of fishes from the shelves to the slope the present analysis has shown that rather than a simple dichotomy between deep-sea fishes and shelf fishes there is a continuum of life history attributes in fishes which correlate strongly with depth of occurrence.

  3. Fish parasites in the Arctic deep-sea: Poor diversity in pelagic fish species vs. heavy parasite load in a demersal fish

    NASA Astrophysics Data System (ADS)

    Klimpel, Sven; Palm, Harry Wilhelm; Busch, Markus Wilhelm; Kellermanns, Esra; Rückert, Sonja

    2006-07-01

    A total of 219 deep-sea fishes belonging to five families were examined for the parasite fauna and stomach contents. The demersal fish Macrourus berglax, bathypelagic Bathylagus euryops, and mesopelagic Argentina silus, Borostomias antarcticus, Chauliodus sloani, and Lampanyctus macdonaldi were caught at 243-708 m trawling depth in the Greenland and the Irminger Sea in 2002. A total of 21 different parasite species, six Digenea, one Monogenea, two Cestoda, seven Nematoda, one Acanthocephala, and four Crustacea, were found. The parasite diversity in the meso- and bathypelagic environment was less diverse in comparison to the benthal. Macrourus berglax had the highest diversity (20 species), usually carrying 4-10 different parasite species (mean 7.1), whereas Bathylagus euryops harbored up to three and Argentina silus, Borostomias antarcticus, Chauliodus sloani and Lampanyctus macdonaldi each up to two species. Most Digenea, Cestoda, Nematoda, Acanthocephala, and Crustacea are known from a wide host range. Several of the encountered parasites occurred at a very low prevalence (<10%), indicating that the studied deep-sea fishes are most probably not instrumental to complete the parasite life cycles in the area of investigation. It is suggested that the lack of nutrients in the meso- and bathypelagial limits the abundance of potential first intermediate hosts of nematodes and cestodes, resulting in low infestation rates even of widely distributed, non-specific species. In contrast, the higher biomass in the benthic deep-sea environment increases the availability of potential intermediate hosts, such as molluscs for the digeneans, resulting in increased parasite diversity. Because many deep-sea fish have a generalistic feeding behavior, the observed different parasite diversity reflects a different depth range of the fish and not necessarily a specific fish feeding ecology.

  4. Trophodynamics of a deep-sea demersal fish assemblage from the bathyal eastern Ionian Sea (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Madurell, T.; Cartes, J. E.

    2005-11-01

    Daily food consumption of the eight dominant demersal fish species of the bathyal eastern Ionian Sea were determined from field data on four seasonal cruises (April 1999, July August 1999, November 1999 and February 2000). Daily ration (DR) estimates ranged from 0.198 to 4.273% WW/WW. Overall, DR estimates were independent of the model used, and they were comparable to the daily consumption of other deep-sea fauna (e.g. fish and crustaceans). Both sharks studied ( Galeus melastomus and Etmopterus spinax) exhibited the highest values of DRs, together with the macrourid Coelorhynchus coelorhynchus in August. Among osteichthyes, DR estimates were related (in a multi-linear regression model) to the nature of their diet (i.e. their trophic level deduced from δ15N isotopic composition, the mean number of prey and trophic diversity). Thus, species feeding at a lower trophic level, ingesting a large number of prey items and with a very diversified diet had higher DR than species from higher trophic level and feeding fewer prey items. By season, the DR of species feeding mainly on mesopelagic prey ( Hoplostethus mediterraneus and Helicolenus dactylopterus) were higher in summer, while DR for benthos/suprabenthos feeders (i.e. C. coelorhynchus and Nezumia sclerorhynchus) were higher in spring. Higher food consumption coincides with maximum food availability, both among mesopelagic feeders (higher availability of euphausiids, Pasiphaea sivado and Sergestes arcticus in summer) and among Macrouridae (higher suprabenthos densities in spring). In a tentative estimate the energy intake deduced from diet (i.e. mean energy value of food ingested) was constant in all seasons for each species studied. Results for the energy intake also indicate higher energy intake in the diet of mesopelagic feeders than in the diet of benthic feeders. Overall results are discussed in relation to the deep-sea ecosystem structure and functioning.

  5. Putative fishery-induced changes in biomass and population size structures of demersal deep-sea fishes in ICES Sub-area VII, Northeast Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Godbold, J. A.; Bailey, D. M.; Collins, M. A.; Gordon, J. D. M.; Spallek, W. A.; Priede, I. G.

    2013-01-01

    A time series from 1977-1989 and 2000-2002 of scientific trawl surveys in the Porcupine Seabight and adjacent abyssal plain of the NE Atlantic was analysed to assess changes in demersal fish biomass and length frequency. These two periods coincide with the onset of the commercial deep-water fishery in the late 1970s and the onset of the regulation of the fishery in the early 2000's, which allowed us to investigate changes in the relationship between total demersal fish biomass and depth between the pre- and post commercial fishing periods, as well as changes in the biomass (kg km-2) depth distribution and length frequency distribution of the most dominant fish species. Our results show a decline in total demersal fish biomass of 36% within the depth range of the commercial fishery (< 1500 m). Whilst there were significant declines in target (e.g. Coryphaenoides rupestris decreased by 57%) and non-target (e.g. C. guentheri and Antimora rostrata) species, not all species declined significantly. Changes in the overall length-frequency distribution were detected for 5 out of the 8 dominant species occupying depth ranges both within and outside the maximum depth for commercial trawling. This suggests that whilst there is evidence for likely fishery impacts on the biomass distribution of the demersal fish population as a whole, species-specific impacts are highly variable. It is clear that changes in population structure can extend beyond the depth at which fishing takes place, highlighting the importance for also considering the indirect effects on deep-sea fish populations.

  6. Demersal fishes from the Antarctic shelf and deep sea: A diet study based on fatty acid patterns and gut content analyses

    NASA Astrophysics Data System (ADS)

    Würzberg, Laura; Peters, Janna; Flores, Hauke; Brandt, Angelika

    2011-10-01

    The gut contents and fatty acid composition of 49 fish belonging to five Antarctic demersal families (Nototheniidae, Macrouridae, Channichtyidae, Bathydraconidae and Artedidraconidae) sampled at two stations at the Southern Ocean shelf and deep sea (600 and 2150 m) were analysed in order to identify their main food resource by linking trophic biomarkers with the dietary items found in the fish guts. Main food items of most fish analysed were amphipod crustaceans (e.g. in 63% of Trematomus bernachii guts) and polychaetes (e.g. in 80% of Bathydraco sp. guts), but other food items including fish, other crustaceans and gastropods were also ingested. The most prominent fatty acids found were 20:5( n-3), 16:0, 22:6( n-3) and 18:1( n-9). The results of gut content and fatty acid analyses indicate that all fish except the Channichthyidae share similar food resources irrespective of their depth distribution, i.e. benthic amphipods and polychaetes. A difference of the dietary spectrum can be observed with ontogenetic phases rather than between species, as high values of typical calanoid copepod marker fatty acids as 22:1( n-11) indicate that younger (smaller) specimens include more zooplankton in their diet.

  7. Colonization of the deep sea by fishes.

    PubMed

    Priede, I G; Froese, R

    2013-12-01

    Analysis of maximum depth of occurrence of 11 952 marine fish species shows a global decrease in species number (N) with depth (x; m): log10 N = -0·000422x + 3·610000 (r(2)  = 0·948). The rate of decrease is close to global estimates for change in pelagic and benthic biomass with depth (-0·000430), indicating that species richness of fishes may be limited by food energy availability in the deep sea. The slopes for the Classes Myxini (-0·000488) and Actinopterygii (-0·000413) follow this trend but Chondrichthyes decrease more rapidly (-0·000731) implying deficiency in ability to colonize the deep sea. Maximum depths attained are 2743, 4156 and 8370 m for Myxini, Chondrichthyes and Actinopterygii, respectively. Endemic species occur in abundance at 7-7800 m depth in hadal trenches but appear to be absent from the deepest parts of the oceans, >9000 m deep. There have been six global oceanic anoxic events (OAE) since the origin of the major fish taxa in the Devonian c. 400 million years ago (mya). Colonization of the deep sea has taken place largely since the most recent OAE in the Cretaceous 94 mya when the Atlantic Ocean opened up. Patterns of global oceanic circulation oxygenating the deep ocean basins became established coinciding with a period of teleost diversification and appearance of the Acanthopterygii. Within the Actinopterygii, there is a trend for greater invasion of the deep sea by the lower taxa in accordance with the Andriashev paradigm. Here, 31 deep-sea families of Actinopterygii were identified with mean maximum depth >1000 m and with >10 species. Those with most of their constituent species living shallower than 1000 m are proposed as invasive, with extinctions in the deep being continuously balanced by export of species from shallow seas. Specialized families with most species deeper than 1000 m are termed deep-sea endemics in this study; these appear to persist in the deep by virtue of global distribution enabling recovery

  8. Colonization of the deep sea by fishes

    PubMed Central

    Priede, I G; Froese, R

    2013-01-01

    Analysis of maximum depth of occurrence of 11 952 marine fish species shows a global decrease in species number (N) with depth (x; m): log10N = −0·000422x + 3·610000 (r2 = 0·948). The rate of decrease is close to global estimates for change in pelagic and benthic biomass with depth (−0·000430), indicating that species richness of fishes may be limited by food energy availability in the deep sea. The slopes for the Classes Myxini (−0·000488) and Actinopterygii (−0·000413) follow this trend but Chondrichthyes decrease more rapidly (−0·000731) implying deficiency in ability to colonize the deep sea. Maximum depths attained are 2743, 4156 and 8370 m for Myxini, Chondrichthyes and Actinopterygii, respectively. Endemic species occur in abundance at 7–7800 m depth in hadal trenches but appear to be absent from the deepest parts of the oceans, >9000 m deep. There have been six global oceanic anoxic events (OAE) since the origin of the major fish taxa in the Devonian c. 400 million years ago (mya). Colonization of the deep sea has taken place largely since the most recent OAE in the Cretaceous 94 mya when the Atlantic Ocean opened up. Patterns of global oceanic circulation oxygenating the deep ocean basins became established coinciding with a period of teleost diversification and appearance of the Acanthopterygii. Within the Actinopterygii, there is a trend for greater invasion of the deep sea by the lower taxa in accordance with the Andriashev paradigm. Here, 31 deep-sea families of Actinopterygii were identified with mean maximum depth >1000 m and with >10 species. Those with most of their constituent species living shallower than 1000 m are proposed as invasive, with extinctions in the deep being continuously balanced by export of species from shallow seas. Specialized families with most species deeper than 1000 m are termed deep-sea endemics in this study; these appear to persist in the deep by virtue of global distribution enabling

  9. Colonization of the deep sea by fishes.

    PubMed

    Priede, I G; Froese, R

    2013-12-01

    Analysis of maximum depth of occurrence of 11 952 marine fish species shows a global decrease in species number (N) with depth (x; m): log10 N = -0·000422x + 3·610000 (r(2)  = 0·948). The rate of decrease is close to global estimates for change in pelagic and benthic biomass with depth (-0·000430), indicating that species richness of fishes may be limited by food energy availability in the deep sea. The slopes for the Classes Myxini (-0·000488) and Actinopterygii (-0·000413) follow this trend but Chondrichthyes decrease more rapidly (-0·000731) implying deficiency in ability to colonize the deep sea. Maximum depths attained are 2743, 4156 and 8370 m for Myxini, Chondrichthyes and Actinopterygii, respectively. Endemic species occur in abundance at 7-7800 m depth in hadal trenches but appear to be absent from the deepest parts of the oceans, >9000 m deep. There have been six global oceanic anoxic events (OAE) since the origin of the major fish taxa in the Devonian c. 400 million years ago (mya). Colonization of the deep sea has taken place largely since the most recent OAE in the Cretaceous 94 mya when the Atlantic Ocean opened up. Patterns of global oceanic circulation oxygenating the deep ocean basins became established coinciding with a period of teleost diversification and appearance of the Acanthopterygii. Within the Actinopterygii, there is a trend for greater invasion of the deep sea by the lower taxa in accordance with the Andriashev paradigm. Here, 31 deep-sea families of Actinopterygii were identified with mean maximum depth >1000 m and with >10 species. Those with most of their constituent species living shallower than 1000 m are proposed as invasive, with extinctions in the deep being continuously balanced by export of species from shallow seas. Specialized families with most species deeper than 1000 m are termed deep-sea endemics in this study; these appear to persist in the deep by virtue of global distribution enabling recovery

  10. Deep-sea macrourid fishes scavenge on plant material: Evidence from in situ observations

    NASA Astrophysics Data System (ADS)

    Jeffreys, Rachel M.; Lavaleye, Marc S. S.; Bergman, Magda J. N.; Duineveld, Gerard C. A.; Witbaard, Rob; Linley, Thom

    2010-04-01

    Deep-sea benthic communities primarily rely on an allochthonous food source. This may be in the form of phytodetritus or as food falls e.g. sinking carcasses of nekton or debris of marine macrophyte algae. Deep-sea macrourids are the most abundant demersal fish in the deep ocean. Macrourids are generally considered to be the apex predators/scavengers in deep-sea communities. Baited camera experiments and stable isotope analyses have demonstrated that animal carrion derived from the surface waters is an important component in the diets of macrourids; some macrourid stomachs also contained vegetable/plant material e.g. onion peels, oranges, algae. The latter observations led us to the question: is plant material an attractive food source for deep-sea scavenging fish? We simulated a plant food fall using in situ benthic lander systems equipped with a baited time-lapse camera. Abyssal macrourids and cusk-eels were attracted to the bait, both feeding vigorously on the bait, and the majority of the bait was consumed in <30 h. These observations indicate (1) plant material can produce an odour plume similar to that of animal carrion and attracts deep-sea fish, and (2) deep-sea fish readily eat plant material. This represents to our knowledge the first in situ documentation of deep-sea fish ingesting plant material and highlights the variability in the scavenging nature of deep-sea fishes. This may have implications for food webs in areas where macrophyte/seagrass detritus is abundant at the seafloor e.g. canyon systems and continental shelves close to seagrass meadows (Bahamas and Mediterranean).

  11. Implication of the visual system in the regulation of activity cycles in the absence of solar light: 2-[125I]iodomelatonin binding sites and melatonin receptor gene expression in the brains of demersal deep-sea gadiform fish

    PubMed Central

    Priede, I. G.; Williams, L. M.; Wagner, H.-J.; Thom, A.; Brierley, I.; Collins, M. A.; Collin, S. P.; Merrett, N. R.; Yau, C.

    1999-01-01

    Relative eye size, gross brain morphology and central localization of 2-[125I]iodomelatonin binding sites and melatonin receptor gene expression were compared in six gadiform fish living at different depths in the north-east Atlantic Ocean: Phycis blennoides (capture depth range 265 to 1260 m), Nezumia aequalis (445 to 1512 m), Coryphaenoides rupestris (706 to 1932 m), Trachyrincus murrayi (1010 to 1884 m), Coryphaenoides guentheri (1030 m) and Coryphaenoides (Nematonurus) armatus (2172 to 4787 m). Amongst these, the eye size range was 0.15 to 0.35 of head length with a value of 0.19 for C. (N.) armatus, the deepest species. Brain morphology reflected behavioural differences with well-developed olfactory regions in P. blennoides, T. murrayi and C. (N.) armatus and evidence of olfactory deficit in N. aequalis, C. rupestris and C. guentheri. All species had a clearly defined optic tectum with 2-[125I]iodomelatonin binding and melatonin receptor gene expression localized to specific brain regions in a similar pattern to that found in shallow-water fish. Melatonin receptors were found throughout the visual structures of the brains of all species. Despite living beyond the depth of penetration of solar light these fish have retained central features associated with the coupling of cycles of growth, behaviour and reproduction to the diel light–dark cycle. How this functions in the deep sea remains enigmatic.

  12. Fisheries: deep-sea fishes qualify as endangered.

    PubMed

    Devine, Jennifer A; Baker, Krista D; Haedrich, Richard L

    2006-01-01

    Criteria from the World Conservation Union (IUCN) have been used to classify marine fish species as endangered since 1996, but deep-sea fish have not so far been evaluated--despite their vulnerability to aggressive deepwater fishing as a result of certain life-history traits. Here we use research-survey data to show that five species of deep-sea fish have declined over a 17-year period in the Canadian waters of the northwest Atlantic to such an extent that they meet the IUCN criteria for being critically endangered. Our results indicate that urgent action is needed for the sustainable management of deep-sea fisheries.

  13. A Scientific Basis for Regulating Deep-Sea Fishing by Depth.

    PubMed

    Clarke, Jo; Milligan, Rosanna J; Bailey, David M; Neat, Francis C

    2015-09-21

    The deep sea is the world's largest ecosystem, with high levels of biodiversity and many species that exhibit life-history characteristics that make them vulnerable to high levels of exploitation. Many fisheries in the deep sea have a track record of being unsustainable. In the northeast Atlantic, there has been a decline in the abundance of commercial fish species since deep-sea fishing commenced in the 1970s. Current management is by effort restrictions and total allowable catch (TAC), but there remain problems with compliance and high levels of bycatch of vulnerable species such as sharks. The European Union is currently considering new legislation to manage deep-sea fisheries, including the introduction of a depth limit to bottom trawling. However, there is little evidence to suggest an appropriate depth limit. Here we use survey data to show that biodiversity of the demersal fish community, the ratio of discarded to commercial biomass, and the ratio of Elasmobranchii (sharks and rays) to commercial biomass significantly increases between 600 and 800 m depth while commercial value decreases. These results suggest that limiting bottom trawling to a maximum depth of 600 m could be an effective management strategy that would fit the needs of European legislations such as the Common Fisheries Policy (EC no. 1380/2013) and the Marine Strategy Framework Directive (2008/56/EC).

  14. A Scientific Basis for Regulating Deep-Sea Fishing by Depth.

    PubMed

    Clarke, Jo; Milligan, Rosanna J; Bailey, David M; Neat, Francis C

    2015-09-21

    The deep sea is the world's largest ecosystem, with high levels of biodiversity and many species that exhibit life-history characteristics that make them vulnerable to high levels of exploitation. Many fisheries in the deep sea have a track record of being unsustainable. In the northeast Atlantic, there has been a decline in the abundance of commercial fish species since deep-sea fishing commenced in the 1970s. Current management is by effort restrictions and total allowable catch (TAC), but there remain problems with compliance and high levels of bycatch of vulnerable species such as sharks. The European Union is currently considering new legislation to manage deep-sea fisheries, including the introduction of a depth limit to bottom trawling. However, there is little evidence to suggest an appropriate depth limit. Here we use survey data to show that biodiversity of the demersal fish community, the ratio of discarded to commercial biomass, and the ratio of Elasmobranchii (sharks and rays) to commercial biomass significantly increases between 600 and 800 m depth while commercial value decreases. These results suggest that limiting bottom trawling to a maximum depth of 600 m could be an effective management strategy that would fit the needs of European legislations such as the Common Fisheries Policy (EC no. 1380/2013) and the Marine Strategy Framework Directive (2008/56/EC). PMID:26320948

  15. In situ comparison of activity in two deep-sea scavenging fishes occupying different depth zones

    PubMed Central

    Collins, M. A.; Priede, I. G.; Bagley, P. M.

    1999-01-01

    The activity of two scavenging deep-sea fishes occupying the same niche in overlapping depth zones were compared by in situ measurements of swimming speeds, tail-beat frequencies and by arrival time at baits. At 4800 m on the Porcupine Abyssal Plain, the grenadier Coryphaenoides (Nematonurus) armatus was the dominant scavenger, arriving at baits after 30 min, and swimming at relatively slow speeds of 0.17 body lengths (BL) sec-1. At 2500 m in the relatively food rich Porcupine Seabight both C. (N.) armatus and the blue-hake, Antimora rostrata, were attracted to bait, but A. rostrata was always the first to arrive and most of the bait was consumed before the C. (N.) armatus arrived. A. rostrata swam at mean speeds of 0.39 BL sec-1, similar to related shallow water species at equivalent temperatures. Observations on tail-beat frequency from video sequences confirmed the greater activity of A. rostrata. The data indicate that, given sufficient food supply, high pressure and low temperature do not limit activity levels of demersal deep-sea fishes. Low activity of C. (N.) armatus is an adaptation to poor food supply in the abyss, where these fishes dominate, but prevents it competing with the more active A. rostrata in shallower depths.

  16. Autonomous video camera system for monitoring impacts to benthic habitats from demersal fishing gear, including longlines

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Robert; Ewing, Graeme; Lamb, Tim; Welsford, Dirk; Constable, Andrew

    2011-04-01

    Studies of the interactions of demersal fishing gear with the benthic environment are needed in order to manage conservation of benthic habitats. There has been limited direct assessment of these interactions through deployment of cameras on commercial fishing gear especially on demersal longlines. A compact, autonomous deep-sea video system was designed and constructed by the Australian Antarctic Division (AAD) for deployment on commercial fishing gear to observe interactions with benthos in the Southern Ocean finfish fisheries (targeting toothfish, Dissostichus spp). The Benthic Impacts Camera System (BICS) is capable of withstanding depths to 2500 m, has been successfully fitted to both longline and demersal trawl fishing gear, and is suitable for routine deployment by non-experts such as fisheries observers or crew. The system is entirely autonomous, robust, compact, easy to operate, and has minimal effect on the performance of the fishing gear it is attached to. To date, the system has successfully captured footage that demonstrates the interactions between demersal fishing gear and the benthos during routine commercial operations. It provides the first footage demonstrating the nature of the interaction between demersal longlines and benthic habitats in the Southern Ocean, as well as showing potential as a tool for rapidly assessing habitat types and presence of mobile biota such as krill ( Euphausia superba).

  17. Functional, size and taxonomic diversity of fish along a depth gradient in the deep sea

    PubMed Central

    Neat, Francis C.; Trueman, Clive N.; Webb, Thomas J.; Blanchard, Julia L.

    2016-01-01

    Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300–2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf. PMID:27672494

  18. Functional, size and taxonomic diversity of fish along a depth gradient in the deep sea

    PubMed Central

    Neat, Francis C.; Trueman, Clive N.; Webb, Thomas J.; Blanchard, Julia L.

    2016-01-01

    Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300–2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf.

  19. Functional, size and taxonomic diversity of fish along a depth gradient in the deep sea.

    PubMed

    Mindel, Beth L; Neat, Francis C; Trueman, Clive N; Webb, Thomas J; Blanchard, Julia L

    2016-01-01

    Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300-2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf. PMID:27672494

  20. [Some peculiarities of brain phospholipids in deep sea fishes].

    PubMed

    Pomazanskaia, L F; Pravdina, N I; Chirkovskaia, E V

    1975-01-01

    Total phospholipids (PL) as well as the content of various phospholipid classes and their fatty acid composition have been investigated in the brain of mesopelagic and abyssal marine teleosts. These species were compared to shallow water ones. The brain of deep sea fishes was found to be very poor in PL as compared to the brain of mesopelagic ans surface water species. No differences concerning the brain PL content were revealed between the two last mentioned groups. The relative content of separate PL classes was very similar in all the species studied irrespectively of the depth of their habitat. Peculiarities were found in fatty acid composition of individual PL from deep sea species as compared to surface ones. The deeper the habitat, the lower the content of saturated fatty acids, especially of the stearic acid. The lowest content of saturated fatty acids, maximum level of polyenoic fatty acids as well as some peculiarities in the relative content of particular fatty acids were found in the brain of ultraabyssal (6, 000 m) Leucicorus sp. PMID:1217333

  1. Characterization of Deep Sea Fish Gut Bacteria with Antagonistic Potential, from Centroscyllium fabricii (Deep Sea Shark).

    PubMed

    Bindiya, E S; Tina, K J; Raghul, Subin S; Bhat, Sarita G

    2015-06-01

    The bacterial isolates from Centroscyllium fabricii (deep sea shark) gut were screened for antagonistic activity by cross-streak method and disc diffusion assay. This study focuses on strain BTSS-3, which showed antimicrobial activity against pathogenic bacteria including Salmonella Typhimurium, Proteus vulgaris, Clostridium perfringens, Staphylococcus aureus, Bacillus cereus, Bacillus circulans, Bacillus macerans and Bacillus pumilus. BTSS3 was subjected to phenotypic characterization using biochemical tests, SEM imaging, exoenzyme profiling and antibiotic susceptibility tests. Comparative 16S rDNA gene sequence analysis indicated that this strain belonged to the genus Bacillus, with high (98%) similarity to 16S rDNA sequences of Bacillus amyloliquefaciens. The chemical nature of the antibacterial substance was identified by treatment with proteolytic enzymes. The antibacterial activity was reduced by the action of these enzymes pointing out its peptide nature. It was observed from the growth and production kinetics that the bacteriocin was produced in the eighth hour of incubation, i.e., during the mid-log growth phase of the bacteria. PMID:25740801

  2. Brain areas in abyssal demersal fishes.

    PubMed

    Wagner, H J

    2001-06-01

    Four areas of the brain which receive primary projections from chemical senses ([1] olfactory bulb, [2] gustatory area including facial and vagal lobes), the eye ([3] optic tectum), and mechanosensory, and-hair-cell based systems i.e. the lateral line, vestibular and auditory systems ([4] trigeminal and octavolateral regions) have been studied and relative size differences used to make deductions on the sensory preferences of 35 fish species living on or near the bottom of the deep sea. Furthermore the relative volumes of the telencephalon and the corpus cerebelli were determined. Two evaluation modes were applied: (1) the relative mean of each system was calculated and species with above-average areas identified; (2) a cluster analysis established multivariate correlations among the sensory systems. The diversity of sensory brain areas in this population of fish suggests that the benthic and epibenthic environment of the abyss presents a rich sensory environment. Vision seems to be the single most important sense suggesting the presence of relevant bioluminescent stimuli. However, in combination the chemical senses, smell and taste, surpass the visual system; most prominent among them is olfaction. The trigeminal/octavolateral area indicating the role of lateral line input and possibly audition is also well represented, but only in association with other sensory modalities. A large volume telencephalon was often observed in combination with a prominent olfactory system, whereas cerebella of unusually large sizes occurred in species with above-average visual, hair-cell based, but also olfactory systems, confirming their role as multimodal sensorimotor coordination centers. In several species the predictions derived from the volumetric brain analyses were confirmed by earlier observations of stomach content and data obtained by baited cameras. PMID:11713385

  3. A Dataset of Deep-Sea Fishes Surveyed by Research Vessels in the Waters around Taiwan

    PubMed Central

    Shao, Kwang-Tsao; Lin, Jack; Yeh, Hsin-Ming; Lee, Mao-Yin; Chen, Lee-Sea; Lin, Hen-Wei

    2014-01-01

    Abstract The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the “Database of Taiwan’s Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/)” as part of the “Fish Database of Taiwan,” can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity. PMID:25610339

  4. A Dataset of Deep-Sea Fishes Surveyed by Research Vessels in the Waters around Taiwan.

    PubMed

    Shao, Kwang-Tsao; Lin, Jack; Yeh, Hsin-Ming; Lee, Mao-Yin; Chen, Lee-Sea; Lin, Hen-Wei

    2014-01-01

    The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the "Database of Taiwan's Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/)" as part of the "Fish Database of Taiwan," can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity.

  5. Habitat Specialization in Tropical Continental Shelf Demersal Fish Assemblages

    PubMed Central

    Fitzpatrick, Ben M.; Harvey, Euan S.; Heyward, Andrew J.; Twiggs, Emily J.; Colquhoun, Jamie

    2012-01-01

    The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1–10 m depth), down the fore reef slope to the reef base (10–30 m depth) then across the adjacent continental shelf (30–110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected

  6. Habitat specialization in tropical continental shelf demersal fish assemblages.

    PubMed

    Fitzpatrick, Ben M; Harvey, Euan S; Heyward, Andrew J; Twiggs, Emily J; Colquhoun, Jamie

    2012-01-01

    The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth), down the fore reef slope to the reef base (10-30 m depth) then across the adjacent continental shelf (30-110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats

  7. Mercury in recent and century-old deep-sea fish. [Antimora rostrata

    SciTech Connect

    Barber, R.T.; Whaling, P.J.; Cohen, D.M.

    1984-01-01

    To determine if mercury discharges to the environment in the last century have increased the mercury content of marine fish, a sample of 21 specimens of one deep-sea fish species collected in the 1880s was compared with a sample of 66 specimens of the same species collected in the 1970s. The specimens of Antimore rostrata were collected from between 2000 and 3000 m in the western North Atlantic Ocean. In both recent and old fish mercury increased as a function of length, but comparison of the two concentration vs. length relationships shows that there has not been an increase in mercury concentration in deep-sea fish in the last century. This result supports the idea that the relatively high concentrations of mercury found in marine fish that inhabit the surface and deep waters of the open ocean result from natural processes, not 20th century industrial pollution.

  8. The economic implications of changing regulations for deep sea fishing under the European Common Fisheries Policy: UK case study.

    PubMed

    Mangi, Stephen C; Kenny, Andrew; Readdy, Lisa; Posen, Paulette; Ribeiro-Santos, Ana; Neat, Francis C; Burns, Finlay

    2016-08-15

    Economic impact assessment methodology was applied to UK fisheries data to better understand the implications of European Commission proposal for regulations to fishing for deep-sea stocks in the North-East Atlantic (EC COM 371 Final 2012) under the Common Fisheries Policy (CFP). The aim was to inform the on-going debate to develop the EC proposal, and to assist the UK fishing industry and Government in evaluating the most effective options to manage deep sea fish stocks. Results indicate that enforcing the EC proposal as originally drafted results in a number of implications for the UK fleet. Because of the proposed changes to the list of species defined as being deep sea species, and a new definition of what constitutes a vessel targeting deep sea species, a total of 695 active UK fishing vessels would need a permit to fish for deep sea species. However, due to existing and capped capacity limits many vessels would potentially not be able to obtain such a permit. The economic impact of these changes from the status quo reveals that in the short term, landings would decrease by 6540 tonnes, reducing gross value added by £3.3 million. Alternative options were also assessed that provide mitigation measures to offset the impacts of the proposed regulations whilst at the same time providing more effective protection of deep sea Vulnerable Marine Ecosystems (VMEs). The options include setting a 400m depth rule that identifies a depth beyond which vessels would potentially be classified as fishing for deep sea species and designating 'core areas' for deep sea fishing at depths>400m to minimise the risk of further impacts of bottom fishing gear on deep sea habitats. Applying a 400m depth limit and 'core fishing' area approach deeper than 400m, the impact of the EC proposal would essentially be reduced to zero, that is, on average no vessels (using the status quo capacity baseline) would be impacted by the proposal. PMID:27100006

  9. The economic implications of changing regulations for deep sea fishing under the European Common Fisheries Policy: UK case study.

    PubMed

    Mangi, Stephen C; Kenny, Andrew; Readdy, Lisa; Posen, Paulette; Ribeiro-Santos, Ana; Neat, Francis C; Burns, Finlay

    2016-08-15

    Economic impact assessment methodology was applied to UK fisheries data to better understand the implications of European Commission proposal for regulations to fishing for deep-sea stocks in the North-East Atlantic (EC COM 371 Final 2012) under the Common Fisheries Policy (CFP). The aim was to inform the on-going debate to develop the EC proposal, and to assist the UK fishing industry and Government in evaluating the most effective options to manage deep sea fish stocks. Results indicate that enforcing the EC proposal as originally drafted results in a number of implications for the UK fleet. Because of the proposed changes to the list of species defined as being deep sea species, and a new definition of what constitutes a vessel targeting deep sea species, a total of 695 active UK fishing vessels would need a permit to fish for deep sea species. However, due to existing and capped capacity limits many vessels would potentially not be able to obtain such a permit. The economic impact of these changes from the status quo reveals that in the short term, landings would decrease by 6540 tonnes, reducing gross value added by £3.3 million. Alternative options were also assessed that provide mitigation measures to offset the impacts of the proposed regulations whilst at the same time providing more effective protection of deep sea Vulnerable Marine Ecosystems (VMEs). The options include setting a 400m depth rule that identifies a depth beyond which vessels would potentially be classified as fishing for deep sea species and designating 'core areas' for deep sea fishing at depths>400m to minimise the risk of further impacts of bottom fishing gear on deep sea habitats. Applying a 400m depth limit and 'core fishing' area approach deeper than 400m, the impact of the EC proposal would essentially be reduced to zero, that is, on average no vessels (using the status quo capacity baseline) would be impacted by the proposal.

  10. Demersal Fish Assemblages on Seamounts and Other Rugged Features in Deep Waters of the Greater and Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Chaytor, J. D.; Quattrini, A.; Demopoulos, A. W.

    2015-12-01

    Caribbean fish communities in shallow waters have been well studied along the Greater and Lesser Antilles for decades; however, the deep (>200 m) assemblages remain poorly known due to the technical challenges associated with focused surveys at these greater depths. The numerous geological features (e.g., seamounts, island ridges, banks) that punctuate the insular margins increase habitat heterogeneity, which may lead to enhanced diversity of the deep demersal fish community in the region. Recent (2013-2014) expeditions in the area using the E/V Nautilus and the ROV Hercules surveyed fish communities during 17 dives across different seafloor features at depths ranging from 64 to 2944 m. These surveys enabled us to investigate whether demersal fish assemblages differed among these seafloor features and/or in response to other environmental factors. Preliminary analyses suggested that assemblage differences are influenced by depth, dissolved oxygen, and differences in benthic microhabitat (i.e., soft substrate, rock outcrop, slope angle). Notably, both abundance and diversity of fishes was low at depths >700 m on seamounts in the Anegada Passage. This pattern is likely due to limited food supply in the region. ROV surveys further elucidated the biogeography of numerous species, as several range and depth extensions were documented. For instance, the morid Lepidion sp., previously known only from the eastern Atlantic and the western North Atlantic, was documented on Norrôit Seamount. A new species, Polylepion sp. A, known only from Curacao, was documented on Conrad Seamount. Also, many common, mesophotic reef species were observed deeper than previously known, including the butterflyfishes Chaetodon sedentarius and Prognathodes aculeatus. This study further supports the importance of environmental conditions influencing local-scale distribution of deep-sea fishes, while demonstrating how little is still known about the biogeography of numerous deep-sea and mesophotic

  11. Hydroxylated PAHs in bile of deep-sea fish. Relationship with xenobiotic metabolizing enzymes

    SciTech Connect

    Escartin, E.; Porte, C.

    1999-08-15

    Polycyclic aromatic hydrocarbon (PAH) pollution in deep-sea environments has been assessed by measuring bile PAH metabolites in deep-sea fish. Five species from the NW Mediterranean were selected for the study: Coryphaenoides guentheri, Lepidion lepidion, Mora moro, Bathypterois mediterraneus, and Alepocephalus rostratus. Bile crude samples were directly analyzed by HPLC-fluorescence at the excitation/emission wavelengths of benzo[a]pyrene. Differences among sampling sites were recorded, which suggests that coastal discharges of contaminants may reach these remote areas. Subsequently, a number of bile samples were hydrolyzed and analyzed by gas chromatography--mass spectrometry (GC-MS) for the determination of individual PAHs. 1-Pyrenol and 2-phenylphenol were among the most abundant compounds detected. The results obtained confirm the long-range transport of PAHs to deep-sea environments, subsequent exposure of fish inhabiting those remote areas, and its ability to metabolize and excrete them through the bile. The data also describe hepatic enzymes (cytochrome P450 and glutathione S-transferases) that appear to be as catalytically efficient as those in shallow water species.

  12. Hydrocarbons, PCBs and DDT in the NW Mediterranean deep-sea fish Mora moro

    NASA Astrophysics Data System (ADS)

    Solé, Montserrat; Porte, Cinta; Albaigés, Joan

    2001-02-01

    Data on aliphatic and polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and DDTs in the deep-sea fish Mora moro are reported in relation to the animal's weight/size and tissues (muscle, liver, digestive tube and gills). Fish samples were collected in the Gulf of Lions (NW Mediterranean) at an approximate depth of 1000 m. The concentrations of these organic pollutants followed the trend musclefish weight/size was observed for gills, digestive tube and liver when the fat contents of these tissues were taken into account. However, the concentrations in muscle decreased with size, possibly implying a simple dilution effect by the increase of body weight. Hydrocarbons, and particularly PAHs, were strongly depleted in all tissues with respect to organochlorinated compounds if compared with the amounts present in bottom waters and sediment. Smaller specimens displayed for most pollutants qualitatively different patterns than larger fish, which could be attributed to their particular habitat/diet. The aliphatic hydrocarbon profiles suggested that Mora moro was exposed to a more predominant intake of biogenic rather than petrogenic hydrocarbons. The entrance and storage organs exhibited characteristic PAH and PCB distributions, reflecting different bioaccumulation and metabolic pathways. Compared with the profiles currently found in surface fish species, a relatively higher contribution of heavier components, namely hepta- and octochlorinated PCBs, and 4-6-ringed PAHs, was found in the deep-sea fish.

  13. Lipid correction for carbon stable isotope analysis of deep-sea fishes

    NASA Astrophysics Data System (ADS)

    Hoffman, Joel C.; Sutton, Tracey T.

    2010-08-01

    Stable isotope analysis of fish tissue can aid studies of deep-sea food webs because sampling difficulties severely limit sample sizes of fish for traditional diet studies. The carbon stable isotope ratio (δ 13C) is widely used in food web studies, but it must be corrected to remove variability associated with varying lipid content in the tissue. A lipid correction has not been determined for any deep-sea fish. These fishes are ideal for studying lipid correction because lipid content varies widely among species. Our objective was to evaluate an application of a mass balance δ 13C correction to a taxonomically diverse group of deep-sea fishes by determining the effect of lipid extraction on the stable isotope ratios, examining the quality of the model parameters derived for the mass balance correction, and comparing the correction to published results. We measured the lipid extraction effect on the nitrogen stable isotope ratio (δ 15N) and δ 13C of muscle tissue from 30 North Atlantic species. Lipid extraction significantly increased tissue δ 15N (+0.66‰) and δ 13C values, but the treatment effect on δ 13C was dependent on C:N, a proxy for lipid content. We compared the lipid-extracted δ 13C to the δ 13C predicted by the mass balance correction using model variables estimated from either all individuals (pooled) or species-by-species or using published values from other species. The correction using the species-by-species approach performed best; however, all three approaches produced corrected values that were generally within 0.5‰ of the measured lipid-free δ 13C and that had a small over-all bias (<0.5‰). We conclude that a generalized mass balance correction works well for correcting δ 13C in deep-sea fishes, is similar to that developed for other fishes, and recommend caution when applying a generalized correction to fish with high lipid content (C:N >8).

  14. Response of a temperate demersal fish community to global warming

    NASA Astrophysics Data System (ADS)

    Punzón, A.; Serrano, A.; Sánchez, F.; Velasco, F.; Preciado, I.; González-Irusta, J. M.; López-López, L.

    2016-09-01

    Changes in the distribution of the demersal fish species have been identified in north-European Atlantic waters. The consequence of these changes has been a northward shift of the distribution limits and changes in richness. In this study a notable increase in demersal fish species richness per sampling station was detected in the southern Bay of Biscay. This rise was due to an increase in frequency of occurrence and abundance of the majority of fish species in the area (53% from the total species). A fisheries relate explanation was discarded because the mismatch between the changes in the fishing effort and the augment in frequency of occurrence and abundance. On the contrary, these changes are in agreement with expected response under the increasing temperature of the sea observed over the last three decades, associated to global warming. These changes were positively correlated with an increase in temperature of intermediate waters in the study area. In addition, some of these species showed a notable western displacements of the Centre of Gravity in the study area, which would be expected if temperate water species would be favoured by an increase in water temperature. Our results are consistent with studies in the North Sea, where many of these species showing widened distribution limits towards north. The analysis of the results shows that the studied ecosystem, the Bay of Biscay is under a meridionalization process. On the other hand, only one tropicalization event (Lepidotrigla dieuzeidei), was recorded, maybe due to the conservative restrictions applied in species selection.

  15. Interspecific variations of inner ear structure in the deep-sea fish family melamphaidae.

    PubMed

    Deng, Xiaohong; Wagner, Hans-Joachim; Popper, Arthur N

    2013-07-01

    Inner ear structures are compared among three major genera of the deep-sea fish family Melamphaidae (bigscales and ridgeheads). Substantial interspecific variation is found in the saccular otoliths, including the presence of a unique otolithic "spur" in the genera Melamphaes and Poromitra. The variation in the saccular otolith is correlated with an increase in the number of hair bundle orientation groups on the sensory epithelia from the genera Scopelogadus to Poromitra to Melamphaes. The diverse structural variations found in the saccule may reflect the evolutionary history of these species. The sensory hair cell bundles in this family have the most variable shapes yet encountered in fish ears. In the saccule, most of the hair bundles are 15-20 μm high, an exceptional height for fish otolithic end organs. These bundles have large numbers of stereovilli, including some that reach the length of the kinocilium. In the utricle, the striolar region separates into two unusually shaped areas that have not been described in any other vertebrates. The brains in all species have a relatively small olfactory bulb and optic tectum, as well as an enlarged posterior cerebellar region that is likely to be involved in inner ear and lateral line (octavolateral) functions. Data from melamphaids support the hypothesis that specialized anatomical structures are found in the ears of some (if not most) deep-sea fishes, presumably enhancing their hearing sensitivity.

  16. Muscular cholinesterase and lactate dehydrogenase activities in deep-sea fish from the NW Mediterranean.

    PubMed

    Koenig, Samuel; Solé, Montserrat

    2014-03-01

    Organisms inhabiting submarine canyons can be potentially exposed to higher inputs of anthropogenic chemicals than their counterparts from the adjacent areas. To find out to what extend this observation applies to a NW Mediterranean canyon (i.e. Blanes canyon) off the Catalan coast, four deep-sea fish species were collected from inside the canyon (BC) and the adjacent open slope (OS). The selected species were: Alepocephalus rostratus, Lepidion lepidion, Coelorinchus mediterraneus and Bathypterois mediterraneus. Prior to the choice of an adequate sentinel species, the natural variation of the selected parameters (biomarkers) in relation to factors such as size, sex, sampling depth and seasonality need to be characterised. In this study, the activities of cholinesterases (ChEs) and lactate dehydrogenase (LDH) enzymes were determined in the muscle of the four deep-sea fish. Of all ChEs, acetylcholinesterase (AChE) activity was dominant and selected for further monitoring. Overall, AChE activity exhibited a significant relationship with fish size whereas LDH activity was mostly dependent on the sex and gonadal development status, although in a species-dependent manner. The seasonal variability of LDH activity was more marked than for AChE activity, and inside-outside canyon (BC-OS) differences were not consistent in all contrasted fish species, and in fact they were more dependent on biological traits. Thus, they did not suggest a differential stress condition between sites inside and outside the canyon. PMID:24296242

  17. Muscular cholinesterase and lactate dehydrogenase activities in deep-sea fish from the NW Mediterranean.

    PubMed

    Koenig, Samuel; Solé, Montserrat

    2014-03-01

    Organisms inhabiting submarine canyons can be potentially exposed to higher inputs of anthropogenic chemicals than their counterparts from the adjacent areas. To find out to what extend this observation applies to a NW Mediterranean canyon (i.e. Blanes canyon) off the Catalan coast, four deep-sea fish species were collected from inside the canyon (BC) and the adjacent open slope (OS). The selected species were: Alepocephalus rostratus, Lepidion lepidion, Coelorinchus mediterraneus and Bathypterois mediterraneus. Prior to the choice of an adequate sentinel species, the natural variation of the selected parameters (biomarkers) in relation to factors such as size, sex, sampling depth and seasonality need to be characterised. In this study, the activities of cholinesterases (ChEs) and lactate dehydrogenase (LDH) enzymes were determined in the muscle of the four deep-sea fish. Of all ChEs, acetylcholinesterase (AChE) activity was dominant and selected for further monitoring. Overall, AChE activity exhibited a significant relationship with fish size whereas LDH activity was mostly dependent on the sex and gonadal development status, although in a species-dependent manner. The seasonal variability of LDH activity was more marked than for AChE activity, and inside-outside canyon (BC-OS) differences were not consistent in all contrasted fish species, and in fact they were more dependent on biological traits. Thus, they did not suggest a differential stress condition between sites inside and outside the canyon.

  18. Fish Food in the Deep Sea: Revisiting the Role of Large Food-Falls

    PubMed Central

    Higgs, Nicholas D.; Gates, Andrew R.; Jones, Daniel O. B.

    2014-01-01

    The carcasses of large pelagic vertebrates that sink to the seafloor represent a bounty of food to the deep-sea benthos, but natural food-falls have been rarely observed. Here were report on the first observations of three large ‘fish-falls’ on the deep-sea floor: a whale shark (Rhincodon typus) and three mobulid rays (genus Mobula). These observations come from industrial remotely operated vehicle video surveys of the seafloor on the Angola continental margin. The carcasses supported moderate communities of scavenging fish (up to 50 individuals per carcass), mostly from the family Zoarcidae, which appeared to be resident on or around the remains. Based on a global dataset of scavenging rates, we estimate that the elasmobranch carcasses provided food for mobile scavengers over extended time periods from weeks to months. No evidence of whale-fall type communities was observed on or around the carcasses, with the exception of putative sulphide-oxidising bacterial mats that outlined one of the mobulid carcasses. Using best estimates of carcass mass, we calculate that the carcasses reported here represent an average supply of carbon to the local seafloor of 0.4 mg m−2d−1, equivalent to ∼4% of the normal particulate organic carbon flux. Rapid flux of high-quality labile organic carbon in fish carcasses increases the transfer efficiency of the biological pump of carbon from the surface oceans to the deep sea. We postulate that these food-falls are the result of a local concentration of large marine vertebrates, linked to the high surface primary productivity in the study area. PMID:24804731

  19. Fish food in the deep sea: revisiting the role of large food-falls.

    PubMed

    Higgs, Nicholas D; Gates, Andrew R; Jones, Daniel O B

    2014-01-01

    The carcasses of large pelagic vertebrates that sink to the seafloor represent a bounty of food to the deep-sea benthos, but natural food-falls have been rarely observed. Here were report on the first observations of three large 'fish-falls' on the deep-sea floor: a whale shark (Rhincodon typus) and three mobulid rays (genus Mobula). These observations come from industrial remotely operated vehicle video surveys of the seafloor on the Angola continental margin. The carcasses supported moderate communities of scavenging fish (up to 50 individuals per carcass), mostly from the family Zoarcidae, which appeared to be resident on or around the remains. Based on a global dataset of scavenging rates, we estimate that the elasmobranch carcasses provided food for mobile scavengers over extended time periods from weeks to months. No evidence of whale-fall type communities was observed on or around the carcasses, with the exception of putative sulphide-oxidising bacterial mats that outlined one of the mobulid carcasses. Using best estimates of carcass mass, we calculate that the carcasses reported here represent an average supply of carbon to the local seafloor of 0.4 mg m(-2)d(-1), equivalent to ∼ 4% of the normal particulate organic carbon flux. Rapid flux of high-quality labile organic carbon in fish carcasses increases the transfer efficiency of the biological pump of carbon from the surface oceans to the deep sea. We postulate that these food-falls are the result of a local concentration of large marine vertebrates, linked to the high surface primary productivity in the study area.

  20. Vertical migrations of a deep-sea fish and its prey.

    PubMed

    Afonso, Pedro; McGinty, Niall; Graça, Gonçalo; Fontes, Jorge; Inácio, Mónica; Totland, Atle; Menezes, Gui

    2014-01-01

    It has been speculated that some deep-sea fishes can display large vertical migrations and likely doing so to explore the full suite of benthopelagic food resources, especially the pelagic organisms of the deep scattering layer (DSL). This would help explain the success of fishes residing at seamounts and the increased biodiversity found in these features of the open ocean. We combined active plus passive acoustic telemetry of blackspot seabream with in situ environmental and biological (backscattering) data collection at a seamount to verify if its behaviour is dominated by vertical movements as a response to temporal changes in environmental conditions and pelagic prey availability. We found that seabream extensively migrate up and down the water column, that these patterns are cyclic both in short-term (tidal, diel) as well as long-term (seasonal) scales, and that they partially match the availability of potential DSL prey components. Furthermore, the emerging pattern points to a more complex spatial behaviour than previously anticipated, suggesting a seasonal switch in the diel behaviour mode (benthic vs. pelagic) of seabream, which may reflect an adaptation to differences in prey availability. This study is the first to document the fine scale three-dimensional behaviour of a deep-sea fish residing at seamounts. PMID:24859231

  1. Vertical migrations of a deep-sea fish and its prey.

    PubMed

    Afonso, Pedro; McGinty, Niall; Graça, Gonçalo; Fontes, Jorge; Inácio, Mónica; Totland, Atle; Menezes, Gui

    2014-01-01

    It has been speculated that some deep-sea fishes can display large vertical migrations and likely doing so to explore the full suite of benthopelagic food resources, especially the pelagic organisms of the deep scattering layer (DSL). This would help explain the success of fishes residing at seamounts and the increased biodiversity found in these features of the open ocean. We combined active plus passive acoustic telemetry of blackspot seabream with in situ environmental and biological (backscattering) data collection at a seamount to verify if its behaviour is dominated by vertical movements as a response to temporal changes in environmental conditions and pelagic prey availability. We found that seabream extensively migrate up and down the water column, that these patterns are cyclic both in short-term (tidal, diel) as well as long-term (seasonal) scales, and that they partially match the availability of potential DSL prey components. Furthermore, the emerging pattern points to a more complex spatial behaviour than previously anticipated, suggesting a seasonal switch in the diel behaviour mode (benthic vs. pelagic) of seabream, which may reflect an adaptation to differences in prey availability. This study is the first to document the fine scale three-dimensional behaviour of a deep-sea fish residing at seamounts.

  2. Vertical Migrations of a Deep-Sea Fish and Its Prey

    PubMed Central

    Afonso, Pedro; McGinty, Niall; Graça, Gonçalo; Fontes, Jorge; Inácio, Mónica; Totland, Atle; Menezes, Gui

    2014-01-01

    It has been speculated that some deep-sea fishes can display large vertical migrations and likely doing so to explore the full suite of benthopelagic food resources, especially the pelagic organisms of the deep scattering layer (DSL). This would help explain the success of fishes residing at seamounts and the increased biodiversity found in these features of the open ocean. We combined active plus passive acoustic telemetry of blackspot seabream with in situ environmental and biological (backscattering) data collection at a seamount to verify if its behaviour is dominated by vertical movements as a response to temporal changes in environmental conditions and pelagic prey availability. We found that seabream extensively migrate up and down the water column, that these patterns are cyclic both in short-term (tidal, diel) as well as long-term (seasonal) scales, and that they partially match the availability of potential DSL prey components. Furthermore, the emerging pattern points to a more complex spatial behaviour than previously anticipated, suggesting a seasonal switch in the diel behaviour mode (benthic vs. pelagic) of seabream, which may reflect an adaptation to differences in prey availability. This study is the first to document the fine scale three-dimensional behaviour of a deep-sea fish residing at seamounts. PMID:24859231

  3. Halogenated persistent organic pollutants in relation to trophic level in deep sea fish.

    PubMed

    Webster, Lynda; Russell, Marie; Walsham, Pam; Hussy, Ines; Lacaze, Jean-Pierre; Phillips, Lesley; Dalgarno, Eric; Packer, Gill; Neat, Francis; Moffat, Colin F

    2014-11-15

    The bioaccumulation of persistent organic pollutants (POPs) in deep sea fish from the Rockall fishing area was investigated. Predator and prey species were analysed for stable isotopes, fatty acids, polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). δ(15)N indicated that black scabbard was at the highest trophic level and the prey the lowest. The fatty acid signatures indicated that black scabbard and black dogfish fed at a higher trophic level compared to the roundnose grenadier. PCBs and PBDEs were detected in the liver of all three predator species. PCB concentrations were significantly higher in the roundnose grenadier, possibly due to their longer life span. PCB concentrations were compared to OSPAR assessment criteria, concentrations were above background but below Environmental Assessment Criteria for all but one congener. PCB concentrations were below food safety levels in the flesh, but exceeded the limit for liver in the roundnose grenadier and black dogfish.

  4. High variability in spatial and temporal size-based trophodynamics of deep-sea fishes from the Mid-Atlantic Ridge elucidated by stable isotopes

    NASA Astrophysics Data System (ADS)

    Reid, William D. K.; Sweeting, Christopher J.; Wigham, Ben D.; McGill, Rona A. R.; Polunin, Nicholas V. C.

    2013-12-01

    Demersal fish play an important role in the deep-sea ecosystem by acting as a link to mobile food in the water column, consuming benthic fauna, breaking down large food parcels and dispersing organic matter over large areas. Poor diet resolution from stomach content analysis often impairs the ability to assess differences in inter- and intra-population trophodynamics and therefore understand resource partitioning among deep-sea fishes. Antimora rostrata (predator-scavenger), Coryphaenoides armatus (predator-scavenger), Coryphaenoides brevibarbis (predator) and Halosauropsis macrochir (predator) were collected from 3 stations on the Mid-Atlantic Ridge (MAR) in 2007 and 2009 to investigate trophic ecology using δ13C and δ15N. Variability in lipid-normalised δ13C (δ13Cn) and δ15N was explained by body length in all species but slope and significance of the isotope-length relationships varied both temporally and spatially. δ15N increases with length were observed in A. rostrata at all stations, C. brevibarbis and H. macrochir at one or more stations but were absent in C. armatus. δ13Cn increased with length in A. rostrata but the slope of δ13Cn-length relationships varied spatially and temporally in C. armatus and C. brevibarbis. The co-occurring δ13Cn and δ15N size-based trends in A. rostrata and H. macrochir suggested that size-based trends were a result of increasing trophic position. In C. armatus and C. brevibarbis the isotope-length trends were difficult to distinguish among trophic position increases, shifts in resource use i.e. benthic to pelagic or internal physiology. However, the overall strength, direction and significance of isotope-length trends varied temporally and spatially which suggested varying degrees of overlap in trophic ecology and feeding plasticity among these species.

  5. The Role of a Game-Simulation in a Project of Change: A Case of Deep-Sea Fishing.

    ERIC Educational Resources Information Center

    Kuipers, Herman

    1983-01-01

    Earlier research in Dutch deep sea fishing showed competition between skippers. Since cooperation in fleets could be a solution to economic and social problems and the industry couldn't accept this, a simulation-experiment was carried out. Although competition existed initially, skippers later tried cooperation under reward conditions. The…

  6. Precision-cut liver slices to investigate responsiveness of deep-sea fish to contaminants at high pressure.

    PubMed

    Lemaire, Benjamin; Debier, Cathy; Calderon, Pedro Buc; Thomé, Jean Pierre; Stegeman, John; Mork, Jarle; Rees, Jean François

    2012-09-18

    While deep-sea fish accumulate high levels of persistent organic pollutants (POPs), the toxicity associated with this contamination remains unknown. Indeed, the recurrent collection of moribund individuals precludes experimental studies to investigate POP effects in this fauna. We show that precision-cut liver slices (PCLS), an in vitro tool commonly used in human and rodent toxicology, can overcome such limitation. This technology was applied to individuals of the deep-sea grenadier Coryphaenoides rupestris directly upon retrieval from 530-m depth in Trondheimsfjord (Norway). PCLS remained viable and functional for 15 h when maintained in an appropriate culture media at 4 °C. This allowed experimental exposure of liver slices to the model POP 3-methylcholanthrene (3-MC; 25 μM) at levels of hydrostatic pressure mimicking shallow (0.1 megapascal or MPa) and deep-sea (5-15 MPa; representative of 500-1500 m depth) environments. As in shallow water fish, 3-MC induced the transcription of the detoxification enzyme cytochrome P4501A (CYP1A; a biomarker of exposure to POPs). This induction was diminished at elevated pressure, suggesting a limited responsiveness of C. rupestris toward POPs in its native environment. This very first in vitro toxicological investigation on a deep-sea fish opens the route for understanding pollutants effects in this highly exposed fauna. PMID:22900608

  7. Foraging Behaviour Patterns of Four Sympatric Demersal Fishes

    NASA Astrophysics Data System (ADS)

    Labropoulou, M.; Papadopoulou-Smith, K.-N.

    1999-08-01

    The trophic relationships of four sympatric demersal fish species (Mullus barbatus, Mullus surmuletus, Pagrus pagrus and Gobius niger) which dominate the shallow coastal areas (25-30 m) of Iraklion Bay (S Aegean, NE Mediterranean) were investigated from samples collected on a monthly basis (August 1990-August 1992). Stomach content analysis revealed that all four species were carnivorous, feeding mainly on benthic invertebrates. Although these species displayed different feeding modes based on principal prey type utilization, they all consumed a considerable number of polychaetes. In order to understand any underlying patterns of predation on polychaetes, prey items were identified to the lowest possible taxonomic level. The polychaete species were further classified into groups according to their microhabitat (surface or burrowing) and feeding (feeding mode, motility and morphology) guilds. Comparisons of the feeding habits were made using the percentage contribution by number of each prey species in the diet of the predators. Similarities in the diets between the fish species were calculated and cluster analysis was used to describe interspecific variations in food selection, concerning polychaetes. The predatory preferences of each fish species were related to the microhabitat distribution of prey species in the sediment. The differential exploitation of polychaete species was a good indicator of disparate foraging behaviour among the fish species examined, since it reflects a transition from a non-selective to a specialized feeding method. The effects of predator size and morphology of feeding apparatus and the availability of polychaete species in the environment are also discussed to explain the differential exploitation of polychaetes exhibited by the fish.

  8. The "pseudo-craniovertebral articulation" in the deep-sea fish Stomias boa (Teleostei: Stomiidae).

    PubMed

    Schnell, Nalani K; Bernstein, Peter; Maier, Wolfgang

    2008-05-01

    Many predatory deep-sea fishes show highly specialized modifications of their feeding apparatus, e.g., elongate jaws studded with long daggerlike teeth, often combined with a very distensible stomach, to be capable of swallowing relatively large prey. These striking features can be observed in members of the marine teleost family Stomiidae. The present study gives a detailed morphological description of the mesopelagic predatory fish, Stomias boa, based on a combined approach of clearing and double staining, serial sections and dissection. In this genus, large pads made of dense connective tissue extend from the first enlarged neural arch to the ventral side of the chordal sheath, embracing the prominent exoccipitals and thus constituting a kind of double ball- and socket joint for the head. The notochordal occipito-vertebral gap is enlarged, probably not by loss of vertebral centra as is proposed for other genera of the stomiid family, e.g., in Astronesthes or Photostomias. We conclude that this "pseudo-craniovertebral articulation" serves as a functional substitute for the absent vertebrae and strengthens the flexible, anterior part of the vertebral column during extreme dorsal expansion of the gape during prey capture and swallowing.

  9. The "pseudo-craniovertebral articulation" in the deep-sea fish Stomias boa (Teleostei: Stomiidae).

    PubMed

    Schnell, Nalani K; Bernstein, Peter; Maier, Wolfgang

    2008-05-01

    Many predatory deep-sea fishes show highly specialized modifications of their feeding apparatus, e.g., elongate jaws studded with long daggerlike teeth, often combined with a very distensible stomach, to be capable of swallowing relatively large prey. These striking features can be observed in members of the marine teleost family Stomiidae. The present study gives a detailed morphological description of the mesopelagic predatory fish, Stomias boa, based on a combined approach of clearing and double staining, serial sections and dissection. In this genus, large pads made of dense connective tissue extend from the first enlarged neural arch to the ventral side of the chordal sheath, embracing the prominent exoccipitals and thus constituting a kind of double ball- and socket joint for the head. The notochordal occipito-vertebral gap is enlarged, probably not by loss of vertebral centra as is proposed for other genera of the stomiid family, e.g., in Astronesthes or Photostomias. We conclude that this "pseudo-craniovertebral articulation" serves as a functional substitute for the absent vertebrae and strengthens the flexible, anterior part of the vertebral column during extreme dorsal expansion of the gape during prey capture and swallowing. PMID:17926347

  10. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys

    USGS Publications Warehouse

    Quattrini, Andrea; Demopoulos, Amanda

    2016-01-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013–2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494–4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities

  11. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys.

    PubMed

    Quattrini, Andrea M; Demopoulos, Amanda W J

    2016-12-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013-2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494-4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities, our

  12. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys.

    PubMed

    Quattrini, Andrea M; Demopoulos, Amanda W J

    2016-12-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013-2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494-4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities, our

  13. The visual ecology of a deep-sea fish, the escolar Lepidocybium flavobrunneum (Smith, 1843)†

    PubMed Central

    Landgren, Eva; Fritsches, Kerstin; Brill, Richard; Warrant, Eric

    2014-01-01

    Escolar (Lepidocybium flavobrunneum, family Gempylidae) are large and darkly coloured deep-sea predatory fish found in the cold depths (more than 200 m) during the day and in warm surface waters at night. They have large eyes and an overall low density of retinal ganglion cells that endow them with a very high optical sensitivity. Escolar have banked retinae comprising six to eight layers of rods to increase the optical path length for maximal absorption of the incoming light. Their retinae possess two main areae of higher ganglion cell density, one in the ventral retina viewing the dorsal world above (with a moderate acuity of 4.6 cycles deg−1), and the second in the temporal retina viewing the frontal world ahead. Electrophysiological recordings of the flicker fusion frequency (FFF) in isolated retinas indicate that escolar have slow vision, with maximal FFF at the highest light levels and temperatures (around 9 Hz at 23°C) which fall to 1–2 Hz in dim light or cooler temperatures. Our results suggest that escolar are slowly moving sit-and-wait predators. In dim, warm surface waters at night, their slow vision, moderate dorsal resolution and highly sensitive eyes may allow them to surprise prey from below that are silhouetted in the downwelling light. PMID:24395966

  14. Extensive gene flow within sibling species in the deep-sea fish Beryx splendens.

    PubMed

    Hoarau, G; Borsa, P

    2000-03-01

    Molecular markers allow insights into the population biology and ecology of deep-sea organisms, which are usually hardly accessible to direct observation and poorly known. Such a study was undertaken here for the deep-sea fish Beryx splendens, a species of growing interest to fisheries. B. splendens populations were sampled on seamounts and continental margins in the southwestern Pacific (New Caledonia, New Zealand, southeastern Australia) and in the northeastern Atlantic. Two hundred and fifty individuals were characterised by their single-strand DNA conformation (SSCP) of a approximately 360-base-pair (bp) fragment of the mitochondrial cytochrome b gene, amplified by the polymerase chain reaction (PCR). Two major SSCP haplotypes were observed in New Caledonia, a and w, whose frequencies were negatively correlated along a north-to-south cline. All SSCP haplotypes in the total sample were sequenced on 273 bp. The phylogenetic tree of B. splendens haplotype sequences, rooted by two B. decadactylus sequences, showed that a and w belong to distinct mitochondrial clades, A and W, which are separated by approximately 4-6% nucleotide divergence. Thirty individuals from New Caledonia were characterised by their DNA fingerprint from arbitrary-primed PCR. The distribution of individual-pairwise similarity indices was strongly bimodal. The larger similarity values all corresponded to comparisons within a clade (A or W) while the lower values were all between clades. Therefore, there was a strict association between the mitochondrial type and the DNA (presumably, nuclear DNA) fingerprint of an individual. Altogether, these results point to the existence of two biological species (sp. A and sp. W) within the current taxon B. splendens. No within-species differentiation was detected at the regional scale (New Caledonia). A remarkable result is that the three cytochrome b haplotypes of northeastern Atlantic B. cf. splendens sp. A were also the three commonest in the southwestern

  15. Population sizes and growth pressure responses of intestinal microfloras of deep-sea fish retrieved from the abyssal zone.

    PubMed

    Yano, Y; Nakayama, A; Yoshida, K

    1995-12-01

    The intestinal floras of seven deep-sea fish retrieved at depths of from 3,200 to 5,900 m were examined for population sizes and growth responses to pressure. Large populations of culturable bacteria, ranging from 1.1 x 10(sup6) to 3.6 x 10(sup8) cells per ml of contents, were detected when samples were incubated at conditions characteristic of those of the deep sea. Culturable cell counts at in situ pressures were greater than those at atmospheric pressure in all samples. Most of the strains isolated by the spread-plating method at atmospheric pressure later proved barophilic. Barophilic bacteria were the predominant inhabitants of the abyssal fish intestines. PMID:16535199

  16. Does the physiology of chondrichthyan fishes constrain their distribution in the deep sea?

    PubMed

    Treberg, Jason R; Speers-Roesch, Ben

    2016-03-01

    The deep sea is the largest ecosystem on Earth but organisms living there must contend with high pressure, low temperature, darkness and scarce food. Chondrichthyan fishes (sharks and their relatives) are important consumers in most marine ecosystems but are uncommon deeper than 3000 m and exceedingly rare, or quite possibly absent, from the vast abyss (depths >4000 m). By contrast, teleost (bony) fishes are commonly found to depths of ∼ 8400 m. Why chondrichthyans are scarce at abyssal depths is a major biogeographical puzzle. Here, after outlining the depth-related physiological trends among chondrichthyans, we discuss several existing and new hypotheses that implicate unique physiological and biochemical characteristics of chondrichthyans as potential constraints on their depth distribution. We highlight three major, and not mutually exclusive, working hypotheses: (1) the urea-based osmoregulatory strategy of chondrichthyans might conflict with the interactive effects of low temperature and high pressure on protein and membrane function at great depth; (2) the reliance on lipid accumulation for buoyancy in chondrichthyans has a unique energetic cost, which might increasingly limit growth and reproductive output as food availability decreases with depth; (3) their osmoregulatory strategy may make chondrichthyans unusually nitrogen limited, a potential liability in the food-poor abyss. These hypotheses acting in concert could help to explain the scarcity of chondrichthyans at great depths: the mechanisms of the first hypothesis may place an absolute, pressure-related depth limit on physiological function, while the mechanisms of the second and third hypotheses may limit depth distribution by constraining performance in the oligotrophic abyss, in ways that preclude the establishment of viable populations or lead to competitive exclusion by teleosts. PMID:26936637

  17. Molecular phylogenetic relationships of the deep-sea fish genus Coryphaenoides (Gadiformes: Macrouridae) based on mitochondrial DNA.

    PubMed

    Morita, T

    1999-12-01

    In order to characterize the phylogenetic relationship and deep-sea adaptation process of the deep-sea fish genus Coryphaenoides, the nucleotide sequences of the mitochondrial (mt) 12 S rRNA and COI gene sequences for seven Coryphaenoides species were analyzed. Our molecular phylogenetic tree shows a new arrangement of seven Coryphaenoides species, which form two distinct groups, abyssal and nonabyssal species, and differs from the results of previous taxonomic studies. Using the mutation rate of mitochondrial genes, the divergence time between abyssal and nonabyssal Coryphaenoides was found to be 3.2-7.6 million years ago. Our study suggests that hydraulic pressure plays an important role in the speciation process in the marine environment. PMID:10620402

  18. New method for isolating barophiles from intestinal contents of deep-sea fishes retrieved from the abyssal zone.

    PubMed

    Nakayama, A; Yano, Y; Yoshida, K

    1994-11-01

    We devised a new method (the dorayaki method) using marine agar under in situ pressures to isolate barophilic bacteria from the intestinal contents of three deep-sea fishes (two Coryphaenoides yaquinae samples and one Ilyophis sp. sample) retrieved from depths of 4,700 to 6,100 m in the Northwest Pacific Ocean. All 10 strains isolated from one sample (C. yaquinae) were obligately barophilic. One of the 10 strains did not grow at atmospheric pressure and 103.4 MPa but did grow well between 20.7 and 82.7 MPa, with optimal growth at 41.4 MPa. This method is useful for isolating psychrophilic and barophilic deep-sea bacteria. PMID:16349450

  19. Pathological alterations typical of human Tay-Sachs disease, in the retina of a deep-sea fish

    NASA Astrophysics Data System (ADS)

    Fishelson, L.; Delarea, Yacov; Galil, Bella S.

    Micrographs of retinas from the deep-sea fish Cataetyx laticeps revealed visual cells containing membranous whorls in the ellipsoids of the inner segments resulting from stretching and modifications of the mitochondria membranes and their cristae. These pathological structures seem to be homologous to the whorls observed in retinas of human carriers of Tay-Sachs disease. This disease, a genetic disorder, is found in humans and some mammals. Our findings in fish suggest that the gene responsible can be found throughout the vertebrate evolutionary tree, possibly dormant in most taxa.

  20. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth.

    PubMed

    Brown, Alastair; Thatje, Sven

    2014-05-01

    Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal

  1. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth.

    PubMed

    Brown, Alastair; Thatje, Sven

    2014-05-01

    Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal

  2. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth

    PubMed Central

    Brown, Alastair; Thatje, Sven

    2014-01-01

    Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity–depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity–depth pattern over time

  3. The bathymetric distribution of the digenean parasites of deep-sea fishes.

    PubMed

    Bray, Rodney A

    2004-06-01

    The bathymetric range of 149 digenean species recorded deeper than 200 m, the approximate depth of the continental shelf/slope break, are presented in graphical form. It is found that only representatives of the four families Lepocreadiidae, Fellodistomidae, Derogenidae and Hemiuridae reach to abyssal regions (>4000 m). Three other families, the Lecithasteridae, Zoogonidae and Opecoelidae, have truly deep-water forms reaching deeper than 3000 m. Bathymetric data are available for the Acanthocolpidae, Accacoeliidae, Bucephalidae, Cryptogonimidae, Faustulidae, Gorgoderidae, Monorchiidae and Sanguinicolidae showing that they reach deeper than 200 m. No bathymetric data are available for the members of the Bivesiculidae and Hirudinellidae which are reported from deep-sea hosts. These results indicate that only seventeen out of the 150 or so digenean families are reported in the deep sea. PMID:15357406

  4. [Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico].

    PubMed

    López-Martínez, Juana; Acevedo-Cervantes, Alejandro; Herrera-Valdivia, Eloisa; Rodríguez-Romero, Jesús; Palacios-Salgado, Deivis S

    2012-03-01

    The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling difficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California's geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

  5. Spatial and seasonal variations in the trophic spectrum of demersal fish assemblages in Jiaozhou Bay, China

    NASA Astrophysics Data System (ADS)

    Han, Dongyan; Xue, Ying; Ren, Yiping; Ma, Qiuyun

    2015-07-01

    Trophic structure of fish communities is fundamental for ecosystem-based fisheries management, and trophic spectrum classifies fishes by their positions in food web, which provides a simple summary on the trophic structure and ecosystem function. In this study, both fish biomass and abundance trophic spectra were constructed to study the spatial and seasonal variations in the trophic structure of demersal fish assemblages in Jiaozhou Bay, China. Data were collected from four seasonal bottom trawl surveys in Jiaozhou Bay from February to November in 2011. Trophic levels (TLs) of fishes were determined by nitrogen stable isotope analysis. This study indicated that most of these trophic spectra had a single peak at trophic level (TL) of 3.4-3.7, suggesting that demersal fish assemblages of Jiaozhou Bay were dominated by secondary consumers (eg. Pholis fangi and Amblychaeturichthys hexanema). The spatial and seasonal variations of trophic spectra of Jiaozhou Bay reflected the influence of fish reproduction, fishing pressure and migration of fishes. Two-way analysis of variance (ANOVA) showed that seasonal variations in trophic spectra in Jiaozhou Bay were significant ( P<0.05), but variations among different areas were not significant ( P>0.05). The trophic spectrum has been proved to be a useful tool to monitor the trophic structure of fish assemblages. This study highlighted the comprehensive application of fish biomass and abundance trophic spectra in the study on trophic structure of fish assemblages.

  6. Proctophantastes nettastomatis (Digenea: Zoogonidae) from Vanuatu deep-sea fish: new morphological features, allometric growth, and phenotypic plasticity aspects.

    PubMed

    Mouahid, Gabriel; Faliex, Elisabeth; Allienne, Jean-François; Cribb, Thomas H; Bray, Rodney A

    2012-05-01

    The present paper deals with Proctophantastes nettastomatis (Digenea: Zoogonidae; Lepidophyllinae) found in the intestine of three species of deep-sea fish, Dicrolene longimana (Ophidiidae, Ophidiiformes), Bathyuroconger sp. (Congridae, Anguilliformes), and Venefica tentaculata (Nettastomatidae, Anguilliformes). The fish were collected near the islands of Espiritu Santo, Erromango, and Epi, respectively, in the archipelago of Vanuatu (Southern Pacific Ocean) at depths ranging from 561 to 990 m. Morphological and histological analyses showed that the Vanuatu specimens differ from Proctophantastes abyssorum, Proctophantastes gillissi, Proctophantastes glandulosum, Proctophantastes infundibulum, and Proctophantastes brayi but are close to P. nettastomatis discovered in Suruga Bay, Japan. P. nettastomatis is redescribed based both on the observations of our specimens and of the Japanese holotype and paratype. The morphological variability of the species is described. Morphometric data allowed the identification of positive allometric growth for the hindbody, negative allometric growth for the ventral sucker, and a growth phenotypic plasticity between Ophidiiformes and Anguilliformes definitive hosts. PMID:22089085

  7. Metal concentrations and metallothionein-like protein levels in deep-sea fishes captured near hydrothermal vents in the Mid-Atlantic Ridge off Azores

    NASA Astrophysics Data System (ADS)

    Company, R.; Felícia, H.; Serafim, A.; Almeida, A. J.; Biscoito, M.; Bebianno, M. J.

    2010-07-01

    The knowledge of metal contamination in deep-sea fishes living in the surroundings of hydrothermal vents is very scarce, along with the detoxification mechanisms that allow them to live near one of the most metal contaminated marine environments. Six deep-sea fish species, although not vent endemic were collected near three Mid-Atlantic Ridge (MAR) hydrothermal vents (Menez Gwen, Lucky Strike and Rainbow) and the gills, muscle and liver were selected for this study due to their importance in metal metabolism and storage. The concentrations of seven metals (Ag, Cd, Cr, Cu, Fe, Mn, and Ni) and a metal-related biomarker (metallothionein-like proteins-MTL) were assessed. Major differences in metal accumulation among fish species are related to their feeding habits and vent site of their capture. The liver and gills are in general the most important tissues for metal accumulation compared to the muscle, but tissue partitioning is very dependent on the fish species considered. Compared to other deep-sea fishes, fish capture in the vicinity of hydrothermal vents accumulates higher amounts of metals in general. However, MTL levels are not considerably different from what is found in commercial coastal fishes, and is poorly correlated with metal concentrations in the tissues. Therefore, MTL may not constitute one major detoxification system for deep-sea species living in the vicinity of three important MAR vent sites.

  8. Amino acid substitutions in malate dehydrogenases of piezophilic bacteria isolated from intestinal contents of deep-sea fishes retrieved from the abyssal zone.

    PubMed

    Saito, Rie; Kato, Chiaki; Nakayama, Akihiko

    2006-02-01

    To examine the occurrence in other deep-sea bacteria of two amino acid substitutions (Ala-180 and His-229) in malate dehydrogenase (MDH) found previously in the deep-sea piezophilic Moritella sp. strain 2D2, we cloned and sequenced MDH genes of deep-sea piezophilic Moritella and Shewanella strains isolated from intestinal contents of deep-sea fishes, as well as other Moritella species from deep-sea water and sediments: M. marina, M. japonica, and M. yayanosii. The piezophilic Moritella strains had a Val residue or an Ala residue at position 180 and all the Moritella strains except for one had a His residue at position 229. However, four piezophilic-strain-specific substitutions at positions 103, 111, 229, and 283 were found to be completely conserved in the MDH of the intestinal Moritella strains of deep-sea fishes, indicating the substitutions may be habitat-specific. The piezophilic Shewanella strains had a Val residue and a Gln residue at positions 180 and 229, respectively. However, the MDHs of the Shewanella strains had five piezophilic-strain-specific substitutions at positions 61, 65, 107, 161, and 202. Therefore, the enzymatic strategies for responding to deep-sea high pressure environments of the MDHs between the genera Moritella and Shewanella are potentially different. Moreover, homology modeling shows these substitutions found in the MDHs of both genera except for position 229 in the subunit interface are located on the exposed region of the MDH molecules, indicating the substitutions may be related to the hydration state of the molecules. PMID:16598154

  9. Biomass of deepwater demersal forage fishes in Lake Huron, 1994-2007: Implications for offshore predators

    USGS Publications Warehouse

    Roseman, E.F.; Riley, S.C.

    2009-01-01

    We estimated the biomass of deepwater demersal forage fishes (those species common in the diets of lake trout and Chinook salmon) in Lake Huron during the period 1994-2007. The estimated total lake-wide biomass of deepwater demersal fishes in 2007 was reduced by 87 percent of that observed in 1994. Alewife biomass remained near the record low observed in 2004. Biomass of young-of-the-year rainbow smelt was at a record high in 2005, but little recruitment appears to have occurred in 2006 or 2007. Record-high estimates of young-of-the-year bloater biomass were observed in 2005 and 2007, and an increase in the biomass of adult bloater in 2007 suggests that some recruitment may be occurring. The biomass of other potential deepwater demersal forage fish species (sculpins, ninespine stickleback, trout-perch and round goby) has also declined since 1994 and remained low in 2007. The forage fish community in 2007 was dominated by small (< 120 mm) bloater and rainbow smelt. These results suggest that lake trout and Chinook salmon in Lake Huron may face nutritional stress in the immediate future.

  10. Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Alemany, Daniela; Acha, Eduardo M.; Iribarne, Oscar O.

    2014-03-01

    The high primary and secondary production associated with frontal systems attract a diversity of organisms due to high prey availability; this is why a strong relationship between fronts and pelagic fisheries has been shown worldwide. In the Argentine Sea, demersal resources are the most important, both in economical and in ecological sense; so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationship between spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the Argentine Sea: the shelf-break front, the southern Patagonia front and the mid-shelf front. Individual vessel satellite monitoring system data (VMS; grouped by fleet type: ice-trawlers, freezer-trawlers and jigging fleet) were studied and fishing events were identified. Fishing events per area were used as a proxy of fishing effort and its spatial distribution by fleet type was visualized and analyzed with Geographic Information Systems. Oceanographic fronts were defined using polygons based on satellite chlorophyll amplitude values, and the percentage of fishing events within each polygon was calculated. Results showed a positive association between fronts and fishing activities of the different fleets, which suggests the aggregation of target species in these zones. The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic level species; Macruronus magellanicus and Illex argentinus respectively) with fronts was higher than the ice-trawler fleet, targeting species of higher trophic level (Merluccius hubbsi). Marine fronts represent important fishing areas, even for demersal resources, as the distribution of fishing fleets and fishing effort are positively associated with frontal zones.

  11. Reproductive biology and recruitment of the deep-sea fish community from the NW Mediterranean continental margin

    NASA Astrophysics Data System (ADS)

    Fernandez-Arcaya, U.; Rotllant, G.; Ramirez-Llodra, E.; Recasens, L.; Aguzzi, J.; Flexas, M. M.; Sanchez-Vidal, A.; López-Fernández, P.; García, J. A.; Company, J. B.

    2013-11-01

    Temporal patterns in deep-sea fish reproduction are presently unknown for the majority of deep continental margins. A series of seasonal trawling surveys between depths of 300 to 1750 m in the Blanes submarine canyon and its adjacent open slope (NW Mediterranean) were conducted. The bathymetric size distributions and reproductive cycles of the most abundant species along the NW Mediterranean margin were analyzed to assess the occurrence of (i) temporal patterns in reproduction (i.e., spawning season) along a bathymetric gradient and (ii) preferential depth strata for recruitment. The fish assemblages were grouped in relation to their bathymetric distribution: upper slope, middle slope and lower slope species. Middle-slope species (i.e., 800-1350 m) showed short (i.e., highly seasonal) reproductive activity compared to the upper (300-800 m) and lower (1350-1750 m) ones. Our results, together with those previously published for megabenthic crustacean decapods in the area, suggest a cross-phyla depth-related trend of seasonality in reproduction. In the middle and lower slope species, the reproductive activity reached a maximum in the autumn-winter months and decreased in the spring. The observed seasonal spawning patterns appear to be ultimately correlated with changes in the downward transport of organic particles and with seasonal changes in the physicochemical characteristics of the surrounding water masses. The distribution of juveniles was associated with the bathymetric stratum where intermediate nepheloid layers interact with the continental margins, indicating that this stratum acts as a deep-sea fish nursery area.

  12. In vitro interaction of emerging contaminants with the cytochrome p450 system of Mediterranean deep-sea fish.

    PubMed

    Ribalta, Carla; Solé, Montserrat

    2014-10-21

    The interactions of emerging contaminants with the xenobiotic and endogenous metabolizing system of deep-sea fish were compared. The drugs diclofenac, fluoxetine, and gemfibrozil belong to different pharmaceutical classes with diverse mechanistic actions, and the personal care products triclosan, galaxolide, and nonylphenol are representative of antibacterial agents, nitro-musks, and surfactants, respectively. The fish compared are representative of the middle and lower slope of deep-sea habitats. The species were adults of Trachyrynchus scabrus, Mora moro, Cataetix laticeps, and Alepocehalus rostratus. The hepatic metabolic system studied were the activities associated with several cytochrome P450 isoforms (CYPs): 7-ethoxyresorufin-O-deethylase (EROD), benzyloxy-4-[trifluoromethyl]-coumarin-O-debenzyloxylase (BFCOD), and 7-ethoxycoumarin-O-deethylase (ECOD). Results showed differences in baseline activities and sensitivity to chemicals which were species, chemical, and pathway dependent. T. scabrous was the most sensitive species to chemical interactions with the xenobiotic and endogenous metabolizing (EROD and BFCOD) systems, especially in the case of diclofenac interference with BFCOD activity (IC50 = 15.7 ± 2.2 μM). Moreover, T. scabrous and A. rostratus possessed high basal ECOD activity, and this was greatly affected by in vitro exposure to diclofenac in T. scabrous also (IC50 = 6.86 ± 1.4 μM). These results highlight the sensitivity of marine fish to emerging contaminants and propose T. scabrous (middle slope) and A. rostratus (lower slope) as sentinels and the inclusion of ECOD activity as a sensitive biomarker to these exposures. PMID:25225740

  13. The effects of submarine canyons and the oxygen minimum zone on deep-sea fish assemblages off Hawai'i

    NASA Astrophysics Data System (ADS)

    De Leo, Fabio C.; Drazen, Jeffrey C.; Vetter, Eric W.; Rowden, Ashley A.; Smith, Craig R.

    2012-06-01

    Submarine canyons are reported to be sites of enhanced fish biomass and productivity on continental margins. However, little is known about the effects of canyons on fish biodiversity, in particular on oceanic islands, which are imbedded in regions of low productivity. Using submersibles and high-definition video surveys, we investigated demersal fish assemblages in two submarine canyons and slope areas off the island of Moloka'i, Hawai'i, at depths ranging from 314 to 1100 m. We addressed the interactions between the abundance, species richness and composition of the fish assemblage, and organic matter input and habitat heterogeneity, testing the hypotheses that heterogeneous bottom habitats and higher organic matter input in canyons enhance demersal fish abundance, and species density, richness and diversity, thereby driving differences in assemblage structure between canyons and slopes. Sediment type, substrate inclination, water-mass properties (temperature and dissolved oxygen) and organic matter input (modeled POC flux and percent detritus occurrence) were put into multivariate multiple regression models to identify potential drivers of fish assemblage structure. A total of 824 fish were recorded during ∼13 h of video yielding 55 putative species. Macrouridae was the most diverse family with 13 species, followed by Congridae (5), Ophidiidae (4) and Halosauridae (3). Assemblage structure changed markedly with depth, with the most abrupt change in species composition occurring between the shallowest stratum (314-480 m) and intermediate and deep strata (571-719 m, 946-1100 m). Chlorophthalmus sp. dominated the shallow stratum, macrourids and synaphobranchid eels at intermediate depths, and halosaurs in the deepest stratum. Assemblages only differed significantly between canyon and slope habitats for the shallow stratum, and the deep stratum at one site. Dissolved oxygen explained the greatest proportion of variance in the multivariate data, followed by POC

  14. Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea.

    PubMed

    Rummel, Christoph D; Löder, Martin G J; Fricke, Nicolai F; Lang, Thomas; Griebeler, Eva-Maria; Janke, Michael; Gerdts, Gunnar

    2016-01-15

    Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (<5mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor K was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected.

  15. Survey of demersal fishes from southern Saudi Arabia, with five new records for the Red Sea.

    PubMed

    Bogorodsky, Sergey V; Alpermann, Tilman J; Mal, Ahmad O; Gabr, Mohamed H

    2014-08-18

    During a survey of demersal fishes of the southern Red Sea coast of Saudi Arabia off Jizan, 98 species were collected by trawling. Five of these represent new records for the Red Sea: Saurida longimanus, Dactyloptena gilberti, Jaydia novaeguineae, Pomadasys maculatus and Parapercis maculata. Additionally a specimen of the rare moray Gymnothorax reticularis, previously known from only three specimens, was collected. Records of two species, Parastromateus niger and Pseudorhombus arsius, that formerly were considered questionable, are confirmed by collection of new voucher specimens. Validity of Laeops sinusarabici is confirmed. This study documents parts of the diversity of the demersal fish communities on sandy areas of the southern Red Sea, but also emphasizes that a large proportion of this area has not been explored. 

  16. Demersal fish distribution and habitat use within and near Baltimore and Norfolk Canyons, U.S. Middle Atlantic Slope

    USGS Publications Warehouse

    Ross, Steve W.; Rhode, Mike; Quattrini, Andrea M.

    2015-01-01

    Numerous submarine canyons along the United States middle Atlantic continental margin support enhanced productivity, diverse and unique habitats, active fisheries, and are vulnerable to various anthropogenic disturbances. During two cruises (15 Aug–2 Oct 2012 and 30 Apr–27 May 2013), Baltimore and Norfolk canyons and nearby areas (including two cold seeps) were intensively surveyed to determine demersal fish distributions and habitat associations. Overall, 34 ROV dives (234–1612 m) resulted in 295 h of bottom video observations and numerous collections. These data were supplemented by 40, 30-min bottom trawl samples. Fish observations were assigned to five general habitat designations: 1) sand-mud (flat), 2) sloping sand-mud with burrows, 3) low profile gravel, rock, boulder, 4) high profile, canyon walls, rocks or ridges, and 5) seep-mixed hard and soft substrata, the later subdivided into seven habitats based on amounts of dead mussel and rock cover. The influence of corals, sponges and live mussels (seeps only) on fish distributions was also investigated. Both canyon areas supported abundant and diverse fish communities and exhibited a wide range of habitats, including extensive areas of deep-sea corals and sponges and two nearby methane seeps (380–430 m, 1455–1610 m). All methods combined yielded a total of 123 species of fishes, 12 of which are either new records for this region or have new range data. Depth was a major factor that separated the fish faunas into two zones with a boundary around 1400 m. Fishes defining the deeper zone included Lycodes sp.,Dicrolene introniger, Gaidropsaurus ensis, Hydrolagus affinis, Antimora rostrata, andAldrovandia sp. Fishes in the deep zone did not exhibit strong habitat affinities, despite the presence of a quite rugged, extensive methane seep. We propose that habitat specificity decreases with increasing depth. Fishes in the shallower zone, characterized by Laemonema sp., Phycis chesteri, Nezumia bairdii, Brosme

  17. Small-scale distribution of deep-sea demersal nekton and other megafauna in the Charlie-Gibbs Fracture Zone of the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Felley, J. D.; Vecchione, M.; Wilson, R. R., Jr.

    2008-01-01

    Videotapes from manned submersibles diving in the area of the Charlie-Gibbs Fracture Zone of the Mid-Atlantic Ridge were used to investigate the distribution of fishes, large crustaceans, epifaunal and sessile organisms, and environmental features along a series of transects. Submersibles MIR 1 and MIR 2 conducted paired dives in an area of mixed sediment and rock (beginning depth ca. 3000 m) and on a large pocket of abyssal-like sediments (depth ca. 4000 m). In the shallower area, the submersibles passed over extremely heterogeneous terrain with a diversity of nekton, epifaunal forms and sessile forms. In the first pair of dives, MIR 1 rose along the Mid-Atlantic Ridge from 3000 to 1700 m, while MIR 2 remained near the 3000 m isobath. Nekton seen in these relatively shallow dives included large and small macrourids (genus Coryphaenoides), shrimp (infraorder Penaeidea), Halosauropsis macrochir, Aldrovandia sp., Antimora rostrata, and alepocephalids. The last two were more characteristic of the upper areas of the slope reached by MIR 1, as it rose along the Mid-Atlantic Ridge to depths less than 3000 m. Distributions of some forms seemed associated with depth and/or the presence of hard substrate. Sessile organisms such as sponges and large cnidaria were more likely to be found in rocky areas. The second pair of dives occurred in an abyssal area and the submersibles passed over sediment-covered plains, with little relief and many fewer countable organisms and features. The most evident of these were holes, mounds, small cerianthid anemones, small macrourids and the holothurian Benthodytes sp. A few large macrourids and shrimp also were seen in these deeper dives, as well as squat lobsters ( Munidopsis sp.). Sponges and larger cnidaria were mostly associated with a few small areas of rocky substrate. Holes and mounds showed distributions suggesting large-scale patterning. Over all dives, most sessile and epifaunal forms showed clumped distributions. However, large

  18. Organohalogen compounds in deep-sea fishes from the western North Pacific, off-Tohoku, Japan: Contamination status and bioaccumulation profiles.

    PubMed

    Takahashi, Shin; Oshihoi, Tomoko; Ramu, Karri; Isobe, Tomohiko; Ohmori, Koji; Kubodera, Tsunemi; Tanabe, Shinsuke

    2010-02-01

    Twelve species of deep-sea fishes collected in 2005 from the western North Pacific, off-Tohoku, Japan were analyzed for organohalogen compounds. Among the compounds analyzed, concentrations of DDTs and PCBs (up to 23,000 and 12,400 ng/g lipid wt, respectively) were the highest. The present study is the foremost to report the occurrence of brominated flame retardants such as PBDEs and HBCDs in deep-sea organisms from the North Pacific region. Significant positive correlations found between delta(15)N ( per thousand) and PCBs, DDTs and PBDEs suggest the high biomagnification potential of these contaminants in food web. The large variation in delta(13)C (per thousand) values observed between the species indicate multiple sources of carbon in the food web and specific accumulation of hydrophobic organohalogen compounds in benthic dwelling carnivore species like snubnosed eel. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment. PMID:19837437

  19. Organohalogen compounds in deep-sea fishes from the western North Pacific, off-Tohoku, Japan: Contamination status and bioaccumulation profiles.

    PubMed

    Takahashi, Shin; Oshihoi, Tomoko; Ramu, Karri; Isobe, Tomohiko; Ohmori, Koji; Kubodera, Tsunemi; Tanabe, Shinsuke

    2010-02-01

    Twelve species of deep-sea fishes collected in 2005 from the western North Pacific, off-Tohoku, Japan were analyzed for organohalogen compounds. Among the compounds analyzed, concentrations of DDTs and PCBs (up to 23,000 and 12,400 ng/g lipid wt, respectively) were the highest. The present study is the foremost to report the occurrence of brominated flame retardants such as PBDEs and HBCDs in deep-sea organisms from the North Pacific region. Significant positive correlations found between delta(15)N ( per thousand) and PCBs, DDTs and PBDEs suggest the high biomagnification potential of these contaminants in food web. The large variation in delta(13)C (per thousand) values observed between the species indicate multiple sources of carbon in the food web and specific accumulation of hydrophobic organohalogen compounds in benthic dwelling carnivore species like snubnosed eel. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment.

  20. Metazoan parasites of deep-sea fishes from the South Eastern Pacific: Exploring the role of ecology and host phylogeny

    NASA Astrophysics Data System (ADS)

    Ñacari, Luis A.; Oliva, Marcelo E.

    2016-09-01

    We studied the parasite fauna of five deep-sea fish species (>1000 m depth), Three members of Macrouridae (Macrourus holotrachys, Coryphaenoides ariommus and Coelorhynchus sp.), the Morid Antimora rostrata and the Synaphobranchidae Diaptobranchus capensis caught as by-catch of the Patagonian toothfish (Dissostichus eleginoides) from central and northern Chile at depths between 1000 and 2000 m. The parasite fauna of M. holotrachys was the most diverse, with 32 species (The higher reported for Macrourus spp.) and the lower occur in the basketwork eel D. capensis (one species). Trophically transmitted parasites, mainly Digenea and Nematoda explain 59.1% of the total number of species obtained (44 species) and the 81.1% of the 1020 specimens collected. Similarity analysis based on prevalence as well as a Correspondence analysis shows that higher similitude in parasite fauna occurs in members of Macrouridae. The importance of diet and phylogeny is discussed as forces behind the characteristics of the endoparasite and ectoparasite communities found in the studied fish species.

  1. The Inner Ear and its Coupling to the Swim Bladder in the Deep-Sea Fish Antimora rostrata (Teleostei: Moridae)

    PubMed Central

    Deng, Xiaohong; Wagner, Hans-Joachim; Popper, Arthur N.

    2011-01-01

    The inner ear structure of Antimora rostrata and its coupling to the swim bladder were analyzed and compared with the inner ears of several shallow-water species that also have similar coupling. The inner ear of Antimora has a long saccular otolith and sensory epithelium as compared to many other fishes. Some parts of the membranous labyrinth are thick and rigid, while other parts are thinner but attached tightly to the bony capsule. The partially rigid membranous labyrinth, along with its intimate connection to the swim bladder, may help the inner ear follow the sound oscillations from the swim bladder with better precision than would occur in a less rigid inner ear. In addition, the saccular sensory epithelium has an elaborate structure and an anterior enlargement that may be correlated with increased hearing sensitivity. Some of the features in the inner ear of Antimora may reflect the functional specialization of deep-water living and support the hypothesis that there is enhanced inner ear sensitivity in some deep-sea fishes. PMID:21532967

  2. Calibration of Productivity Proxy Based on Fish Tooth Flux and Biogenic Barium in Pacific Deep-Sea Sediments

    NASA Astrophysics Data System (ADS)

    Vincent, K.

    2015-12-01

    Biological production is a key variable in paleoceanography, yet most measures reflect the detailed responses of specific biological communities—opal for biosiliceous producters, alkenones for some coccolithophorids, and percent carbonate for a heterogeneous mixture of calcareous phytoplankton and zooplankton, among others. We are developing a new method for extracting biogenic barite and fish teeth from deep-sea sediments and calibrating the fluxes of both components to satellite-derived ocean productivity. Both fish teeth and barite capture major components of biological production in the ocean. Teeth capture dynamics of high trophic level communities who depend upon lower level production in mostly short food chains. Barite reflects export flux of marine particulate carbon, and hence records the major producers of marine snow. Our methods digest sediments to remove carbonates, and concentrate teeth with heavy liquid separation. Barite is also concentrated by acid dissolution of carbonate, but then we dissolve barite, collect the sulfate in solution, and re-precipitate barite rather than use the time consuming and dangerous methods that are currently the industry standard. Counting the number of fish teeth present in the sample and extracting the amount of biogenic barium will discover two different proxies of productivity. The sample sites range throughout the Pacific Ocean, giving a wide scope of variability along with satellite productivity levels. The results between the amount of fish teeth as well as the biogenic barite levels will hopefully be at a similar level, indicating that this method is a new tried and true proxy for productivity in the future.

  3. Deep-sea fish distribution varies between seamounts: results from a seamount complex off New Zealand.

    PubMed

    Tracey, Dianne M; Clark, Malcolm R; Anderson, Owen F; Kim, Susan W

    2012-01-01

    Fish species data from a complex of seamounts off New Zealand termed the "Graveyard Seamount Complex' were analysed to investigate whether fish species composition varied between seamounts. Five seamount features were included in the study, with summit depths ranging from 748-891 m and elevation from 189-352 m. Measures of fish species dominance, rarity, richness, diversity, and similarity were examined. A number of factors were explored to explain variation in species composition, including latitude, water temperature, summit depth, depth at base, elevation, area, slope, and fishing effort. Depth at base and slope relationships were significant with shallow seamounts having high total species richness, and seamounts with a more gradual slope had high mean species richness. Species similarity was modelled and showed that the explanatory variables were driven primarily by summit depth, as well as by the intensity of fishing effort and elevation. The study showed that fish assemblages on seamounts can vary over very small spatial scales, in the order of several km. However, patterns of species similarity and abundance were inconsistent across the seamounts examined, and these results add to a growing literature suggesting that faunal communities on seamounts may be populated from a broad regional species pool, yet show considerable variation on individual seamounts. PMID:22745656

  4. Deep-sea fish distribution varies between seamounts: results from a seamount complex off New Zealand.

    PubMed

    Tracey, Dianne M; Clark, Malcolm R; Anderson, Owen F; Kim, Susan W

    2012-01-01

    Fish species data from a complex of seamounts off New Zealand termed the "Graveyard Seamount Complex' were analysed to investigate whether fish species composition varied between seamounts. Five seamount features were included in the study, with summit depths ranging from 748-891 m and elevation from 189-352 m. Measures of fish species dominance, rarity, richness, diversity, and similarity were examined. A number of factors were explored to explain variation in species composition, including latitude, water temperature, summit depth, depth at base, elevation, area, slope, and fishing effort. Depth at base and slope relationships were significant with shallow seamounts having high total species richness, and seamounts with a more gradual slope had high mean species richness. Species similarity was modelled and showed that the explanatory variables were driven primarily by summit depth, as well as by the intensity of fishing effort and elevation. The study showed that fish assemblages on seamounts can vary over very small spatial scales, in the order of several km. However, patterns of species similarity and abundance were inconsistent across the seamounts examined, and these results add to a growing literature suggesting that faunal communities on seamounts may be populated from a broad regional species pool, yet show considerable variation on individual seamounts.

  5. Diversity of demersal fish in the East China Sea: Implication of eutrophication and fishery

    NASA Astrophysics Data System (ADS)

    Chang, Ni-Na; Shiao, Jen-Chieh; Gong, Gwo-Ching

    2012-09-01

    The environment of the East China Sea has been greatly impacted by both fishing and land-based pollution over the past decades, with a concomitant decline of fishery resources. Imposition of a seasonal fishing moratorium and a trawling prohibition zone has failed to engender recovery of fish communities. To help understand the respective impacts of environmental factors and fishing activities in the East China Sea ecosystem, fish samples and environmental parameters were collected in prohibited and open fishing areas, during the seasonal fishing moratorium. The inshore area of the East China Sea, corresponding to the prohibited zone for trawling, had extremely high nutrient concentrations and relatively low dissolved oxygen. The diversity index of demersal fish showed significantly negative correlations with nutrient concentrations and positive correlations with bottom-water dissolved oxygen. The inshore area of the East China Sea was heavily dominated by small-sized fishes, such as Gobiids—Amblychaeturichthys hexanema and Apogonids—Apogon lineatus, reflecting low survival of most fish species. In contrast, the offshore areas, with lower nutrient concentrations and higher dissolved oxygen, had higher biodiversity. These findings suggest that eutrophication and subsequent hypoxia is responsible for the limited recovery of fishery resources in the trawling prohibition area of the East China Sea. Therefore, a multi-pronged fishery management that involves both fishing restriction and environmental improvement is urgently needed in the East China Sea.

  6. Accumulation of dioxins in deep-sea crustaceans, fish and sediments from a submarine canyon (NW Mediterranean)

    NASA Astrophysics Data System (ADS)

    Castro-Jiménez, Javier; Rotllant, Guiomar; Ábalos, Manuela; Parera, Jordi; Dachs, Jordi; Company, Joan B.; Calafat, Antoni; Abad, Esteban

    2013-11-01

    Submarine canyons are efficient pathways transporting sediments and associated pollutants to deep sea. The objective of this work was to provide with the first assessment of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) levels and accumulation in deep-sea megafauna (crustacean and fish) and sediments in the Blanes submarine canyon (North-Western Mediterranean Sea). The influence of the selected species habitats (pelagic, nektobenthic, and benthic) and the trophic chain level on the accumulation of dioxins was also investigated. Bottom sediment and biota samples were collected at different depths and locations inside the canyon and in the adjacent slope outside the canyon influence. ∑2,3,7,8-PCDD/F concentrations in sediments varied from 102 to 680 pg g-1 dry weight (d.w.) (1-6 WHO98-TEQ pg g-1 d.w.). Dioxins are enriched in bottom sediments at higher depths inside the canyon and in particular in the deepest parts of the canyon axis (1700 m depth), whereas no enrichment of dioxins was verified at the deepest sediments from the adjacent open slope outside the canyon influence. The proportion of ∑2,3,7,8-PCDF (furans) to ∑2,3,7,8-PCDD (dioxins) increased for sediments with higher soot carbon content consistent with the higher affinity of PCDF for sorption onto soot carbon. Higher ∑2,3,7,8-PCDD/F levels were found in crustaceans than in fish, ranging from 220 to 795 pg g-1 lipid weight (l.w.) (13-90 WHO98-TEQ pg g-1 l.w.) and 110 to 300 pg g-1 l.w. (22-33 WHO98-TEQ pg g-1 l.w.) in crustaceans and fish, respectively. Dioxin highest concentrations were found in nektobenthic organisms, i.e., benthic organism with swimming capabilities (both fish and crustaceans). These higher levels are consistent with the higher trophic level and predicted biomagnification factors (BMFs) of nektobenthic species. The reduced availability of sediment-bound PCDD/F for benthic species mainly due to soot and organic carbon sorption of these contaminants most

  7. High contents of trimethylamine oxide correlating with depth in deep-sea teleost fishes, skates, and decapod crustaceans.

    PubMed

    Kelly, R H; Yancey, P H

    1999-02-01

    In muscles of shallow-living marine animals, the osmolyte trimethylamine N-oxide (TMAO) is reportedly found (in millimoles of TMAO per kilogram of tissue wet weight) at 30-90 in shrimp, 5-50 in crabs, 61-181 in skates, and 10-70 in most teleost fish. Recently our laboratory reported higher levels (83-211 mmol/kg), correlating with habitat depth, in deep-sea gadiform teleosts. We now report the same trend in muscles of other animals, collected off the coast of Oregon from bathyal (1800-2000 m) and abyssal plain (2850 m) sites. TMAO contents (mmol/kg +/- SD) were as follows: zoarcid teleosts, 103 +/- 9 (bathyal) and 197 +/- 2 (abyssal); scorpaenid teleosts, 32 +/- 0 (shallow) and 141 +/- 16 (bathyal); rajid skates, 215 +/- 13 (bathyal) and 244 +/- 23 (abyssal); caridean shrimp, 76 +/- 16 (shallow), 203 +/- 35 (bathyal), and 299 +/- 28 (abyssal); Chionoecetes crabs, 22 +/- 2 (shallow) and 164 +/- 15 (bathyal). Deep squid, clams, and anemones also had higher contents than shallow species. Osmoconformers showed compensation between TMAO and other osmolytes. Urea contents (typically 300 mmol/kg in shallow elasmobranchs) in skates were 214 +/- 5 (bathyal) and 136 +/- 9 (abyssal). Glycine contents in shrimp were 188 +/- 17 (shallow) and 52 +/- 20 (abyssal). High TMAO contents may reflect diet, reduce osmoregulatory costs, increase buoyancy, or counteract destabilization of proteins by pressure. PMID:25575382

  8. Lipid Correction for Carbon Stable Isotope Analysis of Deep-sea Fishes

    EPA Science Inventory

    Lipid extraction is used prior to stable isotope analysis of fish tissues to remove variability in the carbon stable isotope ratio (d13C) caused by varying lipid content among samples. Our objective was to evaluate an application of a mass balance correction for the effect of lip...

  9. [Cyclic reproductive activity in bathyal and abyssel deep-sea fishes].

    PubMed

    Rannou, M

    1975-10-01

    A female of the rare Brotulid fish Cataetyx laticeps has been caught; it contained a great number of larvae all of the same size. Growth marks can be noticed on its otoliths as well as on those of various species caught to the depth of 4 700 m. They are indications of a cyclic activity in the abyssal depths. PMID:813869

  10. The occupation of trawl fishing and the medical aid available to the Grimsby deep sea fisherman1

    PubMed Central

    Moore, S. R. W.

    1969-01-01

    Moore, S. R. W. (1969).Brit. J. industr. Med.,26, 1-24. The occupation of trawl fishing and the medical aid available to the Grimsby deep sea fisherman. The mortality of fishermen is twice that of coalminers. Because of the method of fishing the mortality of the trawlerman is probably higher. Outside the industry little is known about the occupation of trawl fishing. Its size, the number of men employed, and the number and distribution of trawlers are therefore described, with particular reference to the port of Grimsby. As near, middle, and deep water trawlers sail from Grimsby, its industry gives a good representation of conditions in the industry as a whole. The port and the fishing grounds are described. The composition of the trawler crew, their conditions of work, accommodation, and remuneration are explained. A description is given of the trawl apparatus, fishing operations, and the hazards involved, and extracts from the writer's diary of a fishing voyage are appended. The United Kingdom has ratified the Accommodation of Crews (Fishermen) Convention 1966 of the International Labour Organisation, and an informal survey of a modern trawler fleet showed that it fell short of the requirements of this Convention. Accommodation is confined and the crew live and work in close proximity and in conditions of physical discomfort. Trawlermen work for long hours under conditions which would not be tolerated by the shore worker. The method of payment is such that trawlermen may take unnecessary risks. Earnings depend on team work so that illness and injury are often not reported with consequent deterioration of the condition. Physical fatigue and lack of sleep contribute to an increased accident rate. It is therefore recommended that more men per trawler should be employed to allow shorter working hours. As the skipper and mate are paid wholly on a share basis, the remainder of the crew receiving, in addition, a basic wage, it `pays' the trawlermen to take risks. A

  11. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis).

    PubMed

    Partridge, J C; Douglas, R H; Marshall, N J; Chung, W-S; Jordan, T M; Wagner, H-J

    2014-05-01

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics.

  12. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis).

    PubMed

    Partridge, J C; Douglas, R H; Marshall, N J; Chung, W-S; Jordan, T M; Wagner, H-J

    2014-05-01

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics. PMID:24648222

  13. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis)

    PubMed Central

    Partridge, J. C.; Douglas, R. H.; Marshall, N. J.; Chung, W.-S.; Jordan, T. M.; Wagner, H.-J.

    2014-01-01

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics. PMID:24648222

  14. North Atlantic demersal deep-water fish distribution and biology: present knowledge and challenges for the future.

    PubMed

    Bergstad, O A

    2013-12-01

    This paper summarizes knowledge and knowledge gaps on benthic and benthopelagic deep-water fishes of the North Atlantic Ocean, i.e. species inhabiting deep continental shelf areas, continental and island slopes, seamounts and the Mid-Atlantic Ridge. While several studies demonstrate that distribution patterns are species specific, several also show that assemblages of species can be defined and such assemblages are associated with circulatory features and water mass distributions. In many subareas, sampling has, however, been scattered, restricted to shallow areas or soft substrata, and results from different studies tend to be difficult to compare quantitatively because of sampler differences. Particularly, few studies have been conducted on isolated deep oceanic seamounts and in Arctic deep-water areas. Time series of data are very few and most series are short. Recent studies of population structure of widely distributed demersal species show less than expected present connectivity and considerable spatial genetic heterogeneity and complexity for some species. In other species, genetic homogeneity across wide ranges was discovered. Mechanisms underlying the observed patterns have been proposed, but to test emerging hypotheses more species should be investigated across their entire distribution ranges. Studies of population biology reveal greater diversity in life-history strategies than often assumed, even between co-occurring species of the same family. Some slope and ridge-associated species are rather short-lived, others very long-lived, and growth patterns also show considerable variation. Recent comparative studies suggest variation in life-history strategies along a continuum correlated with depth, ranging from shelf waters to the deep sea where comparatively more species have extended lifetimes, and slow rates of growth and reproduction. Reproductive biology remains too poorly known for most deep-water species, and temporal variation in recruitment has

  15. North Atlantic demersal deep-water fish distribution and biology: present knowledge and challenges for the future.

    PubMed

    Bergstad, O A

    2013-12-01

    This paper summarizes knowledge and knowledge gaps on benthic and benthopelagic deep-water fishes of the North Atlantic Ocean, i.e. species inhabiting deep continental shelf areas, continental and island slopes, seamounts and the Mid-Atlantic Ridge. While several studies demonstrate that distribution patterns are species specific, several also show that assemblages of species can be defined and such assemblages are associated with circulatory features and water mass distributions. In many subareas, sampling has, however, been scattered, restricted to shallow areas or soft substrata, and results from different studies tend to be difficult to compare quantitatively because of sampler differences. Particularly, few studies have been conducted on isolated deep oceanic seamounts and in Arctic deep-water areas. Time series of data are very few and most series are short. Recent studies of population structure of widely distributed demersal species show less than expected present connectivity and considerable spatial genetic heterogeneity and complexity for some species. In other species, genetic homogeneity across wide ranges was discovered. Mechanisms underlying the observed patterns have been proposed, but to test emerging hypotheses more species should be investigated across their entire distribution ranges. Studies of population biology reveal greater diversity in life-history strategies than often assumed, even between co-occurring species of the same family. Some slope and ridge-associated species are rather short-lived, others very long-lived, and growth patterns also show considerable variation. Recent comparative studies suggest variation in life-history strategies along a continuum correlated with depth, ranging from shelf waters to the deep sea where comparatively more species have extended lifetimes, and slow rates of growth and reproduction. Reproductive biology remains too poorly known for most deep-water species, and temporal variation in recruitment has

  16. Distribution of Polyunsaturated Fatty Acids in Bacteria Present in Intestines of Deep-Sea Fish and Shallow-Sea Poikilothermic Animals

    PubMed Central

    Yano, Y.; Nakayama, A.; Yoshida, K.

    1997-01-01

    The lipid and fatty acid compositions in nine obligate and facultative barophilic bacteria isolated from the intestinal contents of seven deep-sea fish were determined. Phospholipid compositions were simple, with phosphatidylethanolamine and phosphatidylglycerol predominating in all strains. Docosahexaenoic acid (DHA; 22:6n-3), which has not been reported in procaryotes except for deep-sea bacteria, was found to be present in eight strains at a level of 8.1 to 21.5% of total fatty acids. In the other strain, eicosapentaenoic acid (EPA; 20:5n-3) was present at a level of 31.5% of total fatty acids. Other fatty acids observed in all strains were typical of marine gram-negative bacteria. Subcultures from pouches prepared from intestinal contents of five deep-sea fish by the most-probable-number (MPN) method were analyzed for fatty acids, and all subcultures contained DHA and/or EPA. Accordingly, viable cell counts of bacteria containing DHA and EPA were estimated at a maximum of 1.3 x 10(sup8) and 2.4 x 10(sup8) cells per ml, respectively, and accounted for 14 and 30%, respectively, of the total cell counts in the intestinal contents of the deep-sea fish. In the case of 10 shallow-sea poikilothermic animals having bacterial populations of 1.1 x 10(sup6) to 1.9 x 10(sup9) CFU per ml in intestinal contents, no DHA was found in the 112 isolates examined, while production of EPA was found in 40 isolates from cold- and temperate-sea samples. These results suggest that DHA and EPA are involved in some adaptations of bacteria to low temperature and high pressure. PMID:16535638

  17. Demersal fishing disturbance increases predation risk for whelks ( Buccinum undatum L.)

    NASA Astrophysics Data System (ADS)

    Ramsay, Kirsten; Kaiser, Michel J.

    1998-06-01

    Field observations by divers indicated that a high rate of predation of whelks ( Buccinum undatum) by starfish ( Asterias rubens) occurred in an area disturbed by scallop dredging, although these whelks mostly appeared to be alive and externally undamaged. The ability of whelks to escape from starfish was tested in the laboratory after they were dropped or rolled to simulate direct physical contact with bottom fishing gear. Dropping whelks did not significantly affect their escape behaviour, but whelks which had been rolled took significantly longer to right themselves and were significantly less likely to perform an escape response than whelks that had not experienced this treatment. This study suggests that demersal fishing may indirectly increase whelk mortality by increasing their risk of predation.

  18. Enzyme activities of demersal fishes from the shelf to the abyssal plain

    NASA Astrophysics Data System (ADS)

    Drazen, Jeffrey C.; Friedman, Jason R.; Condon, Nicole E.; Aus, Erica J.; Gerringer, Mackenzie E.; Keller, Aimee A.; Elizabeth Clarke, M.

    2015-06-01

    The present study examined metabolic enzyme activities of 61 species of demersal fishes (331 individuals) trawled from a 3000 m depth range. Citrate synthase, lactate dehydrogenase, malate dehydrogenase, and pyruvate kinase activities were measured as proxies for aerobic and anaerobic activity and metabolic rate. Fishes were classified according to locomotory mode, either benthic or benthopelagic. Fishes with these two locomotory modes were found to exhibit differences in metabolic enzyme activity. This was particularly clear in the overall activity of citrate synthase, which had higher activity in benthopelagic fishes. Confirming earlier, less comprehensive studies, enzyme activities declined with depth in benthopelagic fishes. For the first time, patterns in benthic species could be explored and these fishes also exhibited depth-related declines in enzyme activity, contrary to expectations of the visual interactions hypothesis. Trends were significant when using depth parameters taken from the literature as well as from the present trawl information, suggesting a robust pattern regardless of the depth metric used. Potential explanations for the depth trends are discussed, but clearly metabolic rate does not vary simply as a function of mass and habitat temperature in fishes as shown by the substantial depth-related changes in enzymatic activities.

  19. Spatial and temporal variability of demersal fishes at Condor seamount (Northeast Atlantic)

    NASA Astrophysics Data System (ADS)

    Menezes, Gui M.; Giacomello, Eva

    2013-12-01

    Temporal and spatial patterns of variation of benthic and benthopelagic fish assemblages on the Condor Seamount of the Azores, Northeast Atlantic, were studied based on longline samples from the depth interval 200-1300 m depth. The seamount was used as a commercial fishing ground for decades but is currently closed to fishing as a temporary protected area for research. The protection regime offers an opportunity to monitor and analyze responses to harvesting and recovery from previous fishing impacts. Species number, catches per unit of effort, and zonation with depth corresponded in general with what was observed elsewhere for the Azorean demersal fish community. Total abundance, species richness and species composition significantly varied in time and space within the seamount, generally showing a North-South asymmetry. Abundance and species richness were higher in the Northern than in the Southern sector of the seamount, mainly due to higher abundances of the species Helicolenus dactylopterus, Pagellus bogaraveo, Beryx splendens and Trachurus picturatus. Analyses of abundance variation of the most frequent species showed an array of species-specific responses. The variability of fish assemblages is discussed in the light of oceanographic and anthropogenic factors, which may drive the observed patterns and trends.

  20. Ingestion of microplastics by demersal fish from the Spanish Atlantic and Mediterranean coasts.

    PubMed

    Bellas, Juan; Martínez-Armental, José; Martínez-Cámara, Ariana; Besada, Victoria; Martínez-Gómez, Concepción

    2016-08-15

    Microplastic pollution has received increased attention over the last few years. This study documents microplastic ingestion in three commercially relevant demersal fish species from the Spanish Atlantic and Mediterranean coasts, the lesser spotted dogfish Scyliorhinus canicula, the European hake Merluccius merluccius and the red mullet Mullus barbatus. Overall 212 fish were examined, 72 dogfish, 12 hakes and 128 red mullets. The percentage of fish with microplastics was 17.5% (15.3% dogfish, 18.8% red mullets and 16.7% hakes), averaging 1.56±0.5 items per fish, and the size of the microplastics ranged from 0.38 to 3.1mm. These fish species are used currently as biomonitors for marine pollution monitoring within the Spanish Marine Pollution Monitoring Programme (SMP), and may be as well suitable candidates for monitoring spatial and temporal trends of ingested litter. The data presented here represent a baseline for the implementation of the Marine Strategy Framework Directive descriptor 10 in Spain. PMID:27289284

  1. Ingestion of microplastics by demersal fish from the Spanish Atlantic and Mediterranean coasts.

    PubMed

    Bellas, Juan; Martínez-Armental, José; Martínez-Cámara, Ariana; Besada, Victoria; Martínez-Gómez, Concepción

    2016-08-15

    Microplastic pollution has received increased attention over the last few years. This study documents microplastic ingestion in three commercially relevant demersal fish species from the Spanish Atlantic and Mediterranean coasts, the lesser spotted dogfish Scyliorhinus canicula, the European hake Merluccius merluccius and the red mullet Mullus barbatus. Overall 212 fish were examined, 72 dogfish, 12 hakes and 128 red mullets. The percentage of fish with microplastics was 17.5% (15.3% dogfish, 18.8% red mullets and 16.7% hakes), averaging 1.56±0.5 items per fish, and the size of the microplastics ranged from 0.38 to 3.1mm. These fish species are used currently as biomonitors for marine pollution monitoring within the Spanish Marine Pollution Monitoring Programme (SMP), and may be as well suitable candidates for monitoring spatial and temporal trends of ingested litter. The data presented here represent a baseline for the implementation of the Marine Strategy Framework Directive descriptor 10 in Spain.

  2. Meiofauna as food source for small-sized demersal fish in the southern North Sea

    NASA Astrophysics Data System (ADS)

    Schückel, Sabine; Sell, Anne F.; Kihara, Terue C.; Koeppen, Annemarie; Kröncke, Ingrid; Reiss, Henning

    2013-06-01

    Meiofauna play an essential role in the diet of small and juvenile fish. However, it is less well documented which meiofaunal prey groups in the sediment are eaten by fish. Trophic relationships between five demersal fish species (solenette, goby, scaldfish, dab <20 cm and plaice <20 cm) and meiofaunal prey were investigated by means of comparing sediment samples and fish stomach contents collected seasonally between January 2009 and January 2010 in the German Bight. In all seasons, meiofauna in the sediment was numerically dominated by nematodes, whereas harpacticoids dominated in terms of occurrence and biomass. Between autumn and spring, the harpacticoid community was characterized by Pseudobradya minor and Halectinosoma canaliculatum, and in summer by Longipedia coronata. Meiofaunal prey dominated the diets of solenette and gobies in all seasons, occurred only seasonally in the diet of scaldfish and dab, and was completely absent in the diet of plaice. For all fish species (excluding plaice) and in each season, harpacticoids were the most important meiofauna prey group in terms of occurrence, abundance and biomass. High values of Ivlev's index of selectivity for Pseudobradya spp. in winter and Longipedia spp. in summer provided evidence that predation on harpacticoids was species-selective, even though both harpacticoids co-occurred in high densities in the sediments. Most surficial feeding strategies of the studied fish species and emergent behaviours of Pseudobradya spp. and Longipedia spp. might have caused this prey selection. With increasing fish sizes, harpacticoid prey densities decreased in the fish stomachs, indicating a diet change towards larger benthic prey during the ontogeny of all fish species investigated.

  3. Status and trends of the Lake Huron offshore Demersal fish community, 1976-2013

    USGS Publications Warehouse

    Riley, Stephen C.; Roseman, Edward F.; Chriscinske, Margret Ann; Tucker, Taaja R.; Ross, Jason E.; Armenio, Patricia M.; Watson, Nicole M.; Woelmer, Whitney

    2014-01-01

    The USGS Great Lakes Science Center has conducted trawl surveys to assess annual changes in the offshore demersal fish community of Lake Huron since 1973. Sample sites include five ports in U.S. waters with less frequent sampling near Goderich, Ontario. The 2013 fall bottom trawl survey was carried out between 25 October – 21 November 2013 and included all U.S. ports as well as Goderich, ON. The 2013 main basin prey fish biomass estimate for Lake Huron was 47 kilotonnes, less than half of the estimate in 2012 (97 Kt), and approximately 13 percent of the maximum estimate in the time series. The biomass etimate for YAO alewife in 2013 was lower than in 2012, remained much lower than levels observed before the crash in 2004, and populations were dominated by small fish. Estimated biomass of rainbow smelt also decreased and was the second lowest observed in the time series. Estimated YAO bloater biomass in Lake Huron was also reduced compared to 2012. YOY alewife, rainbow smelt, and bloater abundance and biomass increased over 2012. Biomass estimates for deepwater and slimy sculpins, trout-perch, ninespine stickleback, and round goby in 2013 were lower than in 2012 and remained low compared to historic estimates. Wild juvenile lake trout were captured again in 2013, suggesting that natural reproduction by lake trout continues to occur.

  4. Metazoan fish parasites of Macrourus berglax Lacepède, 1801 and other macrourids of the North Atlantic: Invasion of the deep sea from the continental shelf

    NASA Astrophysics Data System (ADS)

    Palm, H. W.; Klimpel, S.

    2008-01-01

    Between 2001 and 2003, a total of 105 Macrourus berglax Lacepède, 1801 were collected from Irminger Sea, at depths between 250 and 450 m, and were studied for parasites. Twenty-four different parasite species were identified. Nematodes (eight spp.) and digeneans (six spp.) were the most species rich, followed by crustaceans (four spp.), cestodes (three spp.), acanthocephalans (two spp.) and monogeneans (one sp.). Core species included the digenean Gonocerca phycidis (maximum 62.9% prevalence), the nematodes Anisakis sp. (62.9%), Capillaria gracilis (65.8%), Hysterothylacium aduncum (60.0%), Neoascarophis macrouri (88.6%), Spinitectus oviflagellis (82.9%), and the acanthocephalan Echinorhynchus gadi (97.1%). M. berglax was the final host for most of the parasites, and was infested with only a few larval forms. The species composition, diversity as well as the prevalence and intensity of infestation for most parasite species collected, were similar in the different years, indicating no distinct interannual variation at this deep-sea locality. Comparisons of the parasite fauna of M. berglax with macrourids belonging to the genera Macrourus, Coryphaenoides, Coelorhynchus and Nezumia revealed a similar infestation pattern amongst these deep-sea fish, consisting of the same or closely related species. This observation suggests that the parasite life-cycles in these benthopelagic deep-sea fishes follow similar pathways independent of geographical location. A similar habitat and food preference of macrourids results in a similar parasite fauna. The host specificity of some of the parasites is low, with most species (nine) infesting Teleostei, Gadiformes (six), Macrouridae (two), Macrourus spp. (one) and specifically M. berglax (five). Overlapping infestation patterns of M. berglax parasites with phylogenetically related gadiform fish from the continental shelf region suggest that the deep-sea parasite fauna in macrourids has evolved along with their hosts from parasite

  5. Changes in species diversity and size composition in the Firth of Clyde demersal fish community (1927–2009)

    PubMed Central

    Heath, M. R.; Speirs, D. C.

    2012-01-01

    Following the repeal in 1962 of a long-standing ban on trawling, yields of demersal fish from the Firth of Clyde, southwest Scotland, increased to a maximum in 1973 and then declined until the directed fishery effectively ceased in the early 2000s. Since then, the only landings of demersal fish from the Firth have been by-catch in the Norway lobster fishery. We analysed changes in biomass density, species diversity and length structure of the demersal fish community between 1927 and 2009 from scientific trawl surveys, and related these to the fishery harvesting rate. As yields collapsed, the community transformed from a state in which biomass was distributed across numerous species (high species evenness) and large maximum length taxa were common, to one in which 90 per cent of the biomass was vested in one species (whiting), and both large individuals and large maximum length species were rare. Species evenness recovered quickly once the directed fishery ceased, but 10 years later, the community was still deficient in large individuals. The changes partly reflected events at a larger regional scale but were more extreme. The lag in response with respect to fishing has implications for attempts at managing a restoration of the ecosystem. PMID:21733900

  6. Ploughing the deep sea floor.

    PubMed

    Puig, Pere; Canals, Miquel; Company, Joan B; Martín, Jacobo; Amblas, David; Lastras, Galderic; Palanques, Albert

    2012-09-13

    Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations and benthic communities has received much attention, but trawling can also modify the physical properties of seafloor sediments, water–sediment chemical exchanges and sediment fluxes. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments, however, where the capacity of trawling to modify the seafloor morphology coexists with high-energy natural processes driving sediment erosion, transport and deposition. Here we show that on upper continental slopes, the reworking of the deep sea floor by trawling gradually modifies the shape of the submarine landscape over large spatial scales. We found that trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep sea floor to become smoother over time, reducing its original complexity as shown by high-resolution seafloor relief maps. Our results suggest that in recent decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution. Given the global dimension of this type of fishery, we anticipate that the morphology of the upper continental slope in many parts of the world’s oceans could be altered by intensive bottom trawling, producing comparable effects on the deep sea floor to those generated by agricultural ploughing on land. PMID:22951970

  7. Ploughing the deep sea floor.

    PubMed

    Puig, Pere; Canals, Miquel; Company, Joan B; Martín, Jacobo; Amblas, David; Lastras, Galderic; Palanques, Albert

    2012-09-13

    Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations and benthic communities has received much attention, but trawling can also modify the physical properties of seafloor sediments, water–sediment chemical exchanges and sediment fluxes. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments, however, where the capacity of trawling to modify the seafloor morphology coexists with high-energy natural processes driving sediment erosion, transport and deposition. Here we show that on upper continental slopes, the reworking of the deep sea floor by trawling gradually modifies the shape of the submarine landscape over large spatial scales. We found that trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep sea floor to become smoother over time, reducing its original complexity as shown by high-resolution seafloor relief maps. Our results suggest that in recent decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution. Given the global dimension of this type of fishery, we anticipate that the morphology of the upper continental slope in many parts of the world’s oceans could be altered by intensive bottom trawling, producing comparable effects on the deep sea floor to those generated by agricultural ploughing on land.

  8. Congruence in demersal fish, macroinvertebrate, and macroalgal community turnover on shallow temperate reefs.

    PubMed

    Thomson, Russell J; Hill, Nicole A; Leaper, Rebecca; Ellis, Nick; Pitcher, C Roland; Barrett, Neville S; Edgar, Graham J

    2014-03-01

    To support coastal planning through improved understanding of patterns of biotic and abiotic surrogacy at broad scales, we used gradient forest modeling (GFM) to analyze and predict spatial patterns of compositional turnover of demersal fishes, macroinvertebrates, and macroalgae on shallow, temperate Australian reefs. Predictive models were first developed using environmental surrogates with estimates of prediction uncertainty, and then the efficacy of the three assemblages as biosurrogates for each other was assessed. Data from underwater visual surveys of subtidal rocky reefs were collected from the southeastern coastline of continental Australia (including South Australia and Victoria) and the northern coastline of Tasmania. These data were combined with 0.01 degree-resolution gridded environmental variables to develop statistical models of compositional turnover (beta diversity) using GFM. GFM extends the machine learning, ensemble tree-based method of random forests (RF), to allow the simultaneous modeling of multiple taxa. The models were used to generate predictions of compositional turnover for each of the three assemblages within unsurveyed areas across the 6600 km of coastline in the region of interest. The most important predictor for all three assemblages was variability in sea surface temperature (measured as standard deviation from measures taken interannually). Spatial predictions of compositional turnover within unsurveyed areas across the region of interest were remarkably congruent across the three taxa. However, the greatest uncertainty in these predictions varied in location among the different assemblages. Pairwise congruency comparisons of observed and predicted turnover among the three assemblages showed that invertebrate and macroalgal biodiversity were most similar, followed by fishes and macroalgae, and lastly fishes and invertebrate biodiversity, suggesting that of the three assemblages, macroalgae would make the best biosurrogate for

  9. Demersal fish assemblages off the Seine and Sedlo seamounts (northeast Atlantic)

    NASA Astrophysics Data System (ADS)

    Menezes, Gui M.; Rosa, Alexandra; Melo, Octávio; Pinho, Mário R.

    2009-12-01

    Seamounts are thought to support special biological communities, and often maintain high standing stocks of demersal and benthopelagic fishes. Seamount fish fauna have been described in several studies but few works have included species taken below 600 m. The demersal fish assemblages of the Seine and Sedlo seamounts (northeast Atlantic) from the summits to 2000 m depth were investigated based on longline survey catch data, conducted as part of the OASIS project. A total of 41 fish species from 24 families were caught at Seine near Madeira, and 30 species from 19 families were caught at Sedlo north of the Azores. Both fish faunas have high affinities with the neighbouring areas of the Azores, Madeira and with the eastern North Atlantic and the Mediterranean Sea. Overall abundances and mean body weights were slightly higher at Sedlo seamount, appearing in conformity with the latitudinal effect of increasing species abundance and productivity from south to north. The differential influence of the Mediterranean Water at each seamount may contribute to explain (a) the differences found in vertical distribution of common species, which tend to distribute deeper at Seine, and (b) the observed changes in the species composition and dominance in deeper waters. Multivariate analysis revealed a vertical structure that is approximately coincident with the expected zonation of water masses at each seamount. Physiological tolerance to the prevailing vertical hydrological conditions may explain the species distribution and the large-scale vertical assemblage structure found. However, further ecological factors like productivity patterns affecting the amount and quality of the available food appear to shape the abundance, diversity or dominance patterns of functional groups within those main assemblages. At Seine, the species Trachurus picturatus dominated the catches, mainly at the shallower edge of the plateau, appearing consistent with the sound-scattering layer interception

  10. Impact on demersal fish of a large-scale and deep sand extraction site with ecosystem-based landscaped sandbars

    NASA Astrophysics Data System (ADS)

    de Jong, Maarten F.; Baptist, Martin J.; van Hal, Ralf; de Boois, Ingeborg J.; Lindeboom, Han J.; Hoekstra, Piet

    2014-06-01

    For the seaward harbour extension of the Port of Rotterdam in the Netherlands, approximately 220 million m3 sand was extracted between 2009 and 2013. In order to decrease the surface area of direct impact, the authorities permitted deep sand extraction, down to 20 m below the seabed. Biological and physical impacts of large-scale and deep sand extraction are still being investigated and largely unknown. For this reason, we investigated the colonization of demersal fish in a deep sand extraction site. Two sandbars were artificially created by selective dredging, copying naturally occurring meso-scale bedforms to increase habitat heterogeneity and increasing post-dredging benthic and demersal fish species richness and biomass. Significant differences in demersal fish species assemblages in the sand extraction site were associated with variables such as water depth, median grain size, fraction of very fine sand, biomass of white furrow shell (Abra alba) and time after the cessation of sand extraction. Large quantities of undigested crushed white furrow shell fragments were found in all stomachs and intestines of plaice (Pleuronectes platessa), indicating that it is an important prey item. One and two years after cessation, a significant 20-fold increase in demersal fish biomass was observed in deep parts of the extraction site. In the troughs of a landscaped sandbar however, a significant drop in biomass down to reference levels and a significant change in species assemblage was observed two years after cessation. The fish assemblage at the crests of the sandbars differed significantly from the troughs with tub gurnard (Chelidonichthys lucerna) being a Dufrêne-Legendre indicator species of the crests. This is a first indication of the applicability of landscaping techniques to induce heterogeneity of the seabed although it remains difficult to draw a strong conclusion due the lack of replication in the experiment. A new ecological equilibrium is not reached after 2

  11. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot.

  12. Evaluating light-based geolocation for estimating demersal fish movements in high latitudes

    USGS Publications Warehouse

    Seitz, Andrew C; Norcross, B.L.; Wilson, D.; Nielsen, Jennifer L.

    2006-01-01

    We evaluated light-based geolocation estimates from pop-up satellite tags in high latitudesbecause some of the largest fisheries in the world are in areas where this technique has not been assessed. Daily longitude and latitude were estimated by using two Wildlife Computers software programs: 1) Argos Message Processor (AMP), which summarizes light intensity data transmitted to satellites, and 2) Time Series Processor (TSP), which uses more detailed data obtained from retrieved tags. Three experiments were conducted in the northern Gulf of Alaska using tags placed on 1) Pacific halibut in outdoor aquaria, 2) a fixed mooring line at various depths and 3) wild Pacific halibut. TSP performed better than AMP because the percentage of days with geolocation estimates was greater and the mean error magnitude and bias were smaller for TSP and increased with depth for both programs; however, latitude errors were much greater than longitude errors at all depths. Light-based geolocation enabled us to discern basin-scale movements and showed that the Pacific halibut in our study remained within the Gulf of Alaska. We conclude that this technique provides a feasible method for inferring large-scale population structure for demersal fishes in high latitudes. 

  13. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life

    PubMed Central

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A.; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G.; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-01-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  14. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

    PubMed

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-06-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  15. Preservation Obscures Pelagic Deep-Sea Fish Diversity: Doubling the Number of Sole-Bearing Opisthoproctids and Resurrection of the Genus Monacoa (Opisthoproctidae, Argentiniformes).

    PubMed

    Poulsen, Jan Yde; Sado, Tetsuya; Hahn, Christoph; Byrkjedal, Ingvar; Moku, Masatoshi; Miya, Masaki

    2016-01-01

    The family Opisthoproctidae (barreleyes) constitutes one of the most peculiar looking and unknown deep-sea fish groups in terms of taxonomy and specialized adaptations. All the species in the family are united by the possession of tubular eyes, with one distinct lineage exhibiting also drastic shortening of the body. Two new species of the mesopelagic opisthoproctid mirrorbelly genus Monacoa are described based on pigmentation patterns of the "sole"-a unique vertebrate structure used in the reflection and control of bioluminescence in most short-bodied forms. Different pigmentation patterns of the soles, previously noted as intraspecific variations based on preserved specimens, are here shown species-specific and likely used for communication in addition to counter-illumination of down-welling sunlight. The genus Monacoa is resurrected from Opisthoproctus based on extensive morphological synaphomorphies pertaining to the anal fin and snout. Doubling the species diversity within sole-bearing opisthoproctids, including recognition of two genera, is unambiguously supported by mitogenomic DNA sequence data. Regular fixation with formalin and alcohol preservation is shown problematic concerning the retention of species-specific pigmentation patterns. Examination or photos of fresh material before formalin fixation is shown paramount for correct species recognition of sole-bearing opisthoproctids-a relatively unknown issue concerning species diversity in the deep-sea pelagic realm.

  16. Preservation Obscures Pelagic Deep-Sea Fish Diversity: Doubling the Number of Sole-Bearing Opisthoproctids and Resurrection of the Genus Monacoa (Opisthoproctidae, Argentiniformes).

    PubMed

    Poulsen, Jan Yde; Sado, Tetsuya; Hahn, Christoph; Byrkjedal, Ingvar; Moku, Masatoshi; Miya, Masaki

    2016-01-01

    The family Opisthoproctidae (barreleyes) constitutes one of the most peculiar looking and unknown deep-sea fish groups in terms of taxonomy and specialized adaptations. All the species in the family are united by the possession of tubular eyes, with one distinct lineage exhibiting also drastic shortening of the body. Two new species of the mesopelagic opisthoproctid mirrorbelly genus Monacoa are described based on pigmentation patterns of the "sole"-a unique vertebrate structure used in the reflection and control of bioluminescence in most short-bodied forms. Different pigmentation patterns of the soles, previously noted as intraspecific variations based on preserved specimens, are here shown species-specific and likely used for communication in addition to counter-illumination of down-welling sunlight. The genus Monacoa is resurrected from Opisthoproctus based on extensive morphological synaphomorphies pertaining to the anal fin and snout. Doubling the species diversity within sole-bearing opisthoproctids, including recognition of two genera, is unambiguously supported by mitogenomic DNA sequence data. Regular fixation with formalin and alcohol preservation is shown problematic concerning the retention of species-specific pigmentation patterns. Examination or photos of fresh material before formalin fixation is shown paramount for correct species recognition of sole-bearing opisthoproctids-a relatively unknown issue concerning species diversity in the deep-sea pelagic realm. PMID:27508419

  17. Preservation Obscures Pelagic Deep-Sea Fish Diversity: Doubling the Number of Sole-Bearing Opisthoproctids and Resurrection of the Genus Monacoa (Opisthoproctidae, Argentiniformes)

    PubMed Central

    Sado, Tetsuya; Hahn, Christoph; Byrkjedal, Ingvar; Miya, Masaki

    2016-01-01

    The family Opisthoproctidae (barreleyes) constitutes one of the most peculiar looking and unknown deep-sea fish groups in terms of taxonomy and specialized adaptations. All the species in the family are united by the possession of tubular eyes, with one distinct lineage exhibiting also drastic shortening of the body. Two new species of the mesopelagic opisthoproctid mirrorbelly genus Monacoa are described based on pigmentation patterns of the “sole”—a unique vertebrate structure used in the reflection and control of bioluminescence in most short-bodied forms. Different pigmentation patterns of the soles, previously noted as intraspecific variations based on preserved specimens, are here shown species-specific and likely used for communication in addition to counter-illumination of down-welling sunlight. The genus Monacoa is resurrected from Opisthoproctus based on extensive morphological synaphomorphies pertaining to the anal fin and snout. Doubling the species diversity within sole-bearing opisthoproctids, including recognition of two genera, is unambiguously supported by mitogenomic DNA sequence data. Regular fixation with formalin and alcohol preservation is shown problematic concerning the retention of species-specific pigmentation patterns. Examination or photos of fresh material before formalin fixation is shown paramount for correct species recognition of sole-bearing opisthoproctids—a relatively unknown issue concerning species diversity in the deep-sea pelagic realm. PMID:27508419

  18. A synthesis of genetic connectivity in deep-sea fauna and implications for marine reserve design.

    PubMed

    Baco, Amy R; Etter, Ron J; Ribeiro, Pedro A; von der Heyden, Sophie; Beerli, Peter; Kinlan, Brian P

    2016-07-01

    With anthropogenic impacts rapidly advancing into deeper waters, there is growing interest in establishing deep-sea marine protected areas (MPAs) or reserves. Reserve design depends on estimates of connectivity and scales of dispersal for the taxa of interest. Deep-sea taxa are hypothesized to disperse greater distances than shallow-water taxa, which implies that reserves would need to be larger in size and networks could be more widely spaced; however, this paradigm has not been tested. We compiled population genetic studies of deep-sea fauna and estimated dispersal distances for 51 studies using a method based on isolation-by-distance slopes. Estimates of dispersal distance ranged from 0.24 km to 2028 km with a geometric mean of 33.2 km and differed in relation to taxonomic and life-history factors as well as several study parameters. Dispersal distances were generally greater for fishes than invertebrates with the Mollusca being the least dispersive sampled phylum. Species that are pelagic as adults were more dispersive than those with sessile or sedentary lifestyles. Benthic species from soft-substrate habitats were generally less dispersive than species from hard substrate, demersal or pelagic habitats. As expected, species with pelagic and/or feeding (planktotrophic) larvae were more dispersive than other larval types. Many of these comparisons were confounded by taxonomic or other life-history differences (e.g. fishes being more dispersive than invertebrates) making any simple interpretation difficult. Our results provide the first rough estimate of the range of dispersal distances in the deep sea and allow comparisons to shallow-water assemblages. Overall, dispersal distances were greater for deeper taxa, although the differences were not large (0.3-0.6 orders of magnitude between means), and imbalanced sampling of shallow and deep taxa complicates any simple interpretation. Our analyses suggest the scales of dispersal and connectivity for reserve design

  19. A synthesis of genetic connectivity in deep-sea fauna and implications for marine reserve design.

    PubMed

    Baco, Amy R; Etter, Ron J; Ribeiro, Pedro A; von der Heyden, Sophie; Beerli, Peter; Kinlan, Brian P

    2016-07-01

    With anthropogenic impacts rapidly advancing into deeper waters, there is growing interest in establishing deep-sea marine protected areas (MPAs) or reserves. Reserve design depends on estimates of connectivity and scales of dispersal for the taxa of interest. Deep-sea taxa are hypothesized to disperse greater distances than shallow-water taxa, which implies that reserves would need to be larger in size and networks could be more widely spaced; however, this paradigm has not been tested. We compiled population genetic studies of deep-sea fauna and estimated dispersal distances for 51 studies using a method based on isolation-by-distance slopes. Estimates of dispersal distance ranged from 0.24 km to 2028 km with a geometric mean of 33.2 km and differed in relation to taxonomic and life-history factors as well as several study parameters. Dispersal distances were generally greater for fishes than invertebrates with the Mollusca being the least dispersive sampled phylum. Species that are pelagic as adults were more dispersive than those with sessile or sedentary lifestyles. Benthic species from soft-substrate habitats were generally less dispersive than species from hard substrate, demersal or pelagic habitats. As expected, species with pelagic and/or feeding (planktotrophic) larvae were more dispersive than other larval types. Many of these comparisons were confounded by taxonomic or other life-history differences (e.g. fishes being more dispersive than invertebrates) making any simple interpretation difficult. Our results provide the first rough estimate of the range of dispersal distances in the deep sea and allow comparisons to shallow-water assemblages. Overall, dispersal distances were greater for deeper taxa, although the differences were not large (0.3-0.6 orders of magnitude between means), and imbalanced sampling of shallow and deep taxa complicates any simple interpretation. Our analyses suggest the scales of dispersal and connectivity for reserve design

  20. A taste of the deep-sea: The roles of gustatory and tactile searching behaviour in the grenadier fish Coryphaenoides armatus

    NASA Astrophysics Data System (ADS)

    Bailey, David M.; Wagner, Hans-Joachim; Jamieson, Alan J.; Ross, Murray F.; Priede, Imants G.

    2007-01-01

    The deep-sea grenadier fishes ( Coryphaenoides spp.) are among the dominant predators and scavengers in the ocean basins that cover much of Earth's surface. Baited camera experiments were used to study the behaviour of these fishes. Despite the apparent advantages of rapidly consuming food, grenadiers attracted to bait spend a large proportion of their time in prolonged periods of non-feeding activity. Video analysis revealed that fish often adopted a head-down swimming attitude (mean of 21.3° between the fish and seafloor), with swimming velocity negatively related to attitude. The fish also swam around and along vertical and horizontal structures of the lander with their head immediately adjacent to the structure. We initially hypothesised that this behaviour was associated with the use of the short chin barbel in foraging. Barbel histology showed numerous taste buds in the skin, and a barbel nerve with about 20,000 axons in adult fish. A tracing experiment in one undamaged animal revealed the termination fields of the barbel neurons in the trigeminal and rhombencephalic regions, indicating both a mechanoreceptory and a gustatory role for the barbel. Our conclusion was that olfactory foraging becomes ineffective at close ranges and is followed by a search phase using tactile and gustatory sensing by the barbel. The development of this sensory method probably co-evolved alongside behavioural changes in swimming mechanics to allow postural stability at low swimming speeds.

  1. Oxygen isotopic distribution along the otolith growth axis by secondary ion mass spectrometry: Applications for studying ontogenetic change in the depth inhabited by deep-sea fishes

    NASA Astrophysics Data System (ADS)

    Shiao, Jen-Chieh; Itoh, Shoichi; Yurimoto, Hisayoshi; Iizuka, Yoshiyuki; Liao, Yun-Chih

    2014-02-01

    This study using tuna otoliths as working standards established a high lateral resolution and precision analysis to measure δ18Ootolith by secondary ion mass spectrometry. This analytical approach of the ion probe was applied to deep-sea fishes to reconstruct the likely depths inhabited by the fishes at different life history stages based on the measured δ18Ootolith values as a proxy of water temperature. Dramatic increases up to 5-6‰ in δ18Ootolith, representing a temperature decrease of approximately 20 °C, were detected in a blind cusk eel (Barathronus maculatus) otolith and in the otoliths of Synaphobranchus kaupii during leptocephalus metamorphosis to glass eel, inferred from the drop of otolith Sr/Ca ratios and increase of otolith growth increment width. δ18Ootolith profiles clearly divided the fish's life history into a planktonic stage in the mixed layer of the ocean and a benthic stage on the deep-sea ocean bottom. The habitat shift signal was recorded within a 150 μm width of otolith growth zone, which was too narrow to be clearly detected by mechanical drilling and conventional isotopic ratio mass spectrometry. However, variations down to -7‰ were found in δ18Ootolith profiles as the result of Cs2+ beam sputter in the core and larval portions of the otoliths. Carbon mapping by electron probe microanalyzer and staining by toluidine blue suggested abundant proteins existed in the areas with anomaly negative δ18Ootolith values, which cannot be interpreted as a habitat change but due to the isotopic fractionation by O emission from the proteins. These results implied that careful design and understanding of the chemical composition of the analytical areas or tracks on the heterogeneous otolith was essential for highly accurate and precise analysis.

  2. Depth related trends in proximate composition of demersal fishes in the eastern North Pacific

    NASA Astrophysics Data System (ADS)

    Drazen, J. C.

    2007-02-01

    The proximate chemistry of the white muscle and liver of 18 species of demersal fish from the eastern North Pacific was studied to determine trends with depth, locomotory mode and buoyancy mechanism, foraging strategy and to elucidate energetic strategies. Data for 24 species from shallow water were taken from the literature and included for analysis of muscle water content. Benthopelagic species, primarily gadiforms, have significantly larger lipid-rich livers than benthic species. The benthopelagic species may use this lipid to add buoyancy, but it is also used as energy storage. Buoyancy mechanism was directly related to proximate composition. Fishes using gasbladders had normal muscle composition. The two species of benthopelagic fishes without gasbladders have either very high muscle lipid content ( Anoplopoma fimbria) or gelatinous muscle ( Alepocephalus tenobrosus) to aid in achieving neutral buoyancy. The macrourid, Albatrossia pectoralis, has a very small gasbladder and also has gelatinous muscle. Both of these benthopelagic fishes with gelatinous muscle feed on pelagic organisms. Gelatinous muscle was also found in two flatfishes that inhabit the oxygen minimum zone. For these fishes, high water content may serve to lower metabolic costs while maintaining large body size. Scavengers such as Coryphaenoides armatus and Coryphaenoides acrolepis have lipid rich livers and others such as A. fimbria and Pachycara sp. have high and variable muscle lipid content. Thus foraging mode also acts to influence proximate composition. Several depth-related trends in proximate composition were found. White muscle water content increased significantly with depth, and all four gelatinous species occurred at bathyal depths. This adds evidence in support of the hypothesis that decreasing light levels shorten reactive distances and relax the selective pressure for high locomotory capacity. In addition significant declines in liver protein content were observed, suggesting that

  3. Demersal fishes associated with Lophelia pertusa coral and hard-substrate biotopes on the continental slope, northern Gulf of Mexico

    USGS Publications Warehouse

    Sulak, Kenneth J.; Allen, Brooks R.; Luke, Kirsten E.; Norem, April D.; Randall, Michael; Quaid, Andrew J.; Yeargin, George E.; Miller, Jana M.; Harden, William M.; Caruso, John H.; Ross, Steve W.

    2007-01-01

    The demersal fish fauna of Lophelia pertusa (Linnaeus, 1758) coral reefs and associated hard-bottom biotopes was investigated at two depth horizons in the northern Gulf of Mexico using a manned submersible and remote sampling. The Viosca Knoll fauna consisted of at least 53 demersal fish species, 37 of which were documented by submersible video. On the 325 m horizon, dominant taxa determined from frame-by-frame video analysis included Stromateidae, Serranidae, Trachichthyidae, Congridae, Scorpaenidae, and Gadiformes. On the 500 m horizon, large mobile visual macrocarnivores of families Stromateidae and Serranidae dropped out, while a zeiform microcarnivore assumed importance on reef "Thicket" biotope, and the open-slope taxa Macrouridae and Squalidae gained in importance. The most consistent faunal groups at both depths included sit-and-wait and hover-and-wait strategists (Scorpaenidae, Congridae, Trachichthyidae), along with generalized mesocarnivores (Gadiformes). The specialized microcarnivore, Grammicolepis brachiusculus Poey, 1873, appears to be highly associated with Lophelia reefs. The coral "Thicket" biotope was extensively developed on the 500 m site, but fish abundance was low with only 95 fish per hectare. In contrast to Lophelia reefs from the eastern the North Atlantic, the coral "Rubble" biotope was essentially absent. This study represents the first quantitative analysis of fishes associated with Lophelia reefs in the Gulf of Mexico, and generally in the western North Atlantic.

  4. Vision in the deep sea.

    PubMed

    Warrant, Eric J; Locket, N Adam

    2004-08-01

    The deep sea is the largest habitat on earth. Its three great faunal environments--the twilight mesopelagic zone, the dark bathypelagic zone and the vast flat expanses of the benthic habitat--are home to a rich fauna of vertebrates and invertebrates. In the mesopelagic zone (150-1000 m), the down-welling daylight creates an extended scene that becomes increasingly dimmer and bluer with depth. The available daylight also originates increasingly from vertically above, and bioluminescent point-source flashes, well contrasted against the dim background daylight, become increasingly visible. In the bathypelagic zone below 1000 m no daylight remains, and the scene becomes entirely dominated by point-like bioluminescence. This changing nature of visual scenes with depth--from extended source to point source--has had a profound effect on the designs of deep-sea eyes, both optically and neurally, a fact that until recently was not fully appreciated. Recent measurements of the sensitivity and spatial resolution of deep-sea eyes--particularly from the camera eyes of fishes and cephalopods and the compound eyes of crustaceans--reveal that ocular designs are well matched to the nature of the visual scene at any given depth. This match between eye design and visual scene is the subject of this review. The greatest variation in eye design is found in the mesopelagic zone, where dim down-welling daylight and bio-luminescent point sources may be visible simultaneously. Some mesopelagic eyes rely on spatial and temporal summation to increase sensitivity to a dim extended scene, while others sacrifice this sensitivity to localise pinpoints of bright bioluminescence. Yet other eyes have retinal regions separately specialised for each type of light. In the bathypelagic zone, eyes generally get smaller and therefore less sensitive to point sources with increasing depth. In fishes, this insensitivity, combined with surprisingly high spatial resolution, is very well adapted to the

  5. Vertical stratification in the distribution of demersal fishes along the walls of the La Jolla and Scripps submarine canyons, California, USA

    NASA Astrophysics Data System (ADS)

    Smith, Joshua G.; Lindholm, James

    2016-08-01

    The geographic distributions of many coastal marine fish assemblages are strongly driven by habitat features, particularly among demersal fishes that live along the seafloor. Ecologists have long recognized the importance of characterizing fish habitat associations, especially where spatial management is under consideration. However, little is known about fish distributions and habitat suitability in unique demersal habitats such as submarine canyons. The active continental margin of the California coast is cut by eight submarine canyons, several of which extend from the shore to the deep abyssal plain. We sampled the demersal fish assemblages in two of those canyons: (1) the Scripps submarine canyon in the San-Diego-Scripps State Marine Conservation Area (SMCA) and (2) the La Jolla canyon in the Matlahuayl State Marine Reserve (SMR) to gain insight into both the distributions and habitat associations of demersal fishes in canyons. A remotely operated vehicle was used to conduct 21 vertically oriented transects along the canyon walls in depths ranging from 20 to 300 m. Species composition was assessed in three depth-stratified zones (100 m per zone) along the canyon walls. Species richness, abundance, and attributes of the surrounding canyon habitat structure (slope and benthic terrain ruggedness) were quantified. Three distinct assemblage groupings were identified, which comprised 35 species of demersal fishes from 17 families. Among all factors analyzed in this study, depth, slope, and ruggedness were strong explanatory variables of patterns of species richness and abundance; however, the relationship between depth and assemblage structure was non-linear. The greatest number of species was observed in the mid depth-stratified zone. These trends suggest that variation in canyon dynamics across depth strata may facilitate distinct assemblage groupings of demersal fishes, which can in turn be used to better manage these unique habitats.

  6. Recovery of a Temperate Reef Assemblage in a Marine Protected Area following the Exclusion of Towed Demersal Fishing

    PubMed Central

    Sheehan, Emma V.; Stevens, Timothy F.; Gall, Sarah C.; Cousens, Sophie L.; Attrill, Martin J.

    2013-01-01

    Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km2 of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as ‘the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls’. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries. PMID:24391841

  7. Recovery of a temperate reef assemblage in a marine protected area following the exclusion of towed demersal fishing.

    PubMed

    Sheehan, Emma V; Stevens, Timothy F; Gall, Sarah C; Cousens, Sophie L; Attrill, Martin J

    2013-01-01

    Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km(2) of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as 'the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls'. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries.

  8. Recovery of a temperate reef assemblage in a marine protected area following the exclusion of towed demersal fishing.

    PubMed

    Sheehan, Emma V; Stevens, Timothy F; Gall, Sarah C; Cousens, Sophie L; Attrill, Martin J

    2013-01-01

    Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km(2) of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as 'the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls'. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries. PMID:24391841

  9. Effects of trawling on the diets of common demersal fish by-catch of a tropical prawn trawl fishery.

    PubMed

    Dell, Q; Griffiths, S P; Tonks, M L; Rochester, W A; Miller, M J; Duggan, M A; van der Velde, T D; Pillans, R D; Coman, G J; Bustamante, R H; Milton, D A

    2013-03-01

    The ecological effect of prawn trawling on the benthos of the Gulf of Carpentaria, northern Australia, was investigated by examining stomach contents of common demersal fishes incidentally caught as by-catch in the fishery. Fishes were collected from high and low fishing intensity sites in three regions based on vessel monitoring system data. The diets of eight species of benthic fish predators were compared between regions and fishing intensities. A regional effect on diet was evident for seven species. Only one generalist species had no significant difference in diet among the three regions. For the comparisons within each region, five predator species had significantly different diet between high and low fishing intensities in at least one region. Across the three regions, high fishing intensity sites had predators that consumed a greater biomass of crustaceans, molluscs and echinoderms. At low fishing intensity sites, predators had diets comprising a greater biomass of cnidarians and teleosts, and a different assemblage of molluscs, crustaceans and fishes. These changes in diet suggest that there may have been a shift in the structure of the benthic community following intensive fishing. Analysis of predator diets is a useful tool to help identify changes in the benthic community composition after exposure to fishing. This study also provided valuable diet information on a range of abundant generalist benthic predators to improve the ecosystem modelling tools needed to support ecosystem-based fisheries management.

  10. Comparing deep-sea fish fauna between coral and non-coral "megahabitats" in the Santa Maria di Leuca cold-water coral province (Mediterranean Sea).

    PubMed

    D'Onghia, Gianfranco; Maiorano, Porzia; Carlucci, Roberto; Capezzuto, Francesca; Carluccio, Angela; Tursi, Angelo; Sion, Letizia

    2012-01-01

    Two experimental longline surveys were carried out in the Santa Maria di Leuca (SML) cold-water coral province (Mediterranean Sea) during May-June and September-October 2010 to investigate the effect of corals on fish assemblages. Two types of "megahabitat" characterized by the virtual absence of fishing were explored. One was characterized by complex topography including mesohabitats with carbonate mounds and corals. The other type of megahabitat, although characterized by complex topographic features, lacks carbonate mounds and corals. The fishing vessel was equipped with a 3,000 m monofilament longline with 500 hooks and snoods of 2.5 m in length. A total of 9 hauls, using about 4,500 hooks, were carried out both in the coral megahabitat and in the non-coral megahabitat during each survey. The fish Leucoraja fullonica and Pteroplatytrygon violacea represent new records for the SML coral province. The coral by-catch was only obtained in the coral megahabitat in about 55% of the stations investigated in both surveys. The total catches and the abundance indices of several species were comparable between the two habitat typologies. The species contributing most to the dissimilarity between the two megahabitat fish assemblages were Pagellus bogaraveo, Galeus melastomus, Etmopterus spinax and Helicolenus dactylopterus for density and P. bogaraveo, Conger conger, Polyprion americanus and G. melastomus for biomass. P. bogaraveo was exclusively collected in the coral megahabitat, whereas C. conger, H. dactylopterus and P. americanus were found with greater abundance in the coral than in the non-coral megahabitat. Differences in the sizes between the two megahabitats were detected in E. spinax, G. melastomus, C. conger and H. dactylopterus. Although these differences most probably related to the presence-absence of corals, both megahabitats investigated play the role of attraction-refuge for deep-sea fish fauna, confirming the important role of the whole SML coral

  11. Comparing Deep-Sea Fish Fauna between Coral and Non-Coral “Megahabitats” in the Santa Maria di Leuca Cold-Water Coral Province (Mediterranean Sea)

    PubMed Central

    D'Onghia, Gianfranco; Maiorano, Porzia; Carlucci, Roberto; Capezzuto, Francesca; Carluccio, Angela; Tursi, Angelo; Sion, Letizia

    2012-01-01

    Two experimental longline surveys were carried out in the Santa Maria di Leuca (SML) cold-water coral province (Mediterranean Sea) during May–June and September–October 2010 to investigate the effect of corals on fish assemblages. Two types of “megahabitat” characterized by the virtual absence of fishing were explored. One was characterized by complex topography including mesohabitats with carbonate mounds and corals. The other type of megahabitat, although characterized by complex topographic features, lacks carbonate mounds and corals. The fishing vessel was equipped with a 3,000 m monofilament longline with 500 hooks and snoods of 2.5 m in length. A total of 9 hauls, using about 4,500 hooks, were carried out both in the coral megahabitat and in the non-coral megahabitat during each survey. The fish Leucoraja fullonica and Pteroplatytrygon violacea represent new records for the SML coral province. The coral by-catch was only obtained in the coral megahabitat in about 55% of the stations investigated in both surveys. The total catches and the abundance indices of several species were comparable between the two habitat typologies. The species contributing most to the dissimilarity between the two megahabitat fish assemblages were Pagellus bogaraveo, Galeus melastomus, Etmopterus spinax and Helicolenus dactylopterus for density and P. bogaraveo, Conger conger, Polyprion americanus and G. melastomus for biomass. P. bogaraveo was exclusively collected in the coral megahabitat, whereas C. conger, H. dactylopterus and P. americanus were found with greater abundance in the coral than in the non-coral megahabitat. Differences in the sizes between the two megahabitats were detected in E. spinax, G. melastomus, C. conger and H. dactylopterus. Although these differences most probably related to the presence-absence of corals, both megahabitats investigated play the role of attraction-refuge for deep-sea fish fauna, confirming the important role of the whole SML coral

  12. 77 FR 35850 - Safety Zone; F/V Deep Sea, Penn Cove, WA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... the Fishing Vessel (F/V) Deep Sea, located in Penn Cove, WA. This action is necessary to ensure the... Fishing Vessel Deep Sea located at approximately 48 13'18'' N, 122 47'42'' W, Penn Cove, WA. (b... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; F/V Deep Sea, Penn Cove, WA AGENCY:...

  13. Food web structure and vulnerability of a deep-sea ecosystem in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Tecchio, Samuele; Coll, Marta; Christensen, Villy; Company, Joan B.; Ramírez-Llodra, Eva; Sardà, Francisco

    2013-05-01

    There is increasing fishing pressure on the continental margins of the oceans, and this raises concerns about the vulnerability of the ecosystems thriving there. The current knowledge of the biology of deep-water fish species identifies potential reduced resilience to anthropogenic disturbance. However, there are extreme difficulties in sampling the deep sea, resulting in poorly resolved and indirectly obtained food-web relationships. Here, we modelled the flows and biomasses of a Mediterranean deep-sea ecosystem, the Catalan Sea continental slope at depths of 1000-1400 m. This is the first model of a deep-water ecosystem in the Mediterranean Sea. The objectives were to (a) quantitatively describe the food web structure of the ecosystem, (b) examine the role of key species in the ecosystem, and (c) explore the vulnerability of this deep-sea ecosystem to potential future fishing exploitation. We used the Ecopath with Ecosim (EwE) modelling approach and software to model the ecosystem. The trophic model included 18 consumers, a marine snow group, and a sediment detritus group. Trophic network analysis identified low levels of consumer biomass cycling and low system omnivory index when compared with expected values of marine ecosystems, and higher cycling and omnivory when compared with available EwE models of shallower areas of the Mediterranean Sea. The majority of flows in the ecosystem were concentrated at the trophic level of first-order consumers (TL 2). Benthic invertebrates and demersal sharks were identified to have key ecological roles in the ecosystem. We used the dynamic temporal model Ecosim to simulate expansion of the red-shrimp benthic trawl fishery that currently operates at shallower depths, down to 800 m depth. The simulations showed reductions in fish biomass and that the state of the deep continental slope ecosystem in the western Mediterranean seems to be the result of a long-term succession process, which has reached ecological stability, and is

  14. Community structure and seasonal variation of an inshore demersal fish community at Goa, West Coast of India

    NASA Astrophysics Data System (ADS)

    Ansari, Z. A.; Chatterji, A.; Ingole, B. S.; Sreepada, R. A.; Rivonkar, C. U.; Parulekar, A. H.

    1995-11-01

    Structure and seasonal variation of an inshore demersal fish assemblage have been described from 52 trawl samples collected between November 1988-November 1989 from Aguada and Marmugao Bays at Goa (west coast of India). A total of 12 519 individuals belonging to 59 species were collected. There was a clear seasonal fluctuation in relative abundance, biomass, species occurrence and species dominance. Families such as Sciaenidae, Leiognathidae, Cynoglossidae, Clupeidae and Ariidae dominated the demersal fish community, both in abundance and in biomass over the two areas. About 50% of the recorded species regularly occurred in the two areas. Density and biomass were high during post- and pre-monsoon seasons and low during the monsoon seasons. The species assemblages at the two sites were similar and showed much overlap of dominant species. Resident and quasi-resident species were dominant throughout the year and the overall population consisted mainly of marine coastal species. Cluster analysis showed species segregation into seasonal groups and intense association among different species groups. There was seasonal fluctuation in diversity indices and a marginal increase in species richness in Aguada bay was noticed. The dominance of juveniles in the catches indicate that the two areas serve as nursery grounds for the juveniles of several commercially important marine teleosts.

  15. Behavioural responses to structures on the seafloor by the deep-sea fish Coryphaenoides armatus: Implications for the use of baited landers

    NASA Astrophysics Data System (ADS)

    Jamieson, A. J.; Bailey, D. M.; Wagner, H.-J.; Bagley, P. M.; Priede, I. G.

    2006-07-01

    Coryphaenoides armatus plays a fundamental role in the dispersal of organic matter on the deep-sea floor by consuming food-falls. The use of baited cameras to study population parameters (e.g. abundances and size frequencies) assumes that members of this species follow odour plumes directly to bait, appear immediately in the field of view, and depart as predicted by optimal foraging theory. Described here are behaviours to the contrary observed during the operation and development of more complex baited camera systems. Of the 247 C. armatus observed by a video lander, 72.5% of the fish explored the structure whilst only 6% fed, and 21.5% were indifferent. This exploratory behaviour increased individual staying time by 38.4% compared to those that just fed. Experiments with several models of in situ fish respirometry lander showed the importance of both equipment design, and an understanding of the behaviour of the target animals in maximising capture success. These results show how previously unexpected aspects of behaviour by C. armatus can greatly affect the chances of capturing members of this species and influence the results of baited camera experiments.

  16. Cold-water coral mounds and sponge-beds as habitats for demersal fish on the Norwegian shelf

    NASA Astrophysics Data System (ADS)

    Kutti, Tina; Bergstad, Odd Aksel; Fosså, Jan Helge; Helle, Kristin

    2014-01-01

    The importance of cold-water coral (CWC) mounds and sponge-beds as habitat for demersal fish was examined in the Træna Deep marine protected area and adjacent areas of the Norwegian continental shelf. Standardised longline fishing was conducted twice, in June and March, and predetermined fishing effort was allocated to multiple plots with varying densities of small CWC mounds and sponges, plus control plots with neither of these habitats. Catches within all examined habitats were dominated by the commercially exploited Brosme brosme (representing >70% of the total catch) followed by Galeus melastomus, Chimaera monstrosa, Etmopterus spinax and the commercially exploited Molva molva. Positive correlations were found between catch rates of B. brosme, G. melastomus and C. monstrosa and the density of small CWC mounds at one or both sampling occasions. No correlations were found between the catch rates of the same three species and sponge density; thus the sponge-beds did not seem to represent an ecologically equivalent habitat to the CWCs. On a local scale the CWC habitat appeared to attract higher abundances of B. brosme, G. melastomus and C. monstrosa; however, the differences in catch rates between coral and non-coral areas were quite low (2-4 times) and for most species the fish-habitat relationships varied temporarily and with the spatial scale used to delineate the habitat. Based on the methods and the results of this study and the fact that CWCs only occupy a very small proportion of the Norwegian shelf, the importance of CWCs as habitat for the populations of the demersal fish species examined is judged as marginal.

  17. Environmental assessment of Buccaneer gas and oil field in the northwestern Gulf of Mexico, 1978-1979. Volume III. Effects of gas and oil field structures and effluents on pelagic and reef fishes, demersal fishes and macrocrustaceans. Annual report

    SciTech Connect

    Gallaway, B.J.; Martin, L.R.

    1980-12-01

    Demersal nekton communities in the Buccaneer Oil Field during research year 1978-79 were dominated by macrocrustaceans, particularly sugar shrimp, Trachypenaeus similis. The most abundant fish was the shoal flounder, Syacium gunteri. The effects of substrate and platform type on seasonal and areal distributional patterns are provided for dominate, demersal species. Several important species, including sugar shrimp, were indicated more abundant at production platforms than at control structures having the same bottom type.

  18. Climate influence on deep sea populations.

    PubMed

    Company, Joan B; Puig, Pere; Sardà, Francesc; Palanques, Albert; Latasa, Mikel; Scharek, Renate

    2008-01-16

    Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought.

  19. Climate Influence on Deep Sea Populations

    PubMed Central

    Company, Joan B.; Puig, Pere; Sardà, Francesc; Palanques, Albert; Latasa, Mikel; Scharek, Renate

    2008-01-01

    Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought. PMID:18197243

  20. Trophic strategies in carnivorous fishes: their significance in energy transfer in the deep-sea benthic ecosystem (Meriadzek Terrace — Bay of Biscay)

    NASA Astrophysics Data System (ADS)

    Mahaut, Marie-Laure; Geistdoerfer, Patrick; Sibuet, Myriam

    Trophic relationships between fish species have been analyzed as a contribution to the construction of an energy transfer model between various groups in the benthic ecosystem of Meriadzek Terrace, located at 170 miles off the west French coast at a depth of 2100m. Attention was given to the carnivorous megafaunal compartment. The importance of the carnivore megafaunal biomass and its part in energy transfer is still unresolved. On the Meriadzek Terrace, numerous Chondrichthyes (sharks and chimeroids) were frequently observed from the manned submersible Cyana or by baited camera; their biomass appears to be exceptionally large. Results of a photographic survey conducted using the unmanned free vehicle Epaulard have given estimates of 22 per 10 4m 2 of teleost fishes (belonging to 8 different families and one suborder) but included no Chondrichthyes (except one specimen of Rajidae). From baited camera observations, however, we conclude that carcasses falling to the bottom on the Terrace are exploited only by selacians as the bait was never seen to be eaten by macrourids, morids or synaphobranchids although they always attended the baits before the arrival of large scavengers. Trophic specialization strategies occur in this deep-sea ecosystem and our further studies on the energy transfer model for the Meriadzek Terrace will differentiate between strategies exploiting two sources of organic input to the bottom environment: organic particles and large carcasses. In one case, carbon transfer is via the whole benthic food web in which each link is specified by size and trophic behaviour. This pathway ends in the carnivorous megafaunal compartment, which includes benthic fishes, consumers of the local epibenthic and sometimes inbenthic, macro- and megafauna. The second pathway originates with carcass falls, and carbon transfer is direct to the benthopelagic scavengers observed frequently at the Meriadzek Terrace.

  1. Fine-scale spatial patterns in the demersal fish and invertebrate community in a northwest Atlantic ecosystem

    NASA Astrophysics Data System (ADS)

    Malek, Anna J.; Collie, Jeremy S.; Gartland, James

    2014-06-01

    The abundance, biomass, diversity, and species composition of the demersal fish and invertebrate community in Rhode Island Sound and Block Island Sound, an area identified for offshore renewable energy development, were evaluated for spatial and seasonal structure. We conducted 58 otter trawls and 51 beam trawls in the spring, summer and fall of 2009-2012, and incorporated additional data from 88 otter trawls conducted by the Northeast Area Monitoring and Assessment Program. We used regionally-grouped abundance, biomass, diversity, and size spectra to assess spatial patterns in the aggregate fish community, and hierarchical cluster analysis to evaluate trends in species assemblages. Our analyses revealed coherent gradients in fish community biomass, diversity and species composition extending from inshore to offshore waters, as well as patterns related to the differing bathymetry of Rhode Island and Block Island Sounds. The fish communities around Block Island and Cox's Ledge are particularly diverse, suggesting that the proximity of hard bottom habitat may be important in structuring fish communities in this area. Species assemblages in Rhode Island and Block Island Sounds are characterized by a combination of piscivores (silver hake, summer flounder, spiny dogfish), benthivores (American lobster, black sea bass, Leucoraja spp. skates, scup) and planktivores (sea scallop), and exhibit geographic patterns that are persistent from year to year, yet variable by season. Such distributions reflect the cross-shelf migration of fish and invertebrate species in the spring and fall, highlighting the importance of considering seasonal fish behavior when planning construction schedules for offshore development projects. The fine spatial scale (10 s of kms) of this research makes it especially valuable for local marine spatial planning efforts by identifying local-scale patterns in fish community structure that will enable future assessment of the ecological impacts of

  2. Extreme Longevity in Proteinaceous Deep-Sea Corals

    SciTech Connect

    Roark, E B; Guilderson, T P; Dunbar, R B; Fallon, S J; Mucciarone, D A

    2009-02-09

    Deep-sea corals are found on hard substrates on seamounts and continental margins world-wide at depths of 300 to {approx}3000 meters. Deep-sea coral communities are hotspots of deep ocean biomass and biodiversity, providing critical habitat for fish and invertebrates. Newly applied radiocarbon age date from the deep water proteinaceous corals Gerardia sp. and Leiopathes glaberrima show that radial growth rates are as low as 4 to 35 {micro}m yr{sup -1} and that individual colony longevities are on the order of thousands of years. The management and conservation of deep sea coral communities is challenged by their commercial harvest for the jewelry trade and damage caused by deep water fishing practices. In light of their unusual longevity, a better understanding of deep sea coral ecology and their interrelationships with associated benthic communities is needed to inform coherent international conservation strategies for these important deep-sea ecosystems.

  3. Patterns of distribution of deepwater demersal fishes of the North Atlantic mid-ocean ridge, continental slopes, islands and seamounts

    NASA Astrophysics Data System (ADS)

    Bergstad, Odd Aksel; Menezes, Gui M. M.; Høines, Åge S.; Gordon, John D. M.; Galbraith, John K.

    2012-03-01

    Basin-scale spatial and depth-related distribution patterns of deepwater demersal fishes were analysed using bottom trawl datasets from the North Atlantic continental margin, slopes of oceanic islands and seamounts, and the mid-Atlantic Ridge. Depth-stratified presence-absence data for 593 species were compiled from fisheries-independent trawl studies with full species lists. The datasets comprised trawls conducted on the upper continental slope (200 m) to abyssal depths, and 750 m wide depth strata were used. Number of species and families declined with depth in all areas. Species number was highest in the western North Atlantic, significantly lower on the mid-Atlantic Ridge and eastern North Atlantic. Observed species numbers are also low in southern areas (Bahamas, NW Africa, southerly seamounts), but the sampling effort in these waters has been much less than in northern sites. Fish assemblages vary by depth, latitude and longitude, and the study corroborates earlier suggestions that assemblages are broadly distributed in relation to regional circulation and watermass features. The mid-Atlantic Ridge assemblages between Iceland and the Azores are most similar to those on eastern North Atlantic slopes and rises, rather dissimilar to all others, including western Atlantic, Greenland, northwest Africa and Azorean seamount and island assemblages. Across the North Atlantic differences between subareas are strongest at slope depths, much less pronounced at the less speciose rise and abyssal depths. Demersal fish biomass estimates suggest that the American slope (New England) has low biomass compared with Newfoundland and European areas, and that the supposedly oligotrophic mid-Atlantic Ridge has a level of biomass similar to or higher than the European margin.

  4. The ecology of the deep-sea benthic and benthopelagic fish on the slopes of the Rockall Trough, Northeastern Atlantic

    NASA Astrophysics Data System (ADS)

    Gordon, J. D. M.; Duncan, J. A. R.

    A total of over 28,000 benthic and benthopelagic fish belonging to 34 families and comprising at least 85 species were collected from the Hebridean Terrace in the Rockall Trough between soundings of 500 and 2000 m. Commercial type trawls (20.6 m Granton or 140 foot German bottom trawls) fished on paired warps at 33 stations accounted for 89% of all individual caught, the remainder being caught by a 16.4 m prawn trawl fished on a single warp (22 stations) and a 3 m Agassiz trawl (12 stations). The stations sampled, with a few exceptions, fell into discrete bathymetric zones separated by increments of approximately 250 m and different combinations of nets were used at each of these zones. The catch composition of the commercial trawls differed from those of the other nets. The most obvious difference was that squalid sharks, the alepocephalid Alepocephalus bairdii and the black scabbard fish Aphanopus carbo were important in the commercial type trawls but were absent or poorly represented in the other nets. Net size and towing speed were considered to be important factors influencing the catch composition. Net selectivity was most apparent on the upper and mid slopes but less apparent on the lower slopes. Relatively few families contribute to the total biomass at a given bathymetric zone and because the families Squalidae and Alepocephalidae contribute significantly to the biomass on the upper and mid slope it is therefore concluded that small nets must grossly underestimate the biomass at these depths. The greatest biomass occurred at mid slope depths (750-1000 m).

  5. Stable-isotope analysis of a deep-sea benthic-fish assemblage: evidence of an enriched benthic food web.

    PubMed

    Boyle, M D; Ebert, D A; Cailliet, G M

    2012-04-01

    In this study, fishes and invertebrates collected from the continental slope (1000 m) of the eastern North Pacific Ocean were analysed using stable-isotope analysis (SIA). Resulting trophic positions (T(P) ) were compared to known diets and habitats from the literature. Dual isotope plots indicated that most species groups (invertebrates and fishes) sorted as expected along the carbon and nitrogen axes, with less intraspecific variability than interspecific variability. Results also indicated an isotopically distinct benthic and pelagic food web, as the benthic food web was more enriched in both nitrogen and carbon isotopes. Trophic positions from SIA supported this finding, resulting in the assignment of fishes to different trophic positions from those expected based on published dietary information. These differences can be explained largely by the habitat of the prey and the percentage of the diet that was scavenged. A mixing model estimated dietary contributions of prey similar to those of the known diet of Bathyraja trachura from stomach-content analysis (SCA). Linear regressions indicated that trophic positions calculated from SIA and SCA, when plotted against B. trachura total length for 32 individuals, exhibited similar variation and patterns. Only the T(P) from SCA yielded significant results (stomach content: P < 0·05, stable isotope: P > 0·05). PMID:22497394

  6. Stable-isotope analysis of a deep-sea benthic-fish assemblage: evidence of an enriched benthic food web.

    PubMed

    Boyle, M D; Ebert, D A; Cailliet, G M

    2012-04-01

    In this study, fishes and invertebrates collected from the continental slope (1000 m) of the eastern North Pacific Ocean were analysed using stable-isotope analysis (SIA). Resulting trophic positions (T(P) ) were compared to known diets and habitats from the literature. Dual isotope plots indicated that most species groups (invertebrates and fishes) sorted as expected along the carbon and nitrogen axes, with less intraspecific variability than interspecific variability. Results also indicated an isotopically distinct benthic and pelagic food web, as the benthic food web was more enriched in both nitrogen and carbon isotopes. Trophic positions from SIA supported this finding, resulting in the assignment of fishes to different trophic positions from those expected based on published dietary information. These differences can be explained largely by the habitat of the prey and the percentage of the diet that was scavenged. A mixing model estimated dietary contributions of prey similar to those of the known diet of Bathyraja trachura from stomach-content analysis (SCA). Linear regressions indicated that trophic positions calculated from SIA and SCA, when plotted against B. trachura total length for 32 individuals, exhibited similar variation and patterns. Only the T(P) from SCA yielded significant results (stomach content: P < 0·05, stable isotope: P > 0·05).

  7. Demersal fish assemblages and spatial diversity patterns in the Arctic-Atlantic transition zone in the Barents Sea.

    PubMed

    Johannesen, Edda; Høines, Åge S; Dolgov, Andrey V; Fossheim, Maria

    2012-01-01

    Direct and indirect effects of global warming are expected to be pronounced and fast in the Arctic, impacting terrestrial, freshwater and marine ecosystems. The Barents Sea is a high latitude shelf Sea and a boundary area between arctic and boreal faunas. These faunas are likely to respond differently to changes in climate. In addition, the Barents Sea is highly impacted by fisheries and other human activities. This strong human presence places great demands on scientific investigation and advisory capacity. In order to identify basic community structures against which future climate related or other human induced changes could be evaluated, we analyzed species composition and diversity of demersal fish in the Barents Sea. We found six main assemblages that were separated along depth and temperature gradients. There are indications that climate driven changes have already taken place, since boreal species were found in large parts of the Barents Sea shelf, including also the northern Arctic area. When modelling diversity as a function of depth and temperature, we found that two of the assemblages in the eastern Barents Sea showed lower diversity than expected from their depth and temperature. This is probably caused by low habitat complexity and the distance to the pool of boreal species in the western Barents Sea. In contrast coastal assemblages in south western Barents Sea and along Novaya Zemlya archipelago in the Eastern Barents Sea can be described as diversity "hotspots"; the South-western area had high density of species, abundance and biomass, and here some species have their northern distribution limit, whereas the Novaya Zemlya area has unique fauna of Arctic, coastal demersal fish. (see Information S1 for abstract in Russian).

  8. Demersal Fish Assemblages and Spatial Diversity Patterns in the Arctic-Atlantic Transition Zone in the Barents Sea

    PubMed Central

    Johannesen, Edda; Høines, Åge S.; Dolgov, Andrey V.; Fossheim, Maria

    2012-01-01

    Direct and indirect effects of global warming are expected to be pronounced and fast in the Arctic, impacting terrestrial, freshwater and marine ecosystems. The Barents Sea is a high latitude shelf Sea and a boundary area between arctic and boreal faunas. These faunas are likely to respond differently to changes in climate. In addition, the Barents Sea is highly impacted by fisheries and other human activities. This strong human presence places great demands on scientific investigation and advisory capacity. In order to identify basic community structures against which future climate related or other human induced changes could be evaluated, we analyzed species composition and diversity of demersal fish in the Barents Sea. We found six main assemblages that were separated along depth and temperature gradients. There are indications that climate driven changes have already taken place, since boreal species were found in large parts of the Barents Sea shelf, including also the northern Arctic area. When modelling diversity as a function of depth and temperature, we found that two of the assemblages in the eastern Barents Sea showed lower diversity than expected from their depth and temperature. This is probably caused by low habitat complexity and the distance to the pool of boreal species in the western Barents Sea. In contrast coastal assemblages in south western Barents Sea and along Novaya Zemlya archipelago in the Eastern Barents Sea can be described as diversity “hotspots”; the South-western area had high density of species, abundance and biomass, and here some species have their northern distribution limit, whereas the Novaya Zemlya area has unique fauna of Arctic, coastal demersal fish. (see Information S1 for abstract in Russian). PMID:22545093

  9. Large-scale spatio-temporal monitoring highlights hotspots of demersal fish diversity in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Granger, Victoria; Fromentin, Jean-Marc; Bez, Nicolas; Relini, Giulio; Meynard, Christine N.; Gaertner, Jean-Claude; Maiorano, Porzia; Garcia Ruiz, Cristina; Follesa, Cristina; Gristina, Michele; Peristeraki, Panagiota; Brind'Amour, Anik; Carbonara, Pierluigi; Charilaou, Charis; Esteban, Antonio; Jadaud, Angélique; Joksimovic, Aleksandar; Kallianiotis, Argyris; Kolitari, Jerina; Manfredi, Chiara; Massuti, Enric; Mifsud, Roberta; Quetglas, Antoni; Refes, Wahid; Sbrana, Mario; Vrgoc, Nedo; Spedicato, Maria Teresa; Mérigot, Bastien

    2015-01-01

    Increasing human pressures and global environmental change may severely affect the diversity of species assemblages and associated ecosystem services. Despite the recent interest in phylogenetic and functional diversity, our knowledge on large spatio-temporal patterns of demersal fish diversity sampled by trawling remains still incomplete, notably in the Mediterranean Sea, one of the most threatened marine regions of the world. We investigated large spatio-temporal diversity patterns by analysing a dataset of 19,886 hauls from 10 to 800 m depth performed annually during the last two decades by standardised scientific bottom trawl field surveys across the Mediterranean Sea, within the MEDITS program. A multi-component (eight diversity indices) and multi-scale (local assemblages, biogeographic regions to basins) approach indicates that only the two most traditional components (species richness and evenness) were sufficient to reflect patterns in taxonomic, phylogenetic or functional richness and divergence. We also put into question the use of widely computed indices that allow comparing directly taxonomic, phylogenetic and functional diversity within a unique mathematical framework. In addition, demersal fish assemblages sampled by trawl do not follow a continuous decreasing longitudinal/latitudinal diversity gradients (spatial effects explained up to 70.6% of deviance in regression tree and generalised linear models), for any of the indices and spatial scales analysed. Indeed, at both local and regional scales species richness was relatively high in the Iberian region, Malta, the Eastern Ionian and Aegean seas, meanwhile the Adriatic Sea and Cyprus showed a relatively low level. In contrast, evenness as well as taxonomic, phylogenetic and functional divergences did not show regional hotspots. All studied diversity components remained stable over the last two decades. Overall, our results highlight the need to use complementary diversity indices through different

  10. Capillostrongyloides morae sp. n. (Nematoda: Capillariidae) from deep-sea fish (Teleostei, Moridae) in the western Mediterranean Sea.

    PubMed

    González-Solís, David; Carrassón, Maite; Pérez-del-Olmo, Ana

    2014-02-01

    A new capillariid nematode, Capillostrongyloides morae sp. n., is described from specimens collected from the stomach and intestine of the common mora, Mora moro (Risso), and the Mediterranean codling, Lepidion lepidion (Risso) (both Gadiformes, Moridae), off the Mediterranean coasts of Spain. The new species shows similar morphological features as other congeneric species occurring in freshwater and marine fishes, but it differs in the length of the body and spicules, the size of the caudal bursa, and the presence of an elevated anterior vulvar lip. Capillostrongyloides morae sp. n. is the second species within the genus for which the presence of a stylet is reported, and the first one in which this structure along with the distribution of cephalic papillae and oral structures (e.g. lips and lobes) are clearly shown by using scanning electron microscopy.

  11. Development and sexual dimorphism of the sonic system in deep sea neobythitine fishes: The upper continental slope

    NASA Astrophysics Data System (ADS)

    Ali, Heba A.; Mok, Hin-Kiu; Fine, Michael L.

    2016-09-01

    The anatomy of sound production in continental-slope fishes has been ignored since the work of NB Marshall in the 1960s. Due to food scarcity at great depths, we hypothesize that sonic muscles will be reduced in deep-water neobythitine cusk-eels (family Ophidiidae). Here we describe and quantify dimensions of the swimbladder and sonic muscles of three species from the upper slope. They have four pairs of well-developed sonic muscles (two medial and two lateral) with origins on the skull and insertions on the medial swimbladder (medial pair) or on modified epineural ribs that attach to the lateral swimbladder (lateral pair). Despite minor differences, relatively similar swimbladder dimensions, muscle length and external morphology suggest a conservative body plan. However, there are major differences in sonic muscle mass: medial muscles are heavier in males and made of relatively small fibers (ca 10 μm in diameter). Lateral muscles are generally larger in females and consist of larger fibers, as in epaxial trunk muscle. Muscle weight varies between species, and we suggest males produce advertisement calls that vary in amplitude and duration in different species. Due to differences in fiber size, we hypothesize that lateral muscles with larger fibers remain contracted during sound production, and medial muscles with smaller fibers will oscillate to drive swimbladder sound production.

  12. The dynamics of biogeographic ranges in the deep sea.

    PubMed

    McClain, Craig R; Hardy, Sarah Mincks

    2010-12-01

    Anthropogenic disturbances such as fishing, mining, oil drilling, bioprospecting, warming, and acidification in the deep sea are increasing, yet generalities about deep-sea biogeography remain elusive. Owing to the lack of perceived environmental variability and geographical barriers, ranges of deep-sea species were traditionally assumed to be exceedingly large. In contrast, seamount and chemosynthetic habitats with reported high endemicity challenge the broad applicability of a single biogeographic paradigm for the deep sea. New research benefiting from higher resolution sampling, molecular methods and public databases can now more rigorously examine dispersal distances and species ranges on the vast ocean floor. Here, we explore the major outstanding questions in deep-sea biogeography. Based on current evidence, many taxa appear broadly distributed across the deep sea, a pattern replicated in both the abyssal plains and specialized environments such as hydrothermal vents. Cold waters may slow larval metabolism and development augmenting the great intrinsic ability for dispersal among many deep-sea species. Currents, environmental shifts, and topography can prove to be dispersal barriers but are often semipermeable. Evidence of historical events such as points of faunal origin and climatic fluctuations are also evident in contemporary biogeographic ranges. Continued synthetic analysis, database construction, theoretical advancement and field sampling will be required to further refine hypotheses regarding deep-sea biogeography.

  13. The dynamics of biogeographic ranges in the deep sea

    PubMed Central

    McClain, Craig R.; Hardy, Sarah Mincks

    2010-01-01

    Anthropogenic disturbances such as fishing, mining, oil drilling, bioprospecting, warming, and acidification in the deep sea are increasing, yet generalities about deep-sea biogeography remain elusive. Owing to the lack of perceived environmental variability and geographical barriers, ranges of deep-sea species were traditionally assumed to be exceedingly large. In contrast, seamount and chemosynthetic habitats with reported high endemicity challenge the broad applicability of a single biogeographic paradigm for the deep sea. New research benefiting from higher resolution sampling, molecular methods and public databases can now more rigorously examine dispersal distances and species ranges on the vast ocean floor. Here, we explore the major outstanding questions in deep-sea biogeography. Based on current evidence, many taxa appear broadly distributed across the deep sea, a pattern replicated in both the abyssal plains and specialized environments such as hydrothermal vents. Cold waters may slow larval metabolism and development augmenting the great intrinsic ability for dispersal among many deep-sea species. Currents, environmental shifts, and topography can prove to be dispersal barriers but are often semipermeable. Evidence of historical events such as points of faunal origin and climatic fluctuations are also evident in contemporary biogeographic ranges. Continued synthetic analysis, database construction, theoretical advancement and field sampling will be required to further refine hypotheses regarding deep-sea biogeography. PMID:20667884

  14. Changes in deep-sea fish and crustacean communities at 1000-2200 m in the Western Mediterranean after 25 years: Relation to hydro-climatic conditions

    NASA Astrophysics Data System (ADS)

    Cartes, J. E.; Maynou, F.; Fanelli, E.; López-Pérez, C.; Papiol, V.

    2015-03-01

    toward these intermediate depths that acquired greater trophic resources. Deep-sea Mediterranean fish and invertebrates, including important commercial species, seemed to undergo long-term changes in its distribution and biomass due to changes in hydro-climatic conditions, mainly a decrease of O2 in the bottom-boundary layer.

  15. Pelagic to demersal transition in a coral-reef fish, the orbicular batfish Platax orbicularis.

    PubMed

    Leis, J M; Hay, A C; Sasal, P; Hicks, A S; Galzin, R

    2013-09-01

    Behavioural and ecological observations were made on young, reared Platax orbicularis in Opunohu Bay, Moorea, French Polynesia, during their transition from the pelagic, dispersive stage to the reef-orientated demersal stage. Seventy-two young P. orbicularis (17-75 mm standard length, LS ) were released in the pelagic zone and 20 (40-70 mm LS ) adjacent to the reefs. Swimming speed was slow (mean 5·2 cm s(-1) ) and independent of size. An ontogenetic descent was observed: the smallest P. orbicularis swam at the surface, medium-sized P. orbicularis swam in midwater (mean 5-13 m) and the largest P. orbicularis swam to the bottom, where many lay on their sides. Platax orbicularis swam southerly on average, away from the ocean and into the bay. Smaller P. orbicularis were more likely to swim directionally than larger individuals. Young P. orbicularis released near reef edges swam at similar, but more variable speeds (mean 6·6 cm s(-1) ). About half of those released near reefs swam away, but fewer swam away from an inshore fringing reef than from a patch reef near the bay mouth. Many P. orbicularis swam up the slope onto the reef top, but the little settlement observed was near the reef base. Average, near-reef swimming direction was also southerly. Some reef residents, in particular the triggerfish Balistapus undulatus, harassed young P. orbicularis. PMID:23991868

  16. Spatial and Temporal Entry Patterns of Fish Larvae into North Carolina Estuaries: Comparisons Among One Pelagic and Two Demersal Species

    NASA Astrophysics Data System (ADS)

    Joyeux, J.-C.

    1998-12-01

    A sampling programme targeting larvae of winter spawning fishes immigrating from the oceanic domain into the Pamlico-Albemarle Sounds system (NC, U.S.A.) was performed at the four major inlets of the lagoon system. Sampling yielded abundant catches of three species, a Clupeid (Atlantic menhaden,Brevoortia tyrannus) and two Sciaenids (Atlantic croaker,Micropogonias undulatusand spot,Leiostomus xanthurus). In this article, the author documents the differences in the mechanisms developed for estuarine recruitment among the three species. Abundance at the tidal inlets was dependent upon numerous factors, such as sampling month, inlet, luminosity, tide flow direction and depth. The spatial and temporal positioning of the larvae differed among the species and affected their capabilities to be transported through the inlets. More specifically, spot and croaker migrated vertically within the water column in accordance with the direction of the water flow. Sciaenids minimized the outwelling effects of ebb tides by migrating into the slowest ebbing currents, near the bottom. Menhaden did not rely on vertical migrations for estuarine transport and retention. For this species, landward transport is provided either when dusk and flood onset are coincident or through non-tidal flows developing under meteorological forcing. The Sciaenids were less, or not, dependent upon these conditions. In one inlet, the retention was dependent upon the strength of the flooding and ebbing flows. In this case, the retention of the pelagic species was lower than the retention of demersal species.

  17. Carbon and nitrogen stable isotopic inventory of the most abundant demersal fish captured by benthic gears in southwestern Iceland (North Atlantic)

    NASA Astrophysics Data System (ADS)

    Sarà, Gianluca; de Pirro, Maurizio; Sprovieri, Mario; Rumolo, Paola; Halldórsson, Halldór Pálmar; Svavarsson, Jörundur

    2009-12-01

    Stable isotopes (δ13C and δ15N) were used to examine the origin of organic matter for the most representative demersal species of the SW Icelandic fishery, accounting for over 70% of landings of those species in the North Atlantic. Samples were collected during a 2-week period in early September 2004 from landings and directly during fishing cruises. Stable isotopes showed that particulate organic matter and sedimentary organic matter were at the base of the food web and appeared to fill two different compartments: the pelagic and the benthic. The pelagic realm was composed of only capelin and sandeel; krill and redfish occupied an intermediate position between pelagic and benthic realms; while anglerfish, haddock, cod and ling resulted as the true demersal species while tusk, rays and plaice were strongly linked to the benthic habitat.

  18. Consideration on the Long Ecological Half-Life Component of (137)Cs in Demersal Fish Based on Field Observation Results Obtained after the Fukushima Accident.

    PubMed

    Tagami, Keiko; Uchida, Shigeo

    2016-02-16

    Radiocesium concentrations in most marine fish collected off the coast of Fukushima and surrounding prefectures have decreased with time, and four years after the Fukushima Daiichi Nuclear Power Plant accident occurred, radiocesium concentrations have generally fallen below the detectable level (ca. < 10 Bq kg(-1)-raw). Only in some demersal fish species have detectable concentration levels still been found, and even these species have showed slow radiocesium decreases. The food web was considered as the major factor causing this phenomenon; however, slow elimination rates of radiocesium from these fish species also could be the cause. The latter effect was examined by considering that the (137)Cs concentration decreasing trend in fish could be fit with a set of three exponentially decreasing components; that is, having short, intermediate, and long biological half-lives. The long ecological half-life component was calculated using a 400-1500 d period of monitoring results for Japanese rockfish (Sebastes cheni) and compared with previous reported laboratory results for biological half-life. The obtained ecological half-lives ranged from 274-365 d, and these values agreed with the biological half-life of this fish species. This result implied that the long biological half-lives of radiocesium in some demersal fish species made their radiocesium contamination periods longer.

  19. Consideration on the Long Ecological Half-Life Component of (137)Cs in Demersal Fish Based on Field Observation Results Obtained after the Fukushima Accident.

    PubMed

    Tagami, Keiko; Uchida, Shigeo

    2016-02-16

    Radiocesium concentrations in most marine fish collected off the coast of Fukushima and surrounding prefectures have decreased with time, and four years after the Fukushima Daiichi Nuclear Power Plant accident occurred, radiocesium concentrations have generally fallen below the detectable level (ca. < 10 Bq kg(-1)-raw). Only in some demersal fish species have detectable concentration levels still been found, and even these species have showed slow radiocesium decreases. The food web was considered as the major factor causing this phenomenon; however, slow elimination rates of radiocesium from these fish species also could be the cause. The latter effect was examined by considering that the (137)Cs concentration decreasing trend in fish could be fit with a set of three exponentially decreasing components; that is, having short, intermediate, and long biological half-lives. The long ecological half-life component was calculated using a 400-1500 d period of monitoring results for Japanese rockfish (Sebastes cheni) and compared with previous reported laboratory results for biological half-life. The obtained ecological half-lives ranged from 274-365 d, and these values agreed with the biological half-life of this fish species. This result implied that the long biological half-lives of radiocesium in some demersal fish species made their radiocesium contamination periods longer. PMID:26828695

  20. An un-commissioned randomized, placebo-controlled double-blind study to test the effect of deep sea fish oil as a pain reliever for dogs suffering from canine OA

    PubMed Central

    2012-01-01

    Background An un-commissioned randomized, double-blinded, placebo controlled clinical study was planned using a deep sea fish oil product for pets. Seventy-seven client-owned dogs with osteoarthritis were randomly assigned to supplement the food with either the fish oil product or corn (=placebo) oil. Our main outcome variables were force platform variables peak vertical force (PVF) and impulse, the validated Helsinki Chronic Pain Index (HCPI) and the use of rescue NSAIDs. Secondary outcome variables were a locomotion visual analog scale (VAS), a Quality of life VAS, a comparative questionnaire, a veterinary assessment, owners’ final assessment of outcome and guessing the product given. Results When comparing the two test groups at the end of the trial (16 weeks) there was no significant difference in any of the main outcome variables but owners of dogs that had taken fish oil were significantly happier with the treatment at the end visit and did significantly better at guessing what group their dogs had been in, compared to the placebo group. When comparing variables within the fish oil group as change from baseline to trial end, there were significant positive changes in PVF, HCPI, NSAID use, Quality of life VAS, as well as in all three scores in the comparative questionnaire (locomotion, every-day situations, and skin & coat). There were similar positive trends in force platform impulse and in the veterinary assessment variables, although they did not reach significance. Within the placebo group there were significant positive changes only in the HCPI and a significant deterioration according to veterinary assessment. Conclusions When compared to placebo, there was not a major statistically significant benefit in using deep sea fish oil as a pain reliever in our study population of dogs suffering from osteoarthritis. However, the fish oil treated patients improved significantly in many of the variables, when comparing baseline values to the study-end values

  1. Depth-related trends in morphological and functional diversity of demersal fish assemblages in the western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Farré, Marc; Tuset, Víctor M.; Cartes, Joan E.; Massutí, Enric; Lombarte, Antoni

    2016-09-01

    The morphological and functional traits of fishes are key factors defining the ecological and biological habits of species within ecosystems. However, little is known about how the depth gradient affects these factors. In the present study, several demersal fish assemblages from the Balearic Islands (western Mediterranean Sea) along a wide depth range (40-2200 m) were morphologically, functionally and ecologically described. The morphological characterization of communities was performed using geometric morphometric methods, while the functional structures were obtained by the functional categorization of species and the application of principal coordinates analysis (PCoA). The results revealed that morphospaces presented less richness of body forms as depth increases, although they showed a progressive spreading of species toward the periphery, with a proliferation of more extreme body traits, demonstrating lower morphological redundancy. In addition, a trend toward the elongation of body shape was also observed with depth. Moreover, functional diversity increased with bathymetry up to 1400 m, where it sharply decreased downwards. This decrease was parallel to a progressive fall of H‧ (ecological diversity) up to 2200 m. Functional redundancy progressively decreased until the deepest assemblage (more constantly in the deeper levels), which was almost exclusively dominated by benthopelagic wandering species feeding on suprabenthos. Redundancy analysis (RDA) demonstrated that both morphological and functional spaces showed high variation along the bathymetric range. Mantel test indicated that the majority of species presented similar spatial distribution within the morphospace and functional space, although in the functional space the more abundant species were always located at the periphery. These results demonstrate that the assessment of the morpho-functional variation between marine communities helps to understand the processes that affect the structure and

  2. [Four cases of pulmonary tuberculosis among deep-sea fishermen].

    PubMed

    Ono, Hidemaro; Murakami, Reiko; Tsuruwaka, Mia; Suzuki, Yoshihiko

    2003-06-01

    Pulmonary tuberculosis among deep-sea fishermen was reported. Four pulmonary tuberculosis cases among fishing boat members engaged in deep-sea fishing were registered at the Kesennuma Health Center during three years period from 2000 to 2002. Crew engaging in deep-sea fishing live together in a narrow cabin with inadequate airconditioning for a long period of time, about 1 year. It is difficult to consult with a medical institution in an open sea. If a tuberculosis patient breaks out in a boat, the risk of transmission of tuberculosis to other members is high. In boats of all four cases in this report, about 30 to 70 percent of crew were Indonesian. Indonesia is one of the high burden countries of tuberculosis in the world. The Japanese fishing boat members have received the medical checkup every year. Indonesians have also received the pre-employment medical checkup, however, the improvement in the quality of this medical checkup is required.

  3. Biophysical Factors Affecting the Distribution of Demersal Fish around the Head of a Submarine Canyon Off the Bonney Coast, South Australia

    PubMed Central

    Currie, David R.; McClatchie, Sam; Middleton, John F.; Nayar, Sasi

    2012-01-01

    We sampled the demersal fish community of the Bonney Canyon, South Australia at depths (100–1,500 m) and locations that are poorly known. Seventy-eight species of demersal fish were obtained from 12 depth-stratified trawls along, and to either side, of the central canyon axis. Distributional patterns in species richness and biomass were highly correlated. Three fish assemblage groupings, characterised by small suites of species with narrow depth distributions, were identified on the shelf, upper slope and mid slope. The assemblage groupings were largely explained by depth (ρw = 0.78). Compared to the depth gradient, canyon-related effects are weak or occur at spatial or temporal scales not sampled in this study. A conceptual physical model displayed features consistent with the depth zonational patterns in fish, and also indicated that canyon upwelling can occur. The depth zonation of the fish assemblage was associated with the depth distribution of water masses in the area. Notably, the mid-slope community (1,000 m) coincided with a layer of Antarctic Intermediate Water, the upper slope community (500 m) resided within the core of the Flinders Current, and the shelf community was located in a well-mixed layer of surface water (<450 m depth). PMID:22253907

  4. Parasites of the deep-sea fish Mora moro (Risso, 1810) from the NW Mediterranean Sea and relationship with fish diet and enzymatic biomarkers

    NASA Astrophysics Data System (ADS)

    Dallarés, Sara; Constenla, María; Padrós, Francesc; Cartes, Joan E.; Solé, Montse; Carrassón, Maite

    2014-10-01

    Specimens of Mora moro were collected in two seasons and three localities of the Balearic Sea (NW Mediterranean Sea) and parasitological, dietary (to prey-species level), enzymatic and histological data were obtained, alongside with environmental information (T, S, O2). The relationships among fish parasite load, condition indices, diet, enzymatic activity of muscular acetylcholinesterase (AChE) and lactate dehydrogenase (LDH), intensity of splenic melano-macrophage centres (MMC) and hepatic granulomas were tested. M. moro showed a rich and abundant parasite fauna, and was a new host record for 17 out of the 18 different endoparasite taxa found. Significant differences were detected among locality-season groups, in turn related to different environmental variables, for Anisakidae gen. sp., Anisakis Type II and Tetraphyllidea fam. gen. sp.; thus, they are proposed as potentially useful as biological tags for geographical discrimination of M. moro in the NW Mediterranean Sea. Detailed relationships were found between parasite taxa and prey ingested (e.g. Anisakidae gen. sp. related with meso-bathypelagic crustaceans; Anisakis Type I with benthopelagic squids). Most parasites were linked to samples with highest levels of near-bottom O2, which is consistent with direct relationships found between near-bottom O2 and zooplankton biomass in the Balearic Basin. Total parasite abundance and the abundance of Tetraphyllidea fam. gen. sp. showed a significant relationship with the activity of AChE and the abundance of Anisakis Type II with LDH. AChE was associated with hepatosomatic index (HSI) and condition factor (K); LDH with gonadosomatic index (GSI), K and fish total length (TL). LDH activity showed differences among sampling groups. Splenic MMC and hepatic granulomas were not associated with fish parasite load. A positive relationship was found between MMC area and fish TL and LDH activity.

  5. Benthos and demersal fish habitats in the German Exclusive Economic Zone (EEZ) of the North Sea

    NASA Astrophysics Data System (ADS)

    Neumann, Hermann; Reiss, Henning; Ehrich, Siegfried; Sell, Anne; Panten, Kay; Kloppmann, Matthias; Wilhelms, Ingo; Kröncke, Ingrid

    2013-09-01

    We compiled data from different monitoring surveys to analyse and compare community and diversity patterns of fish, epi- and infauna in the German Exclusive Economic Zone (EEZ) of the North Sea in order to identify benthic habitats common to all faunal components. We found congruent community patterns of fish, epi- and infauna for the coastal waters, the Oysterground and the area called "Duck's Bill", which coincided with specific abiotic characteristics of these regions. The three regions were defined as special habitats for fish, epi- and infauna species in the German EEZ. The differences in the seasonal variability of abiotic factors seem to be the most important discriminating abiotic characteristic for the three habitats. The spatial distribution of fish, epifauna and infauna communities remained stable over time although habitat characteristics such as sea surface temperature increased due to climate change. However, it is expected that the coastal habitat will be more sensitive to future climate change effects in contrast to the Oysterground and Duck's Bill habitat.

  6. Energy profiling of demersal fish: a case-study in wind farm artificial reefs.

    PubMed

    De Troch, Marleen; Reubens, Jan T; Heirman, Elke; Degraer, Steven; Vincx, Magda

    2013-12-01

    The construction of wind farms introduces artificial hard substrates in sandy sediments. As Atlantic cod (Gadus morhua) and pouting (Trisopterus luscus) tend to aggregate in order to feed around these reefs, energy profiling and trophic markers were applied to study their feeding ecology in a wind farm in the Belgian part of the North Sea. The proximate composition (carbohydrates, proteins and lipids) differed significantly between liver and muscle tissue but not between fish species or between their potential prey species. Atlantic cod showed to consume more energy than pouting. The latter had a higher overall energy reserve and can theoretically survive twice as long on the available energy than cod. In autumn, both fish species could survive longer on their energy than in spring. Polyunsaturated fatty acids were found in high concentrations in fish liver. The prey species Jassa and Pisidia were both rich in EPA while Jassa had a higher DHA content than Pisidia. Energy profiling supported the statement that wind farm artificial reefs are suitable feeding ground for both fish species. Sufficient energy levels were recorded and there is no indication of competition.

  7. Energy profiling of demersal fish: a case-study in wind farm artificial reefs.

    PubMed

    De Troch, Marleen; Reubens, Jan T; Heirman, Elke; Degraer, Steven; Vincx, Magda

    2013-12-01

    The construction of wind farms introduces artificial hard substrates in sandy sediments. As Atlantic cod (Gadus morhua) and pouting (Trisopterus luscus) tend to aggregate in order to feed around these reefs, energy profiling and trophic markers were applied to study their feeding ecology in a wind farm in the Belgian part of the North Sea. The proximate composition (carbohydrates, proteins and lipids) differed significantly between liver and muscle tissue but not between fish species or between their potential prey species. Atlantic cod showed to consume more energy than pouting. The latter had a higher overall energy reserve and can theoretically survive twice as long on the available energy than cod. In autumn, both fish species could survive longer on their energy than in spring. Polyunsaturated fatty acids were found in high concentrations in fish liver. The prey species Jassa and Pisidia were both rich in EPA while Jassa had a higher DHA content than Pisidia. Energy profiling supported the statement that wind farm artificial reefs are suitable feeding ground for both fish species. Sufficient energy levels were recorded and there is no indication of competition. PMID:24210053

  8. Metal concentrations in demersal fish species from Santa Maria Bay, Baja California Sur, Mexico (Pacific coast).

    PubMed

    Jonathan, M P; Aurioles-Gamboa, David; Villegas, Lorena Elizabeth Campos; Bohórquez-Herrera, Jimena; Hernández-Camacho, Claudia J; Sujitha, S B

    2015-10-15

    Concentrations of 11 trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) in 40 fish species from Santa Maria Bay, Baja California Sur, Mexico, the strategically important area for marine mammals and organisms were analyzed. Based on their concentrations the ranking of metals Fe>Zn>Ni>Cr>Mn>Pb>Cu>Co>As>Cd>Hg suggests that organism size, metabolism and feeding habits are correlated with metal concentrations. Local geological formations affect the concentrations of different metals in the aquatic environment and are subsequently transferred to fishes. The correlation analysis suggests that metabolism and nurturing habits impact the concentration of metals. Concentrations of Fe and Mn appear to be influenced by scavenging and absorption processes, which vary by species. The considerable variability in the metal concentrations obtained in different species underscores the importance of regular monitoring.

  9. Efficacy of a vacuum benthos sampler for collecting demersal fish eggs from gravel substratum

    USGS Publications Warehouse

    Ruetz, C. R.; Jennings, C.A.

    1997-01-01

    We used two densities of eggs (low=900 eggs/m2; high=5100 eggs/m2) in laboratory experiments to estimate the recovery efficiency of the Brown benthos sampler for collecting fish eggs from gravel substrate and to determine if differences (e.g., 5-fold) in egg density in the substratum could be detected with the sampler. The mean egg recovery efficiency of the sampler in the low and high density treatments was 30% (SE=8.7) and 35% (SE=3.8), respectively. The difference between the treatment means was not significant. Therefore, data from the two treatments were pooled and used to estimate the recovery efficiency of the sampler (32.7%, SE=4.4). However, we were able to detect a 5?? difference in the number of eggs collected with the sampler between the two treatments. Our estimate of the recovery efficiency of the sampler for collecting fish eggs was less than those reported for the sampler's efficiency for collecting benthic macroinvertebrates. The low recovery efficiency of the sampler for collecting fish eggs does not lessen the utility of the device. Rather, ecologists planning to use the sampler must estimate the recovery efficiency of target fauna, especially if density estimates are to be calculated, because recovery efficiency probably is less than 100%. ?? Munksgaard, 1997.

  10. Exxon Valdez oil spill. State/federal natural resource damage assessment. Injury to demersal rockfish and shallow reef habitats in Prince William Sound, 1989-1991. Subtidal study number 6. Fish/shellfish study number 17. Final report

    SciTech Connect

    1994-09-01

    Demersal rockfish (Sebastes spp.) in Prince William Sound were studied from 1989 through 1991 to assess injury due to the Exxon Valdez oil spill. Injury was assessed by establishing the exposure of rockfish to petroleum hydrocarbons and then determining if any histopathological lesions occurred with increased frequency in fish from sites with oil-exposed fish.

  11. Taxonomic Distinctness of Demersal Fishes of the California Current: Moving Beyond Simple Measures of Diversity for Marine Ecosystem-Based Management

    PubMed Central

    Tolimieri, Nick; Anderson, Marti J.

    2010-01-01

    Background Large-scale patterns or trends in species diversity have long interested ecologists. The classic pattern is for diversity (e.g., species richness) to decrease with increasing latitude. Taxonomic distinctness is a diversity measure based on the relatedness of the species within a sample. Here we examined patterns of taxonomic distinctness in relation to latitude (ca. 32–48 °N) and depth (ca. 50–1220 m) for demersal fishes on the continental shelf and slope of the US Pacific coast. Methodology/Principal Findings Both average taxonomic distinctness (AvTD) and variation in taxonomic distinctness (VarTD) changed with latitude and depth. AvTD was highest at approximately 500 m and lowest at around 200 m bottom depth. Latitudinal trends in AvTD were somewhat weaker and were depth-specific. AvTD increased with latitude on the shelf (50–150 m) but tended to decrease with latitude at deeper depths. Variation in taxonomic distinctness (VarTD) was highest around 300 m. As with AvTD, latitudinal trends in VarTD were depth-specific. On the shelf (50–150 m), VarTD increased with latitude, while in deeper areas the patterns were more complex. Closer inspection of the data showed that the number and distribution of species within the class Chondrichthyes were the primary drivers of the overall patterns seen in AvTD and VarTD, while the relatedness and distribution of species in the order Scorpaeniformes appeared to cause the relatively low observed values of AvTD at around 200 m. Conclusions/Significance These trends contrast to some extent the patterns seen in earlier studies for species richness and evenness in demersal fishes along this coast and add to our understanding of diversity of the demersal fishes of the California Current. PMID:20498727

  12. When does fishing lead to more fish? Community consequences of bottom trawl fisheries in demersal food webs.

    PubMed

    van Denderen, P Daniel; van Kooten, Tobias; Rijnsdorp, Adriaan D

    2013-10-22

    Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and promote growth and even fisheries yield of target fish species. If and how this occurs is the subject of ongoing debate, with evidence both in favour and against. We model the effects of trawling on a simple ecosystem of benthivorous fish and two food populations (benthos), susceptible and resistant to trawling. We show that the ecosystem response to trawling depends on whether the abundance of benthos is top-down or bottom-up controlled. Fishing may result in higher fish abundance, higher (maximum sustainable) yield and increased persistence of fish when the benthos which is the best-quality fish food is also more resistant to trawling. These positive effects occur in bottom-up controlled systems and systems with limited impact of fish feeding on benthos, resembling bottom-up control. Fishing leads to lower yields and fish persistence in all configurations where susceptible benthos are more profitable prey. Our results highlight the importance of mechanistic ecosystem knowledge as a requirement for successful management.

  13. When does fishing lead to more fish? Community consequences of bottom trawl fisheries in demersal food webs

    PubMed Central

    van Denderen, P. Daniel; van Kooten, Tobias; Rijnsdorp, Adriaan D.

    2013-01-01

    Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and promote growth and even fisheries yield of target fish species. If and how this occurs is the subject of ongoing debate, with evidence both in favour and against. We model the effects of trawling on a simple ecosystem of benthivorous fish and two food populations (benthos), susceptible and resistant to trawling. We show that the ecosystem response to trawling depends on whether the abundance of benthos is top-down or bottom-up controlled. Fishing may result in higher fish abundance, higher (maximum sustainable) yield and increased persistence of fish when the benthos which is the best-quality fish food is also more resistant to trawling. These positive effects occur in bottom-up controlled systems and systems with limited impact of fish feeding on benthos, resembling bottom-up control. Fishing leads to lower yields and fish persistence in all configurations where susceptible benthos are more profitable prey. Our results highlight the importance of mechanistic ecosystem knowledge as a requirement for successful management. PMID:24004941

  14. Parasite communities of the deep-sea fish Alepocephalus rostratus Risso, 1820 in the Balearic Sea (NW Mediterranean) along the slope and relationships with enzymatic biomarkers and health indicators

    NASA Astrophysics Data System (ADS)

    Pérez-i-García, D.; Constenla, M.; Padrós, F.; Soler-Membrives, A.; Solé, M.; Carrassón, M.

    2015-05-01

    This study examines the parasite communities of Alepocephalus rostratus and its influence on some fish biochemical markers and histological alterations. A. rostratus constitutes the second most important fish species, in terms of biomass, inhabiting the deep slope of the Catalan Sea (Balearic Sea, NW Mediterranean). The study revealed eight different parasite species in this host: one coccidian, one digenean, one monogenean, one cestode and four nematodes. The parasite fauna of A. rostratus was partially dominated by larval forms (four of the seven metazoan taxa found), which combined with low species richness corresponds to a parasite fauna pattern more typical of bathypelagic fish species rather than demersal ones. The larval tetraphyllideans and cucullanid nematodes were the predominant species. In relation to depth, differences in abundance of the nematodes Cucullaninae gen. sp. and Hysterothylacium aduncum were found, probably due to the dietary shift in the fish host at greater depth. Thus, Cucullaninae gen. sp. and H. aduncum could be regarded as indicators for discriminating populations of A. rostratus in relation to depth in NW Mediterranean waters. Of the biochemical markers examined, acetylcholinesterase (AChE) and lactate dehydrogenase (LDH) activities and lipid peroxidation (LP) levels, only LP showed significant differences between depths. A positive relationship was found between AChE activity and Tetraphyllidea fam. gen. sp., Anisakis physeteris and H. aduncum abundance and a negative one with the abundance of Cucullaninae gen. sp. LDH showed a positive relationship with the abundance of the parasites Paracyclocotyla cherbonnieri and Tetraphyllidea fam. gen. sp. At cyto-histological level, coccidians were detected in the pyloric caeca with a prevalence of 90% in Barcelona, but in the rest of organs almost no alterations were detected. The restricted macroplanktonic diet of A. rostratus, that maintains it distant from the sea-floor for longer periods

  15. Estimation of Bottom Trawl Catch Efficiency for Two Demersal Fishes, Atlantic Croaker and White Perch in Chesapeake Bay

    EPA Science Inventory

    We present an efficiency analysis of a fisheries-independent demersal trawl survey in Chesapeake Bay, the largest estuary in the United States, that is presently being used for multi-species fisheries assessment and management. The manuscript presents an in situ analysis of demer...

  16. Seasonal variation in species composition and abundance of demersal fish and invertebrates in a Seagrass Natural Reserve on the eastern coast of the Shandong Peninsula, China

    NASA Astrophysics Data System (ADS)

    Xu, Qiang; Guo, Dong; Zhang, Peidong; Zhang, Xiumei; Li, Wentao; Wu, Zhongxin

    2016-03-01

    Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve (SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August-October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina.

  17. Sidescan sonar as a tool for detection of demersal fish habitats

    USGS Publications Warehouse

    Able, Kenneth W.; Twichell, David C.; Grimes, Churchill B.; Jones, R. S.

    1987-01-01

    Sidescan sonar can be an effective tool for the determination of the habitat distribution of commercially important species.  This technique has the advantage of rapidly mapping large areas of the seafloor.  Sidescan images (sonographs) may also help to identify appropriate fishing gears for different types of seafloor or areas to be avoided with certain types of gears.  During the early stages of exploration, verification of sidescan sonar sonographs is critical to successful identification of important habitats.  Tilefishes (Lopholatilus and Caulolatilus) are especially good target species because the construct large burrows in the seafloor or live around boulders, both of which are easily detectable on sonographs.  In some special circumstances the estimates of tilefish burrow densities from sonographs can be used to estimate standing stock. In many localities the burrow and boulder habitats of tilefish are shared with other commercially important species such as American lobsters, Homarus americanus; cusk, Brosme brosme; and ocean pout, Macrozoarces americanus.

  18. Extreme longevity in proteinaceous deep-sea corals.

    PubMed

    Roark, E Brendan; Guilderson, Thomas P; Dunbar, Robert B; Fallon, Stewart J; Mucciarone, David A

    2009-03-31

    Deep-sea corals are found on hard substrates on seamounts and continental margins worldwide at depths of 300 to approximately 3,000 m. Deep-sea coral communities are hotspots of deep ocean biomass and biodiversity, providing critical habitat for fish and invertebrates. Newly applied radiocarbon age dates from the deep water proteinaceous corals Gerardia sp. and Leiopathes sp. show that radial growth rates are as low as 4 to 35 mum year(-1) and that individual colony longevities are on the order of thousands of years. The longest-lived Gerardia sp. and Leiopathes sp. specimens were 2,742 years and 4,265 years, respectively. The management and conservation of deep-sea coral communities is challenged by their commercial harvest for the jewelry trade and damage caused by deep-water fishing practices. In light of their unusual longevity, a better understanding of deep-sea coral ecology and their interrelationships with associated benthic communities is needed to inform coherent international conservation strategies for these important deep-sea habitat-forming species. PMID:19307564

  19. Extreme longevity in proteinaceous deep-sea corals.

    PubMed

    Roark, E Brendan; Guilderson, Thomas P; Dunbar, Robert B; Fallon, Stewart J; Mucciarone, David A

    2009-03-31

    Deep-sea corals are found on hard substrates on seamounts and continental margins worldwide at depths of 300 to approximately 3,000 m. Deep-sea coral communities are hotspots of deep ocean biomass and biodiversity, providing critical habitat for fish and invertebrates. Newly applied radiocarbon age dates from the deep water proteinaceous corals Gerardia sp. and Leiopathes sp. show that radial growth rates are as low as 4 to 35 mum year(-1) and that individual colony longevities are on the order of thousands of years. The longest-lived Gerardia sp. and Leiopathes sp. specimens were 2,742 years and 4,265 years, respectively. The management and conservation of deep-sea coral communities is challenged by their commercial harvest for the jewelry trade and damage caused by deep-water fishing practices. In light of their unusual longevity, a better understanding of deep-sea coral ecology and their interrelationships with associated benthic communities is needed to inform coherent international conservation strategies for these important deep-sea habitat-forming species.

  20. Targeted demersal fish species exhibit variable responses to long-term protection from fishing at the Houtman Abrolhos Islands

    NASA Astrophysics Data System (ADS)

    Bornt, Katrina R.; McLean, Dianne L.; Langlois, Tim J.; Harvey, Euan S.; Bellchambers, Lynda M.; Evans, Scott N.; Newman, Stephen J.

    2015-12-01

    Natural fluctuations in the abundance and length of targeted fish are often disrupted by acute environmental changes and anthropogenic impacts, particularly fishing pressure. Long-term assessments of targeted fish populations inside and outside areas closed to fishing are often necessary to elucidate these effects, yet few of these studies extend over long time periods. We assessed trends in the abundance and length of six targeted fish species in areas open and closed to fishing on seven occasions spanning a 9-year period (2005-2010 and 2013) at the Houtman Abrolhos Islands, Western Australia. Shallow (8-12 m) and deep (22-26 m) coral-dominated reef sites were sampled across four geographically separated island groups using baited remote underwater stereo-video (stereo-BRUV). Between 2005 and 2010, populations of Lethrinus miniatus, Lethrinus nebulosus, Plectropomus leopardus, and Chrysophrys auratus became increasingly dominated by larger individuals, potentially indicative of an ageing population. Between 2010 and 2013, however, there was a significant increase in the proportion of smaller L. miniatus, L. nebulosus, and P. leopardus in both open and closed areas, reflecting increased recruitment perhaps due to changing environmental conditions associated with a marine heat wave anomaly. This recruitment pulse was not observed for the other species in this study ( Chr. auratus, Choerodon rubescens, and Glaucosoma hebraicum). Lethrinus miniatus, L. nebulosus, Chr. auratus, and P. leopardus were larger in closed areas relative to open areas; however, they were not more abundant. These complex responses to protection also varied across sampling years for certain species (e.g., P. leopardus). Monitoring changes over the long-term in areas open and closed to fishing provides a sound basis for separating environmental variability from that associated with fishing mortality, which is crucial for optimising fisheries management.

  1. A Deep-Sea Simulation.

    ERIC Educational Resources Information Center

    Montes, Georgia E.

    1997-01-01

    Describes an activity that simulates exploration techniques used in deep-sea explorations and teaches students how this technology can be used to take a closer look inside volcanoes, inspect hazardous waste sites such as nuclear reactors, and explore other environments dangerous to humans. (DDR)

  2. The seascape of demersal fish nursery areas in the North Mediterranean Sea, a first step towards the implementation of spatial planning for trawl fisheries.

    PubMed

    Colloca, Francesco; Garofalo, Germana; Bitetto, Isabella; Facchini, Maria Teresa; Grati, Fabio; Martiradonna, Angela; Mastrantonio, Gianluca; Nikolioudakis, Nikolaos; Ordinas, Francesc; Scarcella, Giuseppe; Tserpes, George; Tugores, M Pilar; Valavanis, Vasilis; Carlucci, Roberto; Fiorentino, Fabio; Follesa, Maria C; Iglesias, Magdalena; Knittweis, Leyla; Lefkaditou, Eugenia; Lembo, Giuseppe; Manfredi, Chiara; Massutí, Enric; Pace, Marie Louise; Papadopoulou, Nadia; Sartor, Paolo; Smith, Christopher J; Spedicato, Maria Teresa

    2015-01-01

    The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem

  3. Long-term changes in species composition of demersal fish and epibenthic species in the Jade area (German Wadden Sea/Southern North Sea) since 1972

    NASA Astrophysics Data System (ADS)

    Meyer, Julia; Kröncke, Ingrid; Bartholomä, Alexander; Dippner, Joachim W.; Schückel, Ulrike

    2016-11-01

    Within this long-term study, the short- and long-term variability of demersal fish and epibenthic species in relation to temperature and climate-driven environmental changes in the inshore tidal bay system of the Jade area was investigated. Semiquantitative sampling took place once per spring and summer period from 1972 to 2014 by using a 2 m beam trawl at one station in the Jade area (German Wadden Sea/southern North Sea). Min/max autocorrelation analysis (MAFA) and Mann-Kendall analysis revealed significant increasing trends in total abundance and species number. Homogeneity analysis revealed shifts for abundance in spring and summer in the late 1980s and for species number in the late 1980s in spring and early 2000s in summer. Abundances of the estuarine crustacean species Carcinus maenas and Liocarcinus holsatus and of the estuarine fish species Pomatoschistus spp. showed significant increasing abundances since the late 1980s. The marine juvenile species Pleuronectes platessa and Limanda limanda showed significant decreasing abundances, while abundances of Solea solea showed significant increasing abundances since the early 2000s. Abundances of L.holsatus and C. maenas showed mass occurrences since the early 2000s. Spearman correlation analysis revealed significant correlations of temperature and abundance data of some characteristic species. Statistical downscaling analysis revealed significant correlations between observations and climate indicators such as the North Sea Environmental (NSE) Index for spring. Thus, it appears that climate effects influenced the long-term variability of species number and abundance of epibenthic and demersal fish species in the Jade area, resulting in community shifts in the late 1980s and early 2000s.

  4. The Seascape of Demersal Fish Nursery Areas in the North Mediterranean Sea, a First Step Towards the Implementation of Spatial Planning for Trawl Fisheries

    PubMed Central

    Colloca, Francesco; Garofalo, Germana; Bitetto, Isabella; Facchini, Maria Teresa; Grati, Fabio; Martiradonna, Angela; Mastrantonio, Gianluca; Nikolioudakis, Nikolaos; Ordinas, Francesc; Scarcella, Giuseppe; Tserpes, George; Tugores, M. Pilar; Valavanis, Vasilis; Carlucci, Roberto; Fiorentino, Fabio; Follesa, Maria C.; Iglesias, Magdalena; Knittweis, Leyla; Lefkaditou, Eugenia; Lembo, Giuseppe; Manfredi, Chiara; Massutí, Enric; Pace, Marie Louise; Papadopoulou, Nadia; Sartor, Paolo; Smith, Christopher J.; Spedicato, Maria Teresa

    2015-01-01

    The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem

  5. The seascape of demersal fish nursery areas in the North Mediterranean Sea, a first step towards the implementation of spatial planning for trawl fisheries.

    PubMed

    Colloca, Francesco; Garofalo, Germana; Bitetto, Isabella; Facchini, Maria Teresa; Grati, Fabio; Martiradonna, Angela; Mastrantonio, Gianluca; Nikolioudakis, Nikolaos; Ordinas, Francesc; Scarcella, Giuseppe; Tserpes, George; Tugores, M Pilar; Valavanis, Vasilis; Carlucci, Roberto; Fiorentino, Fabio; Follesa, Maria C; Iglesias, Magdalena; Knittweis, Leyla; Lefkaditou, Eugenia; Lembo, Giuseppe; Manfredi, Chiara; Massutí, Enric; Pace, Marie Louise; Papadopoulou, Nadia; Sartor, Paolo; Smith, Christopher J; Spedicato, Maria Teresa

    2015-01-01

    The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem

  6. Species distribution models of tropical deep-sea snappers.

    PubMed

    Gomez, Céline; Williams, Ashley J; Nicol, Simon J; Mellin, Camille; Loeun, Kim L; Bradshaw, Corey J A

    2015-01-01

    Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and

  7. Species Distribution Models of Tropical Deep-Sea Snappers

    PubMed Central

    Gomez, Céline; Williams, Ashley J.; Nicol, Simon J.; Mellin, Camille; Loeun, Kim L.; Bradshaw, Corey J. A.

    2015-01-01

    Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and

  8. Species distribution models of tropical deep-sea snappers.

    PubMed

    Gomez, Céline; Williams, Ashley J; Nicol, Simon J; Mellin, Camille; Loeun, Kim L; Bradshaw, Corey J A

    2015-01-01

    Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and

  9. 85 million years of pelagic ecosystem evolution: Pacific Ocean deep-sea ichthyolith records reveal fish community dynamics and a long-term decline in sharks

    NASA Astrophysics Data System (ADS)

    Sibert, E. C.; Norris, R. D.; Cuevas, J. M.; Graves, L. G.

    2015-12-01

    The structure and productivity of open ocean consumers has undergone major changes over the past 85 million years. Here, we present the first long-term detailed records of pelagic fish and sharks utilizing the record of ichthyoliths (teeth and dermal scales) from the deep Pacific Ocean. While the North and South Pacific Oceans show similar patterns throughout the 85 million year history, the North Pacific ichthyolith accumulation is significantly higher than the South Pacific, suggesting that the basin has been a more productive region for tens of millions of years. Fish and sharks were not abundant in the Pacific gyres until ~75 million years ago (Ma) suggesting that neither group was quantitatively important in oligotrophic pelagic food webs prior to the latest Cretaceous. Relative to ray-finned fish, sharks were common in the ancient ocean. Most ichthyolith assemblages have >50% shark dermal scales (denticles), but denticle abundance has been declining in both absolute and relative abundance since the Cretaceous-Paleogene (K/Pg) mass extinction. The accumulation rate of ichthyoliths of both sharks and ray-finned fish was highest in the Early Eocene, during the peak of the Cenozoic 'greenhouse' climate where production of shark dermal denticles and fish teeth increased almost five times over Paleocene production rates. Ichthyolith fluxes fell with cooler climates in the later Eocene and Oligocene, but fish production is almost always higher than in the Cretaceous and Paleocene reflecting the expanded ecological roles and importance of pelagic fish in marine ecosystems. Shark denticle production fell to less than half that of the Cretaceous by 20 Ma when it dropped abruptly to near-zero levels. Currently denticles make up <2% of the ichthyolith assemblages when present at all. Ecologically, pelagic sharks appear to be falling as major pelagic consumers over the Late Cretaceous and Cenozoic, and particularly over the past 20 Ma, perhaps reflecting demographic

  10. Advanced deep sea diving equipment

    NASA Technical Reports Server (NTRS)

    Danesi, W. A.

    1972-01-01

    Design requirements are generated for a deep sea heavy duty diving system to equip salvage divers with equipment and tools that permit work of the same quality and in times approaching that done on the surface. The system consists of a helmet, a recirculator for removing carbon dioxide, and the diver's dress. The diver controls the inlet flow by the recirculatory control valve and is able to change closed cycle operation to open cycle if malfunction occurs. Proper function of the scrubber in the recirculator minimizes temperature and humidity effects as it filters the returning air.

  11. Tissue and size-related changes in the fatty acid and stable isotope signatures of the deep sea grenadier fish Coryphaenoides armatus from the Charlie-Gibbs Fracture Zone region of the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Mayor, Daniel J.; Sharples, Caroline J.; Webster, Lynda; Walsham, Pamela; Lacaze, Jean-Pierre; Cousins, Nicola J.

    2013-12-01

    Coryphaenoides armatus is a cosmopolitan deep-sea fish that plays a major role in the ecology of abyssal ecosystems. We investigated the trophic ecology and physiology of this species by determining the δ13C, δ15N and fatty acid signatures of muscle, liver and ovary tissues of individuals collected from ∼2700 m to the north and south of the Charlie-Gibbs Fracture Zone (CGFZ) of the Mid-Atlantic Ridge, NE Atlantic. Fatty acid and δ13C data both suggested that C. armatus shows an ontogenetic dietary shift, with the relative contributions of benthic and pelagic prey decreasing and increasing respectively as the animals grow. They also indicated that dietary overlap between animals living to the north and south of the CGFZ increases as they grow, suggesting that larger animals forage over greater distances and are not hindered by the presence of the CGFZ. Comparison of tissue-specific fatty acid signatures with previously published data suggests compositional homeostasis of the fatty acids 20:5(n-3) and 22:6(n-3) in the muscle, and 18:1(n-9) in the liver tissues. We ascribe this primarily to strict physiological requirements for these compounds, rather than simply to their abundance in the diet. We pose several speculative mechanisms to explain the observed trends in tissue-specific δ13C and δ15N values, illustrating some of the numerous processes that can influence the isotopic signatures of bulk tissues.

  12. Ecosystem function and services provided by the deep sea

    NASA Astrophysics Data System (ADS)

    Thurber, A. R.; Sweetman, A. K.; Narayanaswamy, B. E.; Jones, D. O. B.; Ingels, J.; Hansman, R. L.

    2014-07-01

    The deep sea is often viewed as a vast, dark, remote, and inhospitable environment, yet the deep ocean and seafloor are crucial to our lives through the services that they provide. Our understanding of how the deep sea functions remains limited, but when treated synoptically, a diversity of supporting, provisioning, regulating and cultural services becomes apparent. The biological pump transports carbon from the atmosphere into deep-ocean water masses that are separated over prolonged periods, reducing the impact of anthropogenic carbon release. Microbial oxidation of methane keeps another potent greenhouse gas out of the atmosphere while trapping carbon in authigenic carbonates. Nutrient regeneration by all faunal size classes provides the elements necessary for fueling surface productivity and fisheries, and microbial processes detoxify a diversity of compounds. Each of these processes occur on a very small scale, yet considering the vast area over which they occur they become important for the global functioning of the ocean. The deep sea also provides a wealth of resources, including fish stocks, enormous bioprospecting potential, and elements and energy reserves that are currently being extracted and will be increasingly important in the near future. Society benefits from the intrigue and mystery, the strange life forms, and the great unknown that has acted as a muse for inspiration and imagination since near the beginning of civilization. While many functions occur on the scale of microns to meters and timescales up to years, the derived services that result are only useful after centuries of integrated activity. This vast dark habitat, which covers the majority of the globe, harbors processes that directly impact humans in a variety of ways; however, the same traits that differentiate it from terrestrial or shallow marine systems also result in a greater need for integrated spatial and temporal understanding as it experiences increased use by society. In

  13. Microplastic pollution in deep-sea sediments.

    PubMed

    Van Cauwenberghe, Lisbeth; Vanreusel, Ann; Mees, Jan; Janssen, Colin R

    2013-11-01

    Microplastics are small plastic particles (<1 mm) originating from the degradation of larger plastic debris. These microplastics have been accumulating in the marine environment for decades and have been detected throughout the water column and in sublittoral and beach sediments worldwide. However, up to now, it has never been established whether microplastic presence in sediments is limited to accumulation hot spots such as the continental shelf, or whether they are also present in deep-sea sediments. Here we show, for the first time ever, that microplastics have indeed reached the most remote of marine environments: the deep sea. We found plastic particles sized in the micrometre range in deep-sea sediments collected at four locations representing different deep-sea habitats ranging in depth from 1100 to 5000 m. Our results demonstrate that microplastic pollution has spread throughout the world's seas and oceans, into the remote and largely unknown deep sea.

  14. Geographical variation in metazoan parasites of the deep-sea fish Bathypterois mediterraneus Bauchot, 1962 (Osteichthyes: Ipnopidae) from the Western Mediterranean

    NASA Astrophysics Data System (ADS)

    Mateu, Paula; Montero, Francisco E.; Carrassón, Maite

    2014-05-01

    This study examines the parasite fauna of Bathypterois mediterraneus, the most common fish below 1500 m in Western Mediterranean waters. Samples were obtained during July 2010 from the continental slope of two different areas (off Catalonia and Balearic Islands) in three different bathymetric strata at depths between 1000 and 2200 m. The parasite fauna of B. mediterraneus included a narrow range of species: Steringophorus cf. dorsolineatum, Scolex pleuronectis, Hysterothylacium aduncum, Anisakis sp. larva 3 type II and Sarcotretes sp. Steringophorus cf. dorsolineatum and H. aduncum were the most predominant parasites. H. aduncum showed significant differences in abundance between depths of 2000-2200 m with 1000-1400 m and 1400-2000 m, irrespective of locality, whereas S. cf. dorsolineatum showed significant differences between the two localities at all depths except for 2000-2200 m. We suggest the possible usefulness of these two parasites as geographical indicators for discriminating discrete stocks of B. mediterraneus in Western Mediterranean waters.

  15. Raphidascaris (Raphidascaris) macrouri n. sp. (Nematoda: Anisakidae) from two deep-sea macrourid fishes in the Western Mediterranean: Morphological and molecular characterisations.

    PubMed

    Pérez-i-García, David; Constenla, María; Carrassón, Maite; Montero, Francisco E; Soler-Membrives, Anna; González-Solís, David

    2015-10-01

    A new nematode species, Raphidascaris (Raphidascaris) macrouri n. sp. (Anisakidae), is described from male and female specimens found in the intestine, and occasionally in stomach and pyloric caeca, of two deep-water macrourid fishes (Gadiformes) off Barcelona, Mediterranean Sea: Nezumia aequalis (Günther) (type-host) and Trachyrincus scabrus (Rafinesque). Based on light and scanning electron microscopy examination, the new species shows similar morphological features as the other four valid species of the subgenus Raphidascaris Railliet & Henry, 1915, but it differs from Raphidascaris (Raphidascaris) acus (Bloch, 1779), Raphidascaris (Raphidascaris) lutjani Olsen, 1952 and Raphidascaris (Raphidascaris) mediterraneus Lèbre & Petter, 1983 in the high number of precloacal papillae (23-32) and from Raphidascaris (Raphidascaris) gigi Fujita, 1928 in the length of the spicules. Moreover, Raphidascaris (Raphidascaris) macrouri n. sp. exhibits a high variability on the number and distribution of caudal papillae, which was not recorded in the other four mentioned species. This is the first species of this subgenus reported from the family Macrouridae. Sequences of ITS1-5.8S-ITS2 region are analysed and compared with closely related nematode species. Molecular analysis confirmed the uniformity of the R. (R.) macrouri n. sp. between hosts.

  16. Genetic structure and history of populations of the deep-sea fish Helicolenus dactylopterus (Delaroche, 1809) inferred from mtDNA sequence analysis.

    PubMed

    Aboim, M A; Menezes, G M; Schlitt, T; Rogers, A D

    2005-04-01

    Helicolenus dactylopterus is an Atlantic benthopelagic fish species inhabiting high-energy habitats on continental slopes, seamounts and islands. Partial sequences of the mitochondrial control region (D-loop) and cytochrome b (cyt b) were used to test the hypothesis that H. dactylopterus disperses between continental margin, island and seamount habitats on intraregional, regional and oceanic scales in the North Atlantic. Individuals were collected from five different geographical areas: Azores, Madeira, Portugal (Peniche), Cape Verde and the northwest Atlantic. D-loop (415 bp) and cyt b (423 bp) regions were partially sequenced for 208 and 212 individuals, respectively. Analysis of variation among mitochondrial DNA sequences based on pairwise F-statistics and AMOVA demonstrated marked genetic differentiation between populations in different geographical regions specifically the Mid-Atlantic Ridge (Azores)/northeast Atlantic (Portugal, Madeira) compared to populations around the Cape Verde Islands and in the northwest Atlantic. Some evidence of intraregional genetic differentiation between populations was found. Minimum-spanning network analysis revealed star-shaped patterns suggesting that populations had undergone expansion following bottlenecks and/or they have been colonized by jump dispersal events across large geographical distances along pathways of major ocean currents. Mismatch distribution analysis indicated that Azores and northwest Atlantic populations fitted a model of historical population expansion following a bottleneck/founder event estimated to be between 0.64 and 1.2 million years ago (Ma).

  17. Distribution, population biology, and trophic ecology of the deepwater demersal fish Halosauropsis macrochir (Pisces: Halosauridae) on the mid-Atlantic Ridge.

    PubMed

    Bergstad, Odd Aksel; Clark, Laura; Hansen, Hege Øverbø; Cousins, Nicola

    2012-01-01

    Halosauropsis macrochir ranked amongst the most abundant and widespread demersal fishes on the mid-Atlantic Ridge of the North Atlantic (Iceland-Azores) with greatest abundance at 1700-3500 m. All sizes, ranging from 10-76 cm total length, occurred in the area without any apparent spatial pattern or depth trend. Using otolith sections displaying growth increments assumed to represent annuli, the age range recorded was 2-36 years, but most individuals were <20 years. Length and weight at age data were used to fit growth models. No differences between sexes in length and weight at age were observed. The majority of samples had a surplus of males. Diet analysis showed that H. macrochir feeds on Crustacea, Teleostei, Polychaeta, and Cephalopoda, but few prey could be identified to lower taxonomical levels. The mid-Atlantic Ridge constitutes a major portion of the North Atlantic living space of the abyssal halosaur where it completes its full life cycle, primarily as an actively foraging euryophagous micronekton/epibenthos and infauna feeder, becoming a partial piscivore with increasing size. PMID:22384030

  18. Temperature impacts on deep-sea biodiversity.

    PubMed

    Yasuhara, Moriaki; Danovaro, Roberto

    2016-05-01

    Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes. PMID:25523624

  19. Temperature Impacts on Deep-Sea Biodiversity

    NASA Astrophysics Data System (ADS)

    Yasuhara, M.; Danovaro, R.

    2015-12-01

    Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes.

  20. Temperature impacts on deep-sea biodiversity.

    PubMed

    Yasuhara, Moriaki; Danovaro, Roberto

    2016-05-01

    Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes.

  1. [Dysbaric accident in deep sea fishing].

    PubMed

    López Oblaré, B; Campos Pascual, F

    1995-05-20

    The case of a dysbaric accident with occurred in a professional athlete during a national competition is herein reported. The clinical symptoms and response to treatment in a depressurization chamber in addition to CT controls should alert physicians in coastal areas in which this sport is carried out in order to take into consideration neurologic disorders which may be due to dysbaric accidents such as those which occur in scuba divers.

  2. Methane-oxidizing Archaea Fix Nitrogen in Cooperation with Sulfate-reducing Bacteria in Deep-Sea Methane Seeps

    NASA Astrophysics Data System (ADS)

    Orphan, V. J.; Dekas, A. E.; Poretsky, R.; Amend, J.

    2010-04-01

    Using 15N2 incubation experiments of deep-sea sediments combined with FISH-nanoSIMS, we show that uncultured syntrophic consortia of ANME-2 and sulfate-reducing bacteria are capable of nitrogen fixation.

  3. Metallothionein, oxidative stress and trace metals in gills and liver of demersal and pelagic fish species from Kuwaits' marine area.

    PubMed

    Beg, M U; Al-Jandal, N; Al-Subiai, S; Karam, Q; Husain, S; Butt, S A; Ali, A; Al-Hasan, E; Al-Dufaileej, S; Al-Husaini, M

    2015-11-30

    Two fish species yellowfin seabream (Acanthopagrus latus) and tonguesole (Cynoglossus arel) were collected from two locations in Kuwait's territorial waters in non-reproductive periods and used as bio-indicator organism for the assessment of metals in the marine environment. Species variation in fish was observed; seabream contained high metal content and metallothionein in liver and gill tissues compared to tonguesole, especially from Kuwait Bay area. Oxidative injury was registered in the gills of both species, but in tonguesole liver was also involved. Consequently, antioxidant enzyme catalase was elevated in tonguesole enabling bottom dwelling fish to combat oxidative assault. The study provided information about the current status of metals in marine sediment and levels of metals accumulated in representative species along with oxidative damage in exposed tissues and the range of biomarker protein metallothionein and enzymes of antioxidant defence mechanism enhancing our understanding about the biological response to the existing marine environment in Kuwait.

  4. Deep-sea macroplankton distribution (at 400 to 2300 m) in the northwestern Mediterranean in relation to environmental factors

    NASA Astrophysics Data System (ADS)

    Cartes, J. E.; Fanelli, E.; López-Pérez, C.; Lebrato, M.

    2013-03-01

    Changes in the composition and biomass distribution of deep-living zooplankton over wide gradients of depth (400-2300 m) and longitude (~ 180 km) have been analyzed in the Balearic Basin (western Mediterranean), seeking the environmental variables responsible for these changes. Zooplankton tends to aggregate at different levels of the water column (forming Deep Scattering Layers, DSL) and in the Benthic Boundary Layer (BBL). Macrozooplankton biomass and composition were analyzed along a transect performed in July 2010 in midwater (between ~ 350 and 450 m) and near the bottom (at ~ 5-200 mab), over soundings of 450-2263 m, including the top of Valencia Seamount (at ~ 40° 25' N-02° 42' E, 1076 m). Zooplankton changed significantly in composition at the mesoscale (~ 180 km) in both the DSL and the BBL. Siphonophores and calanoid copepods were the most dominant deep zooplankton taxa, calanoids reaching higher abundance in the BBL (1761-5177 individuals/1000 m3) than in the DSL (1568-1743 individuals/1000 m3). There was a significant increase in near-bottom zooplankton biomass over the middle slope, at 1000-1300 m, linked to an increase in scyphozoans and siphonophores (Lensia spp. and Abylopsis tetragona) with peaks of 1.5-2.0 gWW/1000 m3. The peak of near-bottom zooplankton at 1000-1300 m coincided with the lowest temperatures (13.08 °C) and maximum O2 concentration (4.40 ml/l) near the bottom and below 1000 m with higher records in near-bottom turbidity. Gelatinous zooplankton are the main prey in the diet of the demersal fish Alepocephalus rostratus in the western Mediterranean, fish responsible for the peak of megafauna biomass reported at around 1200-1400 m in the deep Mediterranean and at similar depths in other oceanic areas (e.g. the NW Atlantic). We suggest that deep-sea environmental conditions can govern peaks of near-bottom zooplankton, as well as influence the structure of the demersal fish community.

  5. Correlations between benthic habitats and demersal fish assemblages — A case study on the Dogger Bank (North Sea)

    NASA Astrophysics Data System (ADS)

    Sell, Anne F.; Kröncke, Ingrid

    2013-07-01

    The interdependence between groundfish assemblages and habitat properties was investigated on the Dogger Bank in the North Sea. Abiotic habitat parameters considered included topography, hydrographic conditions, sediment composition, and the biotic habitat variable the prevailing benthic invertebrates. Distinct epi- and infauna communities occurred at different locations on the Dogger Bank. Fish assemblages were clearly linked to both the biotic and abiotic habitat characteristics. Overall, fish and benthic communities revealed similar spatial distribution, represented in the respective clusters of characteristic and abundant species. Distribution patterns corresponded with the prevailing abiotic conditions such as depth and sediment composition, which appear to relate to autecological preferences of individual species. The apparently most generalist species, grey gurnard (Eutrigla gurnardus) and dab (Limanda limanda) occurred at all stations and dominated in terms of biomass in most cases. The absolute numbers of grey gurnards were related to the abundance of suitable prey, invertebrate and fish species, which stomach analyses revealed as part of the diet in an independent study during the same research cruise. Haddock (Melanogrammus aeglefinus) and whiting (Merlangius merlangus) were only abundant at deep stations along the flanks of the bank. The occurrence of lemon sole (Microstomus kitt), American plaice (Hippoglossoides platessoides) and cod (Gadus morhua) was also positively correlated with depth, whereas especially lesser weever (Echiichthys vipera), sandeel species and solenette (Buglossidium luteum) occurred predominantly at the shallower sites. At the same time, individual fish species such as solenette and lesser weever were associated with high densities of selected epi- or infauna species.

  6. Multi Year Observations Reveal Variability in Residence of a Tropical Demersal Fish, Lethrinus nebulosus: Implications for Spatial Management

    PubMed Central

    Pillans, Richard D.; Bearham, Douglas; Boomer, Andrew; Downie, Ryan; Patterson, Toby A.; Thomson, Damian P.; Babcock, Russel C.

    2014-01-01

    Off the Ningaloo coast of North West Western Australia, Spangled Emperor Lethrinus nebulosus are among the most highly targeted recreational fish species. The Ningaloo Reef Marine Park comprises an area of 4,566 km2 of which 34% is protected from fishing by 18 no-take sanctuary zones ranging in size from 0.08–44.8 km2. To better understand Spangled Emperor movements and the adequacy of sanctuary zones within the Ningaloo Reef Marine Park for this species, 84 Spangled Emperor of a broad spectrum of maturity and sex were tagged using internal acoustic tags in a range of lagoon and reef slope habitats both inside and adjacent to the Mangrove Bay Sanctuary zone. Kernel Utilisation Distribution (KUD) was calculated for 39 resident individuals that were detected for more than 30 days. There was no relationship with fish size and movement or site fidelity. Average home range (95% KUD) for residents was 8.5±0.5 km2 compared to average sanctuary zone size of 30 km2. Calculated home range was stable over time resulting in resident animals tagged inside the sanctuary zone spending ∼80% of time within the sanctuary boundaries. The number of fish remaining within the array of receivers declined steadily over time and after one year more than 60% of tagged fish had moved outside the sanctuary zone and also beyond the 28 km2 array of receivers. Long term monitoring identified the importance of shifting home range and was essential for understanding overall residency within protected areas and also for identifying spawning related movements. This study indicates that despite exhibiting stable and small home ranges over periods of one to two years, more than half the population of spangled emperor move at scales greater than average sanctuary size within the Ningaloo Reef Marine Park. PMID:25181537

  7. In Brief: Deep-sea observatory

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2008-11-01

    The first deep-sea ocean observatory offshore of the continental United States has begun operating in the waters off central California. The remotely operated Monterey Accelerated Research System (MARS) will allow scientists to monitor the deep sea continuously. Among the first devices to be hooked up to the observatory are instruments to monitor earthquakes, videotape deep-sea animals, and study the effects of acidification on seafloor animals. ``Some day we may look back at the first packets of data streaming in from the MARS observatory as the equivalent of those first words spoken by Alexander Graham Bell: `Watson, come here, I need you!','' commented Marcia McNutt, president and CEO of the Monterey Bay Aquarium Research Institute, which coordinated construction of the observatory. For more information, see http://www.mbari.org/news/news_releases/2008/mars-live/mars-live.html.

  8. Measurement of light scattering in deep sea

    NASA Astrophysics Data System (ADS)

    Maragos, N.; Balasi, K.; Domvoglou, T.; Kiskiras, I.; Lenis, D.; Maniatis, M.; Stavropoulos, G.

    2016-04-01

    The deep-sea neutrino telescope in the Mediterranean Sea, being prepared by the KM3NET collaboration, will contain thousands of optical sensors to readout. The accurate knowledge of the optical properties of deep-sea water is of great importance for the neutrino event reconstruction process. In this study we describe our progress in designing an experimental setup and studying a method to measure the parameters describing the absorption and scattering characteristics of deep-sea water. Three PMTs will be used to measure in situ the scattered light emitted from six laser diodes in three different wavelengths covering the Cherenkov radiation spectrum. The technique for the evaluation of the parameters is based on Monte Carlo simulations and our results show that we are able to determine these parameters with satisfying precision.

  9. The study of deep-sea cephalopods.

    PubMed

    Hoving, Henk-Jan T; Perez, Jose Angel A; Bolstad, Kathrin S R; Braid, Heather E; Evans, Aaron B; Fuchs, Dirk; Judkins, Heather; Kelly, Jesse T; Marian, José E A R; Nakajima, Ryuta; Piatkowski, Uwe; Reid, Amanda; Vecchione, Michael; Xavier, José C C

    2014-01-01

    "Deep-sea" cephalopods are here defined as cephalopods that spend a significant part of their life cycles outside the euphotic zone. In this chapter, the state of knowledge in several aspects of deep-sea cephalopod research are summarized, including information sources for these animals, diversity and general biogeography and life cycles, including reproduction. Recommendations are made for addressing some of the remaining knowledge deficiencies using a variety of traditional and more recently developed methods. The types of oceanic gear that are suitable for collecting cephalopod specimens and images are reviewed. Many groups of deep-sea cephalopods require taxonomic reviews, ideally based on both morphological and molecular characters. Museum collections play a vital role in these revisions, and novel (molecular) techniques may facilitate new use of old museum specimens. Fundamental life-cycle parameters remain unknown for many species; techniques developed for neritic species that could potentially be applied to deep-sea cephalopods are discussed. Reproductive tactics and strategies in deep-sea cephalopods are very diverse and call for comparative evolutionary and experimental studies, but even in the twenty-first century, mature individuals are still unknown for many species. New insights into diet and trophic position have begun to reveal a more diverse range of feeding strategies than the typically voracious predatory lifestyle known for many cephalopods. Regular standardized deep-sea cephalopod surveys are necessary to provide insight into temporal changes in oceanic cephalopod populations and to forecast, verify and monitor the impacts of global marine changes and human impacts on these populations.

  10. Experimental investigation of deep sea riser interaction

    SciTech Connect

    Huse, E.

    1996-12-31

    In future deep sea field developments the drag force and corresponding static deflections of the risers due to current can become quite large. The prevention of mechanical contact (collision) between the risers will need more careful evaluation than in moderate water depths. The paper describes a series of model experiments in a Norwegian fjord to determine criteria for on-set of collisions between the risers of a deep sea TLP. The current was modeled using the natural tidal current in the fjord. Results from the tests are summarized and used for verification of numerical calculations of collision criteria.

  11. Reviews and syntheses: the first records of deep-sea fauna - a correction and discussion

    NASA Astrophysics Data System (ADS)

    Etter, W.; Hess, H.

    2015-11-01

    The soundings in deep waters of Baffin Bay, together with the recovery of a basket star by John Ross in 1818, was a milestone in the history of deep-sea research. Although the alleged water depths of up to 1950 m were by far not reached, these were nevertheless the first soundings in deep bathyal (to perhaps uppermost abyssal) depths. Furthermore, the recovery of a benthic animal proved that animal life existed at great depths. Yet this was not the first published record of deep-sea fauna as it is often portrayed. This merit goes to accidental catches of the stalked crinoid Cenocrinus asterius that were recovered with fishing lines from upper bathyal environments near Antillean islands. In addition, the description of several deep-sea fishes considerably predated the John Ross episode.

  12. Acoustical Detection of High-Density Krill Demersal Layers in the Submarine Canyons off Georges Bank.

    PubMed

    Greene, C H; Wiebe, P H; Burczynski, J; Youngbluth, M J

    1988-07-15

    High-density demersal layers of krill have been detected in the submarine canyons off Georges Bank by means of a high-frequency, dual-beam bioacoustical technique. Krill densities in these demersal layers were observed to be two to three orders of magnitude greater than the highest densities observed in water-column scattering layers. Such abundances may help explain the unusually high squid and demersal fish production estimates attributed to the Georges Bank ecosystem. PMID:17734865

  13. Acoustical Detection of High-Density Krill Demersal Layers in the Submarine Canyons off Georges Bank.

    PubMed

    Greene, C H; Wiebe, P H; Burczynski, J; Youngbluth, M J

    1988-07-15

    High-density demersal layers of krill have been detected in the submarine canyons off Georges Bank by means of a high-frequency, dual-beam bioacoustical technique. Krill densities in these demersal layers were observed to be two to three orders of magnitude greater than the highest densities observed in water-column scattering layers. Such abundances may help explain the unusually high squid and demersal fish production estimates attributed to the Georges Bank ecosystem.

  14. Autonomous, Retrievable, Deep Sea Microbial Fuel Cell

    NASA Astrophysics Data System (ADS)

    Richter, K.

    2014-12-01

    Microbial fuel cells (MFCs) work by providing bacteria in anaerobic sediments with an electron acceptor (anode) that stimulates metabolism of organic matter. The buried anode is connected via control circuitry to a cathode exposed to oxygen in the overlying water. During metabolism, bacteria release hydrogen ions into the sediment and transfer electrons extra-cellularly to the anode, which eventually reduce dissolved oxygen at the cathode, forming water. The open circuit voltage is approximately 0.8 v. The voltage between electrodes is operationally kept at 0.4 v with a potentiastat. The current is chiefly limited by the rate of microbial metabolism at the anode. The Office of Naval Research has encouraged development of microbial fuel cells in the marine environment at a number of academic and naval institutions. Earlier work in shallow sediments of San Diego Bay showed that the most important environmental parameters that control fuel cell power output in San Diego Bay were total organic carbon in the sediment and seasonal water temperature. Current MFC work at SPAWAR includes extension of microbial fuel cell tests to the deep sea environment (>1000 m) and, in parallel, testing microbial fuel cells in the laboratory under deep sea conditions. One question we are asking is whether MFC power output from deep water sediments repressurized and chilled in the laboratory comparable to those measured in situ. If yes, mapping the power potential of deep sea sediments may be made much easier, requiring sediment grabs and lab tests rather than deployment and retrieval of fuel cells. Another question we are asking is whether in situ temperature and total organic carbon in the deep sea sediment can predict MFC power. If yes, then we can make use of the large collection of publicly available, deep sea oceanographic measurements to make these predictions, foregoing expensive work at sea. These regressions will be compared to those derived from shallow water measurements.

  15. Mass extinctions in the deep sea

    NASA Technical Reports Server (NTRS)

    Thomas, E.

    1988-01-01

    The character of mass extinctions can be assessed by studying extinction patterns of organisms, the fabric of the extinction, and assessing the environmental niche and mode of life of survivors. Deep-sea benthic foraminifera have been listed as little affected by the Cretaceous-Tertiary (K-T) mass extinction, but very few quantitative data are available. New data on deep-sea Late Maestrichtian-Eocene benthic foraminifera from Maud Rise (Antractica) indicate that about 10 percent of the species living at depths of 2000 to 2500 m had last appearances within 1 my of the Cretaceous-Tertiary (K-T) boundary, versus about 25 percent of species at 1000 to 1500 m. Many survivors from the Cretaceous became extinct in a period of global deep-sea benthic foraminiferal extinction at the end of the Paleocene, a time otherwise marked by very few extinctions. Preliminary conclusions suggest that the deep oceanic environment is essentially decoupled from the shallow marine and terrestrial environment, and that even major disturbances of one of these will not greatly affect the other. This gives deep-sea benthic faunas a good opportunity to recolonize shallow environments from greater depths and vice versa after massive extinctions. The decoupling means that data on deep-sea benthic boundary was caused by the environmental effects of asteriod impact or excessive volcanism. The benthic foraminiferal data strongly suggest, however, that the environmental results were strongest at the Earth's surface, and that there was no major disturbance of the deep ocean; this pattern might result both from excessive volcanism and from an impact on land.

  16. Ecosystem function and services provided by the deep sea

    NASA Astrophysics Data System (ADS)

    Thurber, A. R.; Sweetman, A. K.; Narayanaswamy, B. E.; Jones, D. O. B.; Ingels, J.; Hansman, R. L.

    2013-11-01

    The deep sea is often viewed as a vast, dark, remote, and inhospitable environment, yet the deep ocean and seafloor are crucial to our lives through the services and provisions that they provide. Our understanding of how the deep sea functions remains limited, but when treated synoptically, a diversity of provisioning, regulating and cultural services become apparent. The biological pump transports carbon from the atmosphere into deep-ocean water masses which are separated over prolonged periods, reducing the impact of anthropogenic carbon release. Microbial oxidation of methane keeps another potent greenhouse gas out of the atmosphere while trapping carbon in authigenic carbonates. Nutrient regeneration by all faunal size classes provides the elements necessary to fuel surface productivity and fisheries, and microbial processes detoxify a diversity of compounds. Each of these processes occur on a very small scale, yet considering the vast area over which they occur they become important for the global functioning of the ocean. The deep sea also provides a diversity of resources, including fish stocks, enormous bioprospecting potential, and elements and energy reserves that are currently being extracted and will be increasingly important in the near future. Society benefits from the intrigue and mystery, the strange life forms, and the great unknown which has acted as a muse for inspiration and imagination since near the beginning of civilization. While many functions occur on the scale of microns to meters and time scales up to years, the derived services that result are only useful after centuries of integrated activity. This vast dark habitat, that covers the majority of the globe, harbors processes that directly impact humans in a diversity of ways, however the same traits that differentiate it from terrestrial or shallow marine systems also result in a greater need for integrated spatial and temporal understanding as it experiences increased use by society.

  17. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea.

    PubMed

    De Leo, Fabio C; Smith, Craig R; Rowden, Ashley A; Bowden, David A; Clark, Malcolm R

    2010-09-22

    Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42 degrees 01' S, 173 degrees 03' E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study. PMID:20444722

  18. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea.

    PubMed

    De Leo, Fabio C; Smith, Craig R; Rowden, Ashley A; Bowden, David A; Clark, Malcolm R

    2010-09-22

    Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42 degrees 01' S, 173 degrees 03' E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study.

  19. Deep sea tides determination from GEOS-3

    NASA Technical Reports Server (NTRS)

    Maul, G. A.; Yanaway, A.

    1978-01-01

    GEOS 3 altimeter data in a 5 degree X 5 degree square centered at 30 deg N, 70 deg W were analyzed to evaluate deep sea tide determination from a spacecraft. The signal to noise ratio of known tidal variability to altimeter measurement of sea level above the ellipsoid was 0.1. A sample was obtained in a 5 deg x 5 deg area approximately once every four days. The randomly spaced time series was analyzed using two independent least squares techniques.

  20. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei

    PubMed Central

    Nakamura, Itsumi; Meyer, Carl G.; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200–300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200–300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats. PMID:26061525

  1. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei.

    PubMed

    Nakamura, Itsumi; Meyer, Carl G; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200-300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200-300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats.

  2. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei.

    PubMed

    Nakamura, Itsumi; Meyer, Carl G; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200-300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200-300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats. PMID:26061525

  3. Predicted Deep-Sea Coral Habitat Suitability for the U.S. West Coast

    PubMed Central

    Guinotte, John M.; Davies, Andrew J.

    2014-01-01

    Regional scale habitat suitability models provide finer scale resolution and more focused predictions of where organisms may occur. Previous modelling approaches have focused primarily on local and/or global scales, while regional scale models have been relatively few. In this study, regional scale predictive habitat models are presented for deep-sea corals for the U.S. West Coast (California, Oregon and Washington). Model results are intended to aid in future research or mapping efforts and to assess potential coral habitat suitability both within and outside existing bottom trawl closures (i.e. Essential Fish Habitat (EFH)) and identify suitable habitat within U.S. National Marine Sanctuaries (NMS). Deep-sea coral habitat suitability was modelled at 500 m×500 m spatial resolution using a range of physical, chemical and environmental variables known or thought to influence the distribution of deep-sea corals. Using a spatial partitioning cross-validation approach, maximum entropy models identified slope, temperature, salinity and depth as important predictors for most deep-sea coral taxa. Large areas of highly suitable deep-sea coral habitat were predicted both within and outside of existing bottom trawl closures and NMS boundaries. Predicted habitat suitability over regional scales are not currently able to identify coral areas with pin point accuracy and probably overpredict actual coral distribution due to model limitations and unincorporated variables (i.e. data on distribution of hard substrate) that are known to limit their distribution. Predicted habitat results should be used in conjunction with multibeam bathymetry, geological mapping and other tools to guide future research efforts to areas with the highest probability of harboring deep-sea corals. Field validation of predicted habitat is needed to quantify model accuracy, particularly in areas that have not been sampled. PMID:24759613

  4. Bathymetric gradients of fecundity and egg size in fishes: A Mediterranean case study

    NASA Astrophysics Data System (ADS)

    Fernandez-Arcaya, Ulla; Drazen, Jeffrey C.; Murua, Hilario; Ramirez-Llodra, Eva; Bahamon, Nixon; Recasens, Laura; Rotllant, Guiomar; Company, Joan B.

    2016-10-01

    There is a general hypothesis that species inhabiting deep-sea waters have lower fecundity and larger eggs than shallower species. However, there are few comparative studies which explore this trend because of the complexity of sampling in deep waters, especially in fishes. We present here the first analysis of fecundity and egg size with depth along an isothermal environment. We calculate the relative fecundity and egg size of 11 species of demersal deep-sea fish from the western Mediterranean and included in our analyses published data for an additional 14 species from the same geographic area. The results show that the relative fecundity (eggs per g of individual) of the analyzed fishes slightly decreased along the bathymetric gradient, whereas egg size increased with depth. When the analysis was conducted including only species from the order Gadiformes, the most speciose group in the region and with the widest depth range of distribution (50-2000 m), there was no relationship between relative fecundity and depth, while the deepest species had larger egg sizes than shallower ones. The finding of similar relative fecundities but larger egg sizes suggests that these deep-sea species are investing a higher amount of energy in the production of offspring than shallower water counterparts. The results are discussed in relation to the isothermal characteristics of the deep Mediterranean Sea and ecological adaptations for reproductive success.

  5. Mesoscale eddies transport deep-sea sediments

    PubMed Central

    Zhang, Yanwei; Liu, Zhifei; Zhao, Yulong; Wang, Wenguang; Li, Jianru; Xu, Jingping

    2014-01-01

    Mesoscale eddies, which contribute to long-distance water mass transport and biogeochemical budget in the upper ocean, have recently been taken into assessment of the deep-sea hydrodynamic variability. However, how such eddies influence sediment movement in the deepwater environment has not been explored. Here for the first time we observed deep-sea sediment transport processes driven by mesoscale eddies in the northern South China Sea via a full-water column mooring system located at 2100 m water depth. Two southwestward propagating, deep-reaching anticyclonic eddies passed by the study site during January to March 2012 and November 2012 to January 2013, respectively. Our multiple moored instruments recorded simultaneous or lagging enhancement of suspended sediment concentration with full-water column velocity and temperature anomalies. We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies. The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons. Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process. PMID:25089558

  6. Mesoscale eddies transport deep-sea sediments.

    PubMed

    Zhang, Yanwei; Liu, Zhifei; Zhao, Yulong; Wang, Wenguang; Li, Jianru; Xu, Jingping

    2014-01-01

    Mesoscale eddies, which contribute to long-distance water mass transport and biogeochemical budget in the upper ocean, have recently been taken into assessment of the deep-sea hydrodynamic variability. However, how such eddies influence sediment movement in the deepwater environment has not been explored. Here for the first time we observed deep-sea sediment transport processes driven by mesoscale eddies in the northern South China Sea via a full-water column mooring system located at 2100 m water depth. Two southwestward propagating, deep-reaching anticyclonic eddies passed by the study site during January to March 2012 and November 2012 to January 2013, respectively. Our multiple moored instruments recorded simultaneous or lagging enhancement of suspended sediment concentration with full-water column velocity and temperature anomalies. We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies. The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons. Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process.

  7. Fish parasites in the bathyal zone: The halosaur Halosauropsis macrochir (Günther, 1878) from the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Klimpel, S.; Palm, H. W.; Busch, M. W.; Kellermanns, E.

    2008-01-01

    A total of 42 Halosauropsis macrochir from a single position on the Mid-Atlantic Ridge (MAR) were collected for studies on parasites and feeding ecology. A total of 9 different parasite species were found, with most of them belonging to the Digenea (4 species) and Nematoda (3). The host specific Degeneria halosauri, (Digenea) and Cystidicolidae indet. (Nematoda) were the predominant species, reaching a prevalence of 100.0% and 57.1% with intensities of infection of 1-12 and 1-10, respectively. Less host specific parasites such as Gonocerca phycidis (Digenea) and Tetraphyllidea indet. (Cestoda) occurred at low rates of infection. The parasite fauna of this bathyal fish can be described as predominantly adult and host specific, with larval and less host specific components. A total of 16 different food groups were identified, most of them of benthic origin or associated with the benthopelagial. The predominant prey organisms belonged to the Crustacea (e.g., Copepoda, Gammaridea, Amphipoda and Isopoda), which serve as main parasite vectors for H. macrochir. This deep-sea fish seems to follow a general pattern of fish parasites in the deep sea, with most isolated parasites belonging to the digeneans, nematodes and a cestode. The parasite composition is caused by the narrow depth range of the species and the restricted distribution of the fish family Halosauridae. The species richness was found to be lower than other demersal fish from the deep sea and shallow waters, however, higher than those from deep-sea fish living in the pelagial.

  8. Platinum group nuggets in deep sea sediments

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.; Bates, B. A.; Wheelock, M. M.

    1984-01-01

    The existence of iron meteor oblation spheres in deep sea sediments was known for over a century. These spheres generally were believed to be composed of either pure magnetite and wustite or an oxide shell surrounding a NiFe metal core. A large number of 300 micron to 600 micron spheres found were pure oxide spheres, usually containing a solitary 10 micron platinum group nugget (pgn) composed almost entirely of group VIII metals. Twelve PGN's were analyzed and most had chondritic abundances with some depletions that correlate with element volatility. PGN formation by oxidation of a molten metal sphere entering the atmosphere cannot occur if the oxygen abundance in the atmosphere is less than half of its present value. The first appearance of PGN's in the geological record should mark when, in the Earth's history, oxygen rose to this level.

  9. Total nitrogen content of deep sea basalts

    NASA Technical Reports Server (NTRS)

    Norris, T. L.; Schaeffer, O. A.

    1982-01-01

    An estimate of the total nitrogen content of the earth's mantle, aimed at furnishing a further constraint for earth atmosphere origin and evolution models, was attempted through thermal neutron activation analysis via N-14(n,p)C-14 for the case of deep sea basalt glasses from the East Pacific Rise, the Mid-Atlantic Rift, and the Juan de Fuca Ridge. The increased nitrogen abundance of matrix material from the same samples as the glasses may be due to the incorporation of chemically-bound nitrogen from sea water, rather than dissolved molecular nitrogen. A discussion is presented of factors affecting observed basalt nitrogen content and its interpretation in terms of mantle nitrogen abundance. A 2 ppm N lower limit is estimated for the mantle.

  10. Adapting to the Deep Sea: A Fun Activity with Bioluminescence

    ERIC Educational Resources Information Center

    Rife, Gwynne

    2006-01-01

    Over the past decade, much has been learned about the ocean's secrets and especially about the creatures of the deep sea. The deepest parts of the oceans are currently the focus of many new discoveries in both the physical and biological sciences. Middle school students find the deep sea fascinating and especially seem to enjoy its mysterious and…

  11. Demersal Fisheries of the Arabian Sea, the Gulf of Oman and the Arabian Gulf

    NASA Astrophysics Data System (ADS)

    Siddeek, M. S. M.; Fouda, M. M.; Hermosa, G. V.

    1999-08-01

    The demersal fisheries of the Arabian Sea, the Gulf of Oman and the Arabian Gulf are reviewed. The region comprises eight countries: Oman, United Arab Emirates (U.A.E.), Qatar, Saudi Arabia, Bahrain, Kuwait, Iraq and Iran. Over 350 commercial fish species, eight shrimp species, two spiny lobster species, one shovel nose lobster species, one cuttlefish species, one crab species, and one abalone species support the demersal fisheries in the continental shelves of the three regions. Artisanal and industrial vessels with over 120 000 fishermen were involved in demersal fisheries. Fishing boats include fish and shrimp trawlers (wooden and steel hulled), large wooden boats (dhow) with inboard engines, small dhows with outboard engines, and fibreglass boats. Fishing gear consists of trawls, bottom gill nets, traps (wire mesh and plastic types), barrier traps, hand lines, and bare hands and knives (to dislodge abalone). Demersal fish (primarily Lethrinidae, Sparidae, Serranidae, Siganidae, Sciaenidae, Stromateidae, Lutjanidae, Trichiuridae, and Nemipteridae) and shrimp (primarily Penaeus semisulcatus, Metapenaeus affinis, Parapenaeopsis stylifera, and Penaeus merguiensis) were the two commercial demersal resources. Approximately 198 000-214 000 tonnes (t) of demersals were landed annually during 1988-1993, accounting for nearly 40% of the total marine landings (475 000-552 000 t). This percentage, however varied among countries: 25% in Oman, 32% in U.A.E., 71% in Qatar, 52% in Saudi Arabia, 56% in Bahrain, 55% in Kuwait, close to 100% in Iraq, and 41% in Iran. Fishing effort on certain stocks may have been below the optimum level (e.g. certain Omani demersal fish), near the optimum level (e.g. Omani shrimp), or above the optimum level (e.g. Arabian Gulf shrimp and demersal fish). Overexploitation led to restriction of fishing effort by limiting fishing licences, regulating fishing gear (mesh size) and capture size, closing fishing areas, restricting fishing season, and

  12. Bathymetric limits of chondrichthyans in the deep sea: A re-evaluation

    NASA Astrophysics Data System (ADS)

    Musick, J. A.; Cotton, C. F.

    2015-05-01

    Chondrichthyans are largely absent in abyssal (>3000 m) habitats in most regions of the world ocean and are uncommon below 2000 m. The deeper-living chondrichthyans include certain rajids, squaliforms and holocephalans. Several hypotheses have been erected to explain the absence of chondrichthyans from the abyss. These are mostly based on energetics: deep-sea food webs are impoverished due to their distance from primary production, and chondrichthyans, occupying the highest trophic levels, cannot be supported due to entropy among trophic levels. We examined this hypothesis by comparing trophic levels, calculated from dietary data, of deep-sea chondrichthyans with those of deep-sea teleosts. Chondrichthyans were mostly above trophic level 4, whereas all the teleosts examined were below that level. Both small and medium squaloids, as well as sharks and skates of large size, feed on fishes, cephalopods and scavenged prey, and thus occupy the highest trophic levels in bathydemersal fish communities. In addition, whereas teleosts and chondrichthyans both store lipids in their livers to support long periods of fasting, chondrichthyans must devote much of their liver lipids to maintain neutral buoyancy. Consequently teleosts with swim bladders are better adapted to survive in the abyss where food sources are sparse and unpredictable. The potential prey field for both chondrichthyans and teleosts declines in biomass and diversity with depth, but teleosts have more flexibility in their feeding mechanisms and food habits, and occupy abyssal trophic guilds for which chondrichthyans are ill adapted.

  13. Oxygen isotopes in deep sea spherules

    NASA Technical Reports Server (NTRS)

    Mayeda, T. K.; Clayton, R. N.; Brownlee, D. E.

    1984-01-01

    The determination of the genetic relationships between the dust and small particles in the solar system, and the meteorites and larger bodies are examined. Oxygen isotopes proved useful in the identification of such relationships between one meteorite group and another. Of the various samples of submillimeter extraterrestrial particles available for laboratory study, only the deep sea spherules are abundant enough for precise oxygen isotope analysis using existing techniques. Complications arise in interpretation of the isotopic data, since these particles were melted during passage through the Earth's atmosphere, and have been in contact with seawater for prolonged periods. Spherules that were originally silicates are considered with the originally metallic ones to deduce their preterrestrial isotopic compositions. The type 1 spherules which enter the atmosphere as metallic particles, contain only atmospheric oxygen. The type S spherules contain a mixture of atmospheric oxygen and their original extraterrestrial oxygen. It is suggested that the Earth's mesosphere is strongly enriched in heavy isotopes of oxygen at altitudes near 90 km at which the iron particles are oxidized. Fractionation due to the combined diffusion of O atoms and O2 molecules may be responsible.

  14. Deep-Sea Submarine 'Ben Franklin'

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The deep-sea submarine 'Ben Franklin' is being docked in the harbor. Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life. It also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effect of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  15. Deep-Sea Research Submarine 'Ben Franklin'

    NASA Technical Reports Server (NTRS)

    1969-01-01

    This is an aerial view of the deep-sea research submarine 'Ben Franklin' at dock. Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life, and also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effects of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  16. Geomicrobiology of Deep-Sea Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Jannasch, Holger W.; Mottl, Michael J.

    1985-08-01

    During the cycling of seawater through the earth's crust along the midocean ridge system, geothermal energy is transferred into chemical energy in the form of reduced inorganic compounds. These compounds are derived from the reaction of seawater with crustal rocks at high temperatures and are emitted from warm (<= 25 degrees C) and hot (~ 350 degrees C) submarine vents at depths of 2000 to 3000 meters. Chemolithotrophic bacteria use these reduced chemical species as sources of energy for the reduction of carbon dioxide (assimilation) to organic carbon. These bacteria form the base of the food chain, which permits copious populations of certain specifically adapted invertebrates to grow in the immediate vicinity of the vents. Such highly prolific, although narrowly localized, deep-sea communities are thus maintained primarily by terrestrial rather than by solar energy. Reduced sulfur compounds appear to represent the major electron donors for aerobic microbial metabolism, but methane-, hydrogen-, iron-, and manganese-oxidizing bacteria have also been found. Methanogenic, sulfur-respiring, and extremely thermophilic isolates carry out anaerobic chemosynthesis. Bacteria grow most abundantly in the shallow crust where upwelling hot, reducing hydrothermal fluid mixes with downwelling cold, oxygenated seawater. The predominant production of biomass, however, is the result of symbiotic associations between chemolithotrophic bacteria and certain invertebrates, which have also been found as fossils in Cretaceous sulfide ores of ophiolite deposits.

  17. Geomicrobiology of deep-sea hydrothermal vents.

    PubMed

    Jannasch, H W; Mottl, M J

    1985-08-23

    During the cycling of seawater through the earth's crust along the mid-ocean ridge system, geothermal energy is transferred into chemical energy in the form of reduced inorganic compounds. These compounds are derived from the reaction of seawater with crustal rocks at high temperatures and are emitted from warm (deep-sea communities are thus maintained primarily by terrestrial rather than by solar energy. Reduced sulfur compounds appear to represent the major electron donors for aerobic microbial metabolism, but methane-, hydrogen-, iron-, and manganese-oxidizing bacteria have also been found. Methanogenic, sulfur-respiring, and extremely thermophilic isolates carry out anaerobic chemosynthesis. Bacteria grow most abundantly in the shallow crust where upwelling hot, reducing hydrothermal fluid mixes with downwelling cold, oxygenated seawater. The predominant production of biomass, however, is the result of symbiotic associations between chemolithotrophic bacteria and certain invertebrates, which have also been found as fossils in Cretaceous sulfide ores of ophiolite deposits.

  18. Role of macroscopic particles in deep-sea oxygen consumption.

    PubMed

    Bochdansky, Alexander B; van Aken, Hendrik M; Herndl, Gerhard J

    2010-05-01

    Macroscopic particles (>500 mum), including marine snow, large migrating zooplankton, and their fast-sinking fecal pellets, represent primary vehicles of organic carbon flux from the surface to the deep sea. In contrast, freely suspended microscopic particles such as bacteria and protists do not sink, and they contribute the largest portion of metabolism in the upper ocean. In bathy- and abyssopelagic layers of the ocean (2,000-6,000 m), however, microscopic particles may not dominate oxygen consumption. In a section across the tropical Atlantic, we show that macroscopic particle peaks occurred frequently in the deep sea, whereas microscopic particles were barely detectable. In 10 of 17 deep-sea profiles (>2,000 m depth), macroscopic particle abundances were more strongly cross-correlated with oxygen deficits than microscopic particles, suggesting that biomass bound to large particles dominates overall deep-sea metabolism.

  19. The MEUST deep sea infrastructure in the Toulon site

    NASA Astrophysics Data System (ADS)

    Lamare, Patrick

    2016-04-01

    The MEUST infrastructure (Mediterranean Eurocentre for Underwater Sciences and Technologies) is a permanent deep sea cabled infrastructure currently being deployed off shore of Toulon, France. The design and the status of the infrastructure are presented.

  20. Deep-sea pennatulaceans (sea pens) - recent discoveries, morphological adaptations, and responses to benthic oceanographic parameters

    NASA Astrophysics Data System (ADS)

    Williams, G. C.

    2015-12-01

    Pennatulaceans are sessile, benthic marine organisms that are bathymetrically wide-ranging, from the intertidal to approximately 6300 m in depth, and are conspicuous constituents of deep-sea environments. The vast majority of species are adapted for anchoring in soft sediments by the cylindrical peduncle - a muscular hydrostatic skeleton. However, in the past decade a few species ("Rockpens") have been discovered and described that can attach to hard substratum such as exposed rocky outcrops at depths between 669 and 1969 m, by a plunger-like adaptation of the base of the peduncle. Of the thirty-six known genera, eleven (or 30%) have been recorded from depths greater than 1000 m. The pennatulacean depth record holders are an unidentified species of Umbellula from 6260 m in the Peru-Chile Trench and a recently-discovered and described genus and species, Porcupinella profunda, from 5300 m the Porcupine Abyssal Plain of the northeastern Atlantic. A morphologically-differentiated type of polyp (acrozooid) have recently been discovered and described in two genera of shallow-water coral reef sea pens. Acrozooids apparently represent asexual buds and presumably can detach from the adult to start clonal colonies through asexual budding. Acrozooids are to be expected in deep-sea pennatulaceans, but so far have not been observed below 24 m in depth. Morphological responses at depths greater than 1000 m in deep-sea pennatulaceas include: fewer polyps, larger polyps, elongated stalks, and clustering of polyps along the rachis. Responses to deep-ocean physical parameters and anthropogenic changes that could affect the abundance and distribution of deep-sea pennatulaceans include changes in bottom current flow and food availability, changes in seawater temperature and pH, habitat destruction by fish trawling, and sunken refuse pollution. No evidence of the effects of ocean acidification or other effects of anthropogenic climate change in sea pens of the deep-sea has been

  1. Deep-Sea Hydrothermal-Vent Sampler

    NASA Technical Reports Server (NTRS)

    Behar, Alberto E.; Venkateswaran, Kasthur; Matthews, Jaret B.

    2008-01-01

    An apparatus is being developed for sampling water for signs of microbial life in an ocean hydrothermal vent at a depth of as much as 6.5 km. Heretofore, evidence of microbial life in deep-sea hydrothermal vents has been elusive and difficult to validate. Because of the extreme conditions in these environments (high pressures and temperatures often in excess of 300 C), deep-sea hydrothermal- vent samplers must be robust. Because of the presumed low density of biomass of these environments, samplers must be capable of collecting water samples of significant volume. It is also essential to prevent contamination of samples by microbes entrained from surrounding waters. Prior to the development of the present apparatus, no sampling device was capable of satisfying these requirements. The apparatus (see figure) includes an intake equipped with a temperature probe, plus several other temperature probes located away from the intake. The readings from the temperature probes are utilized in conjunction with readings from flowmeters to determine the position of the intake relative to the hydrothermal plume and, thereby, to position the intake to sample directly from the plume. Because it is necessary to collect large samples of water in order to obtain sufficient microbial biomass but it is not practical to retain all the water from the samples, four filter arrays are used to concentrate the microbial biomass (which is assumed to consist of particles larger than 0.2 m) into smaller volumes. The apparatus can collect multiple samples per dive and is designed to process a total volume of 10 L of vent fluid, of which most passes through the filters, leaving a total possibly-microbe-containing sample volume of 200 mL remaining in filters. A rigid titanium nose at the intake is used for cooling the sample water before it enters a flexible inlet hose connected to a pump. As the water passes through the titanium nose, it must be cooled to a temperature that is above a mineral

  2. Challenging Oil Bioremediation at Deep-Sea Hydrostatic Pressure.

    PubMed

    Scoma, Alberto; Yakimov, Michail M; Boon, Nico

    2016-01-01

    The Deepwater Horizon accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (bio)technology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons within deep-sea environments remain unanswered, as well as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil bioassimilation are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled oil. The fate of solid alkanes (tar), hydrocarbon degradation rates and the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea despite being present at hydrocarbon seeps at the Gulf of Mexico have been largely overlooked. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation.

  3. Challenging Oil Bioremediation at Deep-Sea Hydrostatic Pressure

    PubMed Central

    Scoma, Alberto; Yakimov, Michail M.; Boon, Nico

    2016-01-01

    The Deepwater Horizon accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (bio)technology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons within deep-sea environments remain unanswered, as well as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil bioassimilation are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled oil. The fate of solid alkanes (tar), hydrocarbon degradation rates and the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea despite being present at hydrocarbon seeps at the Gulf of Mexico have been largely overlooked. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation. PMID:27536290

  4. Challenging Oil Bioremediation at Deep-Sea Hydrostatic Pressure.

    PubMed

    Scoma, Alberto; Yakimov, Michail M; Boon, Nico

    2016-01-01

    The Deepwater Horizon accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (bio)technology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons within deep-sea environments remain unanswered, as well as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil bioassimilation are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled oil. The fate of solid alkanes (tar), hydrocarbon degradation rates and the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea despite being present at hydrocarbon seeps at the Gulf of Mexico have been largely overlooked. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation. PMID:27536290

  5. Exposure to hydrocarbons 10 years after the Exxon Valdez oil spill: evidence from cytochrome P4501A expression and biliary FACs in nearshore demersal fishes.

    PubMed

    Jewett, Stephen C; Dean, Thomas A; Woodin, Bruce R; Hoberg, Max K; Stegeman, John J

    2002-01-01

    Three biomarkers of hydrocarbon exposure, CYP1A in liver vascular endothelium, liver ethoxyresorufin O-deethylase (EROD), and biliary fluorescent aromatic compounds (FACs), were examined in the nearshore fishes, masked greenling (Hexagrammos octogrammus) and crescent gunnel (Pholis laeta), collected in Prince William Sound, Alaska, 7-10 years after the Exxon Valdez oil spill (EVOS). All biomarkers were elevated in fish collected from sites originally oiled, in comparison to fish from unoiled sites. In 1998, endothelial CYP1A in masked greenling from sites that were heavily oiled in 1989 was significantly higher than in fish collected outside the spill trajectory. In 1999, fishes collected from sites adjacent to intertidal mussel beds containing lingering Exxon Valdez oil had elevated endothelial CYP1A and EROD, and high concentrations of biliary FACs. Fishes from sites near unoiled mussel beds, but within the original spill trajectory, also showed evidence of hydrocarbon exposure, although there were no correlations between sediment petroleum hydrocarbon and any of the biomarkers. Our data show that 10 years after the spill, nearshore fishes within the original spill zone were still exposed to residual EVOS hydrocarbons.

  6. Exposure to hydrocarbons 10 years after the Exxon Valdez oil spill: evidence from cytochrome P4501A expression and biliary FACs in nearshore demersal fishes.

    PubMed

    Jewett, Stephen C; Dean, Thomas A; Woodin, Bruce R; Hoberg, Max K; Stegeman, John J

    2002-01-01

    Three biomarkers of hydrocarbon exposure, CYP1A in liver vascular endothelium, liver ethoxyresorufin O-deethylase (EROD), and biliary fluorescent aromatic compounds (FACs), were examined in the nearshore fishes, masked greenling (Hexagrammos octogrammus) and crescent gunnel (Pholis laeta), collected in Prince William Sound, Alaska, 7-10 years after the Exxon Valdez oil spill (EVOS). All biomarkers were elevated in fish collected from sites originally oiled, in comparison to fish from unoiled sites. In 1998, endothelial CYP1A in masked greenling from sites that were heavily oiled in 1989 was significantly higher than in fish collected outside the spill trajectory. In 1999, fishes collected from sites adjacent to intertidal mussel beds containing lingering Exxon Valdez oil had elevated endothelial CYP1A and EROD, and high concentrations of biliary FACs. Fishes from sites near unoiled mussel beds, but within the original spill trajectory, also showed evidence of hydrocarbon exposure, although there were no correlations between sediment petroleum hydrocarbon and any of the biomarkers. Our data show that 10 years after the spill, nearshore fishes within the original spill zone were still exposed to residual EVOS hydrocarbons. PMID:12148943

  7. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic deep-sea... 46 Shipping 7 2011-10-01 2011-10-01 false Deep-sea sounding apparatus. 167.40-20 Section...

  8. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic deep-sea... 46 Shipping 7 2010-10-01 2010-10-01 false Deep-sea sounding apparatus. 167.40-20 Section...

  9. Prokaryote diversity and viral production in deep-sea sediments and seamounts

    NASA Astrophysics Data System (ADS)

    Danovaro, Roberto; Corinaldesi, Cinzia; Luna, Gian Marco; Magagnini, Mirko; Manini, Elena; Pusceddu, Antonio

    2009-05-01

    Despite the fact that marine prokaryotes and viruses have been increasingly investigated over the last decade, knowledge on prokaryote diversity and viral production in bathyal sediments is limited. We investigated microbial variables in the deep-sea sediments around two seamounts at 3000-m depth in the Tyrrhenian Sea and sediments located at the same depth, but not affected by the presence of the seamounts. We hypothesized that seamounts altered significantly prokaryotes-viruses interactions in surrounding deep-sea sediments. Sediments surrounding seamounts were characterised by prokaryotic abundances significantly higher than those observed in non-seamount sediments. Benthic viral production was about double in sediments close to seamounts than in non-seamount sediments, where virus turnover was up to 3 times lower. Total Bacteria, as assessed by CARD-FISH, dominated prokaryotic community structure, whereas Archaea accounted on average for approximately 10%. The fraction of Crenarchaeota was always higher than Euryarchaeota. Bacterial diversity, estimated using ARISA, was high, with up to 127 different microbial operational taxonomic units (OTUs) in a single sample. Archaeal richness (determined using T-RFLP of the 16S rRNA gene) ranged from 12 to 20 OTUs, while Archaeal evenness was comprised between 0.529±0.018 and 0.623±0.08. Results represent a pointer for future investigations dealing with the interactions between viruses and prokaryotes in deep-sea sediments.

  10. Activity and growth of microbial populations in pressurized deep-sea sediment and animal gut samples.

    PubMed

    Tabor, P S; Deming, J W; Ohwada, K; Colwell, R R

    1982-08-01

    Benthic animals and sediment samples were collected at deep-sea stations in the northwest (3,600-m depth) and southeast (4,300- and 5200-m depths) Atlantic Ocean. Utilization rates of [14C]glutamate (0.67 to 0.74 nmol) in sediment suspensions incubated at in situ temperatures and pressures (3 to 5 degrees C and 360, 430, or 520 atmospheres) were relatively slow, ranging from 0.09 to 0.39 nmol g-1 day-1, whereas rates for pressurized samples of gut suspensions varied widely, ranging from no detectable activity to a rapid rate of 986 nmol g-1 day-1. Gut flora from a holothurian specimen and a fish demonstrated rapid, barophilic substrate utilization, based on relative rates calculated for pressurized samples and samples held at 1 atm (101.325 kPa). Substrate utilization by microbial populations in several sediment samples was not inhibited by in situ pressure. Deep-sea pressures did not restrict growth, measured as doubling time, of culturable bacteria present in a northwest Atlantic sediment sample and in a gut suspension prepared from an abyssal scavenging amphipod. From the results of this study, it was concluded that microbial populations in benthic environments can demonstrate significant metabolic activity under deep-ocean conditions of temperature and pressure. Furthermore, rates of microbial activity in the guts of benthic macrofauna are potentially more rapid than in surrounding deep-sea sediments. PMID:6127054

  11. Evolutionary Process of Deep-Sea Bathymodiolus Mussels

    PubMed Central

    Miyazaki, Jun-Ichi; de Oliveira Martins, Leonardo; Fujita, Yuko; Matsumoto, Hiroto; Fujiwara, Yoshihiro

    2010-01-01

    Background Since the discovery of deep-sea chemosynthesis-based communities, much work has been done to clarify their organismal and environmental aspects. However, major topics remain to be resolved, including when and how organisms invade and adapt to deep-sea environments; whether strategies for invasion and adaptation are shared by different taxa or unique to each taxon; how organisms extend their distribution and diversity; and how they become isolated to speciate in continuous waters. Deep-sea mussels are one of the dominant organisms in chemosynthesis-based communities, thus investigations of their origin and evolution contribute to resolving questions about life in those communities. Methodology/Principal Finding We investigated worldwide phylogenetic relationships of deep-sea Bathymodiolus mussels and their mytilid relatives by analyzing nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4) genes. Phylogenetic analysis of the concatenated sequence data showed that mussels of the subfamily Bathymodiolinae from vents and seeps were divided into four groups, and that mussels of the subfamily Modiolinae from sunken wood and whale carcasses assumed the outgroup position and shallow-water modioline mussels were positioned more distantly to the bathymodioline mussels. We provisionally hypothesized the evolutionary history of Bathymodilolus mussels by estimating evolutionary time under a relaxed molecular clock model. Diversification of bathymodioline mussels was initiated in the early Miocene, and subsequently diversification of the groups occurred in the early to middle Miocene. Conclusions/Significance The phylogenetic relationships support the “Evolutionary stepping stone hypothesis,” in which mytilid ancestors exploited sunken wood and whale carcasses in their progressive adaptation to deep-sea environments. This hypothesis is also supported by the evolutionary transition of symbiosis in that

  12. INDEX SATAL Expedition 2010, a discovery of deep sea potentials

    NASA Astrophysics Data System (ADS)

    Wirasantosa, S.; Hammond, S. R.; Pandoe, W.; Holden, J. F.; Djamaluddin, R.; Permana, H.; Nganro, N.; Abidin, H.; Shank, T. M.; Priadi, B.; Fryer, P.; Makarim, S.; Sulistiyo, B.; Triarso, E.; Troa, R.; Iswinardi, I.; Potter, J.; Anantasena, Y.; Triyono, T.; Surachman, Y.

    2010-12-01

    A joint Indonesia - U.S. Expedition to Sangihe Talaud waters (INDEX SATAL) in the north area of the North Sulawesi Province has been conducted by the Okeanos Explorer of NOAA and the Baruna Jaya IV of Indonesia during July - August, 2010. The joint expedition was the first of its kind that covered multi aspects of science which aimed at discoveries of deep sea potential resources and processes in the sea of Sangihe Talaud. Considering the advantage of both ship capabilities, the Okeanos Explorer covered the area of larger depths of 2000 metres to 6000 metres, while the Baruna Jaya IV worked the area of less than 2000 metres. Using multibeam equipment, the Okeanos Explorer discovered deep sea features of seamounts and bathymetric pattern of the western Sangihe ridge, Talaud ridge and the northeastern part of the exploration area. Deep sea morphology and bathymetric features of the area show newly discovery of seamounts and other deep sea features. The largest seamount in the explored area, the Kawio Barat seamount, has been discovered as an active submarine volcano showing hydrothermal activities. CTD casts in selected locations indicated the occurence of hydrothermal activities, which were later confirmed by ROV (Remotely Operated Vehicles) equipped with high definition cameras. Chimneys and smokers in the Kawio Barat and their associated deep sea biotas were recorded. Variety of seabed rocks in the dive areas were also recorded. Baruna Jaya IV explored the Sangihe ridge with multibeam and supported by CTD casts and sampling devices. Bathymetric features of less than 2000 metres were recorded and various deep sea biotas were discovered and sampled. Discoveries by INDEX SATAL 2010 has provided an insight into deep sea resources, specific features, volcanic and hydrothermal processes and potentials for further identifications.

  13. Fungi and macroaggregation in deep-sea sediments.

    PubMed

    Damare, Samir; Raghukumar, Chandralata

    2008-07-01

    Whereas fungi in terrestrial soils have been well studied, little is known of them in deep-sea sediments. Recent studies have demonstrated the presence of fungal hyphae in such sediments but in low abundance. We present evidence in this study that one of the apparent reasons for the poor detection of fungi in deep-sea sediments is their cryptic presence in macroaggregates. Fungal biomass carbon from different core sections of deep-sea sediments from approximately 5000 m depth in the Central Indian Ocean was estimated based on direct microscopic detection of fungal mycelia. Treatment of sediment samples with ethylenediamine tetra-acetic acid (EDTA) enabled more frequent detection and significantly higher biomass than in samples without such treatment. Treatment with EDTA resulted in detecting various stages of breakdown of aggregates in the sediments, gradually revealing the presence of fungal hyphae within them. Experimental studies of a deep-sea, as well as three terrestrial isolates of fungi, showed that all could grow at 200 bar and 5 degrees C in a nutrient medium and in deep-sea sediment extract. Hyphae of fungi grown in sediment extract under the above conditions showed various stages of accretion of particles around them, leading to the formation of aggregates. Such aggregates showed the presence of humic material, carbohydrate, and proteins. We suggest that fungi in deep-sea sediments may be involved in humic aggregate formation by processes very similar to those in terrestrial sediments. The importance of such a process in carbon sequestration and food web in the deep sea needs to be examined.

  14. Deep-Sea Field Studies of the Biological Consequences of Direct Ocean CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Barry, J. P.; Seibel, B. A.; Lovera, C.

    2001-12-01

    infaunal worms and crustaceans were lower near CO2 pools after 5 weeks than control sites. In addition, the physiological condition (gut fullness and tissue density) of infaunal amphipods exposed to CO2 was poorer than in control groups. Additional studies of the response of sediment-dwelling meiofauna, the sediment microbial community, and mobile scavenger species (fishes, amphipods) to elevated CO2 exposure are underway. A wide variety of field and laboratory studies of a phylogenetically diverse suite of deep-sea species from benthic and midwater environments, coupled with careful estimation of the degree and areal extent of changes in seawater chemistry to be expected with any CO2 disposal scenario, is required before any realistic estimate of the impacts of sequestration on deep-sea ecosystems is possible.

  15. A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents

    USGS Publications Warehouse

    Reysenbach, A.-L.; Liu, Yajing; Banta, A.B.; Beveridge, T.J.; Kirshtein, J.D.; Schouten, S.; Tivey, M.K.; Von Damm, K. L.; Voytek, M.A.

    2006-01-01

    Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2). Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75??C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents. ?? 2006 Nature Publishing Group.

  16. ECONOMIC GEOLOGY: Lessons Learned from Deep-Sea Mining.

    PubMed

    Glasby, G P

    2000-07-28

    The first attempt to exploit deep-sea manganese nodules ended in failure as a result of the collapse of world metal prices, the onerous provisions imposed by the U. N. Conference on the Law of the Sea (UNCLOS), and the overoptimistic assumptions about the viability of nodule mining. Attention then focused on cobalt-rich manganese crusts from seamounts. Since the mid-1980s, a number of new players have committed themselves to long-term programs to establish the viability of mining deep-sea manganese nodules. These programs require heavy subsidy by host governments. Gold-rich submarine hydrothermal deposits located at convergent plate margins are now emerging as a more promising prospect for mining than deep-sea manganese deposits.

  17. Rapid scavenging of jellyfish carcasses reveals the importance of gelatinous material to deep-sea food webs

    PubMed Central

    Sweetman, Andrew K.; Smith, Craig R.; Dale, Trine; Jones, Daniel O. B.

    2014-01-01

    Jellyfish blooms are common in many oceans, and anthropogenic changes appear to have increased their magnitude in some regions. Although mass falls of jellyfish carcasses have been observed recently at the deep seafloor, the dense necrophage aggregations and rapid consumption rates typical for vertebrate carrion have not been documented. This has led to a paradigm of limited energy transfer to higher trophic levels at jelly falls relative to vertebrate organic falls. We show from baited camera deployments in the Norwegian deep sea that dense aggregations of deep-sea scavengers (more than 1000 animals at peak densities) can rapidly form at jellyfish baits and consume entire jellyfish carcasses in 2.5 h. We also show that scavenging rates on jellyfish are not significantly different from fish carrion of similar mass, and reveal that scavenging communities typical for the NE Atlantic bathyal zone, including the Atlantic hagfish, galatheid crabs, decapod shrimp and lyssianasid amphipods, consume both types of carcasses. These rapid jellyfish carrion consumption rates suggest that the contribution of gelatinous material to organic fluxes may be seriously underestimated in some regions, because jelly falls may disappear much more rapidly than previously thought. Our results also demonstrate that the energy contained in gelatinous carrion can be efficiently incorporated into large numbers of deep-sea scavengers and food webs, lessening the expected impacts (e.g. smothering of the seafloor) of enhanced jellyfish production on deep-sea ecosystems and pelagic–benthic coupling. PMID:25320167

  18. Orbital forcing of deep-sea benthic species diversity

    USGS Publications Warehouse

    Cronin, T. M.; Raymo, M.E.

    1997-01-01

    Explanations for the temporal and spatial patterns of species biodiversity focus on stability-time, disturbance-mosaic (biogenic microhabitat heterogeneity) and competition-predation (biotic interactions) hypotheses. The stability-time hypothesis holds that high species diversity in the deep sea and in the tropics reflects long-term climatic stability. But the influence of climate change on deep-sea diversity has not been studied and recent evidence suggests that deep-sea environments undergo changes in climatically driven temperature and flux of nutrients and organic-carbon during glacial-interglacial cycles. Here we show that Pliocene (2.85-2.40 Myr) deep-sea North Atlantic benthic ostracod (Crustacea) species diversity is related to solar insolation changes caused by 41,000-yr cycles of Earth's obliquity (tilt). Temporal changes in diversity, as measured by the Shannon- Weiner index, H(S), correlate with independent climate indicators of benthic foraminiferal oxygen-isotope ratios (mainly ice volume) and ostracod Mg:Ca ratios (bottomwater temperature). During glacial periods, H(S) = 0.2-0.6, whereas during interglacials, H(S) = 1.2-1.6, which is three to four times as high. The control of deep-sea benthic diversity by cyclic climate change at timescales of 103-104 yr does not support the stability-time hypothesis because it shows that the deep sea is a temporally dynamic environment. Diversity oscillations reflect large-scale response of the benthic community to climatically driven changes in either thermohaline circulation, bottom temperature (or temperature-related factors) and food, and a coupling of benthic diversity to surface productivity.

  19. Graphoglyptid burrows in modern deep-sea sediment.

    PubMed

    Ekdale, A A

    1980-01-18

    The complex, highly patterned, invertebrate burrow systems known as "graphoglyptids" in ancient sedimentary rocks have now been recovered in box cores of modern deep-sea sediment. Spiroraphe, Cosmoraphe, and Paleodictyon occur as grooves in the tops of washed cores, and they apparently were produced and maintained as horizontal tunnel systems just a few millimeters below the sediment surface. These burrows, which are important as indicators of deepwater sedimentary environments in ancient strata, have been predicted in the modern deep sea but have not been found there until now.

  20. Population connectivity of deep-sea corals: Chapter 12

    USGS Publications Warehouse

    Morrison, Cheryl L.; Baco, Amy; Nizinski, Martha S.; Coykendall, Dolly K.; Demopoulos, Amanda W. J.; Cho, Walter; Shank, Tim

    2015-01-01

    Identifying the scale of dispersal among habitats has been a challenge in marine ecology for decades (Grantham et al., 2003; Kinlan & Gaines, 2003; Hixon, 2011). Unlike terrestrial habitats in which barriers to dispersal may be obvious (e.g. mountain ranges, rivers), few absolute barriers to dispersal are recognizable in the sea. Additionally, most marine species have complex life cycles in which juveniles are more mobile than adults. As such, the dynamics of populations may involve processes in distant habitats that are coupled by a transport mechanism. Studies of population connectivity try to quantify the transport, or dispersal of individuals, among geographically separated populations. For benthic marine species, such as corals and demersal fishes, colonization of new populations occurs primarily by dispersal of larvae (Figure 1; Shank, 2010). Successful dispersal and recruitment, followed by maturation and reproduction of these new migrants ensures individuals contribute to the gene pool (Hedgecock, 2007). Thus, successful dispersal links and cohesively maintains spatially separated sub-populations. At shorter time scales (10-100s years), connectivity regulates community structure by influencing the genetic composition, diversity and demographic stability of the population, whereas at longer time scales (1000s years), geographic distributions are affected (McClain and Hardy, 2010). Alternatively, populations may become extinct or speciation may occur if connectivity ceases (Cowen et al., 2007). Therefore, the genetic exchange of individuals between populations is fundamental to the short-term resilience and long-term maintenance of the species. However, for the vast majority of marine species, population connectivity remains poorly understood.

  1. Review of Deep-Sea Ecology and Monitoring as They Relate to Deep-Sea Oil and Gas Operations

    SciTech Connect

    Kropp, Roy K.

    2004-01-30

    This review summarizes available information concerning deep-sea benthic ecology and how that information might be used to monitor and eventually reduce the potential impacts resulting from oil and gas production activities. The paper provides a brief overview of deep-sea ecology and benthic faunal groups and summarizes some of the physical and biological features that may be important in evaluating potential impacts. In addition, presented is a synopsis of issues related to the design of a sampling program and a discussion of analytical considerations related to the uncertain knowledge of deep faunas. Also included is an overview of some of the variety of sampling techniques and equipment available to study the deep sea. The review concludes with management considerations and recommendations.

  2. Light and vision in the deep-sea benthos: II. Vision in deep-sea crustaceans.

    PubMed

    Frank, Tamara M; Johnsen, Sönke; Cronin, Thomas W

    2012-10-01

    Using new collecting techniques with the Johnson-Sea-Link submersible, eight species of deep-sea benthic crustaceans were collected with intact visual systems. Their spectral sensitivities and temporal resolutions were determined shipboard using electroretinography. Useable spectral sensitivity data were obtained from seven species, and in the dark-adapted eyes, the spectral sensitivity peaks were in the blue region of the visible spectrum, ranging from 470 to 497 nm. Under blue chromatic adaptation, a secondary sensitivity peak in the UV portion of the spectrum appeared for two species of anomuran crabs: Eumunida picta (λ(max)363 nm) and Gastroptychus spinifer (λ(max)383 nm). Wavelength-specific differences in response waveforms under blue chromatic adaptation in these two species suggest that two populations of photoreceptor cells are present. Temporal resolution was determined in all eight species using the maximum critical flicker frequency (CFF(max)). The CFF(max) for the isopod Booralana tricarinata of 4 Hz proved to be the lowest ever measured using this technique, and suggests that this species is not able to track even slow-moving prey. Both the putative dual visual pigment system in the crabs and the extremely slow eye of the isopod may be adaptations for seeing bioluminescence in the benthic environment.

  3. Light and vision in the deep-sea benthos: II. Vision in deep-sea crustaceans.

    PubMed

    Frank, Tamara M; Johnsen, Sönke; Cronin, Thomas W

    2012-10-01

    Using new collecting techniques with the Johnson-Sea-Link submersible, eight species of deep-sea benthic crustaceans were collected with intact visual systems. Their spectral sensitivities and temporal resolutions were determined shipboard using electroretinography. Useable spectral sensitivity data were obtained from seven species, and in the dark-adapted eyes, the spectral sensitivity peaks were in the blue region of the visible spectrum, ranging from 470 to 497 nm. Under blue chromatic adaptation, a secondary sensitivity peak in the UV portion of the spectrum appeared for two species of anomuran crabs: Eumunida picta (λ(max)363 nm) and Gastroptychus spinifer (λ(max)383 nm). Wavelength-specific differences in response waveforms under blue chromatic adaptation in these two species suggest that two populations of photoreceptor cells are present. Temporal resolution was determined in all eight species using the maximum critical flicker frequency (CFF(max)). The CFF(max) for the isopod Booralana tricarinata of 4 Hz proved to be the lowest ever measured using this technique, and suggests that this species is not able to track even slow-moving prey. Both the putative dual visual pigment system in the crabs and the extremely slow eye of the isopod may be adaptations for seeing bioluminescence in the benthic environment. PMID:22956247

  4. An early footprint of fisheries: Changes for a demersal fish assemblage in the German Bight from 1902-1932 to 1991-2009

    NASA Astrophysics Data System (ADS)

    Fock, Heino O.; Kloppmann, Matthias H. F.; Probst, Wolfgang N.

    2014-01-01

    Groundfish survey data from the German Bight from 1902-08, 1919-23, and 1930-1932 and ICES International Bottom Trawl Survey (IBTS) quarter 3 data from 1991 to 2009 were analysed with respect to species frequencies, maximum length, trends in catch-per-unit-effort, species richness parameters (SNR) and presence of large fish (Φ40), the latter defined as average presence of species per haul with specimens larger than 40 cm given. Four different periods are distinguished: (a) before 1914 with medium commercial CPUE and low landings, Φ40 ≈ 2, high abundance in elasmobranchs and SNR conditions indicating highly diverse assemblages, (b) conditions immediately after 1918 with higher commercial CPUE, recovering landings, Φ40 at > 4 in 1919, and SNR conditions indicating highly diverse assemblages, (c) conditions from 1920 to the early 1930's with decreasing commercial CPUE, increased landings, decreasing Φ40, SNR conditions similar to later years indicating less diverse assemblages, and a decrease in elasmobranchs. In the IBTS series (d), Φ40 remains low indicating an increased rarity of large specimens, and SNR characteristics are similar to the third period. Dab, whiting and grey gurnard have increased considerably in the IBTS series as compared to the historic data. Φ40 is suggested an alternative indicator reflecting community functional diversity when weight based indicators cannot be applied.

  5. Proximate composition, fatty acid and lipid class composition of the muscle from deep-sea teleosts and elasmobranchs.

    PubMed

    Økland, Hege M W; Stoknes, Iren S; Remme, Jannicke F; Kjerstad, Margareth; Synnes, Marianne

    2005-03-01

    Proximate composition of muscle was determined for the following deep-sea fish species: roughhead grenadier (Macrourus berglax), mora/deep-sea cod (Mora moro), Portuguese dogfish (Centroscymnus coelolepis), black dogfish (Centroscyllium fabricii), leafscale gulper shark (Centrophorus squamosus), greater lantern shark (Etmopterus princeps), smalleyed rabbitfish/ghostshark (Hydrolagus affinis), birdbeak dogfish (Deania calcea) and two species of smooth head (Alepocephalus bairdii and Alepocephalus agassizii). The first eight species contained less than 1% fat in the muscle, while the last two contained 3.0% and 3.6% fat, respectively. Fatty acid and lipid class composition was determined for the first five fish species and showed that the dominant class of lipids was phospholipids. The lipids consisted mainly of polyunsaturated fatty acids (PUFA), and docosahexaenoic acid (DHA) was the dominant fatty acid. Roughhead grenadier and mora showed resemblance to cod (Gadus morhua) regarding protein content, fat content and fatty acid composition. However, the muscle from the deep-sea fish species did contain a higher proportion of arachidonic acid (20:4n-6) than cod muscle.

  6. The deep sea is a major sink for microplastic debris.

    PubMed

    Woodall, Lucy C; Sanchez-Vidal, Anna; Canals, Miquel; Paterson, Gordon L J; Coppock, Rachel; Sleight, Victoria; Calafat, Antonio; Rogers, Alex D; Narayanaswamy, Bhavani E; Thompson, Richard C

    2014-12-01

    Marine debris, mostly consisting of plastic, is a global problem, negatively impacting wildlife, tourism and shipping. However, despite the durability of plastic, and the exponential increase in its production, monitoring data show limited evidence of concomitant increasing concentrations in marine habitats. There appears to be a considerable proportion of the manufactured plastic that is unaccounted for in surveys tracking the fate of environmental plastics. Even the discovery of widespread accumulation of microscopic fragments (microplastics) in oceanic gyres and shallow water sediments is unable to explain the missing fraction. Here, we show that deep-sea sediments are a likely sink for microplastics. Microplastic, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in contaminated sea-surface waters. Our results show evidence for a large and hitherto unknown repository of microplastics. The dominance of microfibres points to a previously underreported and unsampled plastic fraction. Given the vastness of the deep sea and the prevalence of microplastics at all sites we investigated, the deep-sea floor appears to provide an answer to the question-where is all the plastic? PMID:26064573

  7. Using near infrared light for deep sea mining observation systems

    NASA Astrophysics Data System (ADS)

    Lu, Huimin; Li, Yujie; Li, Xin; Yang, Jianmin; Serikawa, Seiichi

    2015-10-01

    In this paper, we design a novel deep-sea near infrared light based imaging equipment for deep-sea mining observation systems. The spectral sensitivity peaks are in the red region of the invisible spectrum, ranging from 750nm to 900nm. In addition, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. The proposed model fully considered the effects of absorption, scattering and refraction. We also develop a locally adaptive Laplacian filtering for enhancing underwater transmission map after underwater dark channel prior estimation. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. In water tank experiments, we made a linear scale of eight turbidity steps ranging from clean to heavily scattered by adding deep sea soil to the seawater (from 500 to 2000 mg/L). We compared the results of different turbidity underwater scene, illuminated alternately with near infrared light vs. white light. Experiments demonstrate that the enhanced NIR images have a reasonable noise level after the illumination compensation in the dark regions and demonstrates an improved global contrast by which the finest details and edges are significantly enhanced. We also demonstrate that the effective distance of the designed imaging system is about 1.5 meters, which can meet the requirement of micro-terrain observation around the deep-sea mining systems. Remotely Operated Underwater Vehicle (ROV)-based experiments also certified the effectiveness of the proposed method.

  8. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    PubMed

    Chown, Steven L

    2012-01-01

    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  9. Evolution: Ocean Models Reveal Life in Deep Seas.

    PubMed

    Eizaguirre, Christophe

    2016-09-26

    Even though the deep sea represents the largest area in the world, evolution of species from those environments remains largely unstudied. A series of recent papers indicate that combining molecular tools with biophysical models can help us resolve some of these deep mysteries.

  10. The deep sea is a major sink for microplastic debris.

    PubMed

    Woodall, Lucy C; Sanchez-Vidal, Anna; Canals, Miquel; Paterson, Gordon L J; Coppock, Rachel; Sleight, Victoria; Calafat, Antonio; Rogers, Alex D; Narayanaswamy, Bhavani E; Thompson, Richard C

    2014-12-01

    Marine debris, mostly consisting of plastic, is a global problem, negatively impacting wildlife, tourism and shipping. However, despite the durability of plastic, and the exponential increase in its production, monitoring data show limited evidence of concomitant increasing concentrations in marine habitats. There appears to be a considerable proportion of the manufactured plastic that is unaccounted for in surveys tracking the fate of environmental plastics. Even the discovery of widespread accumulation of microscopic fragments (microplastics) in oceanic gyres and shallow water sediments is unable to explain the missing fraction. Here, we show that deep-sea sediments are a likely sink for microplastics. Microplastic, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in contaminated sea-surface waters. Our results show evidence for a large and hitherto unknown repository of microplastics. The dominance of microfibres points to a previously underreported and unsampled plastic fraction. Given the vastness of the deep sea and the prevalence of microplastics at all sites we investigated, the deep-sea floor appears to provide an answer to the question-where is all the plastic?

  11. Evolution: Ocean Models Reveal Life in Deep Seas.

    PubMed

    Eizaguirre, Christophe

    2016-09-26

    Even though the deep sea represents the largest area in the world, evolution of species from those environments remains largely unstudied. A series of recent papers indicate that combining molecular tools with biophysical models can help us resolve some of these deep mysteries. PMID:27676306

  12. The deep sea is a major sink for microplastic debris

    PubMed Central

    Woodall, Lucy C.; Sanchez-Vidal, Anna; Canals, Miquel; Paterson, Gordon L.J.; Coppock, Rachel; Sleight, Victoria; Calafat, Antonio; Rogers, Alex D.; Narayanaswamy, Bhavani E.; Thompson, Richard C.

    2014-01-01

    Marine debris, mostly consisting of plastic, is a global problem, negatively impacting wildlife, tourism and shipping. However, despite the durability of plastic, and the exponential increase in its production, monitoring data show limited evidence of concomitant increasing concentrations in marine habitats. There appears to be a considerable proportion of the manufactured plastic that is unaccounted for in surveys tracking the fate of environmental plastics. Even the discovery of widespread accumulation of microscopic fragments (microplastics) in oceanic gyres and shallow water sediments is unable to explain the missing fraction. Here, we show that deep-sea sediments are a likely sink for microplastics. Microplastic, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in contaminated sea-surface waters. Our results show evidence for a large and hitherto unknown repository of microplastics. The dominance of microfibres points to a previously underreported and unsampled plastic fraction. Given the vastness of the deep sea and the prevalence of microplastics at all sites we investigated, the deep-sea floor appears to provide an answer to the question—where is all the plastic? PMID:26064573

  13. Potential biomass in deep-sea hydrothermal vent ecosystem

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Takai, K.

    2012-12-01

    Since the first discovery of black smoker vents hosting chemosynthetic macrofaunal communities (Spiess et al., 1980), submarine hydrothermal systems and associated biota have attracted interest of many researchers (e.g., Humphris et al., 1995; Van Dover, 2000; Wilcock et al., 2004). In the past couple of decades, particular attention has been paid to chemolithoautotrophic microorganisms that sustain the hydrothermal vent-endemic animal communities as the primary producer. This type of microorganisms obtains energy from inorganic substances (e.g., sulfur, hydrogen, and methane) derived from hydrothermal vent fluids, and is often considered as an important modern analogue to the early ecosystems of the Earth as well as the extraterrestrial life in other planets and moons (e.g., Jannasch and Mottl, 1985; Nealson et al., 2005; Takai et al., 2006). Even today, however, the size of this type of chemosynthetic deep-sea hydrothermal vent ecosystem is largely unknown. Here, we present geophysical and geochemical constraints on potential biomass in the deep-sea hydrothermal vent ecosystem. The estimation of the potential biomass in the deep-sea hydrothermal vent ecosystem is based on hydrothermal fluid flux calculated from heat flux (Elderfield and Schltz, 1996), maximum chemical energy available from metabolic reactions during mixing between hydrothermal vent fluids and seawater (McCollom, 2007), and maintenance energy requirements of the chemolithoautotrophic microorganisms (Hoehler, 2004). The result shows that the most of metabolic energy sustaining the deep-sea hydrothermal vent ecosystem is produced by oxidation reaction of reduced sulfur, although some parts of the energy are derived from hydrogenotrophic and methanotrophic reactions. The overall total of the potential biomass in deep-sea hydrothermal vent ecosystem is calculated to be much smaller than that in terrestrial ecosystems including terrestrial plants. The big difference in biomass between the

  14. Deep-sea diversity patterns are shaped by energy availability

    NASA Astrophysics Data System (ADS)

    Woolley, Skipton N. C.; Tittensor, Derek P.; Dunstan, Piers K.; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J.; Wintle, Brendan A.; Worm, Boris; O’Hara, Timothy D.

    2016-05-01

    The deep ocean is the largest and least-explored ecosystem on Earth, and a uniquely energy-poor environment. The distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. Here we analyse a database of more than 165,000 distribution records of Ophiuroidea (brittle stars), a dominant component of sea-floor fauna, and find patterns of biodiversity unlike known terrestrial or coastal marine realms. Both patterns and environmental predictors of deep-sea (2,000–6,500 m) species richness fundamentally differ from those found in coastal (0–20 m), continental shelf (20–200 m), and upper-slope (200–2,000 m) waters. Continental shelf to upper-slope richness consistently peaks in tropical Indo-west Pacific and Caribbean (0–30°) latitudes, and is well explained by variations in water temperature. In contrast, deep-sea species show maximum richness at higher latitudes (30–50°), concentrated in areas of high carbon export flux and regions close to continental margins. We reconcile this structuring of oceanic biodiversity using a species–energy framework, with kinetic energy predicting shallow-water richness, while chemical energy (export productivity) and proximity to slope habitats drive deep-sea diversity. Our findings provide a global baseline for conservation efforts across the sea floor, and demonstrate that deep-sea ecosystems show a biodiversity pattern consistent with ecological theory, despite being different from other planetary-scale habitats.

  15. Deep-sea diversity patterns are shaped by energy availability.

    PubMed

    Woolley, Skipton N C; Tittensor, Derek P; Dunstan, Piers K; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J; Wintle, Brendan A; Worm, Boris; O'Hara, Timothy D

    2016-05-11

    The deep ocean is the largest and least-explored ecosystem on Earth, and a uniquely energy-poor environment. The distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. Here we analyse a database of more than 165,000 distribution records of Ophiuroidea (brittle stars), a dominant component of sea-floor fauna, and find patterns of biodiversity unlike known terrestrial or coastal marine realms. Both patterns and environmental predictors of deep-sea (2,000-6,500 m) species richness fundamentally differ from those found in coastal (0-20 m), continental shelf (20-200 m), and upper-slope (200-2,000 m) waters. Continental shelf to upper-slope richness consistently peaks in tropical Indo-west Pacific and Caribbean (0-30°) latitudes, and is well explained by variations in water temperature. In contrast, deep-sea species show maximum richness at higher latitudes (30-50°), concentrated in areas of high carbon export flux and regions close to continental margins. We reconcile this structuring of oceanic biodiversity using a species-energy framework, with kinetic energy predicting shallow-water richness, while chemical energy (export productivity) and proximity to slope habitats drive deep-sea diversity. Our findings provide a global baseline for conservation efforts across the sea floor, and demonstrate that deep-sea ecosystems show a biodiversity pattern consistent with ecological theory, despite being different from other planetary-scale habitats.

  16. Deep-sea diversity patterns are shaped by energy availability.

    PubMed

    Woolley, Skipton N C; Tittensor, Derek P; Dunstan, Piers K; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J; Wintle, Brendan A; Worm, Boris; O'Hara, Timothy D

    2016-05-19

    The deep ocean is the largest and least-explored ecosystem on Earth, and a uniquely energy-poor environment. The distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. Here we analyse a database of more than 165,000 distribution records of Ophiuroidea (brittle stars), a dominant component of sea-floor fauna, and find patterns of biodiversity unlike known terrestrial or coastal marine realms. Both patterns and environmental predictors of deep-sea (2,000-6,500 m) species richness fundamentally differ from those found in coastal (0-20 m), continental shelf (20-200 m), and upper-slope (200-2,000 m) waters. Continental shelf to upper-slope richness consistently peaks in tropical Indo-west Pacific and Caribbean (0-30°) latitudes, and is well explained by variations in water temperature. In contrast, deep-sea species show maximum richness at higher latitudes (30-50°), concentrated in areas of high carbon export flux and regions close to continental margins. We reconcile this structuring of oceanic biodiversity using a species-energy framework, with kinetic energy predicting shallow-water richness, while chemical energy (export productivity) and proximity to slope habitats drive deep-sea diversity. Our findings provide a global baseline for conservation efforts across the sea floor, and demonstrate that deep-sea ecosystems show a biodiversity pattern consistent with ecological theory, despite being different from other planetary-scale habitats. PMID:27193685

  17. Deep-sea diversity patterns are shaped by energy availability

    NASA Astrophysics Data System (ADS)

    Woolley, Skipton N. C.; Tittensor, Derek P.; Dunstan, Piers K.; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J.; Wintle, Brendan A.; Worm, Boris; O'Hara, Timothy D.

    2016-05-01

    The deep ocean is the largest and least-explored ecosystem on Earth, and a uniquely energy-poor environment. The distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. Here we analyse a database of more than 165,000 distribution records of Ophiuroidea (brittle stars), a dominant component of sea-floor fauna, and find patterns of biodiversity unlike known terrestrial or coastal marine realms. Both patterns and environmental predictors of deep-sea (2,000-6,500 m) species richness fundamentally differ from those found in coastal (0-20 m), continental shelf (20-200 m), and upper-slope (200-2,000 m) waters. Continental shelf to upper-slope richness consistently peaks in tropical Indo-west Pacific and Caribbean (0-30°) latitudes, and is well explained by variations in water temperature. In contrast, deep-sea species show maximum richness at higher latitudes (30-50°), concentrated in areas of high carbon export flux and regions close to continental margins. We reconcile this structuring of oceanic biodiversity using a species-energy framework, with kinetic energy predicting shallow-water richness, while chemical energy (export productivity) and proximity to slope habitats drive deep-sea diversity. Our findings provide a global baseline for conservation efforts across the sea floor, and demonstrate that deep-sea ecosystems show a biodiversity pattern consistent with ecological theory, despite being different from other planetary-scale habitats.

  18. Chemical extraction of Nd isotopes from deep-sea sediments for Cenozoic and Cretaceous paleoceanographic studies

    NASA Astrophysics Data System (ADS)

    Martin, E. E.; Blair, S. W.; Kamenov, G. D.; Scher, H. D.; Bourbon, E.; Basak, C.; Newkirk, D.

    2009-12-01

    Nd isotopes preserved in deep sea sediments are now a common proxy for reconstructing past ocean circulation patterns. While studies on Holocene-Pleistocene time scales frequently use chemical extractions of Nd that target dispersed ferromanganese (Fe-Mn) coatings on the bulk sediment, studies on longer, Cenozoic time scales are generally limited to data from fossil fish teeth and Fe-Mn crusts due to concerns about diagenetic alteration of oxides over longer time scales and potential contamination of the extracted Nd. Fish teeth and Fe-Mn crusts are robust archives for Nd isotopes over these time scales; however, separation and preparation of the teeth is laborious, and not all deep sea samples contain sufficient teeth for analysis. In addition, Fe-Mn crusts accumulate very slowly, integrate the seawater isotopic signal over an extended period of time, and are difficult to date. This study evaluates the integrity of Nd isotopes that were chemically-extracted from Cenozoic to Cretaceous Ocean Drilling Program sediments by comparing these results to data from contemporaneous fish teeth. Nd was extracted from the > 63μm fraction of deep sea sediments following carbonate removal using a 2 hour leach in 0.02M hydroxylamine hydrochloride (HH) solution. All 94 paired samples of chemically-extracted and fossil fish tooth Nd produced isotopic values that agree within error. These samples include material from the Miocene to Eocene from sites in the north (Sites 647 and 982) and south Atlantic (Sites 689, 690 and 1090), as well as Cretaceous black shales from the tropical Atlantic (Sites 1258 and 1260). This detailed comparison illustrates that Nd extracted from bulk deep sea sediments, which is derived at least in part from dispersed Fe-Mn oxide coatings, represents a promising archive for Nd isotopes on longer time scales. This archive is widely available through time and space and the extraction procedure is relatively simple and rapid. The observed correlation between

  19. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  20. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  1. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  2. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  3. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Deep-sea sounding apparatus. 167.40-20 Section 167.40-20... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic...

  4. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Submarine and deep sea cable expense. 32.6424... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine and deep sea cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2424....

  5. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Deep-sea sounding apparatus. 167.40-20 Section 167.40-20... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic...

  6. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Deep-sea sounding apparatus. 167.40-20 Section 167.40-20... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic...

  7. New insights into mercury bioaccumulation in deep-sea organisms from the NW Mediterranean and their human health implications.

    PubMed

    Koenig, Samuel; Solé, Montserrat; Fernández-Gómez, Cristal; Díez, Sergi

    2013-01-01

    A number of studies have found high levels of mercury (Hg) in deep-sea organisms throughout the world's oceans, but the underlying causes are not clear as there is no consensus on the origin and cycling of Hg in the ocean. Recent findings suggested that Hg accumulation may increase with increasing forage depth and pointed to the deep-water column as the origin of most Hg in marine biota, especially its organic methylmercury (MeHg) form. In the present study, we determined the total mercury (THg) levels in 12 deep-sea fish species and a decapod crustacean and investigated their relationship with the species' nitrogen stable isotope ratio (δ(15)N) as an indicator of their trophic level, average weight and habitat depth. THg levels ranged from 0.27 to 4.42 μg/g w.w. and exceeded in all, except one species, the recommended 0.5 μg/g w.w. guideline value. While THg levels exhibited a strong relationship with δ(15)N values and to a lesser extent with weight, the habitat depth, characterized as the species' depth of maximum abundance (DMA), had also a significant effect on Hg accumulation. The fish species with a shallower depth range exhibited lower THg values than predicted by their trophic level (δ(15)N) and body mass, while measured THg values were higher than predicted in deeper-dwelling fish. Overall, the present results point out a potential risk for human health from the consumption of deep-sea fish. In particular, for both, the red shrimp Aristeus antennatus, which is one of the most valuable fishing resources of the Mediterranean, as well as the commercially exploited fish Mora moro, THg levels considerably exceeded the recommended 0.5μg/g w.w. limit and should be consumed with caution.

  8. Diazotrophy in the Deep: Measuring Rates and Identifying Biological Mediators of N2 fixation in Deep-Sea Sediments

    NASA Astrophysics Data System (ADS)

    Dekas, A. E.; Fike, D. A.; Chadwick, G.; Connon, S. A.; Orphan, V. J.

    2013-12-01

    Biological N2 fixation (the conversion of N2 to NH3) is the largest natural source of bioavailable nitrogen to the biosphere, and dictates the rate of community productivity in many nitrogen-limited environments. Deep-sea sediments are traditionally not thought to host N2 fixation, however evidence from a metagenomics dataset targeting deep-sea methanotrophic archaea (ANME) suggested their ability to fix N2 (Pernthaler, et al., PNAS 2008). Using stable isotope labeling experiments and FISH-NanoSIMS, a technique which allows the visualization of isotopic composition within phylogenetically identified cells on the nanometer scale, we demonstrated that the ANME are capable of N2 fixation (Dekas et al., Science 2009). In the present work, we use FISH-NanoSIMS and bulk Isotope Ratio Mass Spectrometry (IRMS) to show that the ANME are the most significant source of new nitrogen at a Costa Rican methane seep. This suggests that the ANME may play a significant role in N2 fixation in methane seeps worldwide. We expand our investigation of deep-sea diazotrophy to include diverse habitats, including sulfide- and carbon-rich whalefalls, and observe that N2 fixation is widespread in sediments on the seafloor. Outside of methane seeps, N2 fixation appears to be mediated by a diversity of anaerobic microbes potentially including methanogens and sulfate reducing bacteria. Interestingly, deep-sea N2 fixation often occurs in the presence of high levels of NH4+. Our observations challenge long-held hypotheses about where and when N2 fixation occurs, and suggest a bigger role for N2 fixation on the seafloor - and potentially the deep-biosphere - than previously realized.

  9. Chronic and intensive bottom trawling impairs deep-sea biodiversity and ecosystem functioning

    PubMed Central

    Pusceddu, Antonio; Bianchelli, Silvia; Martín, Jacobo; Puig, Pere; Palanques, Albert; Masqué, Pere; Danovaro, Roberto

    2014-01-01

    Bottom trawling has many impacts on marine ecosystems, including seafood stock impoverishment, benthos mortality, and sediment resuspension. Historical records of this fishing practice date back to the mid-1300s. Trawling became a widespread practice in the late 19th century, and it is now progressively expanding to greater depths, with the concerns about its sustainability that emerged during the first half of the 20th century now increasing. We show here that compared with untrawled areas, chronically trawled sediments along the continental slope of the north-western Mediterranean Sea are characterized by significant decreases in organic matter content (up to 52%), slower organic carbon turnover (ca. 37%), and reduced meiofauna abundance (80%), biodiversity (50%), and nematode species richness (25%). We estimate that the organic carbon removed daily by trawling in the region under scrutiny represents as much as 60–100% of the input flux. We anticipate that such an impact is causing the degradation of deep-sea sedimentary habitats and an infaunal depauperation. With deep-sea trawling currently conducted along most continental margins, we conclude that trawling represents a major threat to the deep seafloor ecosystem at the global scale. PMID:24843122

  10. Chronic and intensive bottom trawling impairs deep-sea biodiversity and ecosystem functioning.

    PubMed

    Pusceddu, Antonio; Bianchelli, Silvia; Martín, Jacobo; Puig, Pere; Palanques, Albert; Masqué, Pere; Danovaro, Roberto

    2014-06-17

    Bottom trawling has many impacts on marine ecosystems, including seafood stock impoverishment, benthos mortality, and sediment resuspension. Historical records of this fishing practice date back to the mid-1300s. Trawling became a widespread practice in the late 19th century, and it is now progressively expanding to greater depths, with the concerns about its sustainability that emerged during the first half of the 20th century now increasing. We show here that compared with untrawled areas, chronically trawled sediments along the continental slope of the north-western Mediterranean Sea are characterized by significant decreases in organic matter content (up to 52%), slower organic carbon turnover (ca. 37%), and reduced meiofauna abundance (80%), biodiversity (50%), and nematode species richness (25%). We estimate that the organic carbon removed daily by trawling in the region under scrutiny represents as much as 60-100% of the input flux. We anticipate that such an impact is causing the degradation of deep-sea sedimentary habitats and an infaunal depauperation. With deep-sea trawling currently conducted along most continental margins, we conclude that trawling represents a major threat to the deep seafloor ecosystem at the global scale.

  11. Movement of deep-sea coral populations on climatic timescales

    NASA Astrophysics Data System (ADS)

    Thiagarajan, Nivedita; Gerlach, Dana; Roberts, Mark L.; Burke, Andrea; McNichol, Ann; Jenkins, William J.; Subhas, Adam V.; Thresher, Ronald E.; Adkins, Jess F.

    2013-06-01

    During the past 40,000 years, global climate has moved into and out of a full glacial period, with the deglaciation marked by several millennial-scale rapid climate change events. Here we investigate the ecological response of deep-sea coral communities to both glaciation and these rapid climate change events. We find that the deep-sea coral populations of Desmophyllum dianthus in both the North Atlantic and the Tasmanian seamounts expand at times of rapid climate change. However, during the more stable Last Glacial Maximum, the coral population globally retreats to a more restricted depth range. Holocene populations show regional patterns that provide some insight into what causes these dramatic changes in population structure. The most important factors are likely responses to climatically driven changes in productivity, [O2] and [CO32-].

  12. Plastic microfibre ingestion by deep-sea organisms

    PubMed Central

    Taylor, M. L.; Gwinnett, C.; Robinson, L. F.; Woodall, L. C.

    2016-01-01

    Plastic waste is a distinctive indicator of the world-wide impact of anthropogenic activities. Both macro- and micro-plastics are found in the ocean, but as yet little is known about their ultimate fate and their impact on marine ecosystems. In this study we present the first evidence that microplastics are already becoming integrated into deep-water organisms. By examining organisms that live on the deep-sea floor we show that plastic microfibres are ingested and internalised by members of at least three major phyla with different feeding mechanisms. These results demonstrate that, despite its remote location, the deep sea and its fragile habitats are already being exposed to human waste to the extent that diverse organisms are ingesting microplastics. PMID:27687574

  13. Plastic microfibre ingestion by deep-sea organisms

    NASA Astrophysics Data System (ADS)

    Taylor, M. L.; Gwinnett, C.; Robinson, L. F.; Woodall, L. C.

    2016-09-01

    Plastic waste is a distinctive indicator of the world-wide impact of anthropogenic activities. Both macro- and micro-plastics are found in the ocean, but as yet little is known about their ultimate fate and their impact on marine ecosystems. In this study we present the first evidence that microplastics are already becoming integrated into deep-water organisms. By examining organisms that live on the deep-sea floor we show that plastic microfibres are ingested and internalised by members of at least three major phyla with different feeding mechanisms. These results demonstrate that, despite its remote location, the deep sea and its fragile habitats are already being exposed to human waste to the extent that diverse organisms are ingesting microplastics.

  14. Recent advances in deep-sea natural products.

    PubMed

    Skropeta, Danielle; Wei, Liangqian

    2014-08-01

    Covering: 2009 to 2013. This review covers the 188 novel marine natural products described since 2008, from deep-water (50->5000 m) marine fauna including bryozoa, chordata, cnidaria, echinodermata, microorganisms, mollusca and porifera. The structures of the new compounds and details of the source organism, depth of collection and country of origin are presented, along with any relevant biological activities of the metabolites. Where reported, synthetic studies on the deep-sea natural products have also been included. Most strikingly, 75% of the compounds were reported to possess bioactivity, with almost half exhibiting low micromolar cytotoxicity towards a range of human cancer cell lines, along with a significant increase in the number of microbial deep-sea natural products reported.

  15. Recent advances in deep-sea natural products.

    PubMed

    Skropeta, Danielle; Wei, Liangqian

    2014-08-01

    Covering: 2009 to 2013. This review covers the 188 novel marine natural products described since 2008, from deep-water (50->5000 m) marine fauna including bryozoa, chordata, cnidaria, echinodermata, microorganisms, mollusca and porifera. The structures of the new compounds and details of the source organism, depth of collection and country of origin are presented, along with any relevant biological activities of the metabolites. Where reported, synthetic studies on the deep-sea natural products have also been included. Most strikingly, 75% of the compounds were reported to possess bioactivity, with almost half exhibiting low micromolar cytotoxicity towards a range of human cancer cell lines, along with a significant increase in the number of microbial deep-sea natural products reported. PMID:24871201

  16. Controls on the distribution of deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Dutkiewicz, A.; O'Callaghan, S.; Müller, R. D.

    2016-08-01

    Deep-sea sediments represent the largest geological deposit on Earth and provide a record of our planet's response to conditions at the sea surface from where the bulk of material originates. We use a machine learning method to analyze how the distribution of 14,400 deep-sea sediment sample lithologies is connected to bathymetry and surface oceanographic parameters. Our probabilistic Gaussian process classifier shows that the geographic occurrence of five major lithologies in the world's ocean can be predicted using just three parameters. Sea-surface salinity and temperature provide a major control for the growth and composition of plankton and specific ranges are also associated with the influx of non-aerosol terrigenous material into the ocean, while bathymetry is an important parameter for discriminating the occurrence of calcareous sediment, clay and coarse lithogenous sediment from each other. We find that calcareous and siliceous oozes are not linked to high surface productivity. Diatom and radiolarian oozes are associated with low salinities at the surface but with discrete ranges of temperatures, reflecting the diversity of planktonic species in different climatic zones. Biosiliceous sediments cannot be used to infer paleodepth, but are good indicators of paleotemperature and paleosalinity. Our analysis provides a new framework for constraining paleosurface ocean environments from the geological record of deep-sea sediments. It shows that small shifts in salinity and temperature significantly affect the lithology of seafloor sediment. As deep-sea sediments represent the largest carbon sink on Earth these shifts need to be considered in the context of global ocean warming.

  17. Antarctic Marine Biodiversity and Deep-Sea Hydrothermal Vents

    PubMed Central

    Chown, Steven L.

    2012-01-01

    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining. PMID:22235192

  18. Life support maintenance for deep-sea diving

    SciTech Connect

    Nuckols, M.L.

    1987-01-01

    A treatise on life support maintenance in diving for the retrieval of radioactively contaminated, submerged materials should include discussions of gas supply requirements, carbon dioxide removal techniques, thermal protection, humidity control, and power sources. For the sake of brevity, this paper highlight only those areas peculiar to deep-sea diving and introduce a design aid being used in the development of new diving life support systems.

  19. Abrupt climate change and collapse of deep-sea ecosystems

    USGS Publications Warehouse

    Yasuhara, Moriaki; Cronin, T. M.; Demenocal, P.B.; Okahashi, H.; Linsley, B.K.

    2008-01-01

    We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern Atlantic. Results show that deep-sea benthic community "collapses" occur with faunal turnover of up to 50% during major climatically driven oceanographic changes. Species diversity as measured by the Shannon-Wiener index falls from 3 to as low as 1.6 during these events. Major disruptions in the benthic communities commenced with Heinrich Event 1, the Inter-Aller??d Cold Period (IACP: 13.1 ka), the Younger Dryas (YD: 12.9-11.5 ka), and several Holocene Bond events when changes in deep-water circulation occurred. The largest collapse is associated with the YD/IACP and is characterized by an abrupt two-step decrease in both the upper North Atlantic Deep Water assemblage and species diversity at 13.1 ka and at 12.2 ka. The ostracode fauna at this site did not fully recover until ???8 ka, with the establishment of Labrador Sea Water ventilation. Ecologically opportunistic slope species prospered during this community collapse. Other abrupt community collapses during the past 20 ka generally correspond to millennial climate events. These results indicate that deep-sea ecosystems are not immune to the effects of rapid climate changes occurring over centuries or less. ?? 2008 by The National Academy of Sciences of the USA.

  20. Species-energy relationships in deep-sea molluscs.

    PubMed

    Tittensor, Derek P; Rex, Michael A; Stuart, Carol T; McClain, Craig R; Smith, Craig R

    2011-10-23

    Consensus is growing among ecologists that energy and the factors influencing its utilization can play overarching roles in regulating large-scale patterns of biodiversity. The deep sea--the world's largest ecosystem--has simplified energetic inputs and thus provides an excellent opportunity to study how these processes structure spatial diversity patterns. Two factors influencing energy availability and use are chemical (productive) and thermal energy, here represented as seafloor particulate organic carbon (POC) flux and temperature. We related regional patterns of benthic molluscan diversity in the North Atlantic to these factors, to conduct an explicit test of species-energy relationships in the modern day fauna of the deep ocean. Spatial regression analyses in a model-averaging framework indicated that POC flux had a substantially higher relative importance than temperature for both gastropods and protobranch bivalves, although high correlations between variables prevented definitive interpretation. This contrasts with recent research on temporal variation in fossil diversity from deep-sea cores, where temperature is generally a more significant predictor. These differences may reflect the scales of time and space at which productivity and temperature operate, or differences in body size; but both lines of evidence implicate processes influencing energy utilization as major determinants of deep-sea species diversity.

  1. Deep-sea smokers: windows to a subsurface biosphere?

    PubMed

    Deming, J W; Baross, J A

    1993-07-01

    Since the discovery of hyperthermophilic microbial activity in hydrothermal fluids recovered from "smoker" vents on the East Pacific Rise, the widely accepted upper temperature limit for life (based on pure culture data) has risen from below the boiling point of water at atmospheric pressure to approximately 115 degrees C. Many microbiologists seem willing to speculate that the maximum may be closer to 150 degrees C. We have postulated not only higher temperatures than these (under deep-sea hydrostatic pressures), but also the existence of a biosphere subsurface to accessible seafloor vents. New geochemical information from the Endeavour Segment of the Juan de Fuca Ridge indicative of subsurface organic material caused us to re-examine both the literature on hyperthermophilic microorganisms cultured from deep-sea smoker environments and recent results of microbial sampling efforts at actively discharging smokers on the Endeavour Segment. Here we offer the case for a subsurface biosphere based on an interdisciplinary view of microbial and geochemical analyses of Endeavour smoker fluids, a case in keeping with rapidly evolving geophysical understanding of organic stability under deep-sea hydrothermal conditions. PMID:11538298

  2. How Deep-Sea Wood Falls Sustain Chemosynthetic Life

    PubMed Central

    Bienhold, Christina; Pop Ristova, Petra; Wenzhöfer, Frank; Dittmar, Thorsten; Boetius, Antje

    2013-01-01

    Large organic food falls to the deep sea – such as whale carcasses and wood logs – are known to serve as stepping stones for the dispersal of highly adapted chemosynthetic organisms inhabiting hot vents and cold seeps. Here we investigated the biogeochemical and microbiological processes leading to the development of sulfidic niches by deploying wood colonization experiments at a depth of 1690 m in the Eastern Mediterranean for one year. Wood-boring bivalves of the genus Xylophaga played a key role in the degradation of the wood logs, facilitating the development of anoxic zones and anaerobic microbial processes such as sulfate reduction. Fauna and bacteria associated with the wood included types reported from other deep-sea habitats including chemosynthetic ecosystems, confirming the potential role of large organic food falls as biodiversity hot spots and stepping stones for vent and seep communities. Specific bacterial communities developed on and around the wood falls within one year and were distinct from freshly submerged wood and background sediments. These included sulfate-reducing and cellulolytic bacterial taxa, which are likely to play an important role in the utilization of wood by chemosynthetic life and other deep-sea animals. PMID:23301092

  3. Viability of Carbon Dioxide Storage in Deep Sea Sediment

    NASA Astrophysics Data System (ADS)

    Bielicki, J. M.

    2007-12-01

    Despite the public's general aversion to using the ocean to dispose of captured carbon dioxide (CO2), recent revisions of the London Protocol have removed a hurdle to subsea injection of CO2. This paper constructs a map of the worldwide "prospectivity" of CO2 storage in deep sea sediment, i.e. amenable locations are determined and storage capacities estimated. CO2 injected into deep sea sediment is expected to be gravitationally trapped and secondarily capped by CO2 hydrate formation. Capture, transport, and storage costs are estimated and a mixed-integer linear programming model that generates spatially optimized infrastructure networks is applied. The model captures CO2 from fixed point sources, uses minimum cost routing paths, aggregates CO2 flow into trunk distribution pipelines where appropriate, and injects the CO2 in potential deep sea injection sites. Economies of scale for this climate change mitigation intervention in the United States Exclusive Economic Zone are discussed, including provisions for destabilizing and/or harvesting methane from in situ gas hydrates.

  4. Russian deep-sea investigations of Antarctic fauna

    NASA Astrophysics Data System (ADS)

    Malyutina, Marina

    2004-07-01

    A review of the Russian deep-sea investigation of Antarctic fauna beginning from the first scientific collection of Soviet whaling fleet expeditions 1946-1952 is presented. The paper deals with the following expeditions, their main tasks and results. These expeditions include three cruises of research vessel (R.V.) Ob in the Indian sector of the Antarctic and in the Southern Pacific (1955-1958); 11 cruises of the R.V. Akademik Kurchatov in the southern Atlantic (November-December 1971); 16 cruises of the R.V. Dmitriy Mendeleev in the Australia-New Zealand area and adjacent water of the Antarctic (December 1975-March 1976); 43 cruises of the R.V. Akademik Kurchatov in the southern Atlantic (October 1985-February 1986); and 43 cruises of the R.V. Dmitriy Mendeleev in the Atlantic sector of the South Ocean (January-May 1989). A list of the main publications on the benthic taxa collected during these expeditions with data of their distribution is presented. The results of Russian explorations of the Antarctic fauna are presented as theoretical conclusions in the following topics: (1) Vertical zonation in the distribution of the Antarctic deep-sea fauna; (2) Biogeographic division of the abyssal and hadal zones; (3) Origin of the Antarctic deep-sea fauna; (4) Distributional pathways of the Antarctic abyssal fauna through the World Ocean.

  5. Chemosynthesis in the deep-sea: life without the sun

    NASA Astrophysics Data System (ADS)

    Smith, C.

    2012-12-01

    Chemosynthetic communities in the deep-sea can be found at hydrothermal vents, cold seeps, whale falls and wood falls. While these communities have been suggested to exist in isolation from solar energy, much of the life associated with them relies either directly or indirectly on photosynthesis in the surface waters of the oceans. The sun indirectly provides oxygen, a byproduct of photosynthesis, which aerobic chemosynthetic microorganisms require to synthesize organic carbon from CO2. Planktonic life stages of many vent and cold seep invertebrates also directly feed on photosynthetically produced organic matter as they disperse to new vent and seep systems. While a large portion of the life at deep-sea chemosynthetic habitats can be linked to the sun and so could not survive without it, a small portion of anaerobically chemosynthetic microorganisms can persist in its absence. These small and exotic organisms have developed a way of life in the deep-sea which involves the use of resources originating in their entirety from terrestrial sources.

  6. Late Eocene impact events recorded in deep-sea sediments

    NASA Technical Reports Server (NTRS)

    Glass, B. P.

    1988-01-01

    Raup and Sepkoski proposed that mass extinctions have occurred every 26 Myr during the last 250 Myr. In order to explain this 26 Myr periodicity, it was proposed that the mass extinctions were caused by periodic increases in cometary impacts. One method to test this hypothesis is to determine if there were periodic increases in impact events (based on crater ages) that correlate with mass extinctions. A way to test the hypothesis that mass extinctions were caused by periodic increases in impact cratering is to look for evidence of impact events in deep-sea deposits. This method allows direct observation of the temporal relationship between impact events and extinctions as recorded in the sedimentary record. There is evidence in the deep-sea record for two (possibly three) impact events in the late Eocene. The younger event, represented by the North American microtektite layer, is not associated with an Ir anomaly. The older event, defined by the cpx spherule layer, is associated with an Ir anomaly. However, neither of the two impact events recorded in late Eocene deposits appears to be associated with an unusual number of extinctions. Thus there is little evidence in the deep-sea record for an impact-related mass extinction in the late Eocene.

  7. Methane-Stimulated Benthic Marine Nitrogen Fixation at Deep-Sea Methane Seeps

    NASA Astrophysics Data System (ADS)

    Dekas, A. E.; Orphan, V.

    2011-12-01

    Biological nitrogen fixation (the conversion of N2 to NH3) is a critical process in the oceans, counteracting the production of N2 gas by dissimilatory bacterial metabolisms and providing a source of bioavailable nitrogen to many nitrogen-limited ecosystems. Although current measurements of N2 production and consumption in the oceans indicate that the nitrogen cycle is not balanced, recent findings on the limits of nitrogen fixation suggest that the perceived imbalance is an artifact of an incomplete assessment of marine diazotrophy. One currently poorly studied and potentially underappreciated habitat for diazotrophic organisms is the sediments of the deep-sea. In the present study we investigate the distribution and magnitude of benthic marine diazotrophy at several active deep-sea methane seeps (Mound 12, Costa Rica; Eel River Basin, CA, USA; Hydrate Ridge, OR, USA; and Monterey Canyon, CA, USA). Using 15N2 and 15NH4 sediment incubation experiments followed by single-cell (FISH-NanoSIMS) and bulk isotopic analysis (EA-IRMS), we observed total protein synthesis (15N uptake from 15NH4) and nitrogen fixation (15N update from 15N2). The highest rates of nitrogen fixation observed in the methane seep sediment incubation experiments were over an order of magnitude greater than those previously published from non-seep deep-sea sediments (Hartwig and Stanley, Deep-Sea Research, 1978, 25:411-417). However, methane seep diazotrophy appears to be highly spatially variable, with sediments exhibiting no nitrogen fixation originating only centimeters away from sediments actively incorporating 15N from 15N2. The greatest spatial variability in diazotrophy was observed with depth in the sediment, and corresponded to steep gradients in sulfate and methane. The maximum rates of nitrogen fixation were observed within the methane-sulfate transition zone, where organisms mediating the anaerobic oxidation of methane are typically in high abundance. Additionally, incubation

  8. Exploitation of deep-sea resources: the urgent need to understand the role of high pressure in the toxicity of chemical pollutants to deep-sea organisms.

    PubMed

    Mestre, Nélia C; Calado, Ricardo; Soares, Amadeu M V M

    2014-02-01

    The advent of industrial activities in the deep sea will inevitably expose deep-sea organisms to potentially toxic compounds. Although international regulations require environmental risk assessment prior to exploitation activities, toxicity tests remain focused on shallow-water model species. Moreover, current tests overlook potential synergies that may arise from the interaction of chemicals with natural stressors, such as the high pressures prevailing in the deep sea. As pressure affects chemical reactions and the physiology of marine organisms, it will certainly affect the toxicity of pollutants arising from the exploitation of deep-sea resources. We emphasize the need for environmental risk assessments based on information generated from ecotoxicological trials that mimic, as close as possible, the deep-sea environment, with emphasis to a key environmental factor - high hydrostatic pressure.

  9. Exploitation of deep-sea resources: the urgent need to understand the role of high pressure in the toxicity of chemical pollutants to deep-sea organisms.

    PubMed

    Mestre, Nélia C; Calado, Ricardo; Soares, Amadeu M V M

    2014-02-01

    The advent of industrial activities in the deep sea will inevitably expose deep-sea organisms to potentially toxic compounds. Although international regulations require environmental risk assessment prior to exploitation activities, toxicity tests remain focused on shallow-water model species. Moreover, current tests overlook potential synergies that may arise from the interaction of chemicals with natural stressors, such as the high pressures prevailing in the deep sea. As pressure affects chemical reactions and the physiology of marine organisms, it will certainly affect the toxicity of pollutants arising from the exploitation of deep-sea resources. We emphasize the need for environmental risk assessments based on information generated from ecotoxicological trials that mimic, as close as possible, the deep-sea environment, with emphasis to a key environmental factor - high hydrostatic pressure. PMID:24230462

  10. The response of abyssal organisms to low pH conditions during a series of CO2-release experiments simulating deep-sea carbon sequestration

    NASA Astrophysics Data System (ADS)

    Barry, J. P.; Buck, K. R.; Lovera, C.; Brewer, P. G.; Seibel, B. A.; Drazen, J. C.; Tamburri, M. N.; Whaling, P. J.; Kuhnz, L.; Pane, E. F.

    2013-08-01

    The effects of low-pH, high-pCO2 conditions on deep-sea organisms were examined during four deep-sea CO2 release experiments simulating deep-ocean C sequestration by the direct injection of CO2 into the deep sea. We examined the survival of common deep-sea, benthic organisms (microbes; macrofauna, dominated by Polychaeta, Nematoda, Crustacea, Mollusca; megafauna, Echinodermata, Mollusca, Pisces) exposed to low-pH waters emanating as a dissolution plume from pools of liquid carbon dioxide released on the seabed during four abyssal CO2-release experiments. Microbial abundance in deep-sea sediments was unchanged in one experiment, but increased under environmental hypercapnia during another, where the microbial assemblage may have benefited indirectly from the negative impact of low-pH conditions on other taxa. Lower abyssal metazoans exhibited low survival rates near CO2 pools. No urchins or holothurians survived during 30-42 days of exposure to episodic, but severe environmental hypercapnia during one experiment (E1; pH reduced by as much as ca. 1.4 units). These large pH reductions also caused 75% mortality for the deep-sea amphipod, Haploops lodo, near CO2 pools. Survival under smaller pH reductions (ΔpH<0.4 units) in other experiments (E2, E3, E5) was higher for all taxa, including echinoderms. Gastropods, cephalopods, and fish were more tolerant than most other taxa. The gastropod Retimohnia sp. and octopus Benthoctopus sp. survived exposure to pH reductions that episodically reached -0.3 pH units. Ninety percent of abyssal zoarcids (Pachycara bulbiceps) survived exposure to pH changes reaching ca. -0.3 pH units during 30-42 day-long experiments.

  11. First glimpse into Lower Jurassic deep-sea biodiversity: in situ diversification and resilience against extinction.

    PubMed

    Thuy, Ben; Kiel, Steffen; Dulai, Alfréd; Gale, Andy S; Kroh, Andreas; Lord, Alan R; Numberger-Thuy, Lea D; Stöhr, Sabine; Wisshak, Max

    2014-07-01

    Owing to the assumed lack of deep-sea macrofossils older than the Late Cretaceous, very little is known about the geological history of deep-sea communities, and most inference-based hypotheses argue for repeated recolonizations of the deep sea from shelf habitats following major palaeoceanographic perturbations. We present a fossil deep-sea assemblage of echinoderms, gastropods, brachiopods and ostracods, from the Early Jurassic of the Glasenbach Gorge, Austria, which includes the oldest known representatives of a number of extant deep-sea groups, and thus implies that in situ diversification, in contrast to immigration from shelf habitats, played a much greater role in shaping modern deep-sea biodiversity than previously thought. A comparison with coeval shelf assemblages reveals that, at least in some of the analysed groups, significantly more extant families/superfamilies have endured in the deep sea since the Early Jurassic than in the shelf seas, which suggests that deep-sea biota are more resilient against extinction than shallow-water ones. In addition, a number of extant deep-sea families/superfamilies found in the Glasenbach assemblage lack post-Jurassic shelf occurrences, implying that if there was a complete extinction of the deep-sea fauna followed by replacement from the shelf, it must have happened before the Late Jurassic.

  12. Persistence of pristine deep-sea coral gardens in the Mediterranean Sea (SW Sardinia).

    PubMed

    Bo, Marzia; Bavestrello, Giorgio; Angiolillo, Michela; Calcagnile, Lucio; Canese, Simonepietro; Cannas, Rita; Cau, Alessandro; D'Elia, Marisa; D'Oriano, Filippo; Follesa, Maria Cristina; Quarta, Gianluca; Cau, Angelo

    2015-01-01

    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy enclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection. PMID:25790333

  13. Persistence of pristine deep-sea coral gardens in the Mediterranean Sea (SW Sardinia).

    PubMed

    Bo, Marzia; Bavestrello, Giorgio; Angiolillo, Michela; Calcagnile, Lucio; Canese, Simonepietro; Cannas, Rita; Cau, Alessandro; D'Elia, Marisa; D'Oriano, Filippo; Follesa, Maria Cristina; Quarta, Gianluca; Cau, Angelo

    2015-01-01

    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy enclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection.

  14. Persistence of Pristine Deep-Sea Coral Gardens in the Mediterranean Sea (SW Sardinia)

    PubMed Central

    Bo, Marzia; Bavestrello, Giorgio; Angiolillo, Michela; Calcagnile, Lucio; Canese, Simonepietro; Cannas, Rita; Cau, Alessandro; D’Elia, Marisa; D’Oriano, Filippo; Follesa, Maria Cristina; Quarta, Gianluca; Cau, Angelo

    2015-01-01

    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy enclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection. PMID:25790333

  15. Deep-sea benthic footprint of the deepwater horizon blowout.

    PubMed

    Montagna, Paul A; Baguley, Jeffrey G; Cooksey, Cynthia; Hartwell, Ian; Hyde, Larry J; Hyland, Jeffrey L; Kalke, Richard D; Kracker, Laura M; Reuscher, Michael; Rhodes, Adelaide C E

    2013-01-01

    The Deepwater Horizon (DWH) accident in the northern Gulf of Mexico occurred on April 20, 2010 at a water depth of 1525 meters, and a deep-sea plume was detected within one month. Oil contacted and persisted in parts of the bottom of the deep-sea in the Gulf of Mexico. As part of the response to the accident, monitoring cruises were deployed in fall 2010 to measure potential impacts on the two main soft-bottom benthic invertebrate groups: macrofauna and meiofauna. Sediment was collected using a multicorer so that samples for chemical, physical and biological analyses could be taken simultaneously and analyzed using multivariate methods. The footprint of the oil spill was identified by creating a new variable with principal components analysis where the first factor was indicative of the oil spill impacts and this new variable mapped in a geographic information system to identify the area of the oil spill footprint. The most severe relative reduction of faunal abundance and diversity extended to 3 km from the wellhead in all directions covering an area about 24 km(2). Moderate impacts were observed up to 17 km towards the southwest and 8.5 km towards the northeast of the wellhead, covering an area 148 km(2). Benthic effects were correlated to total petroleum hydrocarbon, polycyclic aromatic hydrocarbons and barium concentrations, and distance to the wellhead; but not distance to hydrocarbon seeps. Thus, benthic effects are more likely due to the oil spill, and not natural hydrocarbon seepage. Recovery rates in the deep sea are likely to be slow, on the order of decades or longer.

  16. Deep-sea benthic footprint of the deepwater horizon blowout.

    PubMed

    Montagna, Paul A; Baguley, Jeffrey G; Cooksey, Cynthia; Hartwell, Ian; Hyde, Larry J; Hyland, Jeffrey L; Kalke, Richard D; Kracker, Laura M; Reuscher, Michael; Rhodes, Adelaide C E

    2013-01-01

    The Deepwater Horizon (DWH) accident in the northern Gulf of Mexico occurred on April 20, 2010 at a water depth of 1525 meters, and a deep-sea plume was detected within one month. Oil contacted and persisted in parts of the bottom of the deep-sea in the Gulf of Mexico. As part of the response to the accident, monitoring cruises were deployed in fall 2010 to measure potential impacts on the two main soft-bottom benthic invertebrate groups: macrofauna and meiofauna. Sediment was collected using a multicorer so that samples for chemical, physical and biological analyses could be taken simultaneously and analyzed using multivariate methods. The footprint of the oil spill was identified by creating a new variable with principal components analysis where the first factor was indicative of the oil spill impacts and this new variable mapped in a geographic information system to identify the area of the oil spill footprint. The most severe relative reduction of faunal abundance and diversity extended to 3 km from the wellhead in all directions covering an area about 24 km(2). Moderate impacts were observed up to 17 km towards the southwest and 8.5 km towards the northeast of the wellhead, covering an area 148 km(2). Benthic effects were correlated to total petroleum hydrocarbon, polycyclic aromatic hydrocarbons and barium concentrations, and distance to the wellhead; but not distance to hydrocarbon seeps. Thus, benthic effects are more likely due to the oil spill, and not natural hydrocarbon seepage. Recovery rates in the deep sea are likely to be slow, on the order of decades or longer. PMID:23950956

  17. Radiocarbon Based Ages and Growth Rates: Hawaiian Deep Sea Corals

    SciTech Connect

    Roark, E B; Guilderson, T P; Dunbar, R B; Ingram, B L

    2006-01-13

    The radial growth rates and ages of three different groups of Hawaiian deep-sea 'corals' were determined using radiocarbon measurements. Specimens of Corallium secundum, Gerardia sp., and Leiopathes glaberrima, were collected from 450 {+-} 40 m at the Makapuu deep-sea coral bed using a submersible (PISCES V). Specimens of Antipathes dichotoma were collected at 50 m off Lahaina, Maui. The primary source of carbon to the calcitic C. secundum skeleton is in situ dissolved inorganic carbon (DIC). Using bomb {sup 14}C time markers we calculate radial growth rates of {approx} 170 {micro}m y{sup -1} and ages of 68-75 years on specimens as tall as 28 cm of C. secundum. Gerardia sp., A. dichotoma, and L. glaberrima have proteinaceous skeletons and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using {sup 14}C we calculate a radial growth rate of 15 {micro}m y{sup -1} and an age of 807 {+-} 30 years for a live collected Gerardia sp., showing that these organisms are extremely long lived. Inner and outer {sup 14}C measurements on four sub-fossil Gerardia spp. samples produce similar growth rate estimates (range 14-45 {micro}m y{sup -1}) and ages (range 450-2742 years) as observed for the live collected sample. Similarly, with a growth rate of < 10 {micro}m y{sup -1} and an age of {approx}2377 years, L. glaberrima at the Makapuu coral bed, is also extremely long lived. In contrast, the shallow-collected A. dichotoma samples yield growth rates ranging from 130 to 1,140 {micro}m y{sup -1}. These results show that Hawaiian deep-sea corals grow more slowly and are older than previously thought.

  18. Deep-sea Lebensspuren of the Australian continental margins

    NASA Astrophysics Data System (ADS)

    Przeslawski, Rachel; Dundas, Kate; Radke, Lynda; Anderson, Tara J.

    Much of the deep sea comprises soft-sediment habitats dominated by comparatively low abundances of species-rich macrofauna and meiofauna. Although often not observed, these animals bioturbate the sediment during feeding and burrowing, leaving signs of their activities called Lebensspuren ('life traces'). In this study, we use still images to quantify Lebensspuren from the eastern (1921 images, 13 stations, 1300-2200 m depth) and western (1008 images, 11 stations, 1500-4400 m depth) Australian margins using a univariate measure of trace richness and a multivariate measure of Lebensspuren assemblages. A total of 46 Lebensspuren types were identified, including those matching named trace fossils and modern Lebensspuren found elsewhere in the world. Most traces could be associated with waste, crawling, dwellings, organism tests, feeding, or resting, but the origin of 15% of trace types remains unknown. Assemblages were significantly different between the two regions and depth profiles, with five Lebensspuren types accounting for over 95% of the differentiation (ovoid pinnate trace, crater row, spider trace, matchstick trace, mesh trace). Lebensspuren richness showed no strong relationships with depth, total organic carbon, or mud, although there was a positive correlation to chlorin index (i.e., organic freshness) in the eastern margin, with richness increasing with organic freshness. Lebensspuren richness was not related to epifauna either, indicating that epifauna may not be the primary source of Lebensspuren. Despite the abundance and distinctiveness of several traces both in the current and previous studies (e.g., ovoid pinnate, mesh, spider), their origin and distribution remains a mystery. We discuss this and several other considerations in the identification and quantification of Lebensspuren. This study represents the first comprehensive catalogue of deep-sea Lebensspuren in Australian waters and highlights the potential of Lebensspuren as valuable and often

  19. Deep sea AUV navigation using multiple acoustic beacons

    NASA Astrophysics Data System (ADS)

    Ji, Da-xiong; Song, Wei; Zhao, Hong-yu; Liu, Jian

    2016-04-01

    Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles (AUVs). To estimate the vehicle position, we present an algorithm using an extended Kalman filter (EKF) to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment. Owing to high latency, variable sound speed multipath transmissions and unreliability in acoustic measurements, outlier recognition techniques are proposed as well. The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments. Our results show the improved performance over prior techniques based on position computation.

  20. A deep-sea diver with cement pulmonary embolism.

    PubMed

    Memarpour, Roya; Tashtoush, Basheer; Nasim, Faria; Grobman, Daniel; Upadhyay, Bharat K; Rahaghi, Franck

    2016-01-01

    Cement pulmonary embolism is a rare complication of cement kyphoplasty. These emboli are often asymptomatic and commonly detected many years after the procedure as incidental findings on radiographic imaging. We herein report a case of a 32-year-old professional diver who was diagnosed with asymptomatic cement pulmonary emboli during his annual diving physical exam. After two years of follow-up the patient remained asymptomatic and resumed his career in professional diving, which included deep sea diving activities with no evidence of respiratory limitations or long-term complications. PMID:27416693

  1. Space Suit Technologies Protect Deep-Sea Divers

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Working on NASA missions allows engineers and scientists to hone their skills. Creating devices for the high-stress rigors of space travel pushes designers to their limits, and the results often far exceed the original concepts. The technologies developed for the extreme environment of space are often applicable here on Earth. Some of these NASA technologies, for example, have been applied to the breathing apparatuses worn by firefighters, the fire-resistant suits worn by racecar crews, and, most recently, the deep-sea gear worn by U.S. Navy divers.

  2. A deep-sea diver with cement pulmonary embolism.

    PubMed

    Memarpour, Roya; Tashtoush, Basheer; Nasim, Faria; Grobman, Daniel; Upadhyay, Bharat K; Rahaghi, Franck

    2016-01-01

    Cement pulmonary embolism is a rare complication of cement kyphoplasty. These emboli are often asymptomatic and commonly detected many years after the procedure as incidental findings on radiographic imaging. We herein report a case of a 32-year-old professional diver who was diagnosed with asymptomatic cement pulmonary emboli during his annual diving physical exam. After two years of follow-up the patient remained asymptomatic and resumed his career in professional diving, which included deep sea diving activities with no evidence of respiratory limitations or long-term complications.

  3. Global ocean conveyor lowers extinction risk in the deep sea

    NASA Astrophysics Data System (ADS)

    Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Wienberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Mélanie; Morrison, Cheryl L.; López Correa, Matthias; Rogers, Alex D.; Ruckelshausen, Mario; Roberts, J. Murray

    2014-06-01

    General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth's largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium-thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

  4. Rhone deep-sea fan: morphostructure and growth pattern

    SciTech Connect

    Droz, L.; Bellaiche, G.

    1985-03-01

    A detailed bathymetric survey of the Rhone deep-sea fan and its feeder canyon using Sea-Beam, reveals morphologic features such as very tight meanders of the canyon and channel courses, cutoff meanders, and downslope narrowing of the inner channel floor. Striking similarities exist between these deep-sea features and some continental landforms, especially in alluvial plain areas or desert environments. Sea-Beam also reveals evidence of huge slump scars affecting the slope and fan. The superficial structure of the Rhone Fan results from the stacking of numerous lenticular acoustic units displaying specific seismic characters in which the authors recognized channel and levee facies. Except in the upper fan area, these units have not been constant; they have generally migrated, owing to shifting of the channel throughout fan evolution. Construction of the fan probably began as early as the early Pliocene and continued to the close of the Wurmian (late Wisconsinian). The fan's growth pattern could be associated with climatic fluctuations. The principal sedimentary mechanism responsible for the growth of the fan appears to be turbidity currents, but mass gravity flows have also been an important factor in building the fan by occasionally blocking the main channel and forcing it to migrate.

  5. Ecology of deep-sea hydrothermal vent communities: A review

    NASA Astrophysics Data System (ADS)

    Lutz, Richard A.; Kennish, Michael J.

    1993-08-01

    Studies of the many active and inactive hydrothermal vents found during the past 15 years have radically altered views of biological and geological processes in the deep sea. The biological communities occupying the vast and relatively stable soft bottom habitats of the deep sea are characterized by low population densities, high species diversity, and low biomass. In contrast, those inhabiting the generally unstable conditions of hydrothermal vent environments exhibit high densities and biomass, low species diversity, rapid growth rates, and high metabolic rates. Biological processes, such as rates of metabolism and growth, in vent organisms are comparable to those observed in organisms from shallow-water ecosystems. An abundant energy source is provided by chemosynthetic bacteria that constitute the primary producers sustaining the lush communities at the hydrothermal sites. Fluxes in vent flow and fluid chemistry cause changes in growth rates, reproduction, mortality, and/or colonization of vent fauna, leading to temporal and spatial variation of the vent communities. Vent populations that cannot adapt to modified flow rates are adversely affected, as is evidenced by high mortality or lower rates of colonization, growth, or reproduction. Substantial changes in biota have been witnessed at several vents, and successional cycles have been proposed for the Galapagos vent fields. Dramatic temporal and spatial variations in vent community structure may also relate to variations in larval dispersal and chance recruitment, as well as biotic interactions.

  6. Age, growth rates, and paleoclimate studies of deep sea corals

    USGS Publications Warehouse

    Prouty, Nancy G; Roark, E. Brendan; Andrews, Allen; Robinson, Laura; Hill, Tessa; Sherwood, Owen; Williams, Branwen; Guilderson, Thomas P.; Fallon, Stewart

    2015-01-01

    Deep-water corals are some of the slowest growing, longest-lived skeletal accreting marine organisms. These habitat-forming species support diverse faunal assemblages that include commercially and ecologically important organisms. Therefore, effective management and conservation strategies for deep-sea corals can be informed by precise and accurate age, growth rate, and lifespan characteristics for proper assessment of vulnerability and recovery from perturbations. This is especially true for the small number of commercially valuable, and potentially endangered, species that are part of the black and precious coral fisheries (Tsounis et al. 2010). In addition to evaluating time scales of recovery from disturbance or exploitation, accurate age and growth estimates are essential for understanding the life history and ecology of these habitat-forming corals. Given that longevity is a key factor for population maintenance and fishery sustainability, partly due to limited and complex genetic flow among coral populations separated by great distances, accurate age structure for these deep-sea coral communities is essential for proper, long-term resource management.

  7. Deep sea mega-geomorphology: Progress and problems

    NASA Technical Reports Server (NTRS)

    Bryan, W. B.

    1985-01-01

    Historically, marine geologists have always worked with mega-scale morphology. This is a consequence both of the scale of the ocean basins and of the low resolution of the observational remote sensing tools available until very recently. In fact, studies of deep sea morphology have suffered from a serious gap in observational scale. Traditional wide-beam echo sounding gave images on a scale of miles, while deep sea photography has been limited to scales of a few tens of meters. Recent development of modern narrow-beam echo sounding coupled with computer-controlled swath mapping systems, and development of high-resolution deep-towed side-scan sonar, are rapidly filling in the scale gap. These technologies also can resolve morphologic detail on a scale of a few meters or less. As has also been true in planetary imaging projects, the ability to observe phenomena over a range of scales has proved very effective in both defining processes and in placing them in proper context.

  8. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  9. Activity rhythms in the deep-sea: a chronobiological approach.

    PubMed

    Aguzzi, Jacopo; Company, Joan Batista; Costa, Corrado; Menesatti, Paolo; Garcia, Jose Antonio; Bahamon, Nixon; Puig, Pere; Sarda, Francesc

    2011-01-01

    Ocean waters deeper than 200 m cover 70% of the Earth's surface. Light intensity gets progressively weaker with increasing depth and internal tides or inertial currents may be the only remaining zeitgebers regulating biorhythms in deep-sea decapods. Benthopelagic coupling, exemplified by vertically moving shrimps within the water column, may also act as a source of indirect synchronisation to the day-night cycle for species living in permanently dark areas. At the same time, seasonal rhythms in growth and reproduction may be an exogenous response to spring-summer changes in upper layer productivity (via phytoplankton) or, alternatively, may be provoked by the synchronisation mediated by an endogenous controlling mechanism (via melatonin). In our review, we will focus on the behavioural rhythms of crustacean decapods inhabiting depths where the sun light is absent. Potential scenarios for future research on deep-sea decapod behaviour are suggested by new in situ observation technologies. Permanent video observatories are, to date, one of the most important tools for marine chronobiology in terms of species recognition and animals' movement tracking.

  10. Activity rhythms in the deep-sea: a chronobiological approach.

    PubMed

    Aguzzi, Jacopo; Company, Joan Batista; Costa, Corrado; Menesatti, Paolo; Garcia, Jose Antonio; Bahamon, Nixon; Puig, Pere; Sarda, Francesc

    2011-01-01

    Ocean waters deeper than 200 m cover 70% of the Earth's surface. Light intensity gets progressively weaker with increasing depth and internal tides or inertial currents may be the only remaining zeitgebers regulating biorhythms in deep-sea decapods. Benthopelagic coupling, exemplified by vertically moving shrimps within the water column, may also act as a source of indirect synchronisation to the day-night cycle for species living in permanently dark areas. At the same time, seasonal rhythms in growth and reproduction may be an exogenous response to spring-summer changes in upper layer productivity (via phytoplankton) or, alternatively, may be provoked by the synchronisation mediated by an endogenous controlling mechanism (via melatonin). In our review, we will focus on the behavioural rhythms of crustacean decapods inhabiting depths where the sun light is absent. Potential scenarios for future research on deep-sea decapod behaviour are suggested by new in situ observation technologies. Permanent video observatories are, to date, one of the most important tools for marine chronobiology in terms of species recognition and animals' movement tracking. PMID:21196163

  11. Reconstruction of demersal fisheries history on the Condor seamount, Azores archipelago (Northeast Atlantic)

    NASA Astrophysics Data System (ADS)

    Menezes, Gui M.; Diogo, Hugo; Giacomello, Eva

    2013-12-01

    Commercial fishing data were analyzed in order to reconstruct the history of the demersal fishery on Condor seamount, a temporarily protected area in the Northeast Atlantic (Azores). Considering the eight commercially most important demersal fish species, estimates for the period 1993-2009 revealed that on average landings from this area represented 2% of the annual landings by weight of these species in the Azores. Over this period the average estimated volume of the Condor landings was 71t/year, with the blackspot seabream (Pagellus bogaraveo) and the wreckfish (Polyprion americanus) representing about 54% of the landings, and the average value was €346 thousand per year. Annual trends of landings and of landings per unit effort suggest species-specific abundance responses to fishing, but most of the exploited species may have been significantly reduced at the Condor seamount. The proportion of large specimens may have declined in some of the studied species. Results suggest that artisanal fisheries are capable of causing important reductions in abundance levels of demersal species living on seamounts. Species life history characteristics, their degree of residency, and dependence on outside source areas may be important determinants for the status and the time scales required for recovery to previous abundances of the species. With the current Condor seamount fishing moratorium, exploitation rate has been reduced to zero and this is a unique opportunity to study the responses of the different previously exploited species to the reduced fishing mortality. New understanding may benefit seamount fisheries management in the region.

  12. Automated Video Quality Assessment for Deep-Sea Video

    NASA Astrophysics Data System (ADS)

    Pirenne, B.; Hoeberechts, M.; Kalmbach, A.; Sadhu, T.; Branzan Albu, A.; Glotin, H.; Jeffries, M. A.; Bui, A. O. V.

    2015-12-01

    Video provides a rich source of data for geophysical analysis, often supplying detailed information about the environment when other instruments may not. This is especially true of deep-sea environments, where direct visual observations cannot be made. As computer vision techniques improve and volumes of video data increase, automated video analysis is emerging as a practical alternative to labor-intensive manual analysis. Automated techniques can be much more sensitive to video quality than their manual counterparts, so performing quality assessment before doing full analysis is critical to producing valid results.Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories that supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea, including video and still cameras. This network of ocean observatories has produced almost 20,000 hours of video (about 38 hours are recorded each day) and an additional 8,000 hours of logs from remotely operated vehicle (ROV) dives. We begin by surveying some ways in which deep-sea video poses challenges for automated analysis, including: 1. Non-uniform lighting: Single, directional, light sources produce uneven luminance distributions and shadows; remotely operated lighting equipment are also susceptible to technical failures. 2. Particulate noise: Turbidity and marine snow are often present in underwater video; particles in the water column can have sharper focus and higher contrast than the objects of interest due to their proximity to the light source and can also influence the camera's autofocus and auto white-balance routines. 3. Color distortion (low contrast): The rate of absorption of light in water varies by wavelength, and is higher overall than in air, altering apparent colors and lowering the contrast of objects at a distance.We also describe measures under development at ONC for detecting and mitigating

  13. New Deep Sea Photometer And Its Biological Applications

    NASA Astrophysics Data System (ADS)

    Roe, H. S. J.

    1982-02-01

    A recently developed deep-sea photometer is described. The photometer uses a silicon photodiode as a light sensor and is interfaced with the Institute of Oceanographic Sciences' acoustically telemetering net monitor system. Using the photometer in conjunction with the I.O.S. midwater trawls it is possible to simultaneously measure irradiance at the depth of the net and collect biological samples. The relationship between light and the distribution of mesopelagic animal communities can thereby be studied directly. The photometer has measured light to a depth of 700m in the northeast Atlantic. It records at least seven decades of irradiance and its response is independent of temperature between -3 and +30°C. Some observations on the subsurface light regime in the northeast Atlantic and Southern Oceans are presented and a biological sampling programme using the photometer is described. Preliminary analysis suggests that the association of oarticular species with specific light levels is not especially close.

  14. Carbon and nitrogen diagenesis in deep sea sediments

    NASA Astrophysics Data System (ADS)

    Waples, Douglas W.; Sloan, Jon R.

    1980-10-01

    The sections penetrated on Leg 58 of the Deep Sea Drilling Project represent periods of geologic time during which depositional conditions apparently remained quite constant, thus offering an unusual opportunity to study the effects of diagenesis on organic material. Organic carbon and nitrogen contents decrease monotonically with increasing depth of burial before levelling off at minimum values of about 0.05-0.10 and 0.01%, respectively. The depths at which minima are reached vary from site to site, but the ages of the sediments at the minima are all about 2-5 Myr. These data indicate that diagenetic transformations are responsible for the gradual depletion of organic carbon and nitrogen. If diagenesis is at least partly the result of microbial activity, then the role of bacterial ecosystems in deep water sediments is much greater than has previously been thought.

  15. Microbial hydrolytic enzyme activities in deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Boetius, A.

    1995-03-01

    The potential hydrolysis rates of five different hydrolytic enzymes were determined in deep-sea sediments from the northeast Atlantic (BIOTRANS area) in March 1992. Fluorogenic substrates were used to assay extracellular α- and β-glucosidase, chitobiase, lipase and aminopeptidase. The potential activity of most of the enzymes investigated decreased to a minimum within the upper two centimetre range, whereas aminopeptidase was high over the upper five centimetre range. Exceptions were found when macrofaunal burrows occurred in the cores, always increasing the activities of some hydrolases, and therefore indicating the impact of bioturbation on degradation rates. The most striking feature of the investigated enzyme spectrum was the 50 2000 times higher specific activity of the aminopeptidase, compared with the other hydrolases. The activity of hydrolytic enzymes most likely reflects the availability of their respective substrates and is not a function of bacterial biomass.

  16. Microbiology to 10,500 meters in the deep sea.

    PubMed

    Yayanos, A A

    1995-01-01

    Microorganisms in the deep sea live at high pressures, low and high temperatures, and in darkness. These parameters and their food supply govern their lives. The study of these creatures gives us an opportunity to see how life processes work at some of the highest temperatures and pressures of the biosphere. Cultured bacterial isolates can grow to over 100 MPa at 2 degrees C and to over 40 MPa at over 100 degrees C. These cultures comprise the foundation for the study of the molecular biology and biotechnology of these isolates. The PTk diagram shows how temperature and pressure affect the growth rate of a bacterium and helps in the search for relationships among bacteria from habitats differing in temperature and pressure.

  17. 'Deep-sea spiders' that walk through the water

    PubMed

    Marshall; Diebel

    1995-01-01

    Deep-sea isopods of the family Munnopsidae exhibit four modes of swimming: forward striding, slow backward pedalling, fast backward pedalling and escape, the first two of which use asymmetric phases of leg movement. Instead of moving the left and right limbs (pereopods, P2­P7) of a segment in-phase (e.g. RP2LP2, RP3LP3, RP4LP4), as do most aquatic insects, leg movement is more like that of fast-walking insects, where closest synchrony occurs between diagonal limbs (e.g. RP2LP3, RP3LP4, RP4LP2). This is similar to the alternating tripod gait used by many animals on land to prevent them from toppling over. It therefore seems likely that this group of isopods learned to walk before they could swim.

  18. Alchemy or Science? Compromising Archaeology in the Deep Sea

    NASA Astrophysics Data System (ADS)

    Adams, Jonathan

    2007-06-01

    In the torrid debate between archaeology and treasure hunting, compromise is often suggested as the pragmatic solution, especially for archaeology carried out either in deep water or beyond the constraints that commonly regulate such activities in territorial seas. Both the wisdom and the need for such compromise have even been advocated by some archaeologists, particularly in forums such as the internet and conferences. This paper argues that such a compromise is impossible, not in order to fuel confrontation but simply because of the nature of any academic discipline. We can define what archaeology is in terms of its aims, theories, methods and ethics, so combining it with an activity founded on opposing principles must transform it into something else. The way forward for archaeology in the deep sea does not lie in a contradictory realignment of archaeology’s goals but in collaborative research designed to mesh with emerging national and regional research and management plans.

  19. Power, fresh water, and food from cold, deep sea water.

    PubMed

    Othmer, D F; Roels, O A

    1973-10-12

    Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water. A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit. PMID:17777883

  20. Power, fresh water, and food from cold, deep sea water.

    PubMed

    Othmer, D F; Roels, O A

    1973-10-12

    Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water. A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit.

  1. Catalysis of carbon monoxide methanation by deep sea manganate minerals

    NASA Technical Reports Server (NTRS)

    Cabrera, A. L.; Maple, M. B.; Arrhenius, G.

    1990-01-01

    The catalytic activity of deep sea manganese nodule minerals for the methanation of carbon monoxide was measured with a microcatalytic technique between 200 and 460 degrees C. The manganate minerals were activated at 248 degrees C by immersion into a stream of hydrogen in which pulses of carbon monoxide were injected. Activation energies for the methanation reaction and hydrogen desorption from the manganate minerals were obtained and compared with those of pure nickel. Similar energy values indicate that the activity of the nodule materials for the reaction appears to be related to the amount of reducible transition metals present in the samples (ca. 11 wt.-%). Since the activity of the nodule minerals per gram is comparable to that of pure nickel, most of the transition metal ions located between manganese oxide layers appear to be exposed and available to catalyze the reaction.

  2. Distribution of Mg and Li in Deep-Sea Scleractinian Corals: Implications for "Vital Effects" and Deep-Sea Thermometry

    NASA Astrophysics Data System (ADS)

    Case, D. H.; Robinson, L. F.; Auro, M. E.; Gagnon, A. C.

    2009-12-01

    The deep ocean is an important component of the climate system, but high resolution records of its behavior are difficult to obtain. Deep-sea corals that form carbonate skeletons have the potential to provide decadal resolution records of the deep ocean. Unfortunately, paleoceanographic approaches to reconstructing temperature in other marine carbonates, including Mg/Ca and ∂18O, are inconsistent with inorganic predictions due to biological mediation, or so called “vital effects." Inspired by a strong Mg/Li to temperature correlation observed in aragonitic and calcitic foraminifera, this study investigated Mg/Li ratios in deep-sea corals as a possible paleothermometer. Two approaches were applied: laser ablation and solution inductively coupled plasma mass spectrometry. For solution analyses Mg/Li was measured to an uncertainty of ~1%, and for laser analyses this uncertainty increased to ~5%. In situ laser analyses across septae and thecae show that Li fractionates similarly to Mg in deep-sea corals relative to Ca, such that the Li/Ca vs. Mg/Ca ratio within a single coral lies on a line with a slope of 3.9 for Balanophyllia and 2.8 for D. dianthus. For D. dianthus, Mg/Ca varies by a factor of nearly three across coral density bands, with high Mg at centers of calcification. Mg/Li varies by only 1.6 times across the same regions. Biomineralization models including a Rayleigh model and a simple open system model are invoked in an attempt to explain these behaviors. As a test of Mg/Li temperature sensitivity twenty-one scleractinian corals, representing five species with a temperature range of 1.8 to 17°C were thoroughly cleaned before dissolution and analysis. Mg/Li correlates to temperature in these corals with R2 values of 0.47 and 0.99 obtained for D. dianthus and Caryophyllia respectively, a significant improvement compared to Mg/Ca. This finding is promising for use of Mg/Li in paleoclimate reconstructions, but further work is required to understand the

  3. Temporal latitudinal-gradient dynamics and tropical instability of deep-sea species diversity

    USGS Publications Warehouse

    Yasuhara, Moriaki; Hunt, G.; Cronin, T. M.; Okahashi, H.

    2009-01-01

    A benthic microfaunal record from the equatorial Atlantic Ocean over the past four glacial-interglacial cycles was investigated to understand temporal dynamics of deep-sea latitudinal species diversity gradients (LSDGs). The results demonstrate unexpected instability and high amplitude fluctuations of species diversity in the tropical deep ocean that are correlated with orbital-scale oscillations in global climate: Species diversity is low during glacial and high during interglacial periods. This implies that climate severely influences deep-sea diversity, even at tropical latitudes, and that deep-sea LSDGs, while generally present for the last 36 million years, were weakened or absent during glacial periods. Temporally dynamic LSDGs and unstable tropical diversity require reconsideration of current ecological hypotheses about the generation and maintenance of biodiversity as they apply to the deep sea, and underscore the potential vulnerability and conservation importance of tropical deep-sea ecosystems.

  4. Work-related lost time accidents in deep-sea fishermen.

    PubMed

    Tomaszunas, S

    1992-01-01

    To evaluate the problem of work-related accidents and injuries in fishermen, a survey was conducted among crews of deep-sea fishing trawlers-factory ships of 3 large fishing companies, covering the period of 10 years (1977-1986). In the surveyed population of 10,475 men and a control group of 4,073 workers employed on shore, there were altogether 1,688 work-related accidents recorded, including 33 fatal accidents. Their incidence was 16.54 per 1000 per year (0.32 fatal cases per 1000 men per year). In the control group (n = 4,073 workers), the incidence was 27.98 per 1000 men (0.03 fatal accidents per 1000). There were more accidents recorded in the control group, than in fishermen. But the incidence of fatal cases was about 10 times higher among fishermen than among workers employed on shore. Among 33 fatal cases in fishermen, there were 12 cases of drowning, 6--injuries, 2--intoxications, 1--burn, and 12 cases sudden death at sea considered as "work-related accidents".

  5. Vertebrate nutrition in a deep-sea hydrothermal vent ecosystem: Fatty acid and stable isotope evidence

    NASA Astrophysics Data System (ADS)

    Pond, D. W.; Fallick, A. E.; Stevens, C. J.; Morrison, D. J.; Dixon, D. R.

    2008-12-01

    The hydrothermal vent zoarcid fish Thermarces cerberus is a top predator that inhabits deep-sea hydrothermal vents on the East Pacific Rise (EPR). Bacterial chemoautotrophy at these sites supports abundant animal communities. Paradoxically, these chemoautotrophic bacteria are not known to produce polyunsaturated fatty acids (PUFA), dietary nutrients essential for all marine vertebrates. To understand how T. cerberus successfully exploits the vent environment and obtains essential PUFA, we compared its fatty acid composition to those of its invertebrate prey. Levels of 20:5(n-3) and 22:6(n-3) in muscle and ovary tissues of T. cerberus were low and contained higher amounts of 20:5(n-3) than 22:6(n-3). This is in contrast to most marine fish where 22:6(n-3) typically dominates. Prey items include the limpet ( Lepetodrilus elevatus) and amphipods ( Halice hesmonectes and Ventiella sulfuris) and all contained PUFA dominated by 20:5(n-3) in amounts likely to support the requirements of T. cerberus. δC13 values of 20:5(n-3) in the invertebrate prey were consistent with synthesis from a chemoautotrophic carbon source within the vent environment. The potential origins of these PUFA are discussed in terms of the nutrition of T. cerberus and more generally in terms of the evolution of vent taxa.

  6. Rhodopsin in the Dark Hot Sea: Molecular Analysis of Rhodopsin in a Snailfish, Careproctus rhodomelas, Living near the Deep-Sea Hydrothermal Vent

    PubMed Central

    Sakata, Rie; Kabutomori, Ryo; Okano, Keiko; Mitsui, Hiromasa; Takemura, Akihiro; Miwa, Tetsuya; Yamamoto, Hiroyuki; Okano, Toshiyuki

    2015-01-01

    Visual systems in deep-sea fishes have been previously studied from a photobiological aspect; however, those of deep-sea fish inhabiting the hydrothermal vents are far less understood due to sampling difficulties. In this study, we analyzed the visual pigment of a deep-sea snailfish, Careproctus rhodomelas, discovered and collected only near the hydrothermal vents of oceans around Japan. Proteins were solubilized from the C. rhodomelas eyeball and subjected to spectroscopic analysis, which revealed the presence of a pigment characterized by an absorption maximum (λmax) at 480 nm. Immunoblot analysis of the ocular protein showed a rhodopsin-like immunoreactivity. We also isolated a retinal cDNA encoding the entire coding sequence of putative C. rhodomelas rhodopsin (CrRh). HEK293EBNA cells were transfected with the CrRh cDNA and the proteins extracted from the cells were subjected to spectroscopic analysis. The recombinant CrRh showed the absorption maximum at 480 nm in the presence of 11-cis retinal. Comparison of the results from the eyeball extract and the recombinant CrRh strongly suggests that CrRh has an A1-based 11-cis-retinal chromophore and works as a photoreceptor in the C. rhodomelas retina, and hence that C. rhodomelas responds to dim blue light much the same as other deep-sea fishes. Because hydrothermal vent is a huge supply of viable food, C. rhodomelas likely do not need to participate diel vertical migration and may recognize the bioluminescence produced by aquatic animals living near the hydrothermal vents. PMID:26275172

  7. Rhodopsin in the Dark Hot Sea: Molecular Analysis of Rhodopsin in a Snailfish, Careproctus rhodomelas, Living near the Deep-Sea Hydrothermal Vent.

    PubMed

    Sakata, Rie; Kabutomori, Ryo; Okano, Keiko; Mitsui, Hiromasa; Takemura, Akihiro; Miwa, Tetsuya; Yamamoto, Hiroyuki; Okano, Toshiyuki

    2015-01-01

    Visual systems in deep-sea fishes have been previously studied from a photobiological aspect; however, those of deep-sea fish inhabiting the hydrothermal vents are far less understood due to sampling difficulties. In this study, we analyzed the visual pigment of a deep-sea snailfish, Careproctus rhodomelas, discovered and collected only near the hydrothermal vents of oceans around Japan. Proteins were solubilized from the C. rhodomelas eyeball and subjected to spectroscopic analysis, which revealed the presence of a pigment characterized by an absorption maximum (λmax) at 480 nm. Immunoblot analysis of the ocular protein showed a rhodopsin-like immunoreactivity. We also isolated a retinal cDNA encoding the entire coding sequence of putative C. rhodomelas rhodopsin (CrRh). HEK293EBNA cells were transfected with the CrRh cDNA and the proteins extracted from the cells were subjected to spectroscopic analysis. The recombinant CrRh showed the absorption maximum at 480 nm in the presence of 11-cis retinal. Comparison of the results from the eyeball extract and the recombinant CrRh strongly suggests that CrRh has an A1-based 11-cis-retinal chromophore and works as a photoreceptor in the C. rhodomelas retina, and hence that C. rhodomelas responds to dim blue light much the same as other deep-sea fishes. Because hydrothermal vent is a huge supply of viable food, C. rhodomelas likely do not need to participate diel vertical migration and may recognize the bioluminescence produced by aquatic animals living near the hydrothermal vents.

  8. Rhodopsin in the Dark Hot Sea: Molecular Analysis of Rhodopsin in a Snailfish, Careproctus rhodomelas, Living near the Deep-Sea Hydrothermal Vent.

    PubMed

    Sakata, Rie; Kabutomori, Ryo; Okano, Keiko; Mitsui, Hiromasa; Takemura, Akihiro; Miwa, Tetsuya; Yamamoto, Hiroyuki; Okano, Toshiyuki

    2015-01-01

    Visual systems in deep-sea fishes have been previously studied from a photobiological aspect; however, those of deep-sea fish inhabiting the hydrothermal vents are far less understood due to sampling difficulties. In this study, we analyzed the visual pigment of a deep-sea snailfish, Careproctus rhodomelas, discovered and collected only near the hydrothermal vents of oceans around Japan. Proteins were solubilized from the C. rhodomelas eyeball and subjected to spectroscopic analysis, which revealed the presence of a pigment characterized by an absorption maximum (λmax) at 480 nm. Immunoblot analysis of the ocular protein showed a rhodopsin-like immunoreactivity. We also isolated a retinal cDNA encoding the entire coding sequence of putative C. rhodomelas rhodopsin (CrRh). HEK293EBNA cells were transfected with the CrRh cDNA and the proteins extracted from the cells were subjected to spectroscopic analysis. The recombinant CrRh showed the absorption maximum at 480 nm in the presence of 11-cis retinal. Comparison of the results from the eyeball extract and the recombinant CrRh strongly suggests that CrRh has an A1-based 11-cis-retinal chromophore and works as a photoreceptor in the C. rhodomelas retina, and hence that C. rhodomelas responds to dim blue light much the same as other deep-sea fishes. Because hydrothermal vent is a huge supply of viable food, C. rhodomelas likely do not need to participate diel vertical migration and may recognize the bioluminescence produced by aquatic animals living near the hydrothermal vents. PMID:26275172

  9. Patterns of deep-sea genetic connectivity in the New Zealand region: implications for management of benthic ecosystems.

    PubMed

    Bors, Eleanor K; Rowden, Ashley A; Maas, Elizabeth W; Clark, Malcolm R; Shank, Timothy M

    2012-01-01

    Patterns of genetic connectivity are increasingly considered in the design of marine protected areas (MPAs) in both shallow and deep water. In the New Zealand Exclusive Economic Zone (EEZ), deep-sea communities at upper bathyal depths (<2000 m) are vulnerable to anthropogenic disturbance from fishing and potential mining operations. Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand's EEZ are not well understood. Using the mitochondrial Cytochrome Oxidase I and 16S rRNA genes as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, significant population structure was detected among distinct populations on the Chatham Rise, the Hikurangi Margin, and the Challenger Plateau. Significant genetic differences existed between slope and seamount populations on the Hikurangi Margin, as did evidence of population differentiation between the northeast and southwest parts of the Chatham Rise. In contrast, no significant population structure was detected across the study area for the squat lobster. Patterns of genetic connectivity in Hyalinoecia longibranchiata are likely influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region.

  10. Patterns of deep-sea genetic connectivity in the New Zealand region: implications for management of benthic ecosystems.

    PubMed

    Bors, Eleanor K; Rowden, Ashley A; Maas, Elizabeth W; Clark, Malcolm R; Shank, Timothy M

    2012-01-01

    Patterns of genetic connectivity are increasingly considered in the design of marine protected areas (MPAs) in both shallow and deep water. In the New Zealand Exclusive Economic Zone (EEZ), deep-sea communities at upper bathyal depths (<2000 m) are vulnerable to anthropogenic disturbance from fishing and potential mining operations. Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand's EEZ are not well understood. Using the mitochondrial Cytochrome Oxidase I and 16S rRNA genes as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, significant population structure was detected among distinct populations on the Chatham Rise, the Hikurangi Margin, and the Challenger Plateau. Significant genetic differences existed between slope and seamount populations on the Hikurangi Margin, as did evidence of population differentiation between the northeast and southwest parts of the Chatham Rise. In contrast, no significant population structure was detected across the study area for the squat lobster. Patterns of genetic connectivity in Hyalinoecia longibranchiata are likely influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region. PMID:23185341

  11. Patterns of Deep-Sea Genetic Connectivity in the New Zealand Region: Implications for Management of Benthic Ecosystems

    PubMed Central

    Bors, Eleanor K.; Rowden, Ashley A.; Maas, Elizabeth W.; Clark, Malcolm R.; Shank, Timothy M.

    2012-01-01

    Patterns of genetic connectivity are increasingly considered in the design of marine protected areas (MPAs) in both shallow and deep water. In the New Zealand Exclusive Economic Zone (EEZ), deep-sea communities at upper bathyal depths (<2000 m) are vulnerable to anthropogenic disturbance from fishing and potential mining operations. Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand’s EEZ are not well understood. Using the mitochondrial Cytochrome Oxidase I and 16S rRNA genes as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, significant population structure was detected among distinct populations on the Chatham Rise, the Hikurangi Margin, and the Challenger Plateau. Significant genetic differences existed between slope and seamount populations on the Hikurangi Margin, as did evidence of population differentiation between the northeast and southwest parts of the Chatham Rise. In contrast, no significant population structure was detected across the study area for the squat lobster. Patterns of genetic connectivity in Hyalinoecia longibranchiata are likely influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region. PMID:23185341

  12. Microbial Evolution at High Pressure: Deep Sea and Laboratory Studies

    NASA Astrophysics Data System (ADS)

    Bartlett, D. H.

    2011-12-01

    Elevated hydrostatic pressures are present in deep-sea and deep-Earth environments where this physical parameter has influenced the evolution and characteristics of life. Piezophilic (high-pressure-adapted) microbes have been isolated from diverse deep-sea settings, and would appear likely to occur in deep-subsurface habitats as well. In order to discern the factors enabling life at high pressure my research group has explored these adaptations at various levels, most recently including molecular analyses of deep-sea trench communities, and through the selective evolution of the model microbe Escherichia coli in the laboratory to progressively higher pressures. Much of the field work has focused on the microbes present in the deeper portions of the Puerto Rico Trench (PRT)and in the Peru-Chile Trench (PCT), from 6-8.5 km below the sea surface (~60-85 megapascals pressure). Culture-independent phylogenetic data on the Bacteria and Archaea present on particles or free-living, along with data on the microeukarya present was complemented with genomic analyses and the isolation and characterization of microbes in culture. Metagenomic analyses of the PRT revealed increased genome sizes and an overrepresentation at depth of sulfatases for the breakdown of sulfated polysaccharides and specific categories of transporters, including those associated with the transport of diverse cations or carboxylate ions, or associated with heavy metal resistance. Single-cell genomic studies revealed several linneages which recruited to the PRT metagenome far better than existing marine microbial genome sequences. analyses. Novel high pressure culture approaches have yielded new piezophiles including species preferring very low nutrient levels, those living off of hydrocarbons, and those adapted to various electron donor/electron acceptor combinations. In order to more specifically focus on functions enabling life at increased pressure selective evolution experiments were performed with

  13. Adaptation to deep-sea methane seeps from Cretaceous shallow-water black shale environments?

    NASA Astrophysics Data System (ADS)

    Kiel, Steffen; Wiese, Frank; Titus, Alan

    2013-04-01

    Sulfide-enriched environments in shallow water were considered as sites where animals acquire pre-adaptations enabling them to colonize deep-sea hydrothermal vents and seeps or where they survived extinction events in their deep-sea habitats. Here we present upper Cenomanian (early Late Cretaceous) shallow-water seep communities from the Tropic Shale in the Western Interior Seaway, USA, that lived during a time of extremely warm deep-water temperatures, which supposedly facilitates adaptations to the deep sea, and time-equivalent with a period of widespread oceanic and photic zone anoxia (OAE 2) that supposedly extinguished deep-water vent and seep faunas. Contrary to the expectation, the taxa inhabiting the Tropic Shale seeps were not found at any coeval or younger deep-water seep or vent deposit. This suggests that (i) pre-adaptations for living at deep-sea vents and seeps do not evolve at shallow-water methane seeps, and probably also not in sulfide-rich shallow-water environments in general; (ii) a low temperature gradient from shallow to deep water does not facilitate onshore-offshore adaptations to deep-sea vents and seeps; and (iii) shallow-water seeps did not act as refuges for deep-sea vent and seep animals. We hypothesize that the vast majority of adaptations to successfully colonize deep-sea vents and seeps are acquired below the photic zone.

  14. Biodiversity Science In The Deep Sea: The ESF EuroDEEP Programme

    NASA Astrophysics Data System (ADS)

    Jonckheere, I. G.

    2007-12-01

    What little we know of deep-sea ecosystems indicates that they host one of the highest biodiversities on the planet as well as important mineral and biological resources, which are increasingly being exploited. Understanding deep-sea biodiversity and ecosystem functioning, from viruses to megafauna, is essential to assess the impact of natural and anthropogenic factors and provide management options. The aim of the multidisciplinary ESF EUROCORES Programme EuroDEEP, Ecosystem Functioning and Biodiversity in Deep Sea, is to further explore and identify the different deep-sea habitats, assessing both the abiotic and biotic processes that sustain and maintain deep-sea communities. The scope is to interpret variations of biodiversity within and between deep-sea habitats, and the interactions of the biota with the ecosystems in which they live. The resulting scientific data are a prerequisite for the sustainable use and the development of management and conservation options aiming at the sustainable use of marine resources that will benefit society as a whole. The Programme aims at providing the necessary framework and funding for the development of top-quality deep- sea research at the European level in a global context (Census of Marine Life and SCOR/IGBP). In particular, it builds on sharing of national large-scale resources, which are essential for deep-sea research (i.e. ships, ROVs, submersibles, AUVs, deep-towed vehicles, deep-sea sampling equipment, new sensors, etc.) as well as the coordination of efforts amongst scientists and laboratories from the countries involved and links with ongoing projects. EuroDEEP will participate in the development of new technologies as well as data management, analysis and modelling. Most of all, EuroDEEP will catalyse excellent research on what biodiversity exists in the deep sea, how it is generated and maintained by abiotic and biotic processes, and what the role of the deep-sea is in the biogeochemical processes affecting the

  15. Marine culturable yeasts in deep-sea hydrothermal vents: species richness and association with fauna.

    PubMed

    Burgaud, Gaëtan; Arzur, Danielle; Durand, Lucile; Cambon-Bonavita, Marie-Anne; Barbier, Georges

    2010-07-01

    Investigations of the diversity of culturable yeasts at deep-sea hydrothermal sites have suggested possible interactions with endemic fauna. Samples were collected during various oceanographic cruises at the Mid-Atlantic Ridge, South Pacific Basins and East Pacific Rise. Cultures of 32 isolates, mostly associated with animals, were collected. Phylogenetic analyses of 26S rRNA gene sequences revealed that the yeasts belonged to Ascomycota and Basidiomycota phyla, with the identification of several genera: Rhodotorula, Rhodosporidium, Candida, Debaryomyces and Cryptococcus. Those genera are usually isolated from deep-sea environments. To our knowledge, this is the first report of yeasts associated with deep-sea hydrothermal animals.

  16. An abyssal mobilome: viruses, plasmids and vesicles from deep-sea hydrothermal vents.

    PubMed

    Lossouarn, Julien; Dupont, Samuel; Gorlas, Aurore; Mercier, Coraline; Bienvenu, Nadege; Marguet, Evelyne; Forterre, Patrick; Geslin, Claire

    2015-12-01

    Mobile genetic elements (MGEs) such as viruses, plasmids, vesicles, gene transfer agents (GTAs), transposons and transpovirions, which collectively represent the mobilome, interact with cellular organisms from all three domains of life, including those thriving in the most extreme environments. While efforts have been made to better understand deep-sea vent microbial ecology, our knowledge of the mobilome associated with prokaryotes inhabiting deep-sea hydrothermal vents remains limited. Here we focus on the abyssal mobilome by reviewing accumulating data on viruses, plasmids and vesicles associated with thermophilic and hyperthermophilic Bacteria and Archaea present in deep-sea hydrothermal vents. PMID:25911507

  17. An abyssal mobilome: viruses, plasmids and vesicles from deep-sea hydrothermal vents.

    PubMed

    Lossouarn, Julien; Dupont, Samuel; Gorlas, Aurore; Mercier, Coraline; Bienvenu, Nadege; Marguet, Evelyne; Forterre, Patrick; Geslin, Claire

    2015-12-01

    Mobile genetic elements (MGEs) such as viruses, plasmids, vesicles, gene transfer agents (GTAs), transposons and transpovirions, which collectively represent the mobilome, interact with cellular organisms from all three domains of life, including those thriving in the most extreme environments. While efforts have been made to better understand deep-sea vent microbial ecology, our knowledge of the mobilome associated with prokaryotes inhabiting deep-sea hydrothermal vents remains limited. Here we focus on the abyssal mobilome by reviewing accumulating data on viruses, plasmids and vesicles associated with thermophilic and hyperthermophilic Bacteria and Archaea present in deep-sea hydrothermal vents.

  18. Resource quality affects carbon cycling in deep-sea sediments

    PubMed Central

    Mayor, Daniel J; Thornton, Barry; Hay, Steve; Zuur, Alain F; Nicol, Graeme W; McWilliam, Jenna M; Witte, Ursula F M

    2012-01-01

    Deep-sea sediments cover ∼70% of Earth's surface and represent the largest interface between the biological and geological cycles of carbon. Diatoms and zooplankton faecal pellets naturally transport organic material from the upper ocean down to the deep seabed, but how these qualitatively different substrates affect the fate of carbon in this permanently cold environment remains unknown. We added equal quantities of 13C-labelled diatoms and faecal pellets to a cold water (−0.7 °C) sediment community retrieved from 1080 m in the Faroe-Shetland Channel, Northeast Atlantic, and quantified carbon mineralization and uptake by the resident bacteria and macrofauna over a 6-day period. High-quality, diatom-derived carbon was mineralized >300% faster than that from low-quality faecal pellets, demonstrating that qualitative differences in organic matter drive major changes in the residence time of carbon at the deep seabed. Benthic bacteria dominated biological carbon processing in our experiments, yet showed no evidence of resource quality-limited growth; they displayed lower growth efficiencies when respiring diatoms. These effects were consistent in contrasting months. We contend that respiration and growth in the resident sediment microbial communities were substrate and temperature limited, respectively. Our study has important implications for how future changes in the biochemical makeup of exported organic matter will affect the balance between mineralization and sequestration of organic carbon in the largest ecosystem on Earth. PMID:22378534

  19. Cellulomonas marina sp. nov., isolated from deep-sea water.

    PubMed

    Zhang, Limin; Xi, Lijun; Qiu, Danheng; Song, Lei; Dai, Xin; Ruan, Jisheng; Huang, Ying

    2013-08-01

    A bacterial strain FXJ8.089(T) was isolated from deep-sea water collected from the southwest Indian Ocean (49° 39' E 37° 47' S) at a depth of 2800 m, and its taxonomic position was investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FXJ8.089(T) belonged to the genus Cellulomonas and had the highest similarities with Cellulomonas oligotrophica (96.9 %) and Cellulomonas aerilata (96.6 %). It contained MK-9(H4) as the predominant menaquinone. The polar lipids were diphosphatidylglycerol and phosphatidylinositol mannosides. The cell-wall peptidoglycan type was A4β with an interpeptide bridge L-Orn-D-Glu. The cell-wall sugars were glucose, mannose and ribose. The DNA G+C content was 70.3 mol%. The strain also showed a number of physiological and biochemical characteristics that were distinct from the closely related species. Based on phenotypic and genotypic data, strain FXJ8.089(T) (= CGMCC 4.6945(T) = DSM 24960(T)) represents a novel species of the genus Cellulomonas, for which the name Cellulomonas marina sp. nov. is proposed.

  20. Deep sea hydrothermal plumes and their interaction with oscillatory flows

    NASA Astrophysics Data System (ADS)

    Xu, Guangyu; di Iorio, Daniela

    2012-09-01

    The acoustic scintillation method is applied to the investigation and monitoring of a vigorous hydrothermal plume from Dante within the Main Endeavour vent field (MEF) in the Endeavour Ridge segment. A 40 day time series of the plume's vertical velocity and temperature fluctuations provides a unique opportunity to study deep sea plume dynamics in a tidally varying horizontal cross flow. An integral plume model that takes into account ambient stratification and horizontal cross flows is established from the conservation equations of mass, momentum and density deficit. Using a linear additive entrainment velocity in the model (E = αUm + βU⊥) that is a function of both the plume relative axial velocity (Um) and the relative ambient flow perpendicular to the plume (U⊥) gives consistent results to the experimental data, suggesting entrainment coefficients α = 0.1 and β = 0.6. Also from the integral model, the plume height in a horizontal cross flow (Ua) is shown to scale as 1.8B1/3Ua-1/3N-2/3 for 0.01 ≤ Ua ≤ 0.1 m/s where B is the initial buoyancy transport and N is the ambient stratification, both of which are assumed constant.

  1. Carbon dioxide sequestration in deep-sea basalt.

    PubMed

    Goldberg, David S; Takahashi, Taro; Slagle, Angela L

    2008-07-22

    Developing a method for secure sequestration of anthropogenic carbon dioxide in geological formations is one of our most pressing global scientific problems. Injection into deep-sea basalt formations provides unique and significant advantages over other potential geological storage options, including (i) vast reservoir capacities sufficient to accommodate centuries-long U.S. production of fossil fuel CO2 at locations within pipeline distances to populated areas and CO2 sources along the U.S. west coast; (ii) sufficiently closed water-rock circulation pathways for the chemical reaction of CO2 with basalt to produce stable and nontoxic (Ca(2+), Mg(2+), Fe(2+))CO(3) infilling minerals, and (iii) significant risk reduction for post-injection leakage by geological, gravitational, and hydrate-trapping mechanisms. CO2 sequestration in established sediment-covered basalt aquifers on the Juan de Fuca plate offer promising locations to securely accommodate more than a century of future U.S. emissions, warranting energized scientific research, technological assessment, and economic evaluation to establish a viable pilot injection program in the future.

  2. Virtual Investigations of an Active Deep Sea Volcano

    NASA Astrophysics Data System (ADS)

    Sautter, L.; Taylor, M. M.; Fundis, A.; Kelley, D. S.; Elend, M.

    2013-12-01

    Axial Seamount, located on the Juan de Fuca spreading ridge 300 miles off the Oregon coast, is an active volcano whose summit caldera lies 1500 m beneath the sea surface. Ongoing construction of the Regional Scale Nodes (RSN) cabled observatory by the University of Washington (funded by the NSF Ocean Observatories Initiative) has allowed for exploration of recent lava flows and active hydrothermal vents using HD video mounted on the ROVs, ROPOS and JASON II. College level oceanography/marine geology online laboratory exercises referred to as Online Concept Modules (OCMs) have been created using video and video frame-captured mosaics to promote skill development for characterizing and quantifying deep sea environments. Students proceed at their own pace through a sequence of short movies with which they (a) gain background knowledge, (b) learn skills to identify and classify features or biota within a targeted environment, (c) practice these skills, and (d) use their knowledge and skills to make interpretations regarding the environment. Part (d) serves as the necessary assessment component of the laboratory exercise. Two Axial Seamount-focused OCMs will be presented: 1) Lava Flow Characterization: Identifying a Suitable Cable Route, and 2) Assessing Hydrothermal Vent Communities: Comparisons Among Multiple Sulfide Chimneys.

  3. Luteimonas abyssi sp. nov., isolated from deep-sea sediment.

    PubMed

    Fan, Xiaoyang; Yu, Tong; Li, Zhao; Zhang, Xiao-Hua

    2014-02-01

    Three Gram-stain-negative, strictly aerobic, rod-shaped with single polar flagellum, yellow-pigmented bacteria, designated strains XH031(T), XH038-3 and XH80-1, were isolated from deep-sea sediment of the South Pacific Gyre (41° 51' S 153° 6' W) during the Integrated Ocean Drilling Program (IODP) Expedition 329. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolates belonged to the genus Luteimonas and showed the highest 16S rRNA gene sequence similarity with Luteimonas aestuarii B9(T) (96.95%), Luteimonas huabeiensis HB2(T) (96.93%) and Xanthomonas cucurbitae LMG 690(T) (96.92 %). The DNA G+C contents of the three isolates were 70.2-73.9 mol%. The major fatty acids were iso-C(15 : 0), iso-C(16 : 0), iso-C(11 : 0) and C16 : 010-methyl and/or iso-C(17 : 1)ω9c. The major respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and one unknown phospholipid. On the basis of data from polyphasic analysis, the three isolates represent a novel species of the genus Luteimonas, for which the name Luteimonas abyssi sp. nov. is proposed. The type strain is XH031(T) ( = DSM 25880(T) = CGMCC 1.12611(T)). PMID:24170776

  4. Adaptive radiation of chemosymbiotic deep-sea mussels

    PubMed Central

    Lorion, Julien; Kiel, Steffen; Faure, Baptiste; Kawato, Masaru; Ho, Simon Y. W.; Marshall, Bruce; Tsuchida, Shinji; Miyazaki, Jun-Ichi; Fujiwara, Yoshihiro

    2013-01-01

    Adaptive radiations present fascinating opportunities for studying the evolutionary process. Most cases come from isolated lakes or islands, where unoccupied ecological space is filled through novel adaptations. Here, we describe an unusual example of an adaptive radiation: symbiotic mussels that colonized island-like chemosynthetic environments such as hydrothermal vents, cold seeps and sunken organic substrates on the vast deep-sea floor. Our time-calibrated molecular phylogeny suggests that the group originated and acquired sulfur-oxidizing symbionts in the Late Cretaceous, possibly while inhabiting organic substrates and long before its major radiation in the Middle Eocene to Early Oligocene. The first appearance of intracellular and methanotrophic symbionts was detected only after this major radiation. Thus, contrary to expectations, the major radiation may have not been triggered by the evolution of novel types of symbioses. We hypothesize that environmental factors, such as increased habitat availability and/or increased dispersal capabilities, sparked the radiation. Intracellular and methanotrophic symbionts were acquired in several independent lineages and marked the onset of a second wave of diversification at vents and seeps. Changes in habitat type resulted in adaptive trends in shell lengths (related to the availability of space and energy, and physiological trade-offs) and in the successive colonization of greater water depths. PMID:24048154

  5. Carbon dioxide sequestration in deep-sea basalt

    PubMed Central

    Goldberg, David S.; Takahashi, Taro; Slagle, Angela L.

    2008-01-01

    Developing a method for secure sequestration of anthropogenic carbon dioxide in geological formations is one of our most pressing global scientific problems. Injection into deep-sea basalt formations provides unique and significant advantages over other potential geological storage options, including (i) vast reservoir capacities sufficient to accommodate centuries-long U.S. production of fossil fuel CO2 at locations within pipeline distances to populated areas and CO2 sources along the U.S. west coast; (ii) sufficiently closed water-rock circulation pathways for the chemical reaction of CO2 with basalt to produce stable and nontoxic (Ca2+, Mg2+, Fe2+)CO3 infilling minerals, and (iii) significant risk reduction for post-injection leakage by geological, gravitational, and hydrate-trapping mechanisms. CO2 sequestration in established sediment-covered basalt aquifers on the Juan de Fuca plate offer promising locations to securely accommodate more than a century of future U.S. emissions, warranting energized scientific research, technological assessment, and economic evaluation to establish a viable pilot injection program in the future. PMID:18626013

  6. Factors controlling ebro deep-sea fan growth, Mediterranean Sea

    SciTech Connect

    Nelson, C.H.; Maldonado, A.; Alonso, B.; Palanques, A.; Ryan, W.B.F.; Kastens, K.; O'Connel, S.

    1985-01-01

    Tectonic, sediment-source and sea-level factors control depositional patterns of the Ebro deep-sea fan system. In unstable, steep continental slope terrain, mass movement of material results in wide gullied canyons and formation of non-channelized debris aprons. These fan channels develop low sinuosity and generally traverse the continental rise without feeding into depositional lobes because of steep gradients (1:50 to 1:100) and sediment draining into the subsiding Valencia Valley graben. An abundance of sediment input points from mass failure and many river-fed canyons contributes to a depositional pattern of side-by-side debris aprons and separate channel-levee complexes. When a large sediment supply feeds a channel for a relatively long period 1) fan valley sinuosity increases: 2) channel walls are modified through undercutting, slumping, and crevasse splays: 3) channel bifurcation occurs: 4) incipient depositional lobe formation begins. Lowering of sea levels in Late Pleistocene time permitted the access of coarse river sediment to slope valleys and promoted deposition of numerous turbidites and active growth of the fan. During the Holocene, when sea levels have been high, a regime of hemipelagic sedimentation, mass movement, and debris apron sedimentation has dominated.

  7. Resource quality affects carbon cycling in deep-sea sediments.

    PubMed

    Mayor, Daniel J; Thornton, Barry; Hay, Steve; Zuur, Alain F; Nicol, Graeme W; McWilliam, Jenna M; Witte, Ursula F M

    2012-09-01

    Deep-sea sediments cover ~70% of Earth's surface and represent the largest interface between the biological and geological cycles of carbon. Diatoms and zooplankton faecal pellets naturally transport organic material from the upper ocean down to the deep seabed, but how these qualitatively different substrates affect the fate of carbon in this permanently cold environment remains unknown. We added equal quantities of (13)C-labelled diatoms and faecal pellets to a cold water (-0.7 °C) sediment community retrieved from 1080 m in the Faroe-Shetland Channel, Northeast Atlantic, and quantified carbon mineralization and uptake by the resident bacteria and macrofauna over a 6-day period. High-quality, diatom-derived carbon was mineralized >300% faster than that from low-quality faecal pellets, demonstrating that qualitative differences in organic matter drive major changes in the residence time of carbon at the deep seabed. Benthic bacteria dominated biological carbon processing in our experiments, yet showed no evidence of resource quality-limited growth; they displayed lower growth efficiencies when respiring diatoms. These effects were consistent in contrasting months. We contend that respiration and growth in the resident sediment microbial communities were substrate and temperature limited, respectively. Our study has important implications for how future changes in the biochemical makeup of exported organic matter will affect the balance between mineralization and sequestration of organic carbon in the largest ecosystem on Earth. PMID:22378534

  8. Luteimonas abyssi sp. nov., isolated from deep-sea sediment.

    PubMed

    Fan, Xiaoyang; Yu, Tong; Li, Zhao; Zhang, Xiao-Hua

    2014-02-01

    Three Gram-stain-negative, strictly aerobic, rod-shaped with single polar flagellum, yellow-pigmented bacteria, designated strains XH031(T), XH038-3 and XH80-1, were isolated from deep-sea sediment of the South Pacific Gyre (41° 51' S 153° 6' W) during the Integrated Ocean Drilling Program (IODP) Expedition 329. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolates belonged to the genus Luteimonas and showed the highest 16S rRNA gene sequence similarity with Luteimonas aestuarii B9(T) (96.95%), Luteimonas huabeiensis HB2(T) (96.93%) and Xanthomonas cucurbitae LMG 690(T) (96.92 %). The DNA G+C contents of the three isolates were 70.2-73.9 mol%. The major fatty acids were iso-C(15 : 0), iso-C(16 : 0), iso-C(11 : 0) and C16 : 010-methyl and/or iso-C(17 : 1)ω9c. The major respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and one unknown phospholipid. On the basis of data from polyphasic analysis, the three isolates represent a novel species of the genus Luteimonas, for which the name Luteimonas abyssi sp. nov. is proposed. The type strain is XH031(T) ( = DSM 25880(T) = CGMCC 1.12611(T)).

  9. Devosia pacifica sp. nov., isolated from deep-sea sediment.

    PubMed

    Jia, Yan-Yu; Sun, Cong; Pan, Jie; Zhang, Wei-Yan; Zhang, Xin-Qi; Huo, Ying-Yi; Zhu, Xu-Fen; Wu, Min

    2014-08-01

    A novel bacterial strain, NH131(T), was isolated from deep-sea sediment of South China Sea. Cells were strictly aerobic, Gram-stain negative, short rod-shaped and motile with a single lateral flagellum. Strain NH131(T) grew optimally at pH 6.5-7.0 and 25-30 °C. 16S rRNA gene sequence analysis revealed that strain NH131(T) belonged to the genus Devosia, sharing the highest sequence similarity with the type strain, Devosia geojensis BD-c194(T) (96.2%). The predominant fatty acids were C(18 : 1)ω7c, 11-methyl C(18 : 1)ω7c, C(18 : 0) and C(16 : 0). Ubiquinone 10 was the predominant ubiquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phospholipid, three glycolipids and two unknown lipids. The DNA G+C content of strain NH131(T) was 63.0 mol%. On the basis of the results of polyphasic identification, it is suggested that strain NH131(T) represents a novel species of the genus Devosia for which the name Devosia pacifica sp. nov. is proposed. The type strain is NH131(T) ( = JCM 19305(T) = KCTC 32437(T)).

  10. To what extent can specialized species succeed in the deep sea? The biology and trophic ecology of deep-sea spiny eels (Notacanthidae) in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Romeu, Oriol Rodríguez; Cartes, Joan E.; Solé, Montse; Carrassón, Maite

    2016-09-01

    found related with either depth or homogenization/stratification of the water column. This lack of changes in diet is probably attributable to the greater stability of the lower slope where P. rissoanus lives. Gut fullness was mainly correlated with surface Chlorophyll a recorded simultaneously with the fish sampling. Lactate dehydrogenase (LDH) activity was similar in the muscle of the two notacanthids (N. bonapartei=3.72-8.75 μmol/min/mg prot; P. rissoanus=7.56 μmol/min/mg prot). Values for N. bonapartei were the highest found compared to other deep-sea fish in the deep Mediterranean. This could be related with the special feeding behaviour of this species when it removes sessile prey from substrate.

  11. [Effects of prolonged work on "deep-sea" fishermen: influence of blood cortisol, prolactinemia and urinary catecholamines].

    PubMed

    Allegri, F; Passarello, B; Orrù, G; Coppola, A; Antona, A; Cannizzaro, E; Gagliano, M

    1996-01-01

    Effects of persistent overwork on the deep-sea fishermen: influence on serum cortisol and prolactin, and on urinary catecholamine levels. Variations in serum prolactin and cortisol levels and in urinary catecholamines levels were studied in fishermen exposed to a persistent overwork period of deep-sea fishing. Results indicate that prolactin was rapidly modified. In fact, the serum prolactin levels already increased on the first day and maximum levels were observed on the fifth day. On the contrary, the physiological rise and fall in the serum levels of cortisol were scarcely influenced on the first day while on the fifth day increased in the morning and fell in the evening in a very significant manner. No significant variation in urinary catecholamine levels was observed at the end of fifth day. These results suggest that, unlike for prolactin, the effects of stress on serum levels of cortisol are complex and, under our conditions, could be due, at least in part, to the duration of the stress and to the functional moment of pituitary-adrenal axis.

  12. Deep-sea in situ observations of gonatid squid and their prey reveal high occurrence of cannibalism

    NASA Astrophysics Data System (ADS)

    Hoving, H. J. T.; Robison, B. H.

    2016-10-01

    In situ observations are rarely applied in food web studies of deep-sea organisms. Using deep-sea observations obtained by remotely operated vehicles in the Monterey Submarine Canyon, we examined the prey choices of more than 100 individual squids of the genus Gonatus. Off the California coast, these squids are abundant, semelparous (one reproductive cycle) oceanic predators but their diet has remained virtually unknown. Gonatus onyx and Gonatus berryi were observed to feed on mesopelagic fishes (in particular the myctophid Stenobrachius leucopsarus) as often as on squids but inter-specific differences in feeding were apparent. Gonatids were the most common squid prey and while cannibalism occurred in both species it was particularly high in Gonatus onyx (42% of all prey items). Typically, the size of prey was similar to the size of the predator but the squids were also seen to take much larger prey. Postjuvenile gonatids are opportunistic predators that consume nektonic members of the meso-and bathypelagic communities, including their own species. Such voracious feeding is likely necessary to support the high energetic demands associated with the single reproductive event; and for females the long brooding period during which they must depend on stored resources.

  13. Carbonate-hosted methanotrophy represents an unrecognized methane sink in the deep sea.

    PubMed

    Marlow, Jeffrey J; Steele, Joshua A; Ziebis, Wiebke; Thurber, Andrew R; Levin, Lisa A; Orphan, Victoria J

    2014-01-01

    The atmospheric flux of methane from the oceans is largely mitigated through microbially mediated sulphate-coupled methane oxidation, resulting in the precipitation of authigenic carbonates. Deep-sea carbonates are common around active and palaeo-methane seepage, and have primarily been viewed as passive recorders of methane oxidation; their role as active and unique microbial habitats capable of continued methane consumption has not been examined. Here we show that seep-associated carbonates harbour active microbial communities, serving as dynamic methane sinks. Microbial aggregate abundance within the carbonate interior exceeds that of seep sediments, and molecular diversity surveys reveal methanotrophic communities within protolithic nodules and well-lithified carbonate pavements. Aggregations of microbial cells within the carbonate matrix actively oxidize methane as indicated by stable isotope FISH-nanoSIMS experiments and (14)CH4 radiotracer rate measurements. Carbonate-hosted methanotrophy extends the known ecological niche of these important methane consumers and represents a previously unrecognized methane sink that warrants consideration in global methane budgets. PMID:25313858

  14. Cultured fungal associates from the deep-sea coral Lophelia pertusa

    USGS Publications Warehouse

    Galkiewicz, Julia P.; Stellick, Sarah H.; Gray, Michael A.; Kellogg, Christina A.

    2012-01-01

    The cold-water coral Lophelia pertusa provides important habitat to many deep-sea fishes and invertebrates. Studies of the microbial taxa associated with L. pertusa thus far have focused on bacteria, neglecting the microeukaryotic members. This is the first study to culture fungi from living L. pertusa and to investigate carbon source utilization by the fungal associates. Twenty-seven fungal isolates from seven families, including both filamentous and yeast morphotypes, were cultured from healthy L. pertusa colonies collected from the northern Gulf of Mexico, the West Florida Slope, and the western Atlantic Ocean off the Florida coast. Isolates from different sites were phylogenetically closely related, indicating these genera are widely distributed in association with L. pertusa. Biolog™ Filamentous Fungi microtiter plates were employed to determine the functional capacity of a subset of isolates to grow on varied carbon sources. While four of the isolates exhibited no growth on any provided carbon source, the rest (n=10) grew on 8.3–66.7% of carbon sources available. Carbohydrates, carboxylic acids, and amino acids were the most commonly metabolized carbon sources, with overlap between the carbon sources used and amino acids found in L. pertusa mucus. This study represents the first attempt to characterize a microeukaryotic group associated with L. pertusa. However, the functional role of fungi within the coral holobiont remains unclear.

  15. Trophic position of deep-sea fish—Assessment through fatty acid and stable isotope analyses

    NASA Astrophysics Data System (ADS)

    Stowasser, G.; McAllen, R.; Pierce, G. J.; Collins, M. A.; Moffat, C. F.; Priede, I. G.; Pond, D. W.

    2009-05-01

    To investigate the trophic ecology of two of the dominant families of deep-sea fish (Macrouridae and Moridae) fatty acid and stable isotope analyses were applied to liver and muscle samples of five abundant species from the NE Atlantic. In conjunction with stomach content data these methods made it possible to identify differences in feeding strategies between the five study species as well as variation in feeding in relation to increasing depth and body size. Biomarkers identified strong similarities between Coryphaenoides armatus and Antimora rostrata though differences were found associating C. armatus more with the benthic food web whereas A. rostrata showed stronger links to the pelagic food web. While Lepidion eques was classified as a species linking benthic and benthopelagic food webs, both fatty acid and stable isotope data suggested that Coryphaenoides guentheri fed on an exclusively benthic diet . Coryphaenoides rupestris on the other hand were largely dependent on a copepod-based food web. Ontogenetic changes in feeding were found for both A. rostrata and C. armatus with the indication of a switch from active predation to scavenging occurring with increasing body size. Biomarkers also reflected the seasonal influx from the photic zone though changes were species-specific and probably reflected the variation in prey availability and abundance in response to these inputs. Our findings have thus demonstrated that the combined use of these biomarkers can elucidate trophic specialisations in situations where conventional methods alone previously provided insufficient data.

  16. Nitrogen Fixation By Sulfate-Reducing Bacteria in Coastal and Deep-Sea Sediments

    NASA Astrophysics Data System (ADS)

    Bertics, V. J.; Löscher, C.; Salonen, I.; Schmitz-Streit, R.; Lavik, G.; Kuypers, M. M.; Treude, T.

    2011-12-01

    Sulfate-reducing bacteria (SRB) can greatly impact benthic nitrogen (N) cycling, by for instance inhibiting coupled denitrification-nitrification through the production of sulfide or by increasing the availability of fixed N in the sediment via dinitrogen (N2)-fixation. Here, we explored several coastal and deep-sea benthic habitats within the Atlantic Ocean and Baltic Sea, for the occurrence of N2-fixation mediated by SRB. A combination of different methods including microbial rate measurements of N2-fixation and sulfate reduction, geochemical analyses (porewater nutrient profiles, mass spectrometry), and molecular analyses (CARD-FISH, HISH-SIMS, "nested" PCR, and QPCR) were applied to quantify and identify the responsible processes and organisms, respectively. Furthermore, we looked deeper into the question of whether the observed nitrogenase activity was associated with the final incorporation of N into microbial biomass or whether the enzyme activity served another purpose. At the AGU Fall Meeting, we will present and compare data from numerous stations with different water depths, temperatures, and latitudes, as well as differences in key geochemical parameters, such as organic carbon content and oxygen availability. Current metabolic and molecular data indicate that N2-fixation is occurring in many of these benthic environments and that a large part of this activity may linked to SRB.

  17. Cultured fungal associates from the deep-sea coral Lophelia pertusa

    NASA Astrophysics Data System (ADS)

    Galkiewicz, Julia P.; Stellick, Sarah H.; Gray, Michael A.; Kellogg, Christina A.

    2012-09-01

    The cold-water coral Lophelia pertusa provides important habitat to many deep-sea fishes and invertebrates. Studies of the microbial taxa associated with L. pertusa thus far have focused on bacteria, neglecting the microeukaryotic members. This is the first study to culture fungi from living L. pertusa and to investigate carbon source utilization by the fungal associates. Twenty-seven fungal isolates from seven families, including both filamentous and yeast morphotypes, were cultured from healthy L. pertusa colonies collected from the northern Gulf of Mexico, the West Florida Slope, and the western Atlantic Ocean off the Florida coast. Isolates from different sites were phylogenetically closely related, indicating these genera are widely distributed in association with L. pertusa. Biolog™ Filamentous Fungi microtiter plates were employed to determine the functional capacity of a subset of isolates to grow on varied carbon sources. While four of the isolates exhibited no growth on any provided carbon source, the rest (n=10) grew on 8.3-66.7% of carbon sources available. Carbohydrates, carboxylic acids, and amino acids were the most commonly metabolized carbon sources, with overlap between the carbon sources used and amino acids found in L. pertusa mucus. This study represents the first attempt to characterize a microeukaryotic group associated with L. pertusa. However, the functional role of fungi within the coral holobiont remains unclear.

  18. A Brief Review of Bioactive Metabolites Derived from Deep-Sea Fungi

    PubMed Central

    Wang, Yan-Ting; Xue, Ya-Rong; Liu, Chang-Hong

    2015-01-01

    Deep-sea fungi, the fungi that inhabit the sea and the sediment at depths of over 1000 m below the surface, have become an important source of industrial, agricultural, and nutraceutical compounds based on their diversities in both structure and function. Since the first study of deep-sea fungi in the Atlantic Ocean at a depth of 4450 m was conducted approximately 50 years ago, hundreds of isolates of deep-sea fungi have been reported based on culture-dependent methods. To date more than 180 bioactive secondary metabolites derived from deep-sea fungi have been documented in the literature. These include compounds with anticancer, antimicrobial, antifungal, antiprotozoal, and antiviral activities. In this review, we summarize the structures and bioactivities of these metabolites to provide help for novel drug development. PMID:26213949

  19. A Brief Review of Bioactive Metabolites Derived from Deep-Sea Fungi.

    PubMed

    Wang, Yan-Ting; Xue, Ya-Rong; Liu, Chang-Hong

    2015-07-23

    Deep-sea fungi, the fungi that inhabit the sea and the sediment at depths of over 1000 m below the surface, have become an important source of industrial, agricultural, and nutraceutical compounds based on their diversities in both structure and function. Since the first study of deep-sea fungi in the Atlantic Ocean at a depth of 4450 m was conducted approximately 50 years ago, hundreds of isolates of deep-sea fungi have been reported based on culture-dependent methods. To date more than 180 bioactive secondary metabolites derived from deep-sea fungi have been documented in the literature. These include compounds with anticancer, antimicrobial, antifungal, antiprotozoal, and antiviral activities. In this review, we summarize the structures and bioactivities of these metabolites to provide help for novel drug development.

  20. Deep-sea benthic community and environmental impact assessment at the Atlantic Frontier

    NASA Astrophysics Data System (ADS)

    Gage, John D.

    2001-05-01

    The seabed community provides a sensitive litmus for environmental change. North Sea analysis of benthic populations provides an effective means for monitoring impacts from man's interventions, such as offshore oil exploitation and fishing, against baseline knowledge of the environment. Comparable knowledge of the benthic biology in the deep waters of the Atlantic Frontier beyond the N.E. Atlantic shelf edge is poorly developed. But uncertainties should not encourage assumptions and extrapolations from the better-known conditions on the continental shelf. While sampling at present still provides the best means to assess the health of the deepwater benthic habitat, protocols developed for deep-sea fauna should be applied. These are necessary because of (a) lower faunal densities, (b) higher species richness, (c) smaller body size, and (d) to ensure comparability with other deep-sea data. As in the North Sea, species richness and relative abundance can be analysed from quantitative samples in order to detect impacts. But analysis based on taxonomic sufficiency above species level is premature, even if arguably possible for coastal communities. Measures also need to ensure identifications are not forced to more familiar coastal species without proper study. Species-level analysis may be applied to seabed photographs of megafauna in relation to data on bottom environment, such as currents and the sediment, to monitor the health of the deep-water community. Although the composition of higher taxa in the benthic community is broadly similar to soft sediments on the shelf, concordance in sensitivities is speculative. Moreover, new organisms occur, such as giant protozoan xenophyophores, unknown on the continental shelf, whose sensitivities remain conjectural. Past knowledge of the benthic biology of the deep-water areas off Scotland is based on scattered stations and some more focussed, multidisciplinary studies, and should be significantly augmented by the results from

  1. Biodiversity of the Deep-Sea Continental Margin Bordering the Gulf of Maine (NW Atlantic): Relationships among Sub-Regions and to Shelf Systems

    PubMed Central

    Kelly, Noreen E.; Shea, Elizabeth K.; Metaxas, Anna; Haedrich, Richard L.; Auster, Peter J.

    2010-01-01

    Background In contrast to the well-studied continental shelf region of the Gulf of Maine, fundamental questions regarding the diversity, distribution, and abundance of species living in deep-sea habitats along the adjacent continental margin remain unanswered. Lack of such knowledge precludes a greater understanding of the Gulf of Maine ecosystem and limits development of alternatives for conservation and management. Methodology/Principal Findings We use data from the published literature, unpublished studies, museum records and online sources, to: (1) assess the current state of knowledge of species diversity in the deep-sea habitats adjacent to the Gulf of Maine (39–43°N, 63–71°W, 150–3000 m depth); (2) compare patterns of taxonomic diversity and distribution of megafaunal and macrofaunal species among six distinct sub-regions and to the continental shelf; and (3) estimate the amount of unknown diversity in the region. Known diversity for the deep-sea region is 1,671 species; most are narrowly distributed and known to occur within only one sub-region. The number of species varies by sub-region and is directly related to sampling effort occurring within each. Fishes, corals, decapod crustaceans, molluscs, and echinoderms are relatively well known, while most other taxonomic groups are poorly known. Taxonomic diversity decreases with increasing distance from the continental shelf and with changes in benthic topography. Low similarity in faunal composition suggests the deep-sea region harbours faunal communities distinct from those of the continental shelf. Non-parametric estimators of species richness suggest a minimum of 50% of the deep-sea species inventory remains to be discovered. Conclusions/Significance The current state of knowledge of biodiversity in this deep-sea region is rudimentary. Our ability to answer questions is hampered by a lack of sufficient data for many taxonomic groups, which is constrained by sampling biases, life

  2. Deep-sea coral aragonite as a recorder for the neodymium isotopic composition of seawater

    NASA Astrophysics Data System (ADS)

    van de Flierdt, Tina; Robinson, Laura F.; Adkins, Jess F.

    2010-11-01

    Deep-sea corals have been shown to be useful archives of rapid changes in ocean chemistry during the last glacial cycle. Their aragonitic skeleton can be absolutely dated by U-Th data, freeing radiocarbon to be used as a water-mass proxy. For certain species of deep-sea corals, the growth rate allows time resolution that is comparable to ice cores. An additional proxy is needed to exploit this opportunity and turn radiocarbon data into rates of ocean overturning in the past. Neodymium isotopes in seawater can serve as a quasi-conservative water-mass tracer and initial results indicate that deep-sea corals may be reliable archives of seawater Nd isotopes. Here we present a systematic study exploring Nd isotopes as a water-mass proxy in deep-sea coral aragonite. We investigated five different genera of modern deep-sea corals ( Caryophyllia, Desmophyllum, Enallopsamia, Flabellum, Lophelia), from global locations covering a large potential range of Nd isotopic compositions. Comparison with ambient seawater measurements yields excellent agreement and suggests that deep-sea corals are reliable archives for seawater Nd isotopes. A parallel study of Nd concentrations in these corals yields distribution coefficients for Nd between seawater and coral aragonite of 1-10, omitting one particular genus ( Enallopsamia). The corals and seawater did however not come from exactly the same location, and further investigations are needed to reach robust conclusions on the incorporation of Nd into deep-sea coral aragonite. Lastly, we studied the viability of extracting the Nd isotope signal from fossil deep-sea corals by carrying out stepwise cleaning experiments. Our results show that physical removal of the ferromanganese coating and chemical pre-cleaning have the highest impact on Nd concentrations, but that oxidative/reductive cleaning is also needed to acquire a seawater Nd isotope signal.

  3. Genomic and population genetic analysis of deep-sea vent chemoautotrophs

    NASA Astrophysics Data System (ADS)

    Nakagawa, S.; Shimamura, S.; Takaki, Y.; Mino, S.; Makita, H.; Sawabe, T.; Takai, K.

    2012-12-01

    Deep-sea vents are the light-independent, highly productive ecosystems driven primarily by chemoautotrophs. Most of the invertebrates thrive there through their relationship with symbiotic chemoautotrophs. Chemoautotrophs are microorganisms that are able to fix inorganic carbon using a chemical energy obtained through the oxidation of reduced compounds. Following the discovery of deep-sea vent ecosystems in 1977, there has been an increasing knowledge that deep-sea vent chemoautotrophs display remarkable physiological and phylogenetic diversity. Recent microbiological studies have led to an emerging view that the majority of deep-sea vent chemoautotrophs have the ability to derive energy from multiple redox couples other than the conventional sulfur-oxygen couple. Genomic, metagenomic and postgenomic studies have considerably accelerated the comprehensive understanding of molecular mechanisms of deep-sea vent chemoautotrophy, even in unculturable endosymbionts of vent fauna. For example, genomic analysis suggested that there were previously unrecognized evolutionary links between deep-sea vent chemoautotrophs and important human/animal pathogens. However, relatively little is known about the genome of horizontally transmitted endosymbionts. In this study, we sequenced whole genomes of the probably horizontally transmitted endosymbionts of two different gastropod species from a deep-sea hydrothermal field, as an effort to address questions about 1) the genome evolution of horizontally transmitted, facultative endosymbionts, 2) their genomic variability, and 3) genetic differences among symbionts of various deep-sea vent invertebrates. Both endosymbiont genomes display features consistent with ongoing genome reduction such as large proportions of pseudogenes and transposable elements. The genomes encode multiple functions for chemoautotrophic respirations, probably reflecting their adaptation to their niches with continuous changes in environmental conditions. When

  4. Microbial community structure in three deep-sea carbonate crusts.

    PubMed

    Heijs, S K; Aloisi, G; Bouloubassi, I; Pancost, R D; Pierre, C; Sinninghe Damsté, J S; Gottschal, J C; van Elsas, J D; Forney, L J

    2006-10-01

    Carbonate crusts in marine environments can act as sinks for carbon dioxide. Therefore, understanding carbonate crust formation could be important for understanding global warming. In the present study, the microbial communities of three carbonate crust samples from deep-sea mud volcanoes in the eastern Mediterranean were characterized by sequencing 16S ribosomal RNA (rRNA) genes amplified from DNA directly retrieved from the samples. In combination with the mineralogical composition of the crusts and lipid analyses, sequence data were used to assess the possible role of prokaryotes in crust formation. Collectively, the obtained data showed the presence of highly diverse communities, which were distinct in each of the carbonate crusts studied. Bacterial 16S rRNA gene sequences were found in all crusts and the majority was classified as alpha-, gamma-, and delta- Proteobacteria. Interestingly, sequences of Proteobacteria related to Halomonas and Halovibrio sp., which can play an active role in carbonate mineral formation, were present in all crusts. Archaeal 16S rRNA gene sequences were retrieved from two of the crusts studied. Several of those were closely related to archaeal sequences of organisms that have previously been linked to the anaerobic oxidation of methane (AOM). However, the majority of archaeal sequences were not related to sequences of organisms known to be involved in AOM. In combination with the strongly negative delta 13C values of archaeal lipids, these results open the possibility that organisms with a role in AOM may be more diverse within the Archaea than previously suggested. Different communities found in the crusts could carry out similar processes that might play a role in carbonate crust formation.

  5. Horizontal distribution patterns in Arctic deep-sea macrobenthic communities

    NASA Astrophysics Data System (ADS)

    Budaeva, Nataliya E.; Mokievsky, Vadim O.; Soltwedel, Thomas; Gebruk, Andrey V.

    2008-09-01

    Horizontal distribution patterns of macrobenthos were studied based on the material collected at the deep-sea long-term observatory HAUSGARTEN in Fram Strait, west of Spitsbergen (79°N), during the R.V. Polarstern expedition ARK XIX/3c in July-August 2003. Macrofauna was obtained with a giant box corer at water depths of about 2500-2600 m. Samples were arranged using a hierarchical approach to analyze benthic fauna distribution at different scales. Three stations were distributed along the 26 km transect. Three cores (0.25 m 2) were taken at each station. Five subcores (156.25 cm 2) were taken from each core. Both qualitative and quantitative methods of statistical analysis showed that all samples belong to one benthic community dominated by three species, Tetractinomorpha gen.sp. A, Myriochele heeri, and Galathowenia fragilis. Total biomasses varied from 2.31 to 6.41 g ww m -2 and densities ranged from 1976 to 3254 ind. m -2. Multivariate analysis showed the division of all samples into two distinct groups (species assemblages) on the core and subcore levels. These assemblages occupied an area several kilometers across, and differed from each other. The second level of heterogeneity occurs between cores and subcores of assemblage B and reflects variations in the abundance of sponge species Tetractinomorpha gen. sp. A. The size of these small patches appears to be about 150 cm 2. The hierarchical organization of benthic macrofauna on the continental slope off Spitsbergen includes at least three levels: communities, which replace each other along the depth gradient, species assemblages, which make up the orthogonal inner mosaics in each vertical zone, and patches of certain species, which form the lowest level of the hierarchy.

  6. Altererythrobacter aurantiacus sp. nov., isolated from deep-sea sediment.

    PubMed

    Zhang, Gaiyun; Yang, Yanliu; Wang, Lina

    2016-09-01

    A Gram-negative, aerobic, coccoid bacterium, strain O30(T), was isolated from a deep-sea sediment sample collected from the west Pacific. 16S rRNA gene sequence analysis revealed that this strain is affiliated with the family Erythrobacteraceae in the class Alphaproteobacteria, and is closely related to the members of the genera Erythromicrobium (96.6 %), Porphyrobacter (95.5-96.3 %), Altererythrobacter (94.1-96.2 %) and Erythrobacter (94.2-96.2 %). Phylogenetic analysis including all described species of the family Erythrobacteraceae revealed that the isolate forms a clade in the cluster of the genus Altererythrobacter. Strain O30(T) was found to grow at 4-40 °C, pH 6.0-10.0 and in the presence of 0.5-7.0 % (w/v) NaCl. Chemotaxonomic analysis revealed ubiquinones Q-8, Q-9 and Q-10 as the predominant respiratory quinones, summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C17:1 ω6c and C16:0 as major fatty acids, and diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid as the major polar lipids. The DNA G + C content was determined to be 56.9 mol %. On the basis of phenotypic and genotypic data presented in this study, strain O30(T) represents a novel species within the genus Altererythrobacter, for which the name Altererythrobacter aurantiacus sp. nov. is proposed; the type strain is O30(T) (= CGMCC 1.12762(T) = JCM 19853(T) = LMG 28110(T) = MCCC 1A09962(T)). PMID:27371378

  7. Heterotrophic Activity of Deep-Sea Sediment Bacteria

    PubMed Central

    Schwarz, J. R.; Colwell, R. R.

    1975-01-01

    Sediment samples, containing mixed microbial populations that were decompressed during retrieval from 7,750 and 8,130 m in the Puerto Rican Trench, were recompressed and incubated at the approximate in situ temperature (3 C) and pressure (775 or 815 atm) in the presence of 14C-labeled amino acids. Heterotrophic activity (total uptake, CO2 respiration, and cellular assimilation) and cellular-associated “pool” concentrations were measured. Compared with atmospheric controls held at 3 C, the total uptake at elevated pressure at 3 C was reduced, on an average, 55 times, CO2 respiration was reduced 45 times, and cellular assimilation was reduced 69 times. Rate of total uptake at elevated pressure was found to range from 4.0 × 10-11 μg/cell per h for leucine to 2.61 × 10-10 μg/cell per h for an amino acid mixture. Also, the percentage of total uptake at elevated pressures, respired as CO2, increased at the expense of cellular assimilation (ca. 22% increase). Two cellular-associated amino acid pools were detected, a large, loosely bound, outer pool and a small, tightly bound internal pool. The loosely bound outer pool was removed by a change in the pH of the incubation medium. Even though heterotrophic uptake and the outer, cellular-associated pool were markedly reduced at an elevated pressure, the percentage of total uptake calculated for the unincorporated, tightly bound, intracellular pool was 2 to 19 times that obtained for cultures held at 1 atm. The results were interpreted as indicating that bacterial metabolism and biosynthesis in the deep sea are markedly reduced, with a greater proportion of metabolic activity devoted to cellular maintenance. PMID:1190762

  8. Altererythrobacter aurantiacus sp. nov., isolated from deep-sea sediment.

    PubMed

    Zhang, Gaiyun; Yang, Yanliu; Wang, Lina

    2016-09-01

    A Gram-negative, aerobic, coccoid bacterium, strain O30(T), was isolated from a deep-sea sediment sample collected from the west Pacific. 16S rRNA gene sequence analysis revealed that this strain is affiliated with the family Erythrobacteraceae in the class Alphaproteobacteria, and is closely related to the members of the genera Erythromicrobium (96.6 %), Porphyrobacter (95.5-96.3 %), Altererythrobacter (94.1-96.2 %) and Erythrobacter (94.2-96.2 %). Phylogenetic analysis including all described species of the family Erythrobacteraceae revealed that the isolate forms a clade in the cluster of the genus Altererythrobacter. Strain O30(T) was found to grow at 4-40 °C, pH 6.0-10.0 and in the presence of 0.5-7.0 % (w/v) NaCl. Chemotaxonomic analysis revealed ubiquinones Q-8, Q-9 and Q-10 as the predominant respiratory quinones, summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C17:1 ω6c and C16:0 as major fatty acids, and diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid as the major polar lipids. The DNA G + C content was determined to be 56.9 mol %. On the basis of phenotypic and genotypic data presented in this study, strain O30(T) represents a novel species within the genus Altererythrobacter, for which the name Altererythrobacter aurantiacus sp. nov. is proposed; the type strain is O30(T) (= CGMCC 1.12762(T) = JCM 19853(T) = LMG 28110(T) = MCCC 1A09962(T)).

  9. Microbacterium marinum sp. nov., isolated from deep-sea water.

    PubMed

    Zhang, Limin; Xi, Lijun; Ruan, Jisheng; Huang, Ying

    2012-03-01

    Two Gram-positive, rod-shaped bacterial strains, H101(T) and H207, were isolated from deep sea water collected from South-West Indian Ocean. Phylogenetic analysis of 16S rRNA gene sequences showed that the two strains were closely related to one another (100% similarity), and had the closest relationship with Microbacterium hominis NBRC 15708(T) and Microbacterium insulae KCTC 19247(T) (98.2-98.3% similarities). DNA-DNA hybridization value between strains H101(T) and H207 was 87.2 ± 3.7%, and the values between the two strains and the closely related type strains were well below 70%. The two strains also shared a number of physiological and biochemical characteristics that were distinct from the closely related species, and grew at 2-37 ° C, pH 5-11 and 0-8% (w/v) NaCl. Both strains contained MK-12, MK-13 and MK-11 as the detected menaquinones. The peptidoglycan was of type B1γ with an interpeptide bridge D-Glu(Hyg)→ Gly(2)→ l-Lys. The major cellular fatty acids were anteiso-C(15:0), anteiso-C(17:0), and iso-C(16:0). Based on the genetic and phenotypic properties, it is proposed that strains H101(T) and H207 be classified as representatives of a novel species of the genus Microbacterium, with the name Microbacterium marinum sp. nov. The type strain is H101(T) (= CGMCC 4.6941(T) = DSM 24947(T)).

  10. Citreicella marina sp. nov., isolated from deep-sea sediment.

    PubMed

    Lai, Qiliang; Fu, Yuanyuan; Wang, Jianning; Chen, Shuangxi; Zhong, Huanzi; Sun, Fengqin; Shao, Zongze

    2011-04-01

    A taxonomic study was carried out on a novel strain, designated CK-I3-6(T), which was isolated from deep-sea sediment of the south-west Indian Ocean Ridge. Cells were Gram-reaction-negative, oxidase- and catalase-positive, rod-shaped and non-motile. Growth was observed at 4-38 °C and in 1-12 % (w/v) NaCl. Cells were able to degrade gelatin and oxidize thiosulfate but did not reduce nitrate. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CK-I3-6(T) belonged to the genus Citreicella with a sequence similarity of 97.3 % to Citreicella thiooxidans CHLG 1(T), while similarities with other taxa were <95.7 %. DNA-DNA hybridization showed that strain CK-I3-6(T) and C. thiooxidans CHLG 1(T) showed a low DNA-DNA relatedness (48±3 %). The principal fatty acids were C(16 : 0) (7.8 %), C(18 : 1)ω7c (66.6 %), summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c; 6.3 %) and C(19 : 0)ω8c cyclo (10.0 %). The chromosomal DNA G+C content was 67.5 mol%. On the basis of the combined genotypic and phenotypic data, strain CK-I3-6(T) represents a novel species of the genus Citreicella, for which the name Citreicella marina sp. nov. is proposed. The type strain is CK-I3-6(T) ( = CCTCC AB 209064(T)  = LMG 25230(T)  = MCCC 1A03060(T)).

  11. Kangiella profundi sp. nov., isolated from deep-sea sediment.

    PubMed

    Xu, Fang-di; Li, Xue-gong; Xiao, Xiang; Xu, Jun

    2015-07-01

    A taxonomic study employing a polyphasic approach was carried out on strain FT102(T), which was isolated from a deep-sea sediment sample collected in the south-west Indian Ocean at a depth of 2784 m. The strain was Gram-stain-negative, non-motile, rod-shaped and non-spore-forming. It grew optimally at 37-42 °C, pH 6.5-8.5 and in the presence of 1-4% (w/v) NaCl. Phylogenetic analysis of 16S rRNA gene sequences confirmed the separation of the novel strain from recognized members of the genus Kangiella that are available in public databases. Strain FT102(T) exhibited 95.5-98.6% 16S rRNA gene sequence similarity to the type strains of the eight recognized species of the genus Kangiella. The chemotaxonomically characteristic fatty acid iso-C15:0 and ubiquinone Q-8 were also detected. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine. The DNA G + C content of strain FT102(T) was 45.0 mol%. The mean DNA-DNA relatedness values between strain FT102(T) and the type strains of Kangiella aquimarina and Kangiella koreensis were 47.3% and 13.7%, respectively. The combined results of phylogenetic, physiological and chemotaxonomic studies indicated that strain FT102(T) was affiliated with the genus Kangiella but differed from the recognized species of the genus Kangiella. Therefore, strain FT102T represents a novel species of the genus Kangiella, for which the name Kangiella profundi sp. nov. is proposed. The type strain is FT102(T) ( = CGMCC 1.12959(T) = KCTC 42297(T) = JCM 30232(T)).

  12. Peptide synthesis in simulated deep sea hydrothermal environments

    NASA Astrophysics Data System (ADS)

    Lemke, K. H.; Rosenbauer, R. J.; Bird, D. K.

    The synthesis of oligomeric biomolecules such as peptides is the key step marking the evolution from prebiotic chemistry to biochemistry[1]. While monomer synthesis has been demonstrated to proceed in high-energy impact shock, lightning, cavitation or UV-radiation^dominated environments,[2] monomer oligomerization requires lower energy yields,[3] typically found in geological settings such as deep-sea hydrothermal environments (DSHE). In particular, increasing temperatures are predicted to shift the thermodynamic equilibrium between amino acids and product peptide as well as between precursor and successor peptide toward the product oligopeptide,[4,5] however, this hypothesis has not been tested experimentally. Using hydrothermal gold cells we demonstrate the formation of short peptides from the amino acid glycine in the temperature range 160°C to 260°C and 200 bar, conditions typical of DSHE. We show that glycine and product peptides enter into equilibrium and demonstrate a lowering of the Gibbs energies of diglycine and diketopiperazine formation from glycine with increasing temperature. Our results confirm that the thermodynamic stability of the peptide bond in diglycine and diketopiperazine increases relative to the free amino acid with increasing temperature.[4] They support a high temperature origin of life and the early emergence of peptides during chemical evolution. [1] Imai, E., Honda, H., Hatori, K., Brack, A. & Matsuno, K., (1999) Science, 283, 831. [2] Chyba, C.F. and Sagan, C. (1992) Nature 355, 125. [3] Kawamura K. and Yukioka M. (2001) Thermochim. Acta, 375, 9 [4] Shock, E.L. (1992) Geochim. Cosmochim. Acta, 56, 3481 [5] Amend J.P. and Helgeson H.C. (2000) Biophy. Chem., 84, 105.

  13. Virus decomposition provides an important contribution to benthic deep-sea ecosystem functioning.

    PubMed

    Dell'Anno, Antonio; Corinaldesi, Cinzia; Danovaro, Roberto

    2015-04-21

    Viruses are key biological agents of prokaryotic mortality in the world oceans, particularly in deep-sea ecosystems where nearly all of the prokaryotic C production is transformed into organic detritus. However, the extent to which the decomposition of viral particles (i.e., organic material of viral origin) influences the functioning of benthic deep-sea ecosystems remains completely unknown. Here, using various independent approaches, we show that in deep-sea sediments an important fraction of viruses, once they are released by cell lysis, undergo fast decomposition. Virus decomposition rates in deep-sea sediments are high even at abyssal depths and are controlled primarily by the extracellular enzymatic activities that hydrolyze the proteins of the viral capsids. We estimate that on a global scale the decomposition of benthic viruses releases ∼37-50 megatons of C per year and thus represents an important source of labile organic compounds in deep-sea ecosystems. Organic material released from decomposed viruses is equivalent to 3 ± 1%, 6 ± 2%, and 12 ± 3% of the input of photosynthetically produced C, N, and P supplied through particles sinking to bathyal/abyssal sediments. Our data indicate that the decomposition of viruses provides an important, previously ignored contribution to deep-sea ecosystem functioning and has an important role in nutrient cycling within the largest ecosystem of the biosphere.

  14. Evidence for Permo-Triassic colonization of the deep sea by isopods.

    PubMed

    Lins, Luana S F; Ho, Simon Y W; Wilson, George D F; Lo, Nathan

    2012-12-23

    The deep sea is one of the largest ecosystems on Earth and is home to a highly diverse fauna, with polychaetes, molluscs and peracarid crustaceans as dominant groups. A number of studies have proposed that this fauna did not survive the anoxic events that occurred during the Mesozoic Era. Accordingly, the modern fauna is thought to be relatively young, perhaps having colonized the deep sea after the Eocene/Oligocene boundary. To test this hypothesis, we performed phylogenetic analyses of nuclear ribosomal 18S and 28S and mitochondrial cytochrome oxidase I and 16S sequences from isopod crustaceans. Using a molecular clock calibrated with multiple isopod fossils, we estimated the timing of deep-sea colonization events by isopods. Our results show that some groups have an ancient origin in the deep sea, with the earliest estimated dates spanning 232-314 Myr ago. Therefore, anoxic events at the Permian-Triassic boundary and during the Mesozoic did not cause the extinction of all the deep-sea fauna; some species may have gone extinct while others survived and proliferated. The monophyly of the 'munnopsid radiation' within the isopods suggests that the ancestors of this group evolved in the deep sea and did not move to shallow-water refugia during anoxic events.

  15. Species-energy relationship in the deep sea: A test using the Quaternary fossil record

    USGS Publications Warehouse

    Hunt, G.; Cronin, T. M.; Roy, K.

    2005-01-01

    Little is known about the processes regulating species richness in deep-sea communities. Here we take advantage of natural experiments involving climate change to test whether predictions of the species-energy hypothesis hold in the deep sea. In addition, we test for the relationship between temperature and species richness predicted by a recent model based on biochemical kinetics of metabolism. Using the deep-sea fossil record of benthic foraminifera and statistical meta-analyses of temperature-richness and productivity-richness relationships in 10 deep-sea cores, we show that temperature but not productivity is a significant predictor of species richness over the past c. 130 000 years. Our results not only show that the temperature-richness relationship in the deep-sea is remarkably similar to that found in terrestrial and shallow marine habitats, but also that species richness tracks temperature change over geological time, at least on scales of c. 100 000 years. Thus, predicting biotic response to global climate change in the deep sea would require better understanding of how temperature regulates the occurrences and geographical ranges of species. ??2005 Blackwell Publishing Ltd/CNRS.

  16. Virus decomposition provides an important contribution to benthic deep-sea ecosystem functioning

    PubMed Central

    Dell’Anno, Antonio; Corinaldesi, Cinzia

    2015-01-01

    Viruses are key biological agents of prokaryotic mortality in the world oceans, particularly in deep-sea ecosystems where nearly all of the prokaryotic C production is transformed into organic detritus. However, the extent to which the decomposition of viral particles (i.e., organic material of viral origin) influences the functioning of benthic deep-sea ecosystems remains completely unknown. Here, using various independent approaches, we show that in deep-sea sediments an important fraction of viruses, once they are released by cell lysis, undergo fast decomposition. Virus decomposition rates in deep-sea sediments are high even at abyssal depths and are controlled primarily by the extracellular enzymatic activities that hydrolyze the proteins of the viral capsids. We estimate that on a global scale the decomposition of benthic viruses releases ∼37–50 megatons of C per year and thus represents an important source of labile organic compounds in deep-sea ecosystems. Organic material released from decomposed viruses is equivalent to 3 ± 1%, 6 ± 2%, and 12 ± 3% of the input of photosynthetically produced C, N, and P supplied through particles sinking to bathyal/abyssal sediments. Our data indicate that the decomposition of viruses provides an important, previously ignored contribution to deep-sea ecosystem functioning and has an important role in nutrient cycling within the largest ecosystem of the biosphere. PMID:25848024

  17. Trawling-induced alterations of deep-sea sediment accumulation rates during the Anthropocene

    NASA Astrophysics Data System (ADS)

    Puig, P.; Paradis, S.; Masque, P.; Martin, J.; Juan, X.; Palanques, A.

    2015-12-01

    Commercial bottom trawling causes direct physical disturbance of the marine sedimentary environments by scraping and ploughing the seabed, generating periodic resuspension of surface sediments. However, the quantification of the sediment that is removed by trawling and exported across the continental margin remains largely unaddressed, and the preservation of the signal of such impacts in the geological record have been mostly overlooked. The analysis of sediment cores collected along the Catalan margin (NW Mediterranean) has allowed evaluating the contribution of this anthropogenic activity to the present-day sediment dynamics. Sediment cores at intensively trawled sites are characterized by over-consolidated sediments with lower 210Pb surface concentrations and inventories that indicate widespread erosion of recent sedimentary deposits. In turn, combined 210Pb and 137Cs chronologies indicate a significant increase of sediment accumulation rates within submarine canyon environments since the 1970s, coincidently with a strong impulse in the industrialization of the trawling fleets of this region. Two sampling sites that exhibited high sediment accumulation rates (0.6-0.7 cm/y) were reoccupied 1-2 decades after the first studies and revealed a second and even larger increase of sediment accumulation rates (>2 cm/y) occurring at the beginning of the XXI century. This recent change has been attributed to a preferential displacement of the trawling fleet towards fishing grounds surrounding submarine canyons and, also, to technical improvements in trawling vessels, presumably related to financial subsidies provided to the fishing sector. The alteration of sediment accumulation rates described in this continental margin may occur in many regions of the World's oceans given the wide geographical distribution of this human activity, and therefore, it could represent a potential marker of the Anthropocene in deep-sea environments.

  18. [Microbial diversity of deep-sea extremophiles--Piezophiles, Hyperthermophiles, and subsurface microorganisms].

    PubMed

    Kato, C; Takai, K

    2000-12-01

    Knowledge of our Planet's biosphere has increased tremendously during the last 10 to 20 years. In the field of Microbiology in particular, scientists have discovered novel "extremophiles", microorganisms capable of living in extreme environments such as highly acidic or alkaline conditions, at high salt concentration, with no oxygen, extreme temperatures (as low as -20 degrees C and as high as 300 degrees C), at high concentrations of heavy metals and in high pressure environments such as the deep-sea. It is apparent that microorganisms can exist in any extreme environment of the Earth, yet already scientists have started to look for life on other planets; the so-called "Exobiology" project. But as yet we have little knowledge of the deep-sea and subsurface biosphere of our own planet. We believe that we should elucidate the Biodiversity of Earth more thoroughly before exploring life on other planets, and these attempts would provide deeper insight into clarifying the existence of extraterrestrial life. We focused on two deep-sea extremophiles in this article; one is "Piezophiles", and another is "Hyperthermophiles". Piezophiles are typical microorganisms adapted to high-pressure and cold temperature environments, and located in deep-sea bottom. Otherwise, hyperthermophiles are living in high temperature environment, and located at around the hydrothermal vent systems in deep-sea. They are not typical deep-sea microorganisms, but they can grow well at high-pressure condition, just like piezophiles. Deming and Baross mentioned that most of the hyperthermophilic archaea isolated from deep-sea hydrothermal vents are able to grow under conditions of high temperature and pressure, and in most cases their optimal pressure for growth was greater than the environmental pressure they were isolated from. It is possible that originally their native environment may have been deeper than the sea floor and that there had to be a deeper biosphere. This implication suggests that

  19. A vertical wall dominated by Acesta excavata and Neopycnodonte zibrowii, part of an undersampled group of deep-sea habitats.

    PubMed

    Johnson, Mark P; White, Martin; Wilson, Annette; Würzberg, Laura; Schwabe, Enrico; Folch, Helka; Allcock, A Louise

    2013-01-01

    We describe a novel biotope at 633 to 762 m depth on a vertical wall in the Whittard Canyon, an extensive canyon system reaching from the shelf to the deep sea on Ireland's continental margin. We explored this wall with an ROV and compiled a photomosaic of the habitat. The assemblage contributing to the biotope was dominated by large limid bivalves, Acesta excavata (mean shell height 10.4 cm), and deep-sea oysters, Neopycnodonte zibrowii, at high densities, particularly at overhangs. Mean density of N. zibrowii increased with depth, with densities of the most closely packed areas of A. excavata also increasing with depth. Other taxa associated with the assemblage included the solitary coral Desmophyllum dianthus, cerianthid anemones, comatulid crinoids, the trochid gastropod Margarites sp., the portunid crab Bathynectes longispina and small fish of the family Bythitidae. The scleractinian coral Madrepora oculata, the pencil urchin Cidaris cidaris and a species of Epizoanthus were also common. Prominent but less abundant species included the flytrap anemone Actinoscyphia saginata, the carrier crab Paramola cuvieri, and the fishes Lepidion eques and Conger conger. Observations of the hydrography of the canyon system identified that the upper 500 m was dominated by Eastern North Atlantic Water, with Mediterranean Outflow Water beneath it. The permanent thermocline is found between 600 and 1000 m depth, i.e., in the depth range of the vertical wall and the dense assemblage of filter feeders. Beam attenuation indicated nepheloid layers present in the canyon system with the greatest amounts of suspended material at the ROV dive site between 500 and 750 m. A cross-canyon CTD transect indicated the presence of internal waves between these depths. We hypothesise that internal waves concentrate suspended sediment at high concentrations at the foot of the vertical wall, possibly explaining the large size and high density of filter-feeding molluscs.

  20. A vertical wall dominated by Acesta excavata and Neopycnodonte zibrowii, part of an undersampled group of deep-sea habitats.

    PubMed

    Johnson, Mark P; White, Martin; Wilson, Annette; Würzberg, Laura; Schwabe, Enrico; Folch, Helka; Allcock, A Louise

    2013-01-01

    We describe a novel biotope at 633 to 762 m depth on a vertical wall in the Whittard Canyon, an extensive canyon system reaching from the shelf to the deep sea on Ireland's continental margin. We explored this wall with an ROV and compiled a photomosaic of the habitat. The assemblage contributing to the biotope was dominated by large limid bivalves, Acesta excavata (mean shell height 10.4 cm), and deep-sea oysters, Neopycnodonte zibrowii, at high densities, particularly at overhangs. Mean density of N. zibrowii increased with depth, with densities of the most closely packed areas of A. excavata also increasing with depth. Other taxa associated with the assemblage included the solitary coral Desmophyllum dianthus, cerianthid anemones, comatulid crinoids, the trochid gastropod Margarites sp., the portunid crab Bathynectes longispina and small fish of the family Bythitidae. The scleractinian coral Madrepora oculata, the pencil urchin Cidaris cidaris and a species of Epizoanthus were also common. Prominent but less abundant species included the flytrap anemone Actinoscyphia saginata, the carrier crab Paramola cuvieri, and the fishes Lepidion eques and Conger conger. Observations of the hydrography of the canyon system identified that the upper 500 m was dominated by Eastern North Atlantic Water, with Mediterranean Outflow Water beneath it. The permanent thermocline is found between 600 and 1000 m depth, i.e., in the depth range of the vertical wall and the dense assemblage of filter feeders. Beam attenuation indicated nepheloid layers present in the canyon system with the greatest amounts of suspended material at the ROV dive site between 500 and 750 m. A cross-canyon CTD transect indicated the presence of internal waves between these depths. We hypothesise that internal waves concentrate suspended sediment at high concentrations at the foot of the vertical wall, possibly explaining the large size and high density of filter-feeding molluscs. PMID:24260319

  1. A Vertical Wall Dominated by Acesta excavata and Neopycnodonte zibrowii, Part of an Undersampled Group of Deep-Sea Habitats

    PubMed Central

    Johnson, Mark P.; White, Martin; Wilson, Annette; Würzberg, Laura; Schwabe, Enrico; Folch, Helka; Allcock, A. Louise

    2013-01-01

    We describe a novel biotope at 633 to 762 m depth on a vertical wall in the Whittard Canyon, an extensive canyon system reaching from the shelf to the deep sea on Ireland’s continental margin. We explored this wall with an ROV and compiled a photomosaic of the habitat. The assemblage contributing to the biotope was dominated by large limid bivalves, Acesta excavata (mean shell height 10.4 cm), and deep-sea oysters, Neopycnodonte zibrowii, at high densities, particularly at overhangs. Mean density of N. zibrowii increased with depth, with densities of the most closely packed areas of A. excavata also increasing with depth. Other taxa associated with the assemblage included the solitary coral Desmophyllum dianthus, cerianthid anemones, comatulid crinoids, the trochid gastropod Margarites sp., the portunid crab Bathynectes longispina and small fish of the family Bythitidae. The scleractinian coral Madrepora oculata, the pencil urchin Cidaris cidaris and a species of Epizoanthus were also common. Prominent but less abundant species included the flytrap anemone Actinoscyphia saginata, the carrier crab Paramola cuvieri, and the fishes Lepidion eques and Conger conger. Observations of the hydrography of the canyon system identified that the upper 500 m was dominated by Eastern North Atlantic Water, with Mediterranean Outflow Water beneath it. The permanent thermocline is found between 600 and 1000 m depth, i.e., in the depth range of the vertical wall and the dense assemblage of filter feeders. Beam attenuation indicated nepheloid layers present in the canyon system with the greatest amounts of suspended material at the ROV dive site between 500 and 750 m. A cross-canyon CTD transect indicated the presence of internal waves between these depths. We hypothesise that internal waves concentrate suspended sediment at high concentrations at the foot of the vertical wall, possibly explaining the large size and high density of filter-feeding molluscs. PMID:24260319

  2. Food for the deep sea: utilization, dispersal, and flux of nekton falls at the Santa catalina basin floor

    NASA Astrophysics Data System (ADS)

    Smith, Craig R.

    1985-04-01

    The role of large food falls in the ecology of deep-sea benthos has been the topic of much speculation and little direct study. The submersible Alvin and free vehicles were used to assess experimentally the fate and flux of nekton falls at a depth of 1310 m in the Santa Catalina Basin. Parcels of dead fish (1 to 40 kg) placed on the basin floor rapidly attracted large aggregations of fish and invertebrate scavengers, which consumed the bulk of the carrion within hours to days. The most strongly attracted megafaunal scavenger was the ophiuroid Ophiophthalmus normani, the dominant megabenthic species in the background epifaunal assemblage. O. normani attained densities of 700 m -2 in aggregations containing thousands of individuals, and remained at elevated abundance around baitfalls for weeks. Six other megafaunal species also appeared to feed directly on carrion, including two of the next ten most abundant megabenthic organisms. Several of these species exhibited roosting behavior near baitfalls; this is probably an adaptation for exploiting rich but unpredictable food resources. Scavengers consumed bait parcels so rapidly and then dispersed so broadly that energy from nekton falls apparently reaches infaunal benthos only in very attenuated form, yielding at most minor community enhancement. Necrophagy was not the sole cause of megafaunal attraction to bait parcels; there is evidence that three predacious species were drawn to high concentrations of their ophiuroid prey. Benthic standing-crop and turnover-rate estimates for nekton falls suggest that perhaps 11% of benthic community respiratory requirements are met by nekton carcasses reaching the basin floor; the flux of energy to the deep sea through such fall events thus merits further study. These energy bonanzas occur frequently enough that O. normani, and other common necrophages, are likely to encounter at least one nekton fall per year. Such windfalls thus could influence the life histories of several

  3. Groundtruthing the Neodymium Isotope Proxy in Deep-Sea Corals

    NASA Astrophysics Data System (ADS)

    van de Flierdt, T.; Robinson, L. F.; Adkins, J. F.

    2007-12-01

    The Nd isotopic composition of marine precipitates is increasingly recognized as a powerful tool in paleoceanography. Unlike nutrient proxies such as δ13C or Cd/Ca, Nd isotopes are not thought to be altered by biological processes, and thus may serve as a quasi-conservative water mass mixing tracer. However, any archive, which is used to extract authigenic Nd isotopes, needs careful examination, to test the integrity of the inferred seawater signal. Here we present first data on cleaning experiments and modern calibration experiments on different species of deep-sea corals. Seven different coral samples ranging in age from modern to ~220ka were selected for experiments designed to remove ferromanganese crusts and / or organic residues that may contain high concentrations of Nd and Th. The aim was to determine whether the rigorous chemical procedure we use to remove Th associated with these crusts is effective at removing Nd, and whether it causes any fractionation in the Nd isotopic composition of the coral aragonite. Crusts were found to contain Th-232 concentrations of up to ~160ppm, with 232Th/230Th ratios dependent on the oceanic location of the coral. Un-cleaned corals had Th-232 concentrations of up to 8ppb and the cleaning procedure reduced these values to less than 0.2ppb in both modern and fossil specimens. Neodymium isotopic compositions reveal that for modern corals, with no visible coating, a pre-cleaning step is sufficient to yield the isotopic composition of ambient seawater. The ferromanganese coating around fossil corals however may have a very different isotopic composition than the coral aragonite since it may be a time-integrated signal biased towards modern values. This bias is observed for intermediate water depth D. dianthus corals from stage 3 in the northwest Atlantic. Modern D. dianthus skeletons from the northwest Atlantic and the Drake Passage reflect the seawater Nd isotopic composition, and we are extending this modern calibration to

  4. Hydrothermal mixing: Fuel for life in the deep-sea

    NASA Astrophysics Data System (ADS)

    Hentscher, M.; Bach, W.; Amend, J.; McCollom, T.

    2009-04-01

    Deep-sea hydrothermal vent systems show a wide range of fluid compositions and temperatures. They reach from highly alkaline and reducing, like the Lost City hydrothermal field, to acidic and reducing conditions, (e. g., the Logatchev hydrothermal field) to acidic and oxidizing conditions (e. g., island arc hosted systems). These apparently hostile vent systems are generally accompanied by high microbial activity forming the base of a food-web that often includes higher organisms like mussels, snails, or shrimp. The primary production is boosted by mixing of chemically reduced hydrothermal vent fluids with ambient seawater, which generates redox disequilibria that serve as energy source for chemolithoautotrophic microbial life. We used geochemical reaction path models to compute the affinities of catabolic (energy-harvesting) and anabolic (biosynthesis) reactions along trajectories of batch mixing between vent fluids and 2 °C seawater. Geochemical data of endmember hydrothermal fluids from 12 different vent fields (Lost City, Rainbow, Logatchev, TAG, EPR 21 °N, Manus Basin, Mariana Arc, etc.) were included in this reconnaissance study of the variability in metabolic energetics in global submarine vent systems. The results show a distinction between ultramafic-hosted and basalt-hosted hydrothermal systems. The highest energy yield for chemolithotrophic catabolism in ultramafic-hosted hydrothermal systems is reached at low temperature and under slightly aerobic to aerobic conditions. The dominant reactions, for example at Rainbow or Lost City, are the oxidation of H2, Fe2+ and methane. At temperatures >60 °C, anaerobic metabolic reactions, e. g., sulphate reduction and methanogenesis, become more profitable. In contrast, basalt-hosted systems, such as TAG and 21 °N EPR uniformly indicate H2S oxidation to be the catabolically dominant reaction over the entire microbial-relevant temperature range. Affinities were calculated for the formation of individual cellular

  5. Aestuariivita atlantica sp. nov., isolated from deep-sea sediment.

    PubMed

    Li, Guizhen; Lai, Qiliang; Du, Yaping; Liu, Xiupian; Sun, Fengqin; Shao, Zongze

    2015-10-01

    A novel strain, 22II-S11-z3T, was isolated from the deep-sea sediment of the Atlantic Ocean. The bacterium was aerobic, Gram-staining-negative, oxidase-positive and catalase-negative, oval- to rod-shaped, and non-motile. Growth was observed at salinities of 1-9 % NaCl and temperatures of 10-45 °C. The isolate could hydrolyse aesculin and Tweens 20, 40 and 80, but not gelatin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S11-z3T belonged to the genus Aestuariivita, with highest sequence similarity to Aestuariivita boseongensis KCTC 42052T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization values between strain 22II-S11-z3T and A. boseongensis KCTC 42052T were 71.5 % and 20.0 ± 2.3 %, respectively. The G+C content of the chromosomal DNA was 65.5 mol%. The principal fatty acids (>5 %) were summed feature 8 (C18 : 1ω7c/ω6c) (35.2 %), C19 : 0 cyclo ω8c (20.9 %), C16 : 0 (11.8 %), 11-methyl C18 : 1ω7c (11.4 %) and C12 : 1 3-OH (9.4 %). The respiratory quinone was determined to be Q-10. Diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, nine unidentified phospholipids, one unidentified aminolipid and two unidentified lipids were present. The combined genotypic and phenotypic data show that strain 22II-S11-z3T represents a novel species of the genus Aestuariivita, for which the name Aestuariivita atlantica sp. nov. is proposed, with the type strain 22II-S11-z3T ( = KCTC 42276T = MCCC 1A09432T).

  6. Galbibacter marinus sp. nov., isolated from deep-sea sediment.

    PubMed

    Li, Chongping; Lai, Qiliang; Fu, Yuanyuan; Chen, Shuangxi; Shao, Zongze

    2013-04-01

    A taxonomic study was carried out on a novel bacterium, designated strain ck-I2-15(T), which was isolated from deep-sea sediment collected from the South-west Indian Ocean Ridge. Cells of strain ck-I2-15(T) were Gram-reaction-negative, rod-shaped, non-motile, moderately halophilic and capable of denitrification. Growth was observed with 0-9 % (w/v) NaCl and at temperatures of 10-37 °C. The novel strain was unable to degrade gelatin. The dominant cellular fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 9 (iso-C17 : 1ω9c and/or 10-methyl C16 : 0). The major respiratory quinone was MK6 and the polar lipid profile comprised phosphatidylethanolamine, one unidentified phospholipid, two unidentified aminolipids, one unidentified glycolipid and four other unidentified lipids. The G+C content of the genomic DNA was 38 mol%. 16S rRNA gene sequence comparison indicated that strain ck-I2-15(T) was most closely related to Galbibacter mesophilus Mok-17(T) (92.9 % sequence similarity), followed by 'Joostella atrarenae' M1-2 (92.8 %), Joostella marina En5(T) (92.7 %) and Zhouia amylolytica HN-171(T) (91.6 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain ck-I2-15(T) formed a clade with the genus Galbibacter, within the family Flavobacteriaceae. Several phenotypic properties allowed strain ck-I2-15(T) to be distinguished from its closest phylogenetic relatives. On the basis of the phenotypic and phylogenetic data, strain ck-I2-15(T) represents a novel species of the genus Galbibacter, for which the name Galbibacter marinus is proposed. The type strain is ck-I2-15(T) ( = CCTCC AB 209062(T) = LMG 25228(T) = MCCC 1A03044(T)).

  7. Man and the Last Great Wilderness: Human Impact on the Deep Sea

    PubMed Central

    Ramirez-Llodra, Eva; Tyler, Paul A.; Baker, Maria C.; Bergstad, Odd Aksel; Clark, Malcolm R.; Escobar, Elva; Levin, Lisa A.; Menot, Lenaick; Rowden, Ashley A.; Smith, Craig R.; Van Dover, Cindy L.

    2011-01-01

    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short

  8. Man and the last great wilderness: human impact on the deep sea.

    PubMed

    Ramirez-Llodra, Eva; Tyler, Paul A; Baker, Maria C; Bergstad, Odd Aksel; Clark, Malcolm R; Escobar, Elva; Levin, Lisa A; Menot, Lenaick; Rowden, Ashley A; Smith, Craig R; Van Dover, Cindy L

    2011-01-01

    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life--SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO(2) and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO(2) and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short

  9. Man and the last great wilderness: human impact on the deep sea.

    PubMed

    Ramirez-Llodra, Eva; Tyler, Paul A; Baker, Maria C; Bergstad, Odd Aksel; Clark, Malcolm R; Escobar, Elva; Levin, Lisa A; Menot, Lenaick; Rowden, Ashley A; Smith, Craig R; Van Dover, Cindy L

    2011-01-01

    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life--SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO(2) and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO(2) and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short

  10. NOAA's efforts to map extent, health and condition of deep sea corals and sponges and their habitat on the banks and island slopes of Southern California

    NASA Astrophysics Data System (ADS)

    Etnoyer, P. J.; Salgado, E.; Stierhoff, K.; Wickes, L.; Nehasil, S.; Kracker, L.; Lauermann, A.; Rosen, D.; Caldow, C.

    2015-12-01

    Southern California's deep-sea corals are diverse and abundant, but subject to multiple stressors, including corallivory, ocean acidification, and commercial bottom fishing. NOAA has surveyed these habitats using a remotely operated vehicle (ROV) since 2003. The ROV was equipped with high-resolution cameras to document deep-water groundfish and their habitat in a series of research expeditions from 2003 - 2011. Recent surveys 2011-2015 focused on in-situ measures of aragonite saturation and habitat mapping in notable habitats identified in previous years. Surveys mapped abundance and diversity of fishes and corals, as well as commercial fisheries landings and frequency of fishing gear. A novel priority setting algorithm was developed to identify hotspots of diversity and fishing intensity, and to determine where future conservation efforts may be warranted. High density coral aggregations identified in these analyses were also used to guide recent multibeam mapping efforts. The maps suggest a large extent of unexplored and unprotected hard-bottom habitat in the mesophotic zone and deep-sea reaches of Channel Islands National Marine Sanctuary.

  11. Transcriptome of the Deep-Sea Black Scabbardfish, Aphanopus carbo (Perciformes: Trichiuridae): Tissue-Specific Expression Patterns and Candidate Genes Associated to Depth Adaptation

    PubMed Central

    Stefanni, Sergio; Bettencourt, Raul; Pinheiro, Miguel; Moro, Gianluca De; Bongiorni, Lucia; Pallavicini, Alberto

    2014-01-01

    Deep-sea fishes provide a unique opportunity to study the physiology and evolutionary adaptation to extreme environments. We carried out a high throughput sequencing analysis on a 454 GS-FLX titanium plate using unnormalized cDNA libraries from six tissues of A. carbo. Assemblage and annotations were performed by Newbler and InterPro/Pfam analyses, respectively. The assembly of 544,491 high quality reads provided 8,319 contigs, 55.6% of which retrieved blast hits against the NCBI nonredundant database or were annotated with ESTscan. Comparison of functional genes at both the protein sequences and protein stability levels, associated with adaptations to depth, revealed similarities between A. carbo and other bathypelagic fishes. A selection of putative genes was standardized to evaluate the correlation between number of contigs and their normalized expression, as determined by qPCR amplification. The screening of the libraries contributed to the identification of new EST simple-sequence repeats (SSRs) and to the design of primer pairs suitable for population genetic studies as well as for tagging and mapping of genes. The characterization of the deep-sea fish A. carbo first transcriptome is expected to provide abundant resources for genetic, evolutionary, and ecological studies of this species and the basis for further investigation of depth-related adaptation processes in fishes. PMID:25309900

  12. The deepwater demersal ichthyofauna of the western Coral Sea.

    PubMed

    Last, Peter R; Pogonoski, John J; Gledhill, Daniel C; White, William T; Walker, Chris J

    2014-01-01

    The highly diverse deepwater demersal ichthyofauna of the western Coral Sea was first systematically surveyed in two exploratory voyages in 1985 and 1986, and these fish assemblages have not been investigated at the same level since. Only recently have catch data and specimens, obtained from these first voyages almost 3 decades ago, been rigorously investigated and analysed. Some 393 species of fishes from 125 families were collected during the 1985 voyage which surveyed the northeastern Australian continental margin, and the Saumarez and Queensland Plateaus. A checklist of the species caught is provided. Levels of endemicity of deepwater fishes in the western Coral Sea are very high with about 50% of well-studied groups, such as sharks and rays, confined to this relatively small geographic region. A very high proportion of species caught during this voyage were either undescribed (78 species or 20%) or new Australian records (96 species or 24%) at the time of the survey. Another 68 species (17%) are the subject of further taxonomic investigation or are currently undergoing formal description. The fauna exhibits some intraregional differences in structure. Biogeographically informative fishes such as skates appear to be cryptically partitioned within the region, differing in composition to other Australian regions and those of French territories to the east. Strong depth-related partitioning of the fauna is also evident, and its structure follows zonation patterns observed across the wider Australian region. Given the high level of micro-endemicity and regional uniqueness of the fauna, there is a compelling argument for the existence of a faunal gyre in the Coral Sea.  New gap-filling surveys are needed to better define the structure of this fauna and determine its distribution. PMID:25543931

  13. Fish communities associated with cold-water corals vary with depth and substratum type

    NASA Astrophysics Data System (ADS)

    Milligan, Rosanna J.; Spence, Gemma; Roberts, J. Murray; Bailey, David M.

    2016-08-01

    Understanding the processes that drive the distribution patterns of organisms and the scales over which these processes operate are vital when considering the effective management of species with high commercial or conservation value. In the deep sea, the importance of scleractinian cold-water corals (CWCs) to fish has been the focus of several studies but their role remains unclear. We propose this may be due to the confounding effects of multiple drivers operating over multiple spatial scales. The aims of this study were to investigate the role of CWCs in shaping fish community structure and individual species-habitat associations across four spatial scales in the NE Atlantic ranging from "regions" (separated by >500 km) to "substratum types" (contiguous). Demersal fish and substratum types were quantified from three regions: Logachev Mounds, Rockall Bank and Hebrides Terrace Seamount (HTS). PERMANOVA analyses showed significant differences in community composition between all regions which were most likely caused by differences in depths. Within regions, significant variation in community composition was recorded at scales of c. 20-3500 m. CWCs supported significantly different fish communities to non-CWC substrata at Rockall Bank, Logachev and the HTS. Single-species analyses using generalised linear mixed models showed that Sebastes sp. was strongly associated with CWCs at Rockall Bank and that Neocyttus helgae was more likely to occur in CWCs at the HTS. Depth had a significant effect on several other fish species. The results of this study suggest that the importance of CWCs to fish is species-specific and depends on the broader spatial context in which the substratum is found. The precautionary approach would be to assume that CWCs are important for associated fish, but must acknowledge that CWCs in different depths will not provide redundancy or replication within spatially-managed conservation networks.

  14. Relationship between pelagic larval duration and abundance of tropical fishes on temperate coasts of Japan.

    PubMed

    Soeparno; Nakamura, Y; Shibuno, T; Yamaoka, K

    2012-02-01

    The influence of pelagic larval duration (PLD) and egg type dispersal capabilities of 35 demersal and pelagic-spawning tropical fish species is examined in relation to their abundance on the temperate coasts of Japan. The PLDs of pelagic spawners were significantly longer than those of demersal spawners, and a high occurrence of pelagic spawners on the temperate coasts suggests that these fishes are more easily transported to temperate coasts than demersal spawners. For demersal spawners, the common species on the temperate coasts had significantly longer PLDs than the rare species; this suggests that PLD is a major factor influencing the distribution patterns of tropical demersal spawners on temperate coasts. Moreover, a negative correlation between PLD and the abundance of some species of pelagic and demersal spawners suggests the presence of reproductively active fishes in northern subtropical and even in temperate waters.

  15. Distinctive microbial community structure in highly stratified deep-sea brine water columns.

    PubMed

    Bougouffa, S; Yang, J K; Lee, O O; Wang, Y; Batang, Z; Al-Suwailem, A; Qian, P Y

    2013-06-01

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools. PMID:23542623

  16. Effects of hydrostatic pressure on yeasts isolated from deep-sea hydrothermal vents.

    PubMed

    Burgaud, Gaëtan; Hué, Nguyen Thi Minh; Arzur, Danielle; Coton, Monika; Perrier-Cornet, Jean-Marie; Jebbar, Mohamed; Barbier, Georges

    2015-11-01

    Hydrostatic pressure plays a significant role in the distribution of life in the biosphere. Knowledge of deep-sea piezotolerant and (hyper)piezophilic bacteria and archaea diversity has been well documented, along with their specific adaptations to cope with high hydrostatic pressure (HHP). Recent investigations of deep-sea microbial community compositions have shown unexpected micro-eukaryotic communities, mainly dominated by fungi. Molecular methods such as next-generation sequencing have been used for SSU rRNA gene sequencing to reveal fungal taxa. Currently, a difficult but fascinating challenge for marine mycologists is to create deep-sea marine fungus culture collections and assess their ability to cope with pressure. Indeed, although there is no universal genetic marker for piezoresistance, physiological analyses provide concrete relevant data for estimating their adaptations and understanding the role of fungal communities in the abyss. The present study investigated morphological and physiological responses of fungi to HHP using a collection of deep-sea yeasts as a model. The aim was to determine whether deep-sea yeasts were able to tolerate different HHP and if they were metabolically active. Here we report an unexpected taxonomic-based dichotomic response to pressure with piezosensitve ascomycetes and piezotolerant basidiomycetes, and distinct morphological switches triggered by pressure for certain strains.

  17. Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

    PubMed Central

    Bougouffa, S.; Yang, J. K.; Lee, O. O.; Wang, Y.; Batang, Z.; Al-Suwailem, A.

    2013-01-01

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools. PMID:23542623

  18. Abrupt changes in deep-sea ecosystem structure and biodiversity during the last deglaciation and Holocene

    NASA Astrophysics Data System (ADS)

    Yasuhara, M.; Cronin, T. M.; Hunt, G.

    2008-12-01

    Recent research on deep-sea sediment cores suggests that the structure and diversity of deep-sea ecosystems exhibit greater instability over millennial and centennial timescales than previously realized. Centennial scale ecosystem shifts during the last deglaciation (Termination 1, 18-11.5 ka) and the Holocene (11.5 ka to recent) have been discovered using several well-dated deep-sea microfossil records. In the northwestern Atlantic ODP site 1055, weakening of North Atlantic Deep Water production around 10 ka appears to have caused the collapse of the deep-sea benthic ecosystem and reduced diversity at ca. 1800 meters water depth. During this and other Holocene events, diversity as measured by the Shannon Index was reduced by as much as 50%. Several lower resolution records also suggest rapid ecosystem change during Termination 1 in the central and northern North Atlantic region. For example, sites 82-24-4PC (mid-Atlantic Ridge) and M23414 (Rockall Plateau) reveal abrupt diversity shifts probably associated with bottom-water temperature and surface productivity changes. This presentation will assemble data on these and other fossil ostracod records from North Atlantic deep-sea sites to discuss possible causes of abrupt ecosystem changes and the application of Ostracoda to paleoceanography.

  19. Organic matter bioavailability controls the active bacterial fraction in deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Luna, G. M.; Giuliano, L.; Danovaro, R.

    2003-04-01

    Deep-sea sediments, covering more than 60% of the earth surface, represent the largest Earth's ecosystem. Bacteria are the most abundant component and the major players of biogeochemical transformations. However, the knowledge of the physiological and metabolic state of bacterial cells in deep-sea sediments is still extremely poor, thus limiting our actual comprehension of bacterial role on C cycling and early diagenesis on global scale. The recent discovery that a large bacterial fraction is dead and/or inactive suggests that the rather constant bacterial number in the deep sea might be due to the inappropriate methodology of estimation. We investigated the abundance of nucleoid-containing cells (NuCC), assumed to be the active bacterial fraction, and their relative contribution to total bacterial counts in Mediterranean deep-sea sediments (from 670 to 2570 m depth), together with measurements of sedimentary organic matter. Our results indicate that living bacterial cells accounted for 14 to 70% of total bacterial number. The active bacterial abundance decreased by 4 times with increasing station depth. Moreover, NuCC abundance strongly decreased with increasing depth in the sediment, together with the decrease of organic matter concentrations (in terms of protein, carbohydrates and pigments). Our findings indicate that the bioavailable fraction of organic matter exert a strong control on activity and turnover rates of microbial assemblages in deep sea.

  20. Identification, visualization, and sorting of translationally active microbial consortia from deep-sea methane seeps

    NASA Astrophysics Data System (ADS)

    Hatzenpichler, R.; Connon, S. A.; Goudeau, D.; Malmstrom, R.; Woyke, T.; Orphan, V. J.

    2015-12-01

    Within the past few years, great progress has been made in tapping the genomes of individual cells separated from environmental samples. Unfortunately, however, most often these efforts have been target blind, as they did not pre-select for taxa of interest or focus on metabolically active cells that could be considered key species of the system at the time. This problem is particularly pronounced in low-turnover systems such as deep sea sediments. In an effort to tap the genetic potential hidden within functionally active cells, we have recently developed an approach for the in situ fluorescent tracking of protein synthesis in uncultured cells via bioorthogonal non-canonical amino acid-tagging (BONCAT). This technique depends on the incorporation of synthetic amino acids that carry chemically modifiable tags into newly made proteins, which later can be visualized via click chemistry-mediated fluorescence-labeling. BONCAT is thus able to specifically target proteins that have been expressed in reaction to an experimental condition. We are particularly interested in using BONCAT to understand the functional potential of slow-growing syntrophic consortia of anaerobic methanotrophic archaea and sulfate-reducing bacteria which together catalyze the anaerobic oxidation of methane (AOM) in marine methane seeps. In order to specifically target consortia that are active under varying environmental regimes, we are studying different subpopulations of these inter-domain consortia via a combination of BONCAT with rRNA-targeted FISH. We then couple the BONCAT-enabled staining of active consortia with their separation from inactive members of the community via fluorescence-activated cell-sorting (FACS) and metagenomic sequencing of individual consortia. Using this approach, we were able to identify previously unrecognized AOM-partnerships. By comparing the mini-metagenomes obtained from individual consortia with each other we are starting to gain a more hollistic understanding

  1. Life history of the deep-sea cephalopod family Histioteuthidae in the western Mediterranean

    NASA Astrophysics Data System (ADS)

    Quetglas, Antoni; de Mesa, Aina; Ordines, Francesc; Grau, Amàlia

    2010-08-01

    The life cycle of the two species of the deep-sea family Histioteuthidae inhabiting the Mediterranean Sea ( Histioteuthis reversa and Histioteuthis bonnellii) was studied from monthly samples taken throughout the year during daytime hours by bottom trawl gears. A small sample of individuals found floating dead on the sea surface was also analyzed. Both species were caught exclusively on the upper slope at depths greater than 300 m. Their frequency of occurrence increased with depth and showed two different peaks, at 500-600 m and 600-700 m depth in H. bonnellii and H. reversa, respectively, which might indicate spatial segregation. Maturity stages were assigned using macroscopic determination and confirmed with histological analyses. Although mature males were caught all year round, no mature females were found, which suggests that their sexual maturation in the western Mediterranean takes place deeper than the maximum depth sampled (800 m). In fact, the increase in mean squid size with increasing depth in H. reversa indicates an ontogenetic migration to deeper waters. The individuals of both species found floating dead on the sea surface were spent females which had a relatively large cluster of small atresic eggs and a small number of remaining mature eggs scattered in the ovary and mantle cavity. The sizes of these females were clearly larger than the largest individuals caught with bottom trawls. A total of 12 and 7 different types of prey, belonging to three major taxonomic groups (crustaceans, osteichthyes and cephalopods), were identified in the stomach contents of H. reversa and H. bonnellii, respectively. In both species fishes were by far the main prey followed by crustaceans, whereas cephalopods were found only occasionally. The preys identified, mainly myctophids and natantian crustaceans, indicate that both histioteuthids base their diet on pelagic nictemeral migrators.

  2. Trimethylamine oxide counteracts effects of hydrostatic pressure on proteins of deep-sea teleosts.

    PubMed

    Yancey, P H; Fyfe-Johnson, A L; Kelly, R H; Walker, V P; Auñón, M T

    2001-02-15

    In shallow marine teleost fishes, the osmolyte trimethylamine oxide (TMAO) is typically found at <70 mmol/kg wet weight. Recently we found deep-sea teleosts have up to 288 mmol/kg, increasing in the order shallow < bathyal < abyssal. We hypothesized that this protein stabilizer counteracts inhibition of proteins by hydrostatic pressure, and showed that, for lactate dehydrogenases (LDH), 250 mM TMAO fully offset an increase in NADH K(m) at physiological pressure, and partly reversed pressure-enhanced losses of activity at supranormal pressures. In this study, we examined other effects of pressure and TMAO on proteins of teleosts that live from 2000-5000 m (200-500 atmospheres [atm]). First, for LDH from a grenadier (Coryphaenoides leptolepis) at 500 atm for 8 hr, there was a significant 15% loss in activity (P < 0.05 relative to 1 atm control) that was reduced with 250 mM TMAO to an insignificant loss. Second, for pyruvate kinase from a morid cod (Antimora microlepis) at 200 atm, there was 73% increase in ADP K(m) without TMAO (P < 0.01 relative to K(m) at 1 atm) but only a 29% increase with 300 mM TMAO. Third, for G-actin from a grenadier (C. armatus) at 500 atm for 16 hr, there was a significant reduction of F-actin polymerization (P < 0.01 compared to polymerization at 1 atm) that was fully counteracted by 250 mM TMAO, but was unchanged in 250 mM glycine. These findings support the hypothesis. J. Exp. Zool. 289:172-176, 2001. PMID:11170013

  3. Iron sequestration in young deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Baldermann, Andre; Warr, Laurence; Letofsky-Papst, Ilse; Böttcher, Michael

    2014-05-01

    average) within the upper 25 m of sediment. Within the first 3 meters of the sedimentary pile, iron sequestration related to green clay formation is ~11 times higher than that of pyritization. Even at greater depths ≥ 3 mbsf, where the pyritization reaction becomes progressively more important and 29 to 66% of the initial detrital ferrihydrite input is almost dissolved, ~50% of iron sequestration can be attributed to glauconitization. Initial mass balance calculations of the sediment's iron budget indicate that iron sequestration at ODP Site 959 is mainly controlled by the competing rates of pyritization and glauconitization. Iron sequestration associated with early diagenetic green clay formation could significantly impact the bioavailability of reactive iron in marine aqueous systems and thus influence both the marine iron cycle and deep biosphere environment. The role of deep-water glauconitization on iron availability and sequestration should be considered in future ocean-atmospheric models of the iron biogeochemical cycle. Baldermann, A., Warr, L.N., Grathoff, G.H. & Dietzel, M. (2013) The rate and mechanism of deep-sea glauconite formation at the Ivory Coast-Ghana Marginal Ridge. Clays and Clay Minerals, 61, 258-276.

  4. Dioxin compounds in the deep-sea rose shrimp Aristeus antennatus (Risso, 1816) throughout the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Rotllant, Guiomar; Abad, Esteban; Sardà, Francisco; Ábalos, Manuela; Company, Joan B.; Rivera, Josep

    2006-12-01

    Polychlorodibenzo- p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) are among the more toxic anthropogenic contaminants. They are fat-soluble and accumulate in animal tissues. Exposure to PCDD/Fs can cause several endocrine, reproductive and developmental problems in animals, including human beings. Several studies have demonstrated that fish and invertebrates living in association with sediments are exposed to and accumulate contaminants, but to date there have been no studies of PCDD/Fs contamination in deep-sea regions. Specimens of Aristeus antennatus (Risso, 1816) were collected from depths of 600-2500 m at different points in the Mediterranean Sea, from the western basin off the coast of Barcelona to the central basin off the Peloponnesian Peninsula, with otter trawl gear. Amounts of PCDD/Fs were measured in different animal tissues by high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC-HRMS). This is the first study to report the presence of PCDD/Fs in deep-sea organisms dwelling at depths below 600 m. A. antennatus presented levels of PCDD/Fs of the same order of magnitude, or slightly higher, as those found in shallow-water species ( Melicertus kerathurus) with respect to land-generated contamination. This highlights the widespread distribution of these pollutants and the potential threat posed to the biodiversity of fragile and vulnerable ecosystems such as the deep-sea. PCDD/F levels detected in the edible parts (muscle) of the commercial shrimp A. antennatus were clearly below the toxic limit value established by European legislation. Levels followed the trend muscle

  5. Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

    SciTech Connect

    Lu, Z.; Deng, Y.; Nostrand, J.D. Van; He, Z.; Voordeckers, J.; Zhou, A.; Lee, Y.-J.; Mason, O.U.; Dubinsky, E.; Chavarria, K.; Tom, L.; Fortney, J.; Lamendella, R.; Jansson, J.K.; D?haeseleer, P.; Hazen, T.C.; Zhou, J.

    2011-06-15

    The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in U.S. history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared to outside the plume, indicating a great potential for intrinsic bioremediation or natural attenuation in the deep-sea. Various other microbial functional genes relevant to carbon, nitrogen, phosphorus, sulfur and iron cycling, metal resistance, and bacteriophage replication were also enriched in the plume. Together, these results suggest that the indigenous marine microbial communities could play a significant role in biodegradation of oil spills in deep-sea environments.

  6. Lunar rhythms in the deep sea: evidence from the reproductive periodicity of several marine invertebrates.

    PubMed

    Mercier, Annie; Sun, Zhao; Baillon, Sandrine; Hamel, Jean-François

    2011-02-01

    While lunar rhythms are commonly documented in plants and animals living in terrestrial and shallow-water environments, deep-sea organisms have essentially been overlooked in that respect. This report describes evidence of lunar periodicity in the reproduction of 6 deep-sea species belonging to 2 phyla. Occurrences of gamete release in free spawners and larval release in brooders exhibited significant peaks around the new and full moons, respectively. The exact nature of this lunar period (endogenous or exogenous rhythm) and its adaptive significance in the deep sea remain elusive. Current knowledge suggests that proxies of moon phases at depth may include fluxes in particulate matter deposition, cyclic currents, and moonlight for species living in the disphotic zone.

  7. Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean

    USGS Publications Warehouse

    Yasuhara, Moriaki; Stepanova, Anna; Okahashi, Hisayo; Cronin, Thomas M.; Brouwers, Elisabeth M.

    2015-01-01

    Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean was conducted to reduce taxonomic uncertainty that will improve our understanding of species ecology, biogeography and relationship to faunas from other deep-sea regions. Fifteen genera and 40 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images, covering most of known deep-sea species in the central Arctic Ocean. Seven new species are described: Bythoceratina lomonosovensis n. sp., Cytheropteron parahamatum n. sp., Cytheropteron lanceae n. sp.,Cytheropteron irizukii n. sp., Pedicythere arctica n. sp., Cluthiawhatleyi n. sp., Krithe hunti n. sp. This study provides a robust taxonomic baseline for application to paleoceanographical reconstruction and biodiversity analyses in this climatically sensitive region.

  8. Ecological impacts of large-scale disposal of mining waste in the deep sea.

    PubMed

    Hughes, David J; Shimmield, Tracy M; Black, Kenneth D; Howe, John A

    2015-05-05

    Deep-Sea Tailings Placement (DSTP) from terrestrial mines is one of several large-scale industrial activities now taking place in the deep sea. The scale and persistence of its impacts on seabed biota are unknown. We sampled around the Lihir and Misima island mines in Papua New Guinea to measure the impacts of ongoing DSTP and assess the state of benthic infaunal communities after its conclusion. At Lihir, where DSTP has operated continuously since 1996, abundance of sediment infauna was substantially reduced across the sampled depth range (800-2020 m), accompanied by changes in higher-taxon community structure, in comparison with unimpacted reference stations. At Misima, where DSTP took place for 15 years, ending in 2004, effects on community composition persisted 3.5 years after its conclusion. Active tailings deposition has severe impacts on deep-sea infaunal communities and these impacts are detectable at a coarse level of taxonomic resolution.

  9. Ecological impacts of large-scale disposal of mining waste in the deep sea

    PubMed Central

    Hughes, David J.; Shimmield, Tracy M.; Black, Kenneth D.; Howe, John A.

    2015-01-01

    Deep-Sea Tailings Placement (DSTP) from terrestrial mines is one of several large-scale industrial activities now taking place in the deep sea. The scale and persistence of its impacts on seabed biota are unknown. We sampled around the Lihir and Misima island mines in Papua New Guinea to measure the impacts of ongoing DSTP and assess the state of benthic infaunal communities after its conclusion. At Lihir, where DSTP has operated continuously since 1996, abundance of sediment infauna was substantially reduced across the sampled depth range (800–2020 m), accompanied by changes in higher-taxon community structure, in comparison with unimpacted reference stations. At Misima, where DSTP took place for 15 years, ending in 2004, effects on community composition persisted 3.5 years after its conclusion. Active tailings deposition has severe impacts on deep-sea infaunal communities and these impacts are detectable at a coarse level of taxonomic resolution. PMID:25939397

  10. Novel use of burrow casting as a research tool in deep-sea ecology

    PubMed Central

    Seike, Koji; Jenkins, Robert G.; Watanabe, Hiromi; Nomaki, Hidetaka; Sato, Kei

    2012-01-01

    Although the deep sea is the largest ecosystem on Earth, its infaunal ecology remains poorly understood because of the logistical challenges. Here we report the morphology of relatively large burrows obtained by in situ burrow casting at a hydrocarbon-seep site and a non-seep site at water depths of 1173 and 1455 m, respectively. Deep and complex burrows are abundant at both sites, indicating that the burrows introduce oxygen-rich sea water into the deep reducing substrate, thereby influencing benthic metabolism and nutrient fluxes, and providing an oxic microhabitat for small organisms. Burrow castings reveal that the solemyid bivalve Acharax johnsoni mines sulphide from the sediment, as documented for related shallow-water species. To our knowledge, this is the first study to examine in situ burrow morphology in the deep sea by means of burrow casting, providing detailed information on burrow structure which will aid the interpretation of seabed processes in the deep sea. PMID:22298806

  11. Options for managing impacts of climate change on a deep-sea community

    NASA Astrophysics Data System (ADS)

    Thresher, Ronald E.; Guinotte, John M.; Matear, Richard J.; Hobday, Alistair J.

    2015-07-01

    The deep sea hosts some of the world's largest, oldest, and most sensitive ecosystems. Climate change and ocean acidification are likely to have severe implications for many deep-sea ecosystems and communities, but what, if anything, can be done to mitigate these threats is poorly understood. To begin to bridge this gap, we convened a stakeholder workshop to assess and prioritize options for conserving legislatively protected deep-sea coral reefs off southeast Australia that, without management intervention, are likely to be severely degraded within decades as a result of climate change. Seventeen possible options were explored that span biological, engineering and regulatory domains and that differed widely in their perceived costs, benefits, time to implementation, and risks. In the short term, the highest priority identified is the need to urgently locate and protect sites globally that are, or will become, refugia areas for the coral and its associated community as climate change progresses.

  12. Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

    PubMed Central

    Lu, Zhenmei; Deng, Ye; Van Nostrand, Joy D; He, Zhili; Voordeckers, James; Zhou, Aifen; Lee, Yong-Jin; Mason, Olivia U; Dubinsky, Eric A; Chavarria, Krystle L; Tom, Lauren M; Fortney, Julian L; Lamendella, Regina; Jansson, Janet K; D'haeseleer, Patrik; Hazen, Terry C; Zhou, Jizhong

    2012-01-01

    The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in the United State history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared with outside the plume, indicating a great potential for intrinsic bioremediation or natural attenuation in the deep sea. Various other microbial functional genes that are relevant to carbon, nitrogen, phosphorus, sulfur and iron cycling, metal resistance and bacteriophage replication were also enriched in the plume. Together, these results suggest that the indigenous marine microbial communities could have a significant role in biodegradation of oil spills in deep-sea environments. PMID:21814288

  13. Global pulses of organic carbon burial in deep-sea sediments during glacial maxima

    PubMed Central

    Cartapanis, Olivier; Bianchi, Daniele; Jaccard, Samuel L.; Galbraith, Eric D.

    2016-01-01

    The burial of organic carbon in marine sediments removes carbon dioxide from the ocean–atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we show that the accumulation rate of organic carbon in the deep sea was consistently higher (50%) during glacial maxima than during interglacials. The spatial pattern and temporal progression of the changes suggest that enhanced nutrient supply to parts of the surface ocean contributed to the glacial burial pulses, with likely additional contributions from more efficient transfer of organic matter to the deep sea and better preservation of organic matter due to reduced oxygen exposure. These results demonstrate a pronounced climate sensitivity for this global carbon cycle sink. PMID:26923945

  14. Global-scale latitudinal patterns of species diversity in the deep-sea benthos

    NASA Astrophysics Data System (ADS)

    Rex, Michael A.; Stuart, Carol T.; Hessler, Robert R.; Allen, John A.; Sanders, Howard L.; Wilson, George D. F.

    1993-10-01

    LATITUDINAL gradients of species diversity are ubiquitous features of terrestrial and coastal marine biotas, and they have inspired the development of theoretical ecology1-3. Since the discovery of high species diversity in the deep-sea benthos4, much has been learned about local5,6and regional7-9patterns of diversity. Variation in diversity on larger scales remains poorly described. Latitudinal gradients of diversity were unexpected because it was assumed that the environmental gradients that cause large-scale patterns in surface environments could not affect communities living at great depths10. Here we report that deep-sea bivalves, gastropods and isopods show clear latitudinal diversity gradients in the North Atlantic, and strong interregional variation in the South Atlantic. Many seemingly incompatible mechanisms have been proposed to explain deep-sea species diversity11. The existence of regular global patterns suggests that these mechanisms operate at different spatial and temporal scales.

  15. Global pulses of organic carbon burial in deep-sea sediments during glacial maxima.

    PubMed

    Cartapanis, Olivier; Bianchi, Daniele; Jaccard, Samuel L; Galbraith, Eric D

    2016-01-01

    The burial of organic carbon in marine sediments removes carbon dioxide from the ocean-atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we show that the accumulation rate of organic carbon in the deep sea was consistently higher (50%) during glacial maxima than during interglacials. The spatial pattern and temporal progression of the changes suggest that enhanced nutrient supply to parts of the surface ocean contributed to the glacial burial pulses, with likely additional contributions from more efficient transfer of organic matter to the deep sea and better preservation of organic matter due to reduced oxygen exposure. These results demonstrate a pronounced climate sensitivity for this global carbon cycle sink. PMID:26923945

  16. Nd isotopes in deep-sea corals in the Northeastern Atantic

    NASA Astrophysics Data System (ADS)

    Copard, K.; Colin, C.; Freiwald, A.; Douville, E.; Gudmundsson, G.; de Mol, B.; Frank, N.

    2009-12-01

    Nd, Mn and Ca concentrations and ɛNd have been investigated on living and fossil L. pertusa, D. dianthus and M. oculata deep-sea corals located between the Strait of Gibraltar and the Norwegian Sea. ɛNd has been also analysed on seawater collected at similar location and water depth than living deep-sea corals in the Bay of Biscay. A rigorous cleaning technique has been developed to remove Nd contamination of the deep-sea corals from manganese-oxide and iron hydroxide coatings. Nd isotopic compositions have been analysed using mass spectrometric Nd-oxide measurements. Mn and Nd concentrations have been systematically analysed to control the efficiency of the applied cleaning protocol. Nd concentration of living deep-sea corals incorporated in the aragonite skeleton varies between 6 and 90 ppb. A slight increasing trend of Nd/Ca ratios is observed along with water depth, qualitatively in agreement with Nd behaviour in seawater. Nd isotopic compositions of living deep-sea corals located from the Strait of Gibraltar to the Norwegian Sea vary from -9.8 to -14.1 and match Nd of seawater bathing the corals. These observed Nd isotopic gradients demonstrate the capability of various corals species to record the Atlantic mid depth Nd isotopic gradients influenced by ocean circulation pattern and Nd fluxes. Consequently, solitary and constructional deep-water corals species can serve as archive of past seawater Nd isotopic compositions. In addition, we demonstrate that ɛNd of fossils deep-sea corals, dated by 230Th/U method, indicate strong hydrological changes at ~700m in the NE Atlantic during the last 2000 yrs that may be linked to changes of the inflow into the Nordic Seas.

  17. Small-Scale Heterogeneity in Deep-Sea Nematode Communities around Biogenic Structures

    PubMed Central

    Hasemann, Christiane; Soltwedel, Thomas

    2011-01-01

    The unexpected high species richness of deep-sea sediments gives rise to the questions, which processes produce and maintain diversity in the deep sea, and at what spatial scales do these processes operate? The idea of a small-scale habitat structure at the deep-sea floor provides the background for this study. At small scales biogenic structures create a heterogeneous environment that influences the structure of the surrounding communities and the dynamics of the meiobenthic populations. As an example for biogenic structures, small deep-sea sponges (Tentorium semisuberites Schmidt 1870) and their sedimentary environment were investigated for small-scale distribution patterns of benthic deep-sea nematodes. Sampling was carried out with the remotely operated vehicle Victor 6000 at the Arctic deep-sea observatory HAUSGARTEN. In order to investigate nematode community patterns sediment cores around three small sponges and corresponding control cores were analysed. A total of approx. 5800 nematodes were identified. The comparison of the nematode communities from sponge and control samples indicated an influence of the biogenic structure “sponge” on diversity patterns and habitat heterogeneity. The increased number of nematode species and functional groups found in the sediments around the sponges suggest that on a small scale the sponge acts as a gradient and creates a more divers habitat structure. The nematode community from the sponge sediments shows a greater taxonomic variance and species richness together with lower relative abundances of the species compared to those from control sediments. Obviously, the more homogeneous habitat conditions of the control sediments offer less micro-habitats than the sediments around the sponges. This seems to reduce the number of functional groups and species coexisting in the control sediments. PMID:22216193

  18. Cloning and characterization of dihydrofolate reductases from deep-sea bacteria.

    PubMed

    Murakami, Chiho; Ohmae, Eiji; Tate, Shin-Ichi; Gekko, Kunihiko; Nakasone, Kaoru; Kato, Chiaki

    2010-04-01

    Enzymes from organisms living in deep-sea are thought to have characteristic pressure-adaptation mechanisms in structure and function. To better understand these mechanisms in dihydrofolate reductase (DHFR), an essential enzyme in living cells, we cloned, overexpressed and purified four new DHFRs from the deep-sea bacteria Shewanella violacea (svDHFR), Photobacterium profundum (ppDHFR), Moritella yayanosii (myDHFR) and Moritella japonica (mjDHFR), and compared their structure and function with those of Escherichia coli DHFR (ecDHFR). These deep-sea DHFRs showed 33-56% primary structure identity to ecDHFR while far-ultraviolet circular dichroism and fluorescence spectra suggested that their secondary and tertiary structures were not largely different. The optimal temperature and pH for deep-sea DHFRs activity were lower than those of ecDHFR and different from each other. Deep-sea DHFRs kinetic parameters K(m) and k(cat) were larger than those of ecDHFR, resulting in 1.5-2.8-fold increase of k(cat)/K(m) except for mjDHFR which had a 28-fold decrease. The enzyme activity of ppDHFR and mjDHFR (moderate piezophilic bacteria) as well as ecDHFR decreased as pressure increased, while svDHFR and myDHFR (piezophilic bacteria) showed a significant tolerance to pressure. These results suggest that DHFRs from deep-sea bacteria possess specific enzymatic properties adapted to their life under high pressure. PMID:20040594

  19. Impact of Deepwater Horizon Spill on food supply to deep-sea benthos communities

    USGS Publications Warehouse

    Prouty, Nancy G.; Swarzenski, Pamela; Mienis, Furu; Duineveld, Gerald; Demopoulos, Amanda; Ross, Steve W.; Brooke, Sandra

    2016-01-01

    Deep-sea ecosystems encompass unique and often fragile communities that are sensitive to a variety of anthropogenic and natural impacts. After the 2010 Deepwater Horizon (DWH) oil spill, sampling efforts documented the acute impact of the spill on some deep-sea coral colonies. To investigate the impact of the DWH spill on quality and quantity of biomass delivered to the deep-sea, a suite of geochemical tracers (e.g., stable and radio-isotopes, lipid biomarkers, and compound specific isotopes) was measured from monthly sediment trap samples deployed near a high-density deep-coral site in the Viosca Knoll area of the north-central Gulf of Mexico prior to (Oct-2008 to Sept-2009) and after the spill (Oct-10 to Sept-11). Marine (e.g., autochthonous) sources of organic matter dominated the sediment traps in both years, however after the spill, there was a pronounced reduction in marinesourced OM, including a reduction in marine-sourced sterols and n-alkanes and a concomitant decrease in sediment trap organic carbon and pigment flux. Results from this study indicate a reduction in primary production and carbon export to the deep-sea in 2010-2011, at least 6-18 months after the spill started. Whereas satellite observations indicate an initial increase in phytoplankton biomass, results from this sediment trap study define a reduction in primary production and carbon export to the deep-sea community. In addition, a dilution from a low-14C carbon source (e.g., petrocarbon) was detected in the sediment trap samples after the spill, in conjunction with a change in the petrogenic composition. The data presented here fills a critical gap in our knowledge of biogeochemical processes and sub-acute impacts to the deep-sea that ensued after the 2010 DWH spill.

  20. Mg isotope fractionation in biogenic carbonates of deep-sea coral, benthic foraminifera, and hermatypic coral.

    PubMed

    Yoshimura, Toshihiro; Tanimizu, Masaharu; Inoue, Mayuri; Suzuki, Atsushi; Iwasaki, Nozomu; Kawahata, Hodaka

    2011-11-01

    High-precision Mg isotope measurements by multiple collector inductively coupled plasma mass spectrometry were applied for determinations of magnesium isotopic fractionation of biogenic calcium carbonates from seawater with a rapid Mg purification technique. The mean δ(26)Mg values of scleractinian corals, giant clam, benthic foraminifera, and calcite deep-sea corals were -0.87‰, -2.57‰, -2.34‰, and -2.43‰, suggesting preferential precipitation of light Mg isotopes to produce carbonate skeleton in biomineralization. Mg isotope fractionation in deep-sea coral, which has high Mg calcite skeleton, showed a clear temperature (T) dependence from 2.5 °C to 19.5 °C: 1,000 × ln(α) = -2.63 (±0.076) + 0.0138 (±0.0051) × T(R(2) = 0.82, p < 0.01). The δ(26)Mg values of large benthic foraminifera, which are also composed of a high-Mg calcite skeleton, can be plotted on the same regression line as that for deep-sea coral. Since the precipitation rates of deep-sea coral and benthic foraminifera are several orders of magnitude different, the results suggest that kinetic isotope fractionation may not be a major controlling factor for high-Mg calcite. The Mg isotope fractionation factors and the slope of temperature dependence from deep-sea corals and benthic foraminifera are similar to that for an inorganically precipitated calcite speleothem. Taking into account element partitioning and the calcification rate of biogenic CaCO(3), the similarity among inorganic minerals, deep-sea corals, and benthic foraminiferas may indicate a strong mineralogical control on Mg isotope fractionation for high-Mg calcite. On the other hand, δ(26)Mg in hermatypic corals composed of aragonite has been comparable with previous data on biogenic aragonite of coral, sclerosponges, and scaphopad, regardless of species differences of samples.

  1. Impact of Deepwater Horizon spill on food supply to deep-sea benthos communities

    NASA Astrophysics Data System (ADS)

    Prouty, N. G.; Campbell, P. L.; Mienis, F.; Duineveld, G.; Demopoulos, A. W. J.; Ross, S. W.; Brooke, S.

    2016-02-01

    Deep-sea ecosystems encompass unique and often fragile communities that are sensitive to a variety of anthropogenic and natural impacts. After the 2010 Deepwater Horizon (DWH) oil spill, sampling efforts documented the acute impact of the spill on some deep-sea coral colonies. To investigate the impact of the DWH spill on quality and quantity of biomass delivered to the deep-sea, a suite of geochemical tracers (e.g., stable and radio-isotopes, lipid biomarkers, and compound-specific isotopes) was measured from monthly sediment trap samples deployed near a high-density deep-coral site in the Viosca Knoll area of the north-central Gulf of Mexico prior to (Oct-2008 to Sept-2009) and after the spill (Oct-10 to Sept-11). Marine (e.g., autochthonous) sources of organic matter (OM) dominated the sediment traps in both years, however after the spill, there was a pronounced reduction in marine-sourced OM, including a reduction in marine-sourced sterols and n-alkanes and a concomitant decrease in sediment trap organic carbon and pigment flux. Results from this study indicate a reduction in primary production and carbon export to the deep-sea in 2010-2011, at least 6-18 months after the spill started. Whereas satellite observations indicate an initial increase in phytoplankton biomass, results from this sediment trap study define a reduction in primary production and carbon export to the deep-sea community. In addition, a dilution from a low-14C carbon source (e.g., petro-carbon) was detected in the sediment trap samples after the spill, in conjunction with a change in the petrogenic composition. The data presented here fills a critical gap in our knowledge of biogeochemical processes and sub-acute impacts to the deep-sea that ensued after the 2010 DWH spill.

  2. 13C-18O bonding (Δ47) in deep-sea corals: a calibration study

    NASA Astrophysics Data System (ADS)

    Kimball, J. B.; Tripati, A.; Dunbar, R. B.; Eagle, R.

    2013-12-01

    Deep-sea corals are a potentially valuable archive of temperature in intermediate and deep waters, regions for which a paucity of temperature data exists. These archives could give valuable insight into the natural variability of areas of the ocean that play an active role in large-scale climate dynamics. Due to significant 'vital effects' (i.e., non-equilibrium mineral compositions) in δ18O, however, deep-sea coral have been challenging to develop as a paleotemperature proxy. Clumped-isotope paleothermometry is a new method that may circumvent some of the known complications with δ18O paleotemperature analysis in deep-sea coral. This geothermometer is based on the ordering of heavy 13C-18O ';clumps' in carbonate minerals. Initial calibration studies have shown that the method is independent from the solution chemistry of the precipitating fluids as well as 'vital effects' in deep-sea corals and other types of carbonates. Some kinetic effects have been observed in tropical corals and speleothems. Here we report new data in order to further develop clumped isotopes as a paleothermometer in deep-sea corals as well as to investigate taxon-specific effects. 13C-18O bond ordering was analyzed in live-collected scleractinian (Enallopsammia sp.) and gorgonian (Isididae and Coralliidae) deep-sea corals. We determined mass 47 anomalies in samples (Δ47), which refers to the parts per thousand excess of 13C-18O-16O in CO2 produced on acid digestion of a sample, relative to the amount predicted to be present if isotopes were randomly distributed amongst all CO2 isotopologues. Measured Δ47 values were compared to in situ temperatures and the relationship between Δ47 and temperature was determined for each group to investigate taxon-specific effects.

  3. Fungi in deep-sea sediments of the Central Indian Basin

    NASA Astrophysics Data System (ADS)

    Damare, Samir; Raghukumar, Chandralata; Raghukumar, S.

    2006-01-01

    Although a great amount of information is available on bacteria inhabiting deep-sea sediments, the occurrence of fungi in this environment has been poorly studied and documented. We report here the occurrence of fungi in deep-sea sediments from ˜5000 m depth in the Central Indian Basin (9-16°S and 73-76°E). A total of 181 cultures of fungi, most of which belong to terrestrial sporulating species, were isolated by a variety of isolation techniques. Species of Aspergillus and non-sporulating fungi were the most common. Several yeasts were also isolated. Maximum species diversity was observed in 0-2 cm sections of the sediment cores. Direct staining of the sediments with Calcofluor, a fluorescent optical brightener, revealed the presence of fungal hyphae in the sediments. Immunofluorescence using polyclonal antibodies raised against a deep-sea isolate of Aspergillus terreus (# A 4634) confirmed its presence in the form of hyphae in the sub-section from which it was isolated. A total of 25 representative species of fungi produced substantial biomass at 200 bar pressure at 30° as well as at 5 °C. Many fungi showed abnormal morphology at 200 bar/5 °C. A comparison of terrestrial isolates with several deep-sea isolates indicated that the former could grow at 200 bar pressure when growth was initiated with mycelial inocula. However, spores of a deep-sea isolate A. terreus (# A 4634), but not the terrestrial ones, showed germination at 200 bar pressure and 30 °C. Our results suggest that terrestrial species of fungi transported to the deep sea are initially stressed but may gradually adapt themselves for growth under these conditions.

  4. The National Deep-Sea Coral and Sponge Database: A Comprehensive Resource for United States Deep-Sea Coral and Sponge Records

    NASA Astrophysics Data System (ADS)

    Dornback, M.; Hourigan, T.; Etnoyer, P.; McGuinn, R.; Cross, S. L.

    2014-12-01

    Research on deep-sea corals has expanded rapidly over the last two decades, as scientists began to realize their value as long-lived structural components of high biodiversity habitats and archives of environmental information. The NOAA Deep Sea Coral Research and Technology Program's National Database for Deep-Sea Corals and Sponges is a comprehensive resource for georeferenced data on these organisms in U.S. waters. The National Database currently includes more than 220,000 deep-sea coral records representing approximately 880 unique species. Database records from museum archives, commercial and scientific bycatch, and from journal publications provide baseline information with relatively coarse spatial resolution dating back as far as 1842. These data are complemented by modern, in-situ submersible observations with high spatial resolution, from surveys conducted by NOAA and NOAA partners. Management of high volumes of modern high-resolution observational data can be challenging. NOAA is working with our data partners to incorporate this occurrence data into the National Database, along with images and associated information related to geoposition, time, biology, taxonomy, environment, provenance, and accuracy. NOAA is also working to link associated datasets collected by our program's research, to properly archive them to the NOAA National Data Centers, to build a robust metadata record, and to establish a standard protocol to simplify the process. Access to the National Database is provided through an online mapping portal. The map displays point based records from the database. Records can be refined by taxon, region, time, and depth. The queries and extent used to view the map can also be used to download subsets of the database. The database, map, and website is already in use by NOAA, regional fishery management councils, and regional ocean planning bodies, but we envision it as a model that can expand to accommodate data on a global scale.

  5. Size distribution of interplanetary iron and stony particles related with deep-sea spherules

    NASA Technical Reports Server (NTRS)

    Matsuzaki, H.; Yamakoshi, K.

    1993-01-01

    To study origin and evolution of the interplanetary dust, it is very important to investigate the size distribution. Here the changes of the size distributions of meteoroid particles due to the ablative effects during atmospheric entry were investigated by numerical computer simulation. Using the results, the pre-atmospheric size distributions of the interplanetary dust particles could be estimated from that of ablated spherules taken from deep-sea sediments. We are now analyzing deep-sea spherules from some aspects and examining if we could get any information about the interplanetary dust.

  6. Another bipolar deep-sea anemone: new species of Iosactis (Actiniaria, Endomyaria) from Antarctica

    NASA Astrophysics Data System (ADS)

    Rodríguez, Estefanía

    2012-06-01

    A new species of deep-sea burrowing sea anemone is described and illustrated from Antarctica. Iosactis antarctica sp. nov. is characterised by easily deciduous tentacles with sphincters in the base, smooth column, endodermal marginal sphincter, same mesenteries proximally and distally, 24 perfect mesenteries regularly arranged, diffuse retractor musculature and basilar muscles well developed. Iosactis antarctica sp. nov. is the second species of the deep-sea abyssal genus Iosactis; it differs from I. vagabunda in internal anatomy, cnidae and geographic distribution. The description of I. antarctica sp. nov. provides the opportunity to revaluate the morphology of the proximal end of this genus.

  7. Thermodynamic and functional characteristics of deep-sea enzymes revealed by pressure effects.

    PubMed

    Ohmae, Eiji; Miyashita, Yurina; Kato, Chiaki

    2013-09-01

    Hydrostatic pressure analysis is an ideal approach for studying protein dynamics and hydration. The development of full ocean depth submersibles and high pressure biological techniques allows us to investigate enzymes from deep-sea organisms at the molecular level. The aim of this review was to overview the thermodynamic and functional characteristics of deep-sea enzymes as revealed by pressure axis analysis after giving a brief introduction to the thermodynamic principles underlying the effects of pressure on the structural stability and function of enzymes.

  8. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    PubMed

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  9. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    PubMed

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-08-02

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  10. Species abundance, sexual encounter and bioluminescent signalling in the deep sea.

    PubMed Central

    Herring, P J

    2000-01-01

    The problems faced by deep-sea animals in achieving sexual and other encounters require sensory and effector systems the synergy of which can span the often very substantial distances that separate individuals. Bioluminescent systems provide one of the links between individuals, and the sexual dimorphism of some photophores suggests that they are employed to attract a mate. However, nearest-neighbour values for many deep-sea animals put them beyond the effective range of bioluminescent signals and it is therefore likely that these signals are employed at intermediate ranges, once an initial contact (perhaps olfactory) has been made. PMID:11079413

  11. Deep-Sea Biodiversity in the Mediterranean Sea: The Known, the Unknown, and the Unknowable

    PubMed Central

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J.; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  12. Diazotrophy in the Deep: An analysis of the distribution, magnitude, geochemical controls, and biological mediators of deep-sea benthic nitrogen fixation

    NASA Astrophysics Data System (ADS)

    Dekas, Anne Elizabeth

    Biological nitrogen fixation (the conversion of N2 to NH3) is a critical process in the oceans, counteracting the production of N2 gas by dissimilatory bacterial metabolisms and providing a source of bioavailable nitrogen to many nitrogen-limited ecosystems. One currently poorly studied and potentially underappreciated habitat for diazotrophic organisms is the sediments of the deep-sea. Although nitrogen fixation was once thought to be negligible in non-photosynthetically driven benthic ecosystems, the present study demonstrates the occurrence and expression of a diversity of nifH genes (those necessary for nitrogen fixation), as well as a widespread ability to fix nitrogen at high rates in these locations. The following research explores the distribution, magnitude, geochemical controls, and biological mediators of nitrogen fixation at several deep-sea sediment habitats, including active methane seeps (Mound 12, Costa Rica; Eel River Basin, CA, USA; Hydrate Ridge, OR, USA; and Monterey Canyon, CA, USA), whale-fall sites (Monterey Canyon, CA), and background deep-sea sediment (off-site Mound 12 Costa Rica, off-site Hydrate Ridge, OR, USA; and Monterey Canyon, CA, USA). The first of the five chapters describes the FISH-NanoSIMS method, which we optimized for the analysis of closely associated microbial symbionts in marine sediments. The second describes an investigation of methane seep sediment from the Eel River Basin, where we recovered nifH sequences from extracted DNA, and used FISH-NanoSIMS to identify methanotrophic archaea (ANME-2) as diazotrophs, when associated with functional sulfate-reducing bacterial symbionts. The third and fourth chapters focus on the distribution and diversity of active diazotrophs (respectively) in methane seep sediment from Mound 12, Costa Rica, using a combination of 15N-labeling experiments, FISH-NanoSIMS, and RNA and DNA analysis. The fifth chapter expands the scope of the investigation by targeting diverse samples from methane

  13. Resource utilization by deep-sea sharks at the Le Danois Bank, Cantabrian Sea, north-east Atlantic Ocean.

    PubMed

    Preciado, I; Cartes, J E; Serrano, A; Velasco, F; Olaso, I; Sánchez, F; Frutos, I

    2009-10-01

    The feeding habits of birdbeak dogfish Deania calcea, velvet belly lantern shark Etmopterus spinax and blackmouth catshark Galeus melastomus at Le Danois Bank, Cantabrian Sea, south Bay of Biscay were studied in relation to their bathymetric distribution. Deep-sea sharks were collected during two multidisciplinary surveys carried out in October 2003 and April 2004 at the Le Danois Bank. Two different habitats were defined: (1) the top of the bank, ranging from 454 to 642 m depth and covered by fine-sand sediments with a low percentage of organic matter, and (2) the inner basin located between the bank and the Cantabrian Sea's continental shelf, at depths of 810-1048 m, which was characterized by a high proportion of silt and organic matter. Deania calcea was not present at the top of the bank but was abundant below 642 m, while E. spinax was abundant in the shallower top of the bank but was not found in the deeper inner basin. There was almost no bathymetric overlap between these two deep-sea shark species. Galeus melastomus was found over the whole depth range. There seemed to be an ontogenetic segregation with depth for this species, however, since 80% of the specimens collected at the top of the bank were < 600 mm total length (L(T)) (mean 510 mm L(T)), whereas larger individuals (mean 620 mm L(T)) inhabited deeper zones. Galeus melastomus exhibited a significantly higher feeding intensity than both E. spinax at the top of the bank and D. calcea in the inner basin. Little dietary overlap between D. calcea and G. melastomus in the inner basin was found, with D. calcea being an ichthyophagous predator while the diet of G. melastomus at these depths was composed of a variety of meso-bathypelagic shrimps (e.g. Acantephyra pelagica, Pasiphaea spp. and Sergia robusta), cephalopods and fishes. The diets of E. spinax and G. melastomus at the top of the bank showed a high dietary overlap of euphausiids, which represented the main prey taxa for both species. Euphausiids

  14. Exploring fungal diversity in deep-sea sediments from Okinawa Trough using high-throughput Illumina sequencing

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-Yong; Wang, Guang-Hua; Xu, Xin-Ya; Nong, Xu-Hua; Wang, Jie; Amin, Muhammad; Qi, Shu-Hua

    2016-10-01

    The present study investigated the fungal diversity in four different deep-sea sediments from Okinawa Trough using high-throughput Illumina sequencing of the nuclear ribosomal internal transcribed spacer-1 (ITS1). A total of 40,297 fungal ITS1 sequences clustered into 420 operational taxonomic units (OTUs) with 97% sequence similarity and 170 taxa were recovered from these sediments. Most ITS1 sequences (78%) belonged to the phylum Ascomycota, followed by Basidiomycota (17.3%), Zygomycota (1.5%) and Chytridiomycota (0.8%), and a small proportion (2.4%) belonged to unassigned fungal phyla. Compared with previous studies on fungal diversity of sediments from deep-sea environments by culture-dependent approach and clone library analysis, the present result suggested that Illumina sequencing had been dramatically accelerating the discovery of fungal community of deep-sea sediments. Furthermore, our results revealed that Sordariomycetes was the most diverse and abundant fungal class in this study, challenging the traditional view that the diversity of Sordariomycetes phylotypes was low in the deep-sea environments. In addition, more than 12 taxa accounted for 21.5% sequences were found to be rarely reported as deep-sea fungi, suggesting the deep-sea sediments from Okinawa Trough harbored a plethora of different fungal communities compared with other deep-sea environments. To our knowledge, this study is the first exploration of the fungal diversity in deep-sea sediments from Okinawa Trough using high-throughput Illumina sequencing.

  15. 76 FR 36511 - Fisheries of the Northeastern United States; Atlantic Deep-Sea Red Crab; Amendment 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... United States; Atlantic Deep-Sea Red Crab; Amendment 3 AGENCY: National Marine Fisheries Service (NMFS... Fishery Management Council (Council) has submitted Amendment 3 to the Atlantic Deep-Sea Red Crab Fishery... envelope, ``Comments on Red Crab Amendment 3.'' Instructions: All comments received are part of the...

  16. Morphology of a new deep-sea acorn worm (class Enteropneusta, phylum Hemichordata): a part-time demersal drifter with externalized ovaries.

    PubMed

    Holland, Nicholas D; Kuhnz, Linda A; Osborn, Karen J

    2012-07-01

    Ten individuals of an enteropneust in the family Torquaratoridae were videotaped between 2,900 and 3,500 m in the Eastern Pacific--one drifting a few centimeters above the bottom, two exposed on the substrate, and seven partly burrowed, reflecting a bentho-pelagic life style. Here, we describe a captured specimen (26 cm living length) as the holotype of Allapasus aurantiacus n. gen., n. sp. The small proboscis is dome-shaped, and the collar is only slightly wider than deep; both of these body regions are more muscular than in other torquaratorids, which presumably facilitates burrowing. The proboscis complex, in contrast to that of shallow-living enteropneusts, lacks a pericardial sac and is located relatively posteriorly in the proboscis stalk. The stomochord is separated from the main course of the gut by the intervention of a small, plate-like proboscis skeleton lacking posterior horns. The most anterior region of the trunk houses the pharynx, in which the pharyngeal skeletal bars are not connected by synapticles. The postpharyngeal trunk comprises three intestinal regions: prehepatic, hepatic (with conspicuous sacculations), and posthepatic. On either side of the worm, a flap of body wall (lateral wing) runs the entire length of the trunk. The two lateral wings can wrap the body so their edges meet in the dorsal midline, although they often gape open along the pharyngeal region. The holotype is a female (presumably the species is gonochoric) with numerous ovaries located in the lateral wings along the pharyngeal region. Each larger ovary contains a single primary oocyte (up to 1,500 μm in diameter) and bulges outwards in an epidermal pouch attached to the rest of the body by a slender stalk. Such externalized ovaries are unprecedented in any animal, and nothing is yet known of their role in the reproductive biology of A. aurantiacus. PMID:22419131

  17. Morphology of a new deep-sea acorn worm (class Enteropneusta, phylum Hemichordata): a part-time demersal drifter with externalized ovaries.

    PubMed

    Holland, Nicholas D; Kuhnz, Linda A; Osborn, Karen J

    2012-07-01

    Ten individuals of an enteropneust in the family Torquaratoridae were videotaped between 2,900 and 3,500 m in the Eastern Pacific--one drifting a few centimeters above the bottom, two exposed on the substrate, and seven partly burrowed, reflecting a bentho-pelagic life style. Here, we describe a captured specimen (26 cm living length) as the holotype of Allapasus aurantiacus n. gen., n. sp. The small proboscis is dome-shaped, and the collar is only slightly wider than deep; both of these body regions are more muscular than in other torquaratorids, which presumably facilitates burrowing. The proboscis complex, in contrast to that of shallow-living enteropneusts, lacks a pericardial sac and is located relatively posteriorly in the proboscis stalk. The stomochord is separated from the main course of the gut by the intervention of a small, plate-like proboscis skeleton lacking posterior horns. The most anterior region of the trunk houses the pharynx, in which the pharyngeal skeletal bars are not connected by synapticles. The postpharyngeal trunk comprises three intestinal regions: prehepatic, hepatic (with conspicuous sacculations), and posthepatic. On either side of the worm, a flap of body wall (lateral wing) runs the entire length of the trunk. The two lateral wings can wrap the body so their edges meet in the dorsal midline, although they often gape open along the pharyngeal region. The holotype is a female (presumably the species is gonochoric) with numerous ovaries located in the lateral wings along the pharyngeal region. Each larger ovary contains a single primary oocyte (up to 1,500 μm in diameter) and bulges outwards in an epidermal pouch attached to the rest of the body by a slender stalk. Such externalized ovaries are unprecedented in any animal, and nothing is yet known of their role in the reproductive biology of A. aurantiacus.

  18. LVP modeling and dynamic characteristics prediction of a hydraulic power unit in deep-sea

    NASA Astrophysics Data System (ADS)

    Cao, Xue-peng; Ye, Min; Deng, Bin; Zhang, Cui-hong; Yu, Zu-ying

    2013-03-01

    A hydraulic power unit (HPU) is the driving "heart" of deep-sea working equipment. It is critical to predict its dynamic performances in deep-water before being immerged in the seawater, while the experimental tests by simulating deep-sea environment have many disadvantages, such as expensive cost, long test cycles, and difficult to achieve low-temperature simulation, which is only used as a supplementary means for confirmatory experiment. This paper proposes a novel theoretical approach based on the linear varying parameters (LVP) modeling to foresee the dynamic performances of the driving unit. Firstly, based on the varying environment features, dynamic expressions of the compressibility and viscosity of hydraulic oil are derived to reveal the fluid performances changing. Secondly, models of hydraulic system and electrical system are accomplished respectively through studying the control process and energy transfer, and then LVP models of the pressure and flow rate control is obtained through the electro-hydraulic models integration. Thirdly, dynamic characteristics of HPU are obtained by the model simulating within bounded closed sets of varying parameters. Finally, the developed HPU is tested in a deep-sea imitating hull, and the experimental results are well consistent with the theoretical analysis outcomes, which clearly declare that the LVP modeling is a rational way to foresee dynamic performances of HPU. The research approach and model analysis results can be applied to the predictions of working properties and product designs for other deep-sea hydraulic pump.

  19. Impacts on the Deep-Sea Ecosystem by a Severe Coastal Storm

    PubMed Central

    Sanchez-Vidal, Anna; Canals, Miquel; Calafat, Antoni M.; Lastras, Galderic; Pedrosa-Pàmies, Rut; Menéndez, Melisa; Medina, Raúl; Company, Joan B.; Hereu, Bernat; Romero, Javier; Alcoverro, Teresa

    2012-01-01

    Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem. PMID:22295084

  20. Draft Genome Sequence of the Deep-Sea Bacterium Shewanella benthica Strain KT99.

    PubMed

    Lauro, F M; Chastain, R A; Ferriera, S; Johnson, J; Yayanos, A A; Bartlett, D H

    2013-01-01

    We report the draft genome sequence of the obligately piezophilic Shewanella benthica strain KT99 isolated from the abyssal South Pacific Ocean. Strain KT99 is the first piezophilic isolate from the Tonga-Kermadec trench, and its genome provides many clues on high-pressure adaptation and the evolution of deep-sea piezophilic bacteria. PMID:23723392