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Sample records for salmon european sea

  1. Differential light intensity and spectral sensitivities of Atlantic salmon, European sea bass and Atlantic cod pineal glands ex vivo.

    PubMed

    Vera, L M; Davie, A; Taylor, J F; Migaud, H

    2010-01-01

    Photoperiod is perceived by pineal photoreceptors and transduced into rhythmic melatonin signals. These rhythms can be influenced by light intensity and spectral content. In this study we compared the light sensitivity of Atlantic salmon, European sea bass and Atlantic cod by testing ex vivo the effect of different intensities and narrow bandwidth lights on nocturnal melatonin suppression by isolated pineal glands in a flow-through culture system. Using combinations of neutral density and bandpass interference filters we tested a range of light intensities (ranging from 1.22x10(13) to 3.85x10(6) photons s(-1) cm(-2)) and three wavelengths of 80 nm width (472, 555 and 661 nm corresponding to blue, green and red, respectively). Results showed clear species specific light intensity and spectral sensitivities, with cod being from 100 to 1000 times more sensitive than sea bass and salmon. Regarding the influence of spectrum, red light was less efficient on suppressing melatonin than blue and green in salmon but results were not as clear in the two other species studied. Finally, the first evidence of relative photoreception in teleosts was obtained in cod suggesting that the definition of illuminance thresholds (day/night perception) would depend on the day intensity. Indeed, a single order of magnitude increase or decrease in day intensity was shown to elicit a significant shift in the intensity response curve of night-time melatonin suppression. Taken together, this study demonstrated species specific light intensity and spectral sensitivities within temperate teleosts. PMID:19501092

  2. Lessons from sea louse and salmon epidemiology.

    PubMed

    Groner, Maya L; Rogers, Luke A; Bateman, Andrew W; Connors, Brendan M; Frazer, L Neil; Godwin, Sean C; Krkošek, Martin; Lewis, Mark A; Peacock, Stephanie J; Rees, Erin E; Revie, Crawford W; Schlägel, Ulrike E

    2016-03-01

    Effective disease management can benefit from mathematical models that identify drivers of epidemiological change and guide decision-making. This is well illustrated in the host-parasite system of sea lice and salmon, which has been modelled extensively due to the economic costs associated with sea louse infections on salmon farms and the conservation concerns associated with sea louse infections on wild salmon. Consequently, a rich modelling literature devoted to sea louse and salmon epidemiology has been developed. We provide a synthesis of the mathematical and statistical models that have been used to study the epidemiology of sea lice and salmon. These studies span both conceptual and tactical models to quantify the effects of infections on host populations and communities, describe and predict patterns of transmission and dispersal, and guide evidence-based management of wild and farmed salmon. As aquaculture production continues to increase, advances made in modelling sea louse and salmon epidemiology should inform the sustainable management of marine resources. PMID:26880836

  3. Sea Louse Infection of Juvenile Sockeye Salmon in Relation to Marine Salmon Farms on Canada's West Coast

    PubMed Central

    Price, Michael H. H.; Proboszcz, Stan L.; Routledge, Rick D.; Gottesfeld, Allen S.; Orr, Craig; Reynolds, John D.

    2011-01-01

    Background Pathogens are growing threats to wildlife. The rapid growth of marine salmon farms over the past two decades has increased host abundance for pathogenic sea lice in coastal waters, and wild juvenile salmon swimming past farms are frequently infected with lice. Here we report the first investigation of the potential role of salmon farms in transmitting sea lice to juvenile sockeye salmon (Oncorhynchus nerka). Methodology/Principal Findings We used genetic analyses to determine the origin of sockeye from Canada's two most important salmon rivers, the Fraser and Skeena; Fraser sockeye migrate through a region with salmon farms, and Skeena sockeye do not. We compared lice levels between Fraser and Skeena juvenile sockeye, and within the salmon farm region we compared lice levels on wild fish either before or after migration past farms. We matched the latter data on wild juveniles with sea lice data concurrently gathered on farms. Fraser River sockeye migrating through a region with salmon farms hosted an order of magnitude more sea lice than Skeena River populations, where there are no farms. Lice abundances on juvenile sockeye in the salmon farm region were substantially higher downstream of farms than upstream of farms for the two common species of lice: Caligus clemensi and Lepeophtheirus salmonis, and changes in their proportions between two years matched changes on the fish farms. Mixed-effects models show that position relative to salmon farms best explained C. clemensi abundance on sockeye, while migration year combined with position relative to salmon farms and temperature was one of two top models to explain L. salmonis abundance. Conclusions/Significance This is the first study to demonstrate a potential role of salmon farms in sea lice transmission to juvenile sockeye salmon during their critical early marine migration. Moreover, it demonstrates a major migration corridor past farms for sockeye that originated in the Fraser River, a complex of populations that are the subject of conservation concern. PMID:21347456

  4. Mortality of seabirds in high-seas salmon gillnets

    USGS Publications Warehouse

    Ainley, D.G.; DeGange, A.R.; Jones, L.L.; Beach, R.J.

    1981-01-01

    Since 1952, the Japanese have operated a large salmon driftnet.fishery in the northern North Pacific Ocean and Bering Sea. This fishery is divided into two components: the high-seas mothership fleet, which consists of several processing ships and their numerous, smaller catcher boats that remain at sea during the entire fishing season, and the land-based fleet, which consists of independent fishing boats that catch and store their own fish and return to Japan at more frequent intervals (Sanger 1976; Fredin et al. 2 ). A similar fishery in the North Atlantic between 1965 and 1976 was responsible for the deaths of large numbers of the thick-billed murre, Uria lomvia, and significant reductions in its breeding populations (Tull et al. 1972). Recent work in the North Pacific and Bering Sea by Sana (1978) and King et al. (1979) indicated that large numbers of seabirds are killed annually in the Japanese salmon fishery also.

  5. Can reduced predation offset negative effects of sea louse parasites on chum salmon?

    PubMed

    Peacock, Stephanie J; Connors, Brendan M; Krkosek, Martin; Irvine, James R; Lewis, Mark A

    2014-02-01

    The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host-parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations. PMID:24352951

  6. Interannual variability in stock abundance and body size of Pacific salmon in the central Bering Sea

    NASA Astrophysics Data System (ADS)

    Ishida, Y.; Azumaya, T.; Fukuwaka, M.; Davis, N.

    2002-10-01

    Variability in catch-per-unit-effort (CPUE) and mean body size was examined for pink, chum and sockeye salmon collected with research gillnets in the central Bering Sea in July from 1972 to 2000. The CPUEs for all three species showed significant increasing trends, but with large interannual variability. The CPUE of pink salmon was higher in odd years than in even years, and abruptly increased in the odd years post-1989. Chum salmon also showed odd/even year fluctuations, which were out-of-phase with those of pink salmon. Sockeye salmon showed no biennial such fluctuations. The CPUEs of chum and sockeye salmon were higher during 1979-1984 and 1992-1998, but lower during 1985-1991, especially for younger age group such as ocean age 2 and 3. Data for sea surface temperature (SST) and abundances of chum and sockeye salmon during four periods (1972-1976, 1977-1984, 1985-1990, and 1991-2000) indicated a portion of chum and sockeye salmon were distributed in the northern Gulf of Alaska in 1985-1990, when SST in the Gulf of Alaska was low. However, the fish were more abundant in the Bering Sea in 1977-1984 and 1991-2000 when SST was relatively high in the Gulf of Alaska. Body size of pink salmon showed a significant decreasing trend. Chum and sockeye salmon also showed significant decreasing trends in body size at ocean age 3 and older ages, but not at ocean age 2. Significant negative relationships between CPUE and body size were found within species. No significant correlations were found between an Aleutian low pressure index (ALPI) with CPUE and body size, but the increases in CPUE around the late 1970s and early 1990s may be partly be the result of shifts in the distributions of chum and sockeye salmon caused by SST changes related to the regime shift in 1977 and 1989 identified by the ALPI.

  7. Preliminary genetic analysis of juvenile chum salmon from the Chukchi Sea and Bering Strait

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The arctic region has experienced warming in recent years, resulting in decreased summer sea ice cover and increased sea surface temperatures. In September 2007, the U.S. BASIS survey extended surface trawling into the Chukchi Sea. Juvenile (young-of-the-year) chum salmon were collected at most stat...

  8. Evidence for competition at sea between Norton Sound chum salmon and Asian hatchery chum salmon

    USGS Publications Warehouse

    Ruggerone, Gregory T.; Agler, B.A.; Nielsen, Jennifer L.

    2012-01-01

    Increasing production of hatchery salmon over the past four decades has led to concerns about possible density-dependent effects on wild Pacific salmon populations in the North Pacific Ocean. The concern arises because salmon from distant regions overlap in the ocean, and wild salmon populations having low productivity may compete for food with abundant hatchery populations. We tested the hypothesis that adult length-at-age, age-at-maturation, productivity, and abundance of a Norton Sound, Alaska, chum salmon population were influenced by Asian hatchery chum salmon, which have become exceptionally abundant and surpassed the abundance of wild chum salmon in the North Pacific beginning in the early 1980s. We found that smaller adult length-at-age, delayed age-at-maturation, and reduced productivity and abundance of the Norton Sound salmon population were associated with greater production of Asian hatchery chum salmon since 1965. Modeling of the density-dependent relationship, while controlling for other influential variables, indicated that an increase in adult hatchery chum salmon abundance from 10 million to 80 million adult fish led to a 72% reduction in the abundance of the wild chum salmon population. These findings indicate that competition with hatchery chum salmon contributed to the low productivity and abundance of Norton Sound chum salmon, which includes several stocks that are classified as Stocks of Concern by the State of Alaska. This study provides new evidence indicating that large-scale hatchery production may influence body size, age-at-maturation, productivity and abundance of a distant wild salmon population.

  9. Linkages between Alaskan sockeye salmon abundance, growth at sea, and climate, 1955 2002

    NASA Astrophysics Data System (ADS)

    Ruggerone, G. T.; Nielsen, J. L.; Bumgarner, J.

    2007-11-01

    We tested the hypothesis that increased growth of salmon during early marine life contributed to greater survival and abundance of salmon following the 1976/1977 climate regime shift and that this, in turn, led to density-dependent reductions in growth during late marine stages. Annual measurements of Bristol Bay (Bering Sea) and Chignik (Gulf of Alaska) sockeye salmon scale growth from 1955 to 2002 were used as indices of body growth. During the first and second years at sea, growth of both stocks tended to be higher after the 1976-1977 climate shift, whereas growth during the third year and homeward migration was often below average. Multiple regression models indicated that return per spawner of Bristol Bay sockeye salmon and adult abundance of western and central Alaska sockeye salmon were positively correlated with growth during the first 2 years at sea and negatively correlated with growth during later life stages. After accounting for competition between Bristol Bay sockeye and Asian pink salmon, age-specific adult length of Bristol Bay salmon increased after the 1976-1977 regime shift, then decreased after the 1989 climate shift. Late marine growth and age-specific adult length of Bristol Bay salmon was exceptionally low after 1989, possibly reducing their reproductive potential. These findings support the hypothesis that greater marine growth during the first 2 years at sea contributed to greater salmon survival and abundance, which in turn led to density-dependent growth during later life stages when size-related mortality was likely lower. Our findings provide new evidence supporting the importance of bottom-up control in marine ecosystems and highlight the complex dynamics of species interactions that continually change as salmon grow and mature in the ocean.

  10. Linkages between Alaskan sockeye salmon abundance, growth at sea, and climate, 1955-2002

    USGS Publications Warehouse

    Ruggerone, G.T.; Nielsen, J.L.; Bumgarner, J.

    2007-01-01

    We tested the hypothesis that increased growth of salmon during early marine life contributed to greater survival and abundance of salmon following the 1976/1977 climate regime shift and that this, in turn, led to density-dependent reductions in growth during late marine stages. Annual measurements of Bristol Bay (Bering Sea) and Chignik (Gulf of Alaska) sockeye salmon scale growth from 1955 to 2002 were used as indices of body growth. During the first and second years at sea, growth of both stocks tended to be higher after the 1976-1977 climate shift, whereas growth during the third year and homeward migration was often below average. Multiple regression models indicated that return per spawner of Bristol Bay sockeye salmon and adult abundance of western and central Alaska sockeye salmon were positively correlated with growth during the first 2 years at sea and negatively correlated with growth during later life stages. After accounting for competition between Bristol Bay sockeye and Asian pink salmon, age-specific adult length of Bristol Bay salmon increased after the 1976-1977 regime shift, then decreased after the 1989 climate shift. Late marine growth and age-specific adult length of Bristol Bay salmon was exceptionally low after 1989, possibly reducing their reproductive potential. These findings support the hypothesis that greater marine growth during the first 2 years at sea contributed to greater salmon survival and abundance, which in turn led to density-dependent growth during later life stages when size-related mortality was likely lower. Our findings provide new evidence supporting the importance of bottom-up control in marine ecosystems and highlight the complex dynamics of species interactions that continually change as salmon grow and mature in the ocean. ?? 2007 Elsevier Ltd. All rights reserved.

  11. Geomagnetic imprinting: A unifying hypothesis of long-distance natal homing in salmon and sea turtles.

    PubMed

    Lohmann, Kenneth J; Putman, Nathan F; Lohmann, Catherine M F

    2008-12-01

    Several marine animals, including salmon and sea turtles, disperse across vast expanses of ocean before returning as adults to their natal areas to reproduce. How animals accomplish such feats of natal homing has remained an enduring mystery. Salmon are known to use chemical cues to identify their home rivers at the end of spawning migrations. Such cues, however, do not extend far enough into the ocean to guide migratory movements that begin in open-sea locations hundreds or thousands of kilometers away. Similarly, how sea turtles reach their nesting areas from distant sites is unknown. However, both salmon and sea turtles detect the magnetic field of the Earth and use it as a directional cue. In addition, sea turtles derive positional information from two magnetic elements (inclination angle and intensity) that vary predictably across the globe and endow different geographic areas with unique magnetic signatures. Here we propose that salmon and sea turtles imprint on the magnetic field of their natal areas and later use this information to direct natal homing. This novel hypothesis provides the first plausible explanation for how marine animals can navigate to natal areas from distant oceanic locations. The hypothesis appears to be compatible with present and recent rates of field change (secular variation); one implication, however, is that unusually rapid changes in the Earth's field, as occasionally occur during geomagnetic polarity reversals, may affect ecological processes by disrupting natal homing, resulting in widespread colonization events and changes in population structure. PMID:19060188

  12. The Interaction between Water Currents and Salmon Swimming Behaviour in Sea Cages

    PubMed Central

    Johansson, David; Laursen, Frida; Fernö, Anders; Fosseidengen, Jan Erik; Klebert, Pascal; Stien, Lars Helge; Vågseth, Tone; Oppedal, Frode

    2014-01-01

    Positioning of sea cages at sites with high water current velocities expose the fish to a largely unknown environmental challenge. In this study we observed the swimming behaviour of Atlantic salmon (Salmo salar L.) at a commercial farm with tidal currents altering between low, moderate and high velocities. At high current velocities the salmon switched from the traditional circular polarized group structure, seen at low and moderate current velocities, to a group structure where all fish kept stations at fixed positions swimming against the current. This type of group behaviour has not been described in sea cages previously. The structural changes could be explained by a preferred swimming speed of salmon spatially restricted in a cage in combination with a behavioural plasticity of the fish. PMID:24830443

  13. Impact of early salmon louse, Lepeophtheirus salmonis, infestation and differences in survival and marine growth of sea-ranched Atlantic salmon, Salmo salar L., smolts 1997–2009

    PubMed Central

    Skilbrei, O T; Finstad, B; Urdal, K; Bakke, G; Kroglund, F; Strand, R

    2013-01-01

    The impact of salmon lice on the survival of migrating Atlantic salmon smolts was studied by comparing the adult returns of sea-ranched smolts treated for sea lice using emamectin benzoate or substance EX with untreated control groups in the River Dale in western Norway. A total of 143 500 smolts were released in 35 release groups in freshwater from 1997 to 2009 and in the fjord system from 2007 to 2009. The adult recaptures declined gradually with release year and reached minimum levels in 2007. This development corresponded with poor marine growth and increased age at maturity of ranched salmon and in three monitored salmon populations and indicated unfavourable conditions in the Norwegian Sea. The recapture rate of treated smolts was significantly higher than the controls in three of the releases performed: the only release in 1997, one of three in 2002 and the only group released in sea water in 2007. The effect of treating the smolts against salmon lice was smaller than the variability in return rates between release groups, and much smaller that variability between release years, but its overall contribution was still significant (P < 0.05) and equivalent to an odds ratio of the probability of being recaptured of 1.17 in favour of the treated smolts. Control fish also tended to be smaller as grilse (P = 0.057), possibly due to a sublethal effect of salmon lice. PMID:23311746

  14. Sea & Space: a New European Educational Programme

    NASA Astrophysics Data System (ADS)

    1998-01-01

    This spring, teachers across Europe will enjoy support for exciting, novel educational projects on astronomy, navigation and environmental observations. The largely web-based and highly interactive SEA & SPACE programme makes it possible for pupils to perform field experiments and astronomical observations and to obtain and process satellite images. A contest will take the best pupils for one week to Lisbon (Portugal), to Europe's space port in Kourou (French Guyana) where the European launcher lifts off or to ESO's Very Large Telescope at the Cerro Paranal Observatory in Chile, the largest optical telescope in the world. The SEA & SPACE project is a joint initiative of the European Space Agency (ESA) , the European Southern Observatory (ESO) , and the European Association for Astronomy Education (EAAE). It builds on these organisations' several years' successful participation in the European Week for Scientific and Technological Culture organised by the European Commission that they intend to continue in 1998. The 1998 World Exhibition EXPO98 in Lisbon will focus on the oceans. This is why the umbrella theme of SEA & SPACE is concerned with the many relations between the oceans and the space that surrounds us, from ancient times to present days. Under the new programme, teaching resources are offered for three major areas, Remote Sensing of Europe's Coastal Environment, Navigation and Oceans of Water. Remote Sensing of Europe's Coastal Environment : observations of the Earth from Space are made accessible to pupils who will appreciate their usefulness through interactive image processing and field observations; Navigation : the capabilities and functioning of different navigation techniques are explored through experiments using navigation by the stars, with GPS, and via satellite images/maps; Oceans of Water : What is the role of water in Nature? How can one detect water from satellites or with telescopes? How much water is there in rivers and floods, in an ocean, on Mars, in comets, in stars, in the Universe? SEA & SPACE will use the Internet and the WWW to transport teaching resources so that teachers and pupils can communicate with the organisers and among themselves. To this end, the National Committees of the European Association for Astronomy Education will operate sites onto which the information and resources provided by ESA and ESO are loaded. The Contest, in which pupils will write and design a poster or a newspaper on a subject related to SEA & SPACE, will be organised simultaneously in most European countries and will not require Internet access. SEA & SPACE will start as from 1 March 1998. Further information is provided on the Home Pages of ESA, ESO and EAAE. In early February, a dedicated joint SEA & SPACE Home Page will be operational where schools can register for the project and for regular mailing of new information: * http://www.esa.int/seaspace * http://www.eso.org/seaspace * http://www.algonet.se/~sirius/eaae/seaspace Note: [1] This press release is published jointly by ESA, ESO and EAAE. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

  15. International arrivals: widespread bioinvasions in European Seas.

    PubMed

    Galil, B S; Marchini, A; Occhipinti-Ambrogi, A; Minchin, D; Narščius, A; Ojaveer, H; Olenin, S

    2014-04-01

    The European Union lacks a comprehensive framework to address the threats posed by the introduction and spread of marine non-indigenous species (NIS). Current efforts are fragmented and suffer substantial gaps in coverage. In this paper we identify and discuss issues relating to the assessment of spatial and temporal patterns of introductions in European Seas (ES), based on a scientifically validated information system of aquatic non-indigenous and cryptogenic species, AquaNIS. While recognizing the limitations of the existing data, we extract information that can be used to assess the relative risk of introductions for different taxonomic groups, geographic regions and likely vectors. The dataset comprises 879 multicellular NIS. We applied a country-based approach to assess patterns of NIS richness in ES, and identify the principal introduction routes and vectors, the most widespread NIS and their spatial and temporal spread patterns. Between 1970 and 2013, the number of recorded NIS has grown by 86, 173 and 204% in the Baltic, Western European margin and the Mediterranean, respectively; 52 of the 879 NIS were recorded in 10 or more countries, and 25 NIS first recorded in European seas since 1990 have since been reported in five or more countries. Our results highlight the ever-rising role of shipping (commercial and recreational) as a vector for the widespread and recently spread NIS. The Suez Canal, a corridor unique to the Mediterranean, is responsible for the increased introduction of new thermophilic NIS into this warming sea. The 2020 goal of the EU Biodiversity Strategy concerning marine Invasive Alien Species may not be fully attainable. The setting of a new target date should be accompanied by scientifically robust, sensible and pragmatic plans to minimize introductions of marine NIS and to study those present. PMID:24899770

  16. International arrivals: widespread bioinvasions in European Seas

    PubMed Central

    Galil, B.S.; Marchini, A.; Occhipinti-Ambrogi, A.; Minchin, D.; Narščius, A.; Ojaveer, H.; Olenin, S.

    2014-01-01

    The European Union lacks a comprehensive framework to address the threats posed by the introduction and spread of marine non-indigenous species (NIS). Current efforts are fragmented and suffer substantial gaps in coverage. In this paper we identify and discuss issues relating to the assessment of spatial and temporal patterns of introductions in European Seas (ES), based on a scientifically validated information system of aquatic non-indigenous and cryptogenic species, AquaNIS. While recognizing the limitations of the existing data, we extract information that can be used to assess the relative risk of introductions for different taxonomic groups, geographic regions and likely vectors. The dataset comprises 879 multicellular NIS. We applied a country-based approach to assess patterns of NIS richness in ES, and identify the principal introduction routes and vectors, the most widespread NIS and their spatial and temporal spread patterns. Between 1970 and 2013, the number of recorded NIS has grown by 86, 173 and 204% in the Baltic, Western European margin and the Mediterranean, respectively; 52 of the 879 NIS were recorded in 10 or more countries, and 25 NIS first recorded in European seas since 1990 have since been reported in five or more countries. Our results highlight the ever-rising role of shipping (commercial and recreational) as a vector for the widespread and recently spread NIS. The Suez Canal, a corridor unique to the Mediterranean, is responsible for the increased introduction of new thermophilic NIS into this warming sea. The 2020 goal of the EU Biodiversity Strategy concerning marine Invasive Alien Species may not be fully attainable. The setting of a new target date should be accompanied by scientifically robust, sensible and pragmatic plans to minimize introductions of marine NIS and to study those present. PMID:24899770

  17. Historical record of Yersinia ruckeri and Aeromonas salmonicida among sea-run Atlantic salmon (Salmo salar) in the Penobscot River

    USGS Publications Warehouse

    Cipriano, R.C.; Coll, J.

    2005-01-01

    Despite restoration efforts, only about 2,000 Atlantic salmon (Salmo salar) salmon have annually returned to New England Rivers and more than 71% of these fish migrate to the Penobscot River alone. This report provides a historical compilation on the prevalence's of both Yersinia ruckeri, cause of enteric redmouth disease, and Aeromonas salmonicida, cause of furunculosis, among mature sea-run Atlantic salmon that returned to the Penobscot River from 1976 to 2003. Aeromonas salmonicida was detected in 28.6% and Yersinia ruckeri was detected among 50% of the yearly returns. Consequently, Atlantic salmon that return to the river are potential reservoirs of infection.

  18. Technical note: Modifying Atlantic salmon (Salmo salar) jumping behavior to facilitate innovation of parasitic sea lice control techniques.

    PubMed

    Dempster, T; Kristiansen, T S; Korsøen, Ø J; Fosseidengen, J E; Oppedal, F

    2011-12-01

    Industrial salmon farms are reservoirs of parasitic sea lice (Lepeophtheirus salmonis and Caligus spp.), which causes both production inefficiencies and contributes to population-level declines of wild salmon and trout. Current control methods vary in effect and stimulate controversy by the discharge of chemicals into the environment. An alternate control method uses a thin, chemical-infused oil layer on the sea surface. As farmed salmon jump through the surface, the treatment makes contact with the lipophilic carapace of sea lice and kills them. To enhance the effectiveness of this method, we tested whether the natural jumping behavior of salmon could be increased and directed. In a 2,000-m(3) experimental sea-cage, we removed the ability of groups of salmon to access the surface for different periods (0 to 48 h) and measured their surface behaviors after the surface became accessible again. Surface removal for 24 and 48 h induced 93% of salmon to jump in the 2 h after surface access was reinstated, a result that differed (P < 0.001) from the shorter duration (0 to 12 h) treatments. Salmon without surface access for 24 and 48 h jumped 2 to 3 times more often (P < 0.001), and made their first jump 2 to 3 times sooner (P = 0.003) on average after surface access became available than salmon in the shorter duration treatments. Our results indicate that removal of surface access for short periods may lead to loss of air from the physostomous swim bladder and cause negative buoyancy. This creates a behavioral drive for salmon to jump, swallow air and fill their swim bladders once surface access is reinstated. By combining the increased jumping behavior induced by this technique with a floating, oil-infused treatment, efficiency of sea lice treatments may be improved and treatment chemicals can be re-collected, thus decreasing environmental pollution. PMID:21821806

  19. Occurrence and potential transfer of mycotoxins in gilthead sea bream and Atlantic salmon by use of novel alternative feed ingredients.

    PubMed

    Nácher-Mestre, Jaime; Serrano, Roque; Beltrán, Eduardo; Pérez-Sánchez, Jaume; Silva, Joana; Karalazos, Vasileios; Hernández, Félix; Berntssen, Marc H G

    2015-06-01

    Plant ingredients and processed animal proteins (PAP) are suitable alternative feedstuffs for fish feeds in aquaculture practice, although their use can introduce contaminants that are not previously associated with marine salmon and gilthead sea bream farming. Mycotoxins are well known natural contaminants in plant feed material, although they also could be present on PAPs after fungi growth during storage. The present study surveyed commercially available plant ingredients (19) and PAP (19) for a wide range of mycotoxins (18) according to the EU regulations. PAP showed only minor levels of ochratoxin A and fumonisin B1 and the mycotoxin carry-over from feeds to fillets of farmed Atlantic salmon and gilthead sea bream (two main species of European aquaculture) was performed with plant ingredient based diets. Deoxynivalenol was the most prevalent mycotoxin in wheat, wheat gluten and corn gluten cereals with levels ranging from 17 to 814 and μg kg(-1), followed by fumonisins in corn products (range 11.1-4901 μg kg(-1) for fumonisin B1+B2+B3). Overall mycotoxin levels in fish feeds reflected the feed ingredient composition and the level of contaminant in each feed ingredient. In all cases the studied ingredients and feeds showed levels of mycotoxins below maximum residue limits established by the Commission Recommendation 2006/576/EC. Following these guidelines no mycotoxin carry-over was found from feeds to edible fillets of salmonids and a typically marine fish, such as gilthead sea bream. As far we know, this is the first report of mycotoxin surveillance in farmed fish species. PMID:25754010

  20. Organohalogen concentrations and feeding status in Atlantic salmon (Salmo salar L.) of the Baltic Sea during the spawning run.

    PubMed

    Vuorinen, Pekka J; Kiviranta, Hannu; Koistinen, Jaana; Pöyhönen, Outi; Ikonen, Erkki; Keinänen, Marja

    2014-01-15

    Changes in the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Baltic salmon muscle were studied during the spawning migration from the southern Baltic Sea to rivers flowing into the northern Gulf of Bothnia and during the spawning period. The aim was to obtain information to facilitate the arrangement of salmon fisheries such that the human dioxin intake is taken into account. The EC maximum allowable total toxic equivalent concentration (WHO-TEQPCDD/F+PCB) was exceeded in the muscle of the majority of the migrating salmon, except in the Baltic Proper. The fresh-weight-based concentrations of all toxicant groups in salmon tended to be the lowest in the Baltic Proper and the Northern Quark, and all toxicant concentrations, except PCDDs and PCDFs, were significantly higher in the spawning salmon than in the salmon caught during the spawning run. The fat content of the salmon muscle decreased by 60% during the spawning run, and the lipid-based total toxicant concentrations were consequently 4.2-6.2 times higher during the spawning period than during the spawning migration. However, the toxicants were concentrated just before spawning, and thus there is no essential difference related to whether the salmon are caught in the sea or the recreational river fishery. PMID:24056447

  1. Spatial variation in transcript and protein abundance of Atlantic salmon during feeding migration in the Baltic Sea.

    PubMed

    Kanerva, Mirella; Vehmas, Anni; Nikinmaa, Mikko; Vuori, Kristiina A

    2014-12-01

    The fitness and reproductive output of fishes can be affected by environmental disturbances. In this study, transcriptomics and label-free proteomics were combined to investigate Atlantic salmon (Salmo salar) sampled from three different field locations within the Baltic Sea (Baltic Main Basin (BMB), Gulf of Finland (GoF), and Bothnian Sea (BS)) during marine migration. The expression of several stress related mRNAs and proteins of xenobiotic metabolism, oxidative stress, DNA damage, and cell death were increased in salmon from GoF compared to salmon from BMB or BS. Respiratory electron chain and ATP synthesis related gene ontology-categories were upregulated in GoF salmon, whereas those associated with RNA processing and synthesis, translation, and protein folding decreased. Differences were seen also in metabolism and immune function related gene expression. Comparisons of the transcriptomic and proteomic profiles between salmon from GoF and salmon from BMB or BS suggest environmental stressors, especially exposure to contaminants, as a main explanation for differences. Salmon feeding in GoF are thus “disturbed by hazardous substances”. The results may also be applied in evaluating the conditions of pelagic ecosystems in the different parts of Baltic Sea. PMID:25356801

  2. The control of sea lice in Atlantic salmon by selective breeding

    PubMed Central

    Gharbi, Karim; Matthews, Louise; Bron, James; Roberts, Ron; Tinch, Alan; Stear, Michael

    2015-01-01

    Sea lice threaten the welfare of farmed Atlantic salmon and the sustainability of fish farming across the world. Chemical treatments are the major method of control but drug resistance means that alternatives are urgently needed. Selective breeding can be a cheap and effective alternative. Here, we combine experimental trials and diagnostics to provide a practical protocol for quantifying resistance to sea lice. We then combined quantitative genetics with epidemiological modelling to make the first prediction of the response to selection, quantified in terms of reduced need for chemical treatments. We infected over 1400 young fish with Lepeophtheirus salmonis, the most important species in the Northern Hemisphere. Mechanisms of resistance were expressed early in infection. Consequently, the number of lice per fish and the ranking of families were very similar at 7 and 17 days post infection, providing a stable window for assessing susceptibility to infection. The heritability of lice numbers within this time window was moderately high at 0.3, confirming that selective breeding is viable. We combined an epidemiological model of sea lice infection and control on a salmon farm with genetic variation in susceptibility among individuals. We simulated 10 generations of selective breeding and examined the frequency of treatments needed to control infection. Our model predicted that substantially fewer chemical treatments are needed to control lice outbreaks in selected populations and chemical treatment could be unnecessary after 10 generations of selection. Selective breeding for sea lice resistance should reduce the impact of sea lice on fish health and thus substantially improve the sustainability of Atlantic salmon production. PMID:26289656

  3. A field efficacy evaluation of emamectin benzoate for the control of sea lice on Atlantic salmon.

    PubMed Central

    Armstrong, R; MacPhee, D; Katz, T; Endris, R

    2000-01-01

    This study evaluated the efficacy of emamectin benzoate, 0.2% aquaculture premix, against sea lice on Atlantic salmon in eastern Canada. Salmon pens received either emamectin benzoate, orally, in feed at 50 micrograms/kg body weight/day for 7 consecutive days, or the same diet with no added medication. The site veterinarian had the option of administering a bath treatment with azamethiphos to any pen in the trial. The mean number of lice per fish was lower (P < 0.05) in the experimental group when measured 1, 3, 4, and 6 weeks after the start of medication. Treatment efficacy was 70%, 88%, 95%, and 61%, respectively. Three azamethiphos bath treatments were applied to each control pen during the trial, while the treatment pens received no bath treatment. No gravid female parasites were observed on any fish in the treatment group, while these life stages were observed on fish in the control group. Orally administered emamectin benzoate was palatable and highly effective for control of sea lice on salmon. PMID:10945125

  4. Evaluation of emamectin benzoate and substance EX against salmon lice in sea-ranched Atlantic salmon smolts.

    PubMed

    Skilbrei, Ove Tommy; Espedal, Per Gunnar; Nilsen, Frank; Garcia, Enrique Perez; Glover, Kevin A

    2015-04-01

    Experimental releases of Atlantic salmon smolts treated with emamectin benzoate (EB) against salmon lice have previously been used to estimate the significance of salmon lice on the survival of migrating smolts. In recent years, the salmon louse has developed reduced sensitivity to EB, which may influence the results of such release experiments. We therefore tested the use of 2 anti-lice drugs: EB was administered to salmon smolts in high doses by intra-peritoneal injection and the prophylactic substance EX (SubEX) was administered by bathing. A third, untreated control group was also established. Salmon were challenged with copepodids of 2 strains of salmon lice (1 EB-sensitive strain and 1 with reduced EB-sensitivity) in mixed-group experimental tanks. At 31 d post-challenge, the numbers of pre-adult lice on treated fish were around 20% compared with the control fish, with minor or no differences between the 2 treatments and lice strains. Both treatments therefore appeared to give the smolts a high degree of protection against infestation of copepodids of salmon lice. However, significantly lower growth of the EB-treatment group indicates that bathing the fish in SubEX is less stressful for smolts than intra-peritoneal injection of EB. PMID:25850396

  5. Transcriptome immunomodulation of in-feed additives in Atlantic salmon Salmo salar infested with sea lice Caligus rogercresseyi.

    PubMed

    Núñez-Acuña, Gustavo; Gonçalves, Ana Teresa; Valenzuela-Muñoz, Valentina; Pino-Marambio, Jorge; Wadsworth, Simon; Gallardo-Escárate, Cristian

    2015-11-01

    One of the most significant threats to the Chilean salmon aquaculture industry is the ectoparasitic sea louse Caligus rogercresseyi. To cope with sea lice infestations, functional diets have become an important component in strengthening the host immune response. The aim of this study was to evaluate molecular mechanisms activated through immunostimulation by in-feed plant-derived additives in Atlantic salmon infected with sea lice. Herein, a transcriptome-wide sequencing analysis was performed from skin and head kidney tissues, evidencing that the immune response genes were the most variable after the challenge, especially in the head kidney, while other genes involved in metabolism were highly expressed individuals fed with the immunostimulants. Interestingly, defensive enzymes such as Cytochrome p450 and serpins were down-regulated in infested individuals, especially in skin tissue. Additionally, MHC-I and MHC-II genes were differentially expressed after the incorporation of the in-feed additives, giving some cues about the protection mechanisms of plant-derived compound as immunostimulants for infested salmons. This is the first published study that evaluates the transcriptomic response of sea lice-infested Atlantic salmon fed with in-feed additives. PMID:26363235

  6. Genetic stock identification of Atlantic salmon (Salmo salar) populations in the southern part of the European range

    PubMed Central

    2010-01-01

    Background Anadromous migratory fish species such as Atlantic salmon (Salmo salar) have significant economic, cultural and ecological importance, but present a complex case for management and conservation due to the range of their migration. Atlantic salmon exist in rivers across the North Atlantic, returning to their river of birth with a high degree of accuracy; however, despite continuing efforts and improvements in in-river conservation, they are in steep decline across their range. Salmon from rivers across Europe migrate along similar routes, where they have, historically, been subject to commercial netting. This mixed stock exploitation has the potential to devastate weak and declining populations where they are exploited indiscriminately. Despite various tagging and marking studies, the effect of marine exploitation and the marine element of the salmon lifecycle in general, remain the "black-box" of salmon management. In a number of Pacific salmonid species and in several regions within the range of the Atlantic salmon, genetic stock identification and mixed stock analysis have been used successfully to quantify exploitation rates and identify the natal origins of fish outside their home waters - to date this has not been attempted for Atlantic salmon in the south of their European range. Results To facilitate mixed stock analysis (MSA) of Atlantic salmon, we have produced a baseline of genetic data for salmon populations originating from the largest rivers from Spain to northern Scotland, a region in which declines have been particularly marked. Using 12 microsatellites, 3,730 individual fish from 57 river catchments have been genotyped. Detailed patterns of population genetic diversity of Atlantic salmon at a sub-continent-wide level have been evaluated, demonstrating the existence of regional genetic signatures. Critically, these appear to be independent of more commonly recognised terrestrial biogeographical and political boundaries, allowing reporting regions to be defined. The implications of these results on the accuracy of MSA are evaluated and indicate that the success of MSA is not uniform across the range studied; our findings indicate large differences in the relative accuracy of stock composition estimates and MSA apportioning across the geographical range of the study, with a much higher degree of accuracy achieved when assigning and apportioning to populations in the south of the area studied. This result probably reflects the more genetically distinct nature of populations in the database from Spain, northwest France and southern England. Genetic stock identification has been undertaken and validation of the baseline microsatellite dataset with rod-and-line and estuary net fisheries of known origin has produced realistic estimates of stock composition at a regional scale. Conclusions This southern European database and supporting phylogeographic and mixed-stock analyses of net samples provide a unique tool for Atlantic salmon research and management, in both their natal rivers and the marine environment. However, the success of MSA is not uniform across the area studied, with large differences in the relative accuracy of stock composition estimates and MSA apportioning, with a much higher degree of accuracy achieved when assigning and apportioning to populations in the south of the region. More broadly, this study provides a basis for long-term salmon management across the region and confirms the value of this genetic approach for fisheries management of anadromous species. PMID:20429926

  7. Identification of hydroxylated and methoxylated polybrominated diphenyl ethers in Baltic Sea salmon (Salmo salar) blood.

    PubMed

    Marsh, Göran; Athanasiadou, Maria; Bergman, Ake; Asplund, Lillemor

    2004-01-01

    Methoxylated and hydroxylated polybrominated diphenyl ethers (MeO-PBDEs and OH-PBDEs) have recently been reported to be present in wildlife from Northern Europe. The structures of a majority of these compounds have however been unknown. In the present study, nine OH-PBDEs and six MeO-PBDEs were identified in Baltic Sea salmon (Salmo salar) blood. All OH- and MeO-PBDEs identified were substituted with four or five bromines, and five of these had one chlorine substituent. Fourteen of the OH- and MeO-PBDEs have the methoxy or hydroxy group substituted in the ortho position to the diphenyl ether bond. Identification was done by comparison of relative retention times of authentic reference standards with compounds present in salmon plasma on two gas chromatographic columns of different polarities. The identification was supported by comparisons of full-scan mass spectrometric data: electron ionization (EI) and electron capture negative ionization (ECNI). Nine of the 15 OH- and MeO-PBDEs identified have not previously been reported to occur in the environment. The structures of several identified OH- and MeO-PBDEs support natural origin. However, at least one of the OH-PBDEs may be a hydroxylated metabolite of anthropogenic polybrominated diphenyl ether (PBDE). PMID:14740711

  8. Temporal variation of genetic composition in Atlantic salmon populations from the Western White Sea Basin: influence of anthropogenic factors?

    PubMed Central

    2013-01-01

    Background Studies of the temporal patterns of population genetic structure assist in evaluating the consequences of demographic and environmental changes on population stability and persistence. In this study, we evaluated the level of temporal genetic variation in 16 anadromous and 2 freshwater salmon populations from the Western White Sea Basin (Russia) using samples collected between 1995 and 2008. To assess whether the genetic stability was affected by human activity, we also evaluated the effect of fishing pressure on the temporal genetic variation in this region. Results We found that the genetic structure of salmon populations in this region was relatively stable over a period of 1.5 to 2.5 generations. However, the level of temporal variation varied among geographical regions: anadromous salmon of the Kola Peninsula exhibited a higher stability compared to that of the anadromous and freshwater salmon from the Karelian White Sea coast. This discrepancy was most likely attributed to the higher census, and therefore effective, population sizes of the populations inhabiting the rivers of the Kola Peninsula compared to salmon of the Karelian White Sea coast. Importantly, changes in the genetic diversity observed in a few anadromous populations were best explained by the increased level of fishing pressure in these populations rather than environmental variation or the negative effects of hatchery escapees. The observed population genetic patterns of isolation by distance remained consistent among earlier and more recent samples, which support the stability of the genetic structure over the period studied. Conclusions Given the increasing level of fishing pressure in the Western White Sea Basin and the higher level of temporal variation in populations exhibiting small census and effective population sizes, further genetic monitoring in this region is recommended, particularly on populations from the Karelian rivers. PMID:24053319

  9. Seabird sockeye salmon co-variation in the eastern Bering Sea: Phenology as an ecosystem indicator and salmonid predictor?

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Abraham, Christine L.; Vernon Byrd, G.

    2008-08-01

    Seabirds ( Rissa spp. and Uria spp.) and sockeye salmon ( Onchorhynchus nerka) of the eastern Bering Sea share similarities in their trophic ecology. We tested the role of seabirds as indicators of food web conditions that affect sockeye salmon at sea survival by investigating co-variation between seabirds breeding on the Pribilof Islands and returns of Bristol Bay sockeyes. We examined seabird phenology (hatching dates of eggs) against sockeye returns based on the year of ocean entry. Annual seabird hatching date was inversely related to sockeye returns, with the strongest co-variation found for sockeye which entered the ocean at 2 years of age (age 2 x smolts). The mechanism supporting this co-variation is unknown, but both birds and salmon may be responding to changes in prey availability (a "bottom-up" effect). The co-variation between seabird hatching date and sockeye returns supports the idea that variation in seabird breeding parameters indicates food web conditions that also affect other upper trophic level predators in marine systems. Coupling seabird phenology with existing annual predictions for Bristol Bay salmon may improve forecasts and fishery management.

  10. Temporally stable population-specific differences in run timing of one-sea-winter Atlantic salmon returning to a large river system.

    PubMed

    Vähä, Juha-Pekka; Erkinaro, Jaakko; Niemelä, Eero; Primmer, Craig R; Saloniemi, Irma; Johansen, Morten; Svenning, Martin; Brørs, Sturla

    2011-01-01

    The understanding of migration patterns can significantly contribute to conservation and management. The spawning migrations of Atlantic salmon (Salmo salar) cover thousands of kilometers from the feeding areas at sea to their natal rivers to reproduce. Migrating salmon are exposed to intensive harvest, but little is known of the population-specific differences in migration behavior. In this study, timing of return migration was investigated among one-sea-winter Atlantic salmon within a river system. By utilizing knowledge of the genetic population structure, population of origin was reliably identified for c. 1500 fish caught in mixed stock fisheries after adopting an approach to minimize the complications arising from potential nonsampled populations. Results demonstrated significant and temporally stable differences among populations as well as between sexes. Generally, female salmon from tributary populations entered fresh water first. Run timing was not however related to in-river migration distance. Rather, one-sea-winter salmon from larger populations and with a higher proportion of multi-sea-winter females arrived later in the season. These findings are a significant step toward a more thorough understanding of the salmon migration behavior and behavioral ecology, providing concrete tools for the management and conservation of the remaining indigenous Atlantic salmon stocks. PMID:25567952

  11. Sea to sky: impacts of residual salmon-derived nutrients on estuarine breeding bird communities.

    PubMed

    Field, Rachel D; Reynolds, John D

    2011-10-22

    Pacific salmon (Oncorhynchus spp.) returning to streams around the North Pacific Rim provide a nutrient subsidy to these ecosystems. While many species of animals feed directly on salmon carcasses each autumn, salmon-derived nutrients can also be stored in coastal habitats throughout the year. The effects of this storage legacy on vertebrates in other seasons are not well understood, especially in estuaries, which can receive a large portion of post-spawning salmon nutrients. We examine the effects of residual salmon-derived nutrients, forest habitats and landscape features on summer breeding birds in estuary forests. We compared models containing environmental variables and combined chum (Oncorhynchus keta) and pink (Oncorhynchus gorbuscha) salmon biomass to test predictions concerning bird density and diversity. We discovered that total bird, insectivore, golden-crowned kinglet and Pacific wren densities and Shannon's diversity in the summer were strongly predicted by salmon biomass in the autumn. For most metrics, this relationship approaches an asymptote beyond 40 000 kg of salmon biomass. Foliage height diversity, watershed catchment area and estuary area were also important predictors of avian communities. Our study suggests that the legacy of salmon nutrients influences breeding bird density and diversity in estuaries that vary across a wide gradient of spawning salmon biomass. PMID:21325324

  12. Sea to sky: impacts of residual salmon-derived nutrients on estuarine breeding bird communities

    PubMed Central

    Field, Rachel D.; Reynolds, John D.

    2011-01-01

    Pacific salmon (Oncorhynchus spp.) returning to streams around the North Pacific Rim provide a nutrient subsidy to these ecosystems. While many species of animals feed directly on salmon carcasses each autumn, salmon-derived nutrients can also be stored in coastal habitats throughout the year. The effects of this storage legacy on vertebrates in other seasons are not well understood, especially in estuaries, which can receive a large portion of post-spawning salmon nutrients. We examine the effects of residual salmon-derived nutrients, forest habitats and landscape features on summer breeding birds in estuary forests. We compared models containing environmental variables and combined chum (Oncorhynchus keta) and pink (Oncorhynchus gorbuscha) salmon biomass to test predictions concerning bird density and diversity. We discovered that total bird, insectivore, golden-crowned kinglet and Pacific wren densities and Shannon's diversity in the summer were strongly predicted by salmon biomass in the autumn. For most metrics, this relationship approaches an asymptote beyond 40 000 kg of salmon biomass. Foliage height diversity, watershed catchment area and estuary area were also important predictors of avian communities. Our study suggests that the legacy of salmon nutrients influences breeding bird density and diversity in estuaries that vary across a wide gradient of spawning salmon biomass. PMID:21325324

  13. The European large air sea interaction facility at IRPHE

    NASA Astrophysics Data System (ADS)

    Giovanangeli, J. P.; Caulliez, G.; Bonmarin, P.; Branger, H.

    2003-04-01

    In the framework of the European Research Programme (Improving Human Potential - Access to Research Infrastructure), the Large Air-Sea Interaction Facility (LASIF) of the Institut de Recherche sur les Phénomènes Hors Equilibre has been classified as European Infrastructure We present the main characteristics of the facility which is a unique facility specifically designed to study small scale interactions processes between the atmospheric boundary layer and the upper ocean. Due to exceptional quality of the wind tunnel the facility is especially good to study wave generation involving nonlinear and complex interactions with drift currents, turbulence and wind. A wave maker and recirculation pumps which create following or opposite current allows to study wave-current interactions. The facility is equipped with a high-performance instrumentatrion: hot wires and hot films, air pressure probes, wave amplitude and wave slope gauges, a Ku Band scatterometer, optical system for measuring 3D wave fields in decimeter range, PIV. The key element of air-sea interaction, wave breaking inducing two phase flows, gas exchange as well as impact on microwave and acoustic backscattering from the sea surface can be investigated. IRPHE/IOA scientific team is highly recognized as one of the leading in the world. We show the most recent and significant results from experiments conducted in the facility. Financial support from the European Community (Grant No: HPRI-CT-2002-00188) is available to fund travel, lodging and experiment expenses for european scientific teams.

  14. Characterization of extreme sea level at the European coast

    NASA Astrophysics Data System (ADS)

    Elizalde, Alberto; Jorda, Gabriel; Mathis, Moritz; Mikolajewicz, Uwe

    2015-04-01

    Extreme high sea levels arise as a combination of storm surges and particular high tides events. Future climate simulations not only project changes in the atmospheric circulation, which induces changes in the wind conditions, but also an increase in the global mean sea level by thermal expansion and ice melting. Such changes increase the risk of coastal flooding, which represents a possible hazard for human activities. Therefore, it is important to investigate the pattern of sea level variability and long-term trends at coastal areas. In order to analyze further extreme sea level events at the European coast in the future climate projections, a new setup for the global ocean model MPIOM coupled with the regional atmosphere model REMO is prepared. The MPIOM irregular grid has enhanced resolution in the European region to resolve the North and the Mediterranean Seas (up to 11 x 11 km at the North Sea). The ocean model includes as well the full luni-solar ephemeridic tidal potential for tides simulation. To simulate the air-sea interaction, the regional atmospheric model REMO is interactively coupled to the ocean model over Europe. Such region corresponds to the EuroCORDEX domain with a 50 x 50 km resolution. Besides the standard fluxes of heat, mass (freshwater), momentum and turbulent energy input, the ocean model is also forced with sea level pressure, in order to be able to capture the full variation of sea level. The hydrological budget within the study domain is closed using a hydrological discharge model. With this model, simulations for present climate and future climate scenarios are carried out to study transient changes on the sea level and extreme events. As a first step, two simulations (coupled and uncoupled ocean) driven by reanalysis data (ERA40) have been conducted. They are used as reference runs to evaluate the climate projection simulations. For selected locations at the coast side, time series of sea level are separated on its different components: tides, short time atmospheric process influence (1-30 days), seasonal cycle and interannual variability. Every sea level component is statistically compared with data from local tide gauges.

  15. Long-term variability and trends of sea level storminess and extremes in European Seas

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Šepić, Jadranka

    2010-03-01

    This paper documents the variability and trends of mean storminess and extreme sea level amplitudes at selected long-term operating tide gauge stations located in the European Seas over different frequency bands, seasons and months. Six stations have been chosen for the analyses-Antalya, Ceuta, Rovinj, Newlyn, Wladyslawowo and Lerwick-which possess at least a half-centurial record of hourly or higher frequency sea level data. The data have been carefully inspected for time shifts and drifts in the record. The analyses included the extraction of sea level amplitudes (envelopes) over four frequency bands: super-diurnal frequencies (0-1 days), small-scale synoptic disturbances (1-3 days), large-scale synoptic disturbances (3-10 days) and planetary-scale disturbances (10-100 days). Interannual variability in sea level amplitudes is occasionally found to coincide with some known variability in the atmosphere. For example, the northern European stations have overall positive sea level storminess and extreme trends, which is opposite from the southern stations, confirming a northward shift in atmosphere storm tracks. Redistribution of sea level amplitudes between different seasons and different frequency bands has been observed at some stations in both variability and trends. The latter may be important for the assessment of a region's total hazard risks and vulnerability, as maximum storminess and extremes may or may not coincide with maximum mean sea level.

  16. Temporal variability in SeaWiFS derived apparent optical properties in European seas

    NASA Astrophysics Data System (ADS)

    Vantrepotte, V.; Mélin, F.

    2010-02-01

    The 10-year record of ocean color data provided by the SeaWiFS mission is an important asset for monitoring and research activities conducted on the optically complex European seas. This study makes use of the SeaWiFS data set of normalized water leaving radiances LWN to study the major characteristics of temporal variability associated with optical properties across the entire European domain. Specifically, the time series of LWN and associated band ratios are decomposed into terms representing a fixed seasonal cycle, irregular variations and trends, and the contribution of these components to the total variance is described for the various basins. The diversity of the European waters is fully reflected by the range of results varying with regions and wavelengths. Generally, the Mediterranean and Baltic seas appear as two end-members with, respectively, high and low contributions of the seasonal component to the total variance. The existence of linear trends affecting the satellite products is also explored for each basin. By focusing the analysis on LWN and band ratios, the validity of the results is not limited by the varying levels of uncertainty that characterize derived products such as the concentration of chlorophyll a in optically complex waters. Statistically significant, and in some cases large, trends are detected in the Atlantic Ocean west of the European western shelf, the central North Sea, the English Channel, the Black Sea, the northern Adriatic, and various regions of the Mediterranean Sea and the northern Baltic Sea, revealing changes in the concentrations of optically significant constituents in these regions.

  17. Climate change, pink salmon, and the nexus between bottom-up and top-down forcing in the subarctic Pacific Ocean and Bering Sea.

    PubMed

    Springer, Alan M; van Vliet, Gus B

    2014-05-01

    Climate change in the last century was associated with spectacular growth of many wild Pacific salmon stocks in the North Pacific Ocean and Bering Sea, apparently through bottom-up forcing linking meteorology to ocean physics, water temperature, and plankton production. One species in particular, pink salmon, became so numerous by the 1990s that they began to dominate other species of salmon for prey resources and to exert top-down control in the open ocean ecosystem. Information from long-term monitoring of seabirds in the Aleutian Islands and Bering Sea reveals that the sphere of influence of pink salmon is much larger than previously known. Seabirds, pink salmon, other species of salmon, and by extension other higher-order predators, are tightly linked ecologically and must be included in international management and conservation policies for sustaining all species that compete for common, finite resource pools. These data further emphasize that the unique 2-y cycle in abundance of pink salmon drives interannual shifts between two alternate states of a complex marine ecosystem. PMID:24706809

  18. Climate change, pink salmon, and the nexus between bottom-up and top-down forcing in the subarctic Pacific Ocean and Bering Sea

    PubMed Central

    Springer, Alan M.; van Vliet, Gus B.

    2014-01-01

    Climate change in the last century was associated with spectacular growth of many wild Pacific salmon stocks in the North Pacific Ocean and Bering Sea, apparently through bottom-up forcing linking meteorology to ocean physics, water temperature, and plankton production. One species in particular, pink salmon, became so numerous by the 1990s that they began to dominate other species of salmon for prey resources and to exert top-down control in the open ocean ecosystem. Information from long-term monitoring of seabirds in the Aleutian Islands and Bering Sea reveals that the sphere of influence of pink salmon is much larger than previously known. Seabirds, pink salmon, other species of salmon, and by extension other higher-order predators, are tightly linked ecologically and must be included in international management and conservation policies for sustaining all species that compete for common, finite resource pools. These data further emphasize that the unique 2-y cycle in abundance of pink salmon drives interannual shifts between two alternate states of a complex marine ecosystem. PMID:24706809

  19. Noise Impact on European Sea Bass Behavior: Temporal Structure Matters.

    PubMed

    Neo, Yik Yaw; Seitz, Johanna; Kastelein, Ronald A; Winter, Hendrik V; Cate, Carel Ten; Slabbekoorn, Hans

    2016-01-01

    Anthropogenic sounds come in different forms, varying not only in amplitude and frequency spectrum but also in temporal structure. Although fish are sensitive to the temporal characteristics of sound, little is known about how their behavior is affected by anthropogenic sounds of different temporal patterns. We investigated this question using groups of Dicentrarchus labrax (European sea bass) in an outdoor basin. Our data revealed that the temporal pattern of sound exposure is important in noise impact assessments. PMID:26611030

  20. Wild salmonids and sea louse infestations on the west coast of Scotland: sources of infection and implications for the management of marine salmon farms.

    PubMed

    Butler, James R A

    2002-06-01

    The sea louse (Lepeophtheirus salmonis Krøyer) is a major health problem for both farmed and wild salmonids. This paper investigates louse epidemiology and management in the salmon-farming zone of western Scotland. Based on a review of the marine ecology of wild salmon (Salmo salar L) and sea trout (Salmo trutta L), and catch and farm production statistics, best estimates were made for numbers of wild and farm hosts present in coastal waters in March-June 2000. Applying data for ovigerous female louse infections and fecundity, the sources and risks of larval transmission to wild salmon and sea trout were modelled. Farm salmon in the second spring of production were the primary host group (98% of fish), while numbers of wild salmonids (< 1%) and escaped farm salmon (2%) were relatively insignificant. Farm salmon produced 97% of louse eggs at high levels (eight ovigerous lice per fish), and 78% at low levels (one per fish). Wild salmonids produced < 1% of eggs under both scenarios, but escaped farm salmon produced 3% and 21%, respectively. All hosts potentially cross-infect one another, but farm salmon are more likely to infect wild and farm smolts, and also other farm salmon. Monitoring of lice on sea trout in June 1998-2000 by the Association of West Coast Fisheries Trusts corroborated the model's conclusions. Localised epizootics occurred every year and coincided with the presence of ovigerous lice on local farms. In areas of mixed-year class production on farms, epizootics were evident every spring, but occurred every second spring in areas of single-year class production. In 1998-2000 at least 14-40% of sea trout were infected with potentially lethal infestations of lice. Ovigerous louse levels of < 0.005 per fish were required on farm salmon in the spring of 2000 to produce less eggs than those emitted by wild salmonids. With the industry's continued expansion, and thus increased numbers of farm salmon, a target of zero ovigerous lice will be required on farms to minimise impacts on wild salmonids. Due to the limited long-term efficacy and availability of louse medicines, management strategies are discussed which will improve control, including single-year class production over large areas, alternate S1-S1/2 smolt inputs, and 11-month production cycles. PMID:12138626

  1. [Evolutionary-physiological aspects of adaptation of the Pacific salmon fry of the Oncorhynchus genus to migration to the sea water].

    PubMed

    Maksimovich, A A

    2008-01-01

    A complex of adaptive changes occurring in the Pacific salmon fry in the process of migration to the sea is described, including behavior, ion content in carcasses, and morphological changes in Stannius bodies, gill epithelium, and nephron tubular epithelium. Participating in experiments with transfer from fresh water into a two-layer aquarium (the lower layer - sea water, the upper layer - fresh water) were smolts of chum salmon and underyearlings of masu salmon as well as the trachurus and leiurus forms of the three-spined stickleback Casterosteus aculeatus. All fish, regardless of their salt preference, at once after placement into the two-layer aquarium, occupied the sea water zone, at the very bottom of the aquarium. After 1 h, there started brief excursions of masu salmon and chum salmon to the upper, fresh water layer; however, both forms of the three-spined stickleback did not participate in these excursions. After 12 h, the chum salmon settled down in the lower, sea water layer, while the masu salmon - in the upper, fresh water layer. Both forms of the three-spined stickleback never left the sea water layer and felt quite comfortably on the aquarium bottom. It seems that the high tolerance of the both stickleback forms to wide salinity limits allows them to choose the convenient position regardless of the water salt composition. By analyzing the material obtained for three years (2001-2003) on structure and functions of the gill epithelium chloride cells (CC), we have come to the conclusion that the fresh water fry of two salmon species, chum and masu salmons, caught at the same time and practically in the same water reservoirs can be divided into three groups. The underyearlings of the masu salmon as a rule are characterized by the thickened epithelium of secondary gill lamellae, but by a very small number of CC. In smolts of chum salmon, on the contrary, the epithelium is sufficiently thin, but enriched in the CC that demonstrate an active structure in the very beginning of migration to sea. However, with approaching the sea (and with an increase of terms of migration) the CC activity drops, but their amount does not change. And only after migration to the sea the CC activity rises again, although their amount seems to remain unchanged. The described peculiarities of behavior and of the ion composition regulation in the migrating salmon fry confirm the hypothesis that the salmons evolutionized in fresh water, that the Oncorhynchus genus appeared in large spaces of saltish waters, such as the Japan Sea at the period of the early Pleistocene, and that learning of fry of the Oncorhynchus genus (for instance, of O. gorbuscha and O. keta) is the most specialized in the salmons migrating to the sea, whereas the fresh water species of chars (Salvelinus) and of trouts (Salmo) are more primitive. PMID:18411513

  2. Multivariate evaluation of the effectiveness of treatment efficacy of cypermethrin against sea lice (Lepeophtheirus salmonis) in Atlantic salmon (Salmo salar)

    PubMed Central

    2013-01-01

    Background The sea louse Lepeophtheirus salmonis is the most important ectoparasite of farmed Atlantic salmon (Salmo salar) in Norwegian aquaculture. Control of sea lice is primarily dependent on the use of delousing chemotherapeutants, which are both expensive and toxic to other wildlife. The method most commonly used for monitoring treatment effectiveness relies on measuring the percentage reduction in the mobile stages of Lepeophtheirus salmonis only. However, this does not account for changes in the other sea lice stages and may result in misleading or incomplete interpretation regarding the effectiveness of treatment. With the aim of improving the evaluation of delousing treatments, we explored multivariate analyses of bath treatments using the topical pyrethroid, cypermethrin, in salmon pens at five Norwegian production sites. Results Conventional univariate analysis indicated reductions of over 90% in mobile stages at all sites. In contrast, multivariate analyses indicated differing treatment effectiveness between sites (p-value < 0.01) based on changes in the proportion and abundance of the chalimus and PAAM (pre-adult and adult males) stages. Low water temperatures and shortened intervals between sampling after treatment may account for the differences in the composition of chalimus and PAAM stage groups following treatment. Using multivariate analysis, such factors could be separated from those which were attributable to inadequate treatment or chemotherapeutant failure. Conclusions Multivariate analyses for evaluation of treatment effectiveness against multiple life cycle stages of L. salmonis yield additional information beyond that derivable from univariate methods. This can aid in the identification of causes of apparent treatment failure in salmon aquaculture. PMID:24354936

  3. Assessment of MERIS reflectance data as processed with SeaDAS over the European seas.

    PubMed

    Mélin, Frédéric; Zibordi, Giuseppe; Berthon, Jean-François; Bailey, Sean; Franz, Bryan; Voss, Kenneth; Flora, Stephanie; Grant, Mike

    2011-12-01

    The uncertainties associated with MERIS remote sensing reflectance (RRS) data derived from the SeaWiFS Data Analysis System (SeaDAS) are assessed with field observations. In agreement with the strategy applied for other sensors, a vicarious calibration is conducted using in situ data from the Marine Optical BuoY offshore Hawaii, and leads to vicarious adjustment factors departing from 1 by 0.2% to 1.6%. The three field data sets used for validation have been collected at fixed stations in the northern Adriatic Sea and the Baltic Sea, and in a variety of European waters in the Baltic, Black, Mediterranean and North Seas. Excluding Baltic waters, the mean absolute relative difference |ψ| between satellite and field data is 10-14% for the spectral interval 490-560 nm, 16-18% at 443 nm, and 24-26% at 413 nm. In the Baltic Sea, the |ψ| values are much higher for the blue bands characterized by low RRS amplitudes, but similar or lower at 560 and 665 nm. For the three validation sets, the root-mean-square differences decrease from approximately 0.0013 sr-1 at 413 nm to 0.0002 sr-1 at 665 nm, and are found similar or lower than those obtained for SeaWiFS or MODIS-Aqua. As derived from SeaDAS, the RRS records associated with these three missions thus provide a multi-mission data stream of consistent accuracy. PMID:22273959

  4. Physiological consequences of the salmon louse (Lepeophtheirus salmonis) on juvenile pink salmon (Oncorhynchus gorbuscha): implications for wild salmon ecology and management, and for salmon aquaculture

    PubMed Central

    Brauner, C. J.; Sackville, M.; Gallagher, Z.; Tang, S.; Nendick, L.; Farrell, A. P.

    2012-01-01

    Pink salmon, Oncorhynchus gorbuscha, are the most abundant wild salmon species and are thought of as an indicator of ecosystem health. The salmon louse, Lepeophtheirus salmonis, is endemic to pink salmon habitat but these ectoparasites have been implicated in reducing local pink salmon populations in the Broughton Archipelago, British Columbia. This allegation arose largely because juvenile pink salmon migrate past commercial open net salmon farms, which are known to incubate the salmon louse. Juvenile pink salmon are thought to be especially sensitive to this ectoparasite because they enter the sea at such a small size (approx. 0.2 g). Here, we describe how ‘no effect’ thresholds for salmon louse sublethal impacts on juvenile pink salmon were determined using physiological principles. These data were accepted by environmental managers and are being used to minimize the impact of salmon aquaculture on wild pink salmon populations. PMID:22566682

  5. European Marine Observation and Data Network (EMODnet) for Geology - A sea-bed substrate map for European marine areas

    NASA Astrophysics Data System (ADS)

    Alanen, Ulla; Kaskela, Anu; Kotilainen, Aarno; Stevenson, Alan; Partners, EMODnet-Geology 2

    2014-05-01

    The European Union's (EU) Marine Strategy Framework Directive aims to achieve good environmental status of the EU's marine waters by 2020. In order imply effective management of the broad marine areas spatial datasets covering all European marine areas are needed. In response the European Commission has adopted the European Marine Observation and Data Network (EMODnet) to assemble fragmented marine data products into publicly available datasets covering broad areas. The marine departments of the geological surveys of Europe (through the Association of European Geological Surveys - Euro GeoSurveys) took an initiative and launched the first EMODnet -Geology project (2009-2012) to compile and harmonize information from the Baltic Sea, Greater North Sea and Celtic Sea at the scale of 1:1 000 000 (http://www.emodnet-geology.eu/). The second phase of the EMODnet -Geology project started in 2013 with an expanded sea area. The 36 members from 31 countries will compile marine geological information at a scale of 1:250,000 from all European sea areas (e.g. the White Sea, Barents Sea, the Iberian Coast, and the Mediterranean Sea within EU waters). The project includes collecting and harmonizing the first sea-bed substrate map for the European Seas. The data will be essential not only for geologists but also for others interested in marine sediments like marine managers and habitat mappers. A 1:250,000 GIS layer on sea-bed substrates will be delivered in the OneGeology-Europe portal, replacing and upgrading the existing 1:1 million map layer from the previous phase. A confidence assessment will be applied to all areas to identify the information that underpins the geological interpretations.

  6. Gonadotropins in European sea bass: Endocrine roles and biotechnological applications.

    PubMed

    Mazón, María José; Molés, Gregorio; Rocha, Ana; Crespo, Berta; Lan-Chow-Wing, Olivier; Espigares, Felipe; Muñoz, Iciar; Felip, Alicia; Carrillo, Manuel; Zanuy, Silvia; Gómez, Ana

    2015-09-15

    Follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) are central endocrine regulators of the gonadal function in vertebrates. They act through specific receptors located in certain cell types found in the gonads. In fish, the differential roles of these hormones are being progressively elucidated due to the development of suitable tools for their study. In European sea bass (Dicentrarchus labrax), isolation of the genes coding for the gonadotropin subunits and receptors allowed in first instance to conduct expression studies. Later, to overcome the limitation of using native hormones, recombinant dimeric gonadotropins, which show different functional characteristics depending on the cell system and DNA construct, were generated. In addition, single gonadotropin beta-subunits have been produced and used as antigens for antibody production. This approach has allowed the development of detection methods for native gonadotropins, with European sea bass being one of the few species where both gonadotropins can be detected in their native form. By administering recombinant gonadotropins to gonad tissues in vitro, we were able to study their effects on steroidogenesis and intracellular pathways. Their administration in vivo has also been tested for use in basic studies and as a biotechnological approach for hormone therapy and assisted reproduction strategies. In addition to the production of recombinant hormones, gene-based therapies using somatic gene transfer have been offered as an alternative. This approach has been tested in sea bass for gonadotropin delivery in vivo. The hormones produced by the genes injected were functional and have allowed studies on the action of gonadotropins in spermatogenesis. PMID:26002037

  7. Biocomplexity in Populations of European Anchovy in the Adriatic Sea

    PubMed Central

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests. PMID:27074008

  8. Biocomplexity in Populations of European Anchovy in the Adriatic Sea.

    PubMed

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests. PMID:27074008

  9. Salmon lice – impact on wild salmonids and salmon aquaculture

    PubMed Central

    Torrissen, O; Jones, S; Asche, F; Guttormsen, A; Skilbrei, O T; Nilsen, F; Horsberg, T E; Jackson, D

    2013-01-01

    Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonids, although the extent of the impact is a matter of debate. Estimates from Ireland and Norway indicate an odds ratio of 1.1:1-1.2:1 for sea lice treated Atlantic salmon smolt to survive sea migration compared to untreated smolts. This is considered to have a moderate population regulatory effect. The development of resistance against drugs most commonly used to treat salmon lice is a serious concern for both wild and farmed fish. Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish. The newly sequenced salmon louse genome will be an important tool in this work. The use of cleaner fish has emerged as a robust method for controlling salmon lice, and aquaculture production of wrasse is important towards this aim. Salmon lice have large economic consequences for the salmon industry, both as direct costs for the prevention and treatment, but also indirectly through negative public opinion. PMID:23311858

  10. Skin mucus proteome map of European sea bass (Dicentrarchus labrax).

    PubMed

    Cordero, Héctor; Brinchmann, Monica F; Cuesta, Alberto; Meseguer, José; Esteban, María A

    2015-12-01

    Skin mucus is the first barrier of fish defence. Proteins from skin mucus of European sea bass (Dicentrarchus labrax) were identified by 2DE followed by LC-MS/MS. From all the identified proteins in the proteome map, we focus on the proteins associated with several immune pathways in fish. Furthermore, the real-time PCR transcript levels in skin are shown. Proteins found include apolipoprotein A1, calmodulin, complement C3, fucose-binding lectin, lysozyme and several caspases. To our knowledge, this is the first skin mucus proteome study and further transcriptional profiling of the identified proteins done on this bony fish species. This not only contributes knowledge on the routes involved in mucosal innate immunity, but also establishes a non-invasive technique based on locating immune markers with a potential use for prevention and/or diagnosis of fish diseases. PMID:26376207

  11. How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere

    PubMed Central

    Costello, Mark J.

    2009-01-01

    Fishes farmed in sea pens may become infested by parasites from wild fishes and in turn become point sources for parasites. Sea lice, copepods of the family Caligidae, are the best-studied example of this risk. Sea lice are the most significant parasitic pathogen in salmon farming in Europe and the Americas, are estimated to cost the world industry €300 million a year and may also be pathogenic to wild fishes under natural conditions. Epizootics, characteristically dominated by juvenile (copepodite and chalimus) stages, have repeatedly occurred on juvenile wild salmonids in areas where farms have sea lice infestations, but have not been recorded elsewhere. This paper synthesizes the literature, including modelling studies, to provide an understanding of how one species, the salmon louse, Lepeophtheirus salmonis, can infest wild salmonids from farm sources. Three-dimensional hydrographic models predicted the distribution of the planktonic salmon lice larvae best when they accounted for wind-driven surface currents and larval behaviour. Caligus species can also cause problems on farms and transfer from farms to wild fishes, and this genus is cosmopolitan. Sea lice thus threaten finfish farming worldwide, but with the possible exception of L. salmonis, their host relationships and transmission adaptations are unknown. The increasing evidence that lice from farms can be a significant cause of mortality on nearby wild fish populations provides an additional challenge to controlling lice on the farms and also raises conservation, economic and political issues about how to balance aquaculture and fisheries resource management. PMID:19586950

  12. Aliphatic hydrocarbon levels in turbot and salmon farmed close to the site of the Aegean Sea oil spill

    SciTech Connect

    Alvarez Pineiro, M.E.; Gonzalez-Barros, S.T.C.; Lozano, J.S.

    1996-12-31

    After the Andros Patria oil spill, the most serious oil tanker accident to occur off the coast of Galicia (N.W. Spain) was the running aground and subsequent conflagration of the Aegean Sea supertanker outside the northern Spanish port of La Coruna (December 3rd 1992). Approximately 60,000 tonnes of Brent oil were spilled into the Atlantic Ocean in the cited coastal region. Subsequently, an impropitious combination of a high tide and a change in wind direction caused the resulting slick to rapidly spread into the port. Measures aimed at cleaning up affected areas and evacuating the ca. 11,215 tonnes of oil remaining in the supertanker were immediately implemented. However, within just a few days the resulting contamination had killed some 15000 turbot juveniles and larvae, which are cultivated in fish farms close to the accident site. The environmental impact of major oil spillages has been widely studied. Several scientists have suggested that, in terms of the negative effects on the seawater quality and productive capacity of the affected maritime regions, the magnitudes of the Aegean Sea and Amoco Cadiz accidents are comparable. This paper reports variations over time of aliphatic hydrocarbon levels in turbot and Atlantic salmon sampled from fish farms close to the site of the Aegean Sea oil spill. 6 refs., 2 figs., 1 tab.

  13. Current knowledge, gaps and challenges in the Southern European Seas

    NASA Astrophysics Data System (ADS)

    Papathanassiou, Evangelos

    2015-04-01

    New knowledge advances our current understanding on the selection and application of the appropriate tools for assessing the state of the marine environment in the Southern European Seas (SES). Diminishing the lack of knowledge is a prerequisite for sound policy decisions. Although gaps and knowledge are fewer today, the health of marine and coastal ecosystems in the SES is under pressure and shows, in places, some signs of deterioration and declining quality. Overall, there is a lack of data accessibility and long time series in the SES, while in many cases poorly constrained processes cannot really support knowledge-based policy making (e.g. ecosystem functioning, climate change, fisheries management, etc.). New knowledge has to be produced and excellence must be promoted to support sustainable economic growth. At the same time, existing and new capacities have to be upgraded and increased in order to support sustainable convergence between SES countries. There are several gaps that have been identified and processes that have been poorly understood in the SES, mainly from research projects that have been working at basin level. The main research priorities that have been identified from the SeasERA Project for both, the Mediterranean and the Black Sea include: the climate change and its impacts, the hydrological cycle, the ventilation and the inter-basin coupling, the marine biodiversity and the provision of goods and services, the marine protected areas, the deep sea ecosystems, the biological invasions, the marine pollution and the ocean and human health, the renewable energy, the maritime transport, the fisheries and aquaculture activities and the biotechnology and the exploitation of marine resources for industrial application. More important, however, is the fact that the economic, the social and the scientific and the environmental challenges must be collectively tackled. They should have prioritisation and clear objectives as well as data sharing for wider use. A multi-stakeholder involvement at multidisciplinary level as well as an integrated cross-sectoral approach has to take place to achieve the best results and opportunities. The emerging new knowledge and new tools from all actions will help the scientific community to create more accurate and dynamic forecasting of possible risk scenarios. Using this input coupled with socio-economic analysis, a substantial science-based advice to policy and decision-makers can be provided, whenever is needed. It is more than certain that this process will help to meet the challenges ahead and increase the potential of the blue growth in the SES, which could, eventually, represent a significant share of the actual countries' growth in the two basins.

  14. A Modelling Framework for Assessing the Risk of Emerging Diseases Associated with the Use of Cleaner Fish to Control Parasitic Sea Lice on Salmon Farms.

    PubMed

    Murray, A G

    2016-04-01

    Sea lice are the most damaging parasite of marine salmonids, both economically and in terms of potential impacts on wild fish. An increasingly widely applied control is the use of cleaner fish (CF) such as wrasse that eat lice. However, such CF can carry pathogens that may cause disease in salmon, including the potential emergence of new diseases. This is not just a theoretical risk, as demonstrated by a recent outbreak of viral haemorrhagic septicaemia in wrasse held on salmon farms in Shetland. A modelling framework is developed to identify conditions in which emergence might occur, and, from this, means of reducing risk. Diseases that might emerge easily in farmed salmon would be likely to have already done so by other routes of exposure, and if risks are very low, they would need to be greatly enhanced to become significant relative to costs of lice control. CF may most enhance risks from disease with moderate probability of emerging. Risks of emergence can be reduced by replacing wild-caught with hatchery-reared CF, minimizing mixing of CF from different sources, surveillance for clinical disease in the CF and ensuring strategic biosecurity (area management with synchronized fallowing). Reuse of CF for a second salmon production cycle may reduce costs and even probability of infection (especially from wild-caught CF), but should only be considered as part of a rigorous area management programme because the practice presents opportunities for pathogens to adapt to salmon by weakening fallowing. PMID:25208602

  15. Infectious diseases of Pacific salmon

    USGS Publications Warehouse

    1954-01-01

    A variety of bacteria has been found responsible for outbreaks of disease in salmon in sea water. The most important of these is a species of Vibrio. Tuberculosis has been found in adult chinook salmon and the evidence indicates that the disease was contracted at sea.

  16. Warming shelf seas drive the subtropicalization of European pelagic fish communities.

    PubMed

    Montero-Serra, Ignasi; Edwards, Martin; Genner, Martin J

    2015-01-01

    Pelagic fishes are among the most ecologically and economically important fish species in European seas. In principle, these pelagic fishes have potential to demonstrate rapid abundance and distribution shifts in response to climatic variability due to their high adult motility, planktonic larval stages, and low dependence on benthic habitat for food or shelter during their life histories. Here, we provide evidence of substantial climate-driven changes to the structure of pelagic fish communities in European shelf seas. We investigated the patterns of species-level change using catch records from 57,870 fisheries-independent survey trawls from across European continental shelf region between 1965 and 2012. We analysed changes in the distribution and rate of occurrence of the six most common species, and observed a strong subtropicalization of the North Sea and Baltic Sea assemblages. These areas have shifted away from cold-water assemblages typically characterized by Atlantic herring and European sprat from the 1960s to 1980s, to warmer-water assemblages including Atlantic mackerel, Atlantic horse mackerel, European pilchard and European anchovy from the 1990s onwards. We next investigated if warming sea temperatures have forced these changes using temporally comprehensive data from the North Sea region. Our models indicated the primary driver of change in these species has been sea surface temperatures in all cases. Together, these analyses highlight how individual species responses have combined to result in a dramatic subtropicalization of the pelagic fish assemblage of the European continental shelf. PMID:25230844

  17. From the European slope to the North Sea

    NASA Astrophysics Data System (ADS)

    Dale, Andy; Porter, Marie

    2015-04-01

    The European slope current is a density driven poleward current tracing the shelf edge from the Bay of Biscay into the Nordic Seas. This current is not entirely coherent along its length and is known to be disrupted by the wind, bathymetric irregularities and local circulation, potentially providing a source of relatively warm and nutrient rich water to the local shelf. On the Malin Shelf, to the north of Ireland and the west of Scotland, persistent intrusions of oceanic water occur onto the shelf near a bend in the slope. Additional pathways onto the shelf result from strong wind events, which cause ingress of slope water at multiple locations, while eddies in the Rockall Trough are known to pull water off the slope into deeper, abyssal regions. In July 2013, 30 surface drifters, 15 drogued at 15 m and 15 at 70 m, were deployed on the Malin Shelf slope. Of these drifters, all of those drogued at 15 m and 10 of those drogued at 70 m moved north-eastward from their release onto the shelf. The majority crossed onto the shelf within a relatively small area, within a 30km radius of 55.5°N, 10°W, and continued as a coherent group along the edge of the Irish coastal front for approximately 38 days. This current, estimated to transport approximately 0.5 Sv of water towards the Scottish coast, follows the Irish Coastal front and then the Islay front until it bifurcates around the Outer Hebrides, with half of the drifters passing inside, to the east through the Minch, and half passing outside, to the west. The control over the path taken is likely to have been the position and strength of the Islay Front. The tendency for the shallow drifters to cross onto the shelf more readily than the deeper ones suggests that the ingress onto the shelf varies with depth and is strongest at the surface. The deeper drifters generally spent longer in the slope region and were frequently pulled into the Rockall Trough. The drifter trajectories highlight a pathway for surface water (15 m) from the European slope, around the Scottish coast and islands and into the North Sea. Highly variable subsurface (70 m) water movement is also seen, with flow both onto and away from the shelf as well as stagnation at points along the slope.

  18. Increased susceptibility to infectious salmon anemia virus (ISAv) in Lepeophtheirus salmonis – infected Atlantic salmon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The salmon louse and infectious salmon anemia virus (ISAv) are the two most significant pathogens of concern to the Atlantic salmon (Salmo salar) aquaculture industry. However, the interactions between sea lice and ISAv, as well as the impact of a prior sea lice infection on the susceptibility of th...

  19. European sea bass, Dicentrarchus labrax, in a changing ocean

    NASA Astrophysics Data System (ADS)

    Pope, E. C.; Ellis, R. P.; Scolamacchia, M.; Scolding, J. W. S.; Keay, A.; Chingombe, P.; Shields, R. J.; Wilcox, R.; Speirs, D. C.; Wilson, R. W.; Lewis, C.; Flynn, K. J.

    2014-05-01

    Ocean acidification, caused by rising concentrations of carbon dioxide (CO2), is widely considered to be a major global threat to marine ecosystems. To investigate the potential effects of ocean acidification on the early life stages of a commercially important fish species, European sea bass (Dicentrarchus labrax), 12 000 larvae were incubated from hatch through metamorphosis under a matrix of two temperatures (17 and 19 °C) and two seawater pCO2 levels (ambient and 1,000 μatm) and sampled regularly for 42 days. Calculated daily mortality was significantly affected by both temperature and pCO2, with both increased temperature and elevated pCO2 associated with lower daily mortality and a significant interaction between these two factors. There was no significant pCO2 effect noted on larval morphology during this period but larvae raised at 19 °C possessed significantly larger eyes and lower carbon:nitrogen ratios at the end of the study compared to those raised under 17 °C. Similarly, when the incubation was continued to post-metamorphic (juvenile) animals (day 67-69), fish raised under a combination of 19 °C and 1000 μatm pCO2 were significantly heavier. However, juvenile D. labrax raised under this combination of 19 °C and 1000 μatm pCO2 also exhibited lower aerobic scopes than those incubated at 19 °C and ambient pCO2. Most studies investigating the effects of near-future oceanic conditions on the early life stages of marine fish have used incubations of relatively short durations and suggested that these animals are resilient to ocean acidification. Whilst the increased survival and growth observed in this study supports this view, we conclude that more work is required to investigate whether the differences in juvenile physiology observed in this study manifest as negative impacts in adult fish.

  20. Quantifying the ocean, freshwater and human effects on year-to-year variability of one-sea-winter Atlantic salmon angled in multiple Norwegian rivers.

    PubMed

    Otero, Jaime; Jensen, Arne J; L'Abée-Lund, Jan Henning; Stenseth, Nils Chr; Storvik, Geir O; Vøllestad, Leif Asbjørn

    2011-01-01

    Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species' distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse) from Norwegian rivers over 29 years (1979-2007). Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the river systems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching for solutions to conserve this species. PMID:21897867

  1. Quantifying the Ocean, Freshwater and Human Effects on Year-to-Year Variability of One-Sea-Winter Atlantic Salmon Angled in Multiple Norwegian Rivers

    PubMed Central

    Otero, Jaime; Jensen, Arne J.; L'Abée-Lund, Jan Henning; Stenseth, Nils Chr.; Storvik, Geir O.; Vøllestad, Leif Asbjørn

    2011-01-01

    Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species' distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse) from Norwegian rivers over 29 years (1979–2007). Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the river systems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching for solutions to conserve this species. PMID:21897867

  2. Effects of salmon lice Lepeophtheirus salmonis on sea trout Salmo trutta at different times after seawater transfer.

    PubMed

    Dawson, L H; Pike, A W; Houlihan, D F; McVicar, A H

    1998-07-30

    The physiological and behavioural effects and skin damage caused by salmon lice Lepeophtheirus salmonis (Krøyer) infections on sea trout Salmo trutta L. smolts were greater in fish infected with lice 2 wk after seawater transfer than in fish infected 6 wk after seawater transfer. The initial prevalence of infection was 100% for both groups and the intensity of infection decreased significantly with time over 5 wk. Significantly fewer of the fish infected 2 wk after seawater transfer had resumed feeding by the end of the experiment, leading to a loss of body condition. Furthermore, these fish suffered more severe damage to the skin and detrimental changes in physiological integrity than fish infected 6 wk after seawater transfer as a direct consequence of feeding preadult lice, leading to osmoregulatory failure and death. Although this study was carried out in laboratory conditions, results indicate that lice infections may potentially have a detrimental impact on the survival of wild smolts after seawater transfer. PMID:9841122

  3. Extensive immigration from compensatory hatchery releases into wild Atlantic salmon population in the Baltic sea: spatio-temporal analysis over 18 years.

    PubMed

    Vasemägi, A; Gross, R; Paaver, T; Koljonen, M-L; Nilsson, J

    2005-07-01

    Genetic homogenization has been recognized as a serious threat in an increasing number of species, including many salmonid fishes. We assessed the rate and impact of immigration from the main hatchery stocks of Atlantic salmon in the Gulf of Bothnia into one of the largest wild salmon populations in the Baltic Sea, the River Vindelälven, within a temporal framework of 18 years (from 1985-2003). We provide genetic evidence based on mtDNA and microsatellite markers, using mixed-stock analysis, that a large proportion (66%) of fin-damaged spawners (n=181) caught in the Ume/Vindelälven during 1997-2003 originated from the hatcheries in the Rivers Angermanälven, Luleälven and Ljusnan. The maximum-likelihood estimate of immigration rate from these hatcheries into the wild Vindelälven population was 0.068 (95% CI 0.021-0.128) over the studied time period (1985-2003) and reached up to a quarter (m=0.249, 95% CI 0.106-0.419) of the total population during 1993-2000. This resulted in significant (P<0.01) genetic homogenization trend between the wild Vindelälven population and hatchery stocks of the Angermanälven and Luleälven. Our results demonstrate extensive straying from geographically distant hatchery releases into wild salmon population and emphasize the genetic risks associated with current large-scale stocking practices in the Baltic Sea. PMID:15931244

  4. SeaDataNet II - EMODNet Bathymetry - building a pan-European infrastructure for marine and ocean data management and a digital high resolution bathymetry for European seas

    NASA Astrophysics Data System (ADS)

    Schaap, Dick M. A.; Fichaut, Michele

    2015-04-01

    The second phase of the project SeaDataNet is well underway since October 2011. The main objective is to improve operations and to progress towards an efficient data management infrastructure able to handle the diversity and large volume of data collected via research cruises and monitoring activities in European marine waters and global oceans. The SeaDataNet infrastructure comprises a network of interconnected data centres and a central SeaDataNet portal. The portal provides users a unified and transparent overview of the metadata and controlled access to the large collections of data sets, managed by the interconnected data centres, and the various SeaDataNet standards and tools,. SeaDataNet is also setting and governing marine data standards, and exploring and establishing interoperability solutions to connect to other e-infrastructures on the basis of standards of ISO (19115, 19139), OGC (WMS, WFS, CS-W and SWE), and OpenSearch. The population of directories has increased considerably in cooperation and involvement in associated EU projects and initiatives. SeaDataNet now gives overview and access to more than 1.6 million data sets for physical oceanography, chemistry, geology, geophysics, bathymetry and biology from more than 100 connected data centres from 34 countries riparian to European seas. Access to marine data is also a key issue for the implementation of the EU Marine Strategy Framework Directive (MSFD). The EU communication 'Marine Knowledge 2020' underpins the importance of data availability and harmonising access to marine data from different sources. SeaDataNet qualified itself for an active role in the data management component of the EMODnet (European Marine Observation and Data network) that is promoted in the EU Communication. Starting 2009 EMODnet pilot portals have been initiated for marine data themes: digital bathymetry, chemistry, physical oceanography, geology, biology, and seabed habitat mapping. These portals are being expanded to all European sea regions as part of EMODnet Phase 2, which started mid 2013. EMODnet encourages more data providers to come forward for data sharing and participating in the process of making complete overviews and homogeneous data products. The EMODnet Bathymetry project is very illustrative for the synergy between SeaDataNet and EMODnet and added value of generating public data products. The project develops and publishes Digital Terrain Models (DTM) for the European seas. These are produced from survey and aggregated data sets. The portal provides a versatile DTM viewing service with many relevant map layers and functions for retrieving. A further refinement is taking place as part of phase 2. The presentation will highlight key achievements in SeaDataNet II and give further details and views on the new EMODNet Digital Bathymetry for European seas as to be released early 2015.

  5. All roads lead to home: panmixia of European eel in the Sargasso Sea.

    PubMed

    Als, Thomas D; Hansen, Michael M; Maes, Gregory E; Castonguay, Martin; Riemann, Lasse; Aarestrup, Kim; Munk, Peter; Sparholt, Henrik; Hanel, Reinhold; Bernatchez, Louis

    2011-04-01

    European eels (Anguilla anguilla) spawn in the remote Sargasso Sea in partial sympatry with American eels (Anguilla rostrata), and juveniles are transported more than 5000 km back to the European and North African coasts. The two species have been regarded as classic textbook examples of panmixia, each comprising a single, randomly mating population. However, several recent studies based on continental samples have found subtle, but significant, genetic differentiation, interpreted as geographical or temporal heterogeneity between samples. Moreover, European and American eels can hybridize, but hybrids have been observed almost exclusively in Iceland, suggesting hybridization in a specific region of the Sargasso Sea and subsequent nonrandom dispersal of larvae. Here, we report the first molecular population genetics study based on analysis of 21 microsatellite loci in larvae of both Atlantic eel species sampled directly in the spawning area, supplemented by analysis of European glass eel samples. Despite a clear East-West gradient in the overlapping distribution of the two species in the Sargasso Sea, we only observed a single putative hybrid, providing evidence against the hypothesis of a wide marine hybrid zone. Analyses of genetic differentiation, isolation by distance, isolation by time and assignment tests provided strong evidence for panmixia in both the Sargasso Sea and across all continental samples of European eel after accounting for the presence of sibs among newly hatched larvae. European eel has declined catastrophically, and our findings call for management of the species as a single unit, necessitating coordinated international conservation efforts. PMID:21299662

  6. The relationship between pink salmon biomass and the body condition of short-tailed shearwaters in the Bering Sea: can fish compete with seabirds?

    PubMed Central

    Toge, Kanako; Yamashita, Rei; Kazama, Kentaro; Fukuwaka, Masaaki; Yamamura, Orio; Watanuki, Yutaka

    2011-01-01

    Seabirds and large fishes are important top predators in marine ecosystems, but few studies have explored the potential for competition between these groups. This study investigates the relationship between an observed biennial change of pink salmon (Oncorhynchus gorbuscha) biomass in the central Bering Sea (23 times greater in odd-numbered than in even-numbered years) and the body condition and diet of the short-tailed shearwater (Puffinus tenuirostris) that spends the post-breeding season there. Samples were collected with research gill nets over seven summers. Both species feed on krill, small fishes and squid. Although the mean pink salmon catch per unit effort (in mass) over the study region was not related significantly with shearwater's stomach content mass or prey composition, the pink salmon biomass showed a negative and significant relationship with the shearwater's body mass and liver mass (proxies of energy reserve). We interpret these results as evidence that fishes can negatively affect mean prey intake of seabirds if they feed on a shared prey in the pelagic ecosystem. PMID:21270043

  7. The relationship between pink salmon biomass and the body condition of short-tailed shearwaters in the Bering Sea: can fish compete with seabirds?

    PubMed

    Toge, Kanako; Yamashita, Rei; Kazama, Kentaro; Fukuwaka, Masaaki; Yamamura, Orio; Watanuki, Yutaka

    2011-09-01

    Seabirds and large fishes are important top predators in marine ecosystems, but few studies have explored the potential for competition between these groups. This study investigates the relationship between an observed biennial change of pink salmon (Oncorhynchus gorbuscha) biomass in the central Bering Sea (23 times greater in odd-numbered than in even-numbered years) and the body condition and diet of the short-tailed shearwater (Puffinus tenuirostris) that spends the post-breeding season there. Samples were collected with research gill nets over seven summers. Both species feed on krill, small fishes and squid. Although the mean pink salmon catch per unit effort (in mass) over the study region was not related significantly with shearwater's stomach content mass or prey composition, the pink salmon biomass showed a negative and significant relationship with the shearwater's body mass and liver mass (proxies of energy reserve). We interpret these results as evidence that fishes can negatively affect mean prey intake of seabirds if they feed on a shared prey in the pelagic ecosystem. PMID:21270043

  8. Seabed substrates and sedimentation rates of the European Seas - EMODnet-Geology2

    NASA Astrophysics Data System (ADS)

    Kaskela, Anu; Kotilainen, Aarno; Alanen, Ulla; Stevenson, Alan; Partners, EMODnet Geology 2

    2015-04-01

    Seas and oceans are important for us. However, increased human activities in marine and coastal areas have altered marine ecosystems worldwide. To ensure sustainable use of marine resources and health of the seas, improved management is needed. The European Union's (EU) Marine Strategy Framework Directive targets to achieve Good Environmental Status (GES) of the EU's marine waters by 2020. However, it has been acknowledged that the poor access to data on the marine environment was a handicap to government decision-making, a barrier to scientific understanding and a break on the economy. The effective management of the broad marine areas requires spatial datasets covering all European marine areas. As a consequence the European Commission adopted the European Marine Observation and Data Network (EMODnet) in 2009 to combine dispersed marine data into publicly available datasets covering broad areas. The second phase of the EMODnet -Geology project started in 2013 and it will run for 3 years. The partnership includes 36 marine organizations from 30 countries. The partners, mainly from the marine departments of the geological surveys of Europe (through the Association of European Geological Surveys - EuroGeoSurveys), aim to assemble marine geological information at a scale of 1:250,000 from all European sea areas (e.g. the White Sea, Baltic Sea, Barents Sea, the Iberian Coast, and the Mediterranean Sea within EU waters). In comparison to the urEMODnet project (2009-2012) the data will be more detailed and aim to cover much larger area. The project includes collecting and harmonizing the first seabed substrate map for the European Seas, as well as data/map showing sedimentation rates at the seabed. The data will be essential not only for geologists but also for others interested in marine sediments like marine managers and habitat mappers. A 1:250,000 GIS layer on seabed substrates will be delivered in the portal, in addition to the existing 1:1 million map layer from the previous phase that will be updated with data from the new sea areas. A confidence assessment will be applied to all areas to identify the information that underpins the geological interpretations. Further information about the EMODnet-Geology 2 project is available on the portal (http://www.emodnet-geology.eu/).

  9. The role of SEA in integrating and balancing high policy objectives in European cohesion funding programmes

    SciTech Connect

    Jiricka, Alexandra Proebstl, Ulrike

    2013-01-15

    Funding programmes for European cohesion policy are a crucial tool to support the sustainability goals of the European Union and national policies of its member states. All these funding programmes require a Strategic Environmental Assessment (SEA) to enhance sustainable development. This article compares five first SEA applications at cohesion policy level to discuss challenges, limitations and benefits of this instrument. In order to support the SEA-process a 'Handbook on SEA for Cohesion Policy 2007-13' (GRDP 2006) was developed. The paper examines the special requirements and challenges at the programme level given the special conditions for stakeholder involvement, integration of SEA in the programme development process and strategies to cope with uncertainties to ensure real compatibility with policy goals. Using action research and in-depth interviews with SEA planners and programme managers enabled us to analyse the suitability of the methodology proposed by the handbook. The results show that some recommendations of the handbook should be changed in order to increase the transparency and to enhance the standard and comparability of the SEA-documents. Overall the SEA proved to be a rather successful tool for the integration of sustainability goals at the EU and national policy levels. Its particular strengths emerged as the process makes uncertainties visible and leads to possible redefinitions while maintaining actual policy goals. - Highlights: Black-Right-Pointing-Pointer Comparing five case studies of first applications of SEA at cohesion policy level. Black-Right-Pointing-Pointer Overall the SEA proved to be a rather successful tool for the integration of sustainability goals. Black-Right-Pointing-Pointer The study makes uncertainties visible and shows how SEA could lead to possible redefinitions.

  10. Contemporary ocean warming and freshwater conditions are related to later sea age at maturity in Atlantic salmon spawning in Norwegian rivers.

    PubMed

    Otero, Jaime; Jensen, Arne J; L'abée-Lund, Jan Henning; Stenseth, Nils Chr; Storvik, Geir O; Vøllestad, Leif Asbjørn

    2012-09-01

    Atlantic salmon populations are reported to be declining throughout its range, raising major management concerns. Variation in adult fish abundance may be due to variation in survival, growth, and timing of life history decisions. Given the complex life history, utilizing highly divergent habitats, the reasons for declines may be multiple and difficult to disentangle. Using recreational angling data of two sea age groups, one-sea-winter (1SW) and two-sea-winter (2SW) fish originated from the same smolt year class, we show that sea age at maturity of the returns has increased in 59 Norwegian rivers over the cohorts 1991-2005. By means of linear mixed-effects models we found that the proportion of 1SW fish spawning in Norway has decreased concomitant with the increasing sea surface temperature experienced by the fish in autumn during their first year at sea. Furthermore, the decrease in the proportion of 1SW fish was influenced by freshwater conditions as measured by water discharge during summer months 1 year ahead of seaward migration. These results suggest that part of the variability in age at maturity can be explained by the large-scale changes occurring in the north-eastern Atlantic pelagic food web affecting postsmolt growth, and by differences in river conditions influencing presmolt growth rate and later upstream migration. PMID:23139878

  11. Intestinal barrier function of Atlantic salmon (Salmo salar L.) post smolts is reduced by common sea cage environments and suggested as a possible physiological welfare indicator

    PubMed Central

    2010-01-01

    Background Fish farmed under high intensity aquaculture conditions are subjected to unnatural environments that may cause stress. Therefore awareness of how to maintain good health and welfare of farmed fish is important. For Atlantic salmon held in sea cages, water flow, dissolved oxygen (DO) levels and temperature will fluctuate over time and the fish can at times be exposed to detrimentally low DO levels and high temperatures. This experimental study investigates primary and secondary stress responses of Atlantic salmon post smolts to long-term exposure to reduced and fluctuating DO levels and high water temperatures, mimicking situations in the sea cages. Plasma cortisol levels and cortisol release to the water were assessed as indicators of the primary stress response and intestinal barrier integrity and physiological functions as indicators of secondary responses to changes in environmental conditions. Results Plasma cortisol levels were elevated in fish exposed to low (50% and 60% saturation) DO levels and low temperature (9°C), at days 9, 29 and 48. The intestinal barrier function, measured as electrical resistance (TER) and permeability of mannitol at the end of the experiment, were reduced at 50% DO, in both proximal and distal intestine. When low DO levels were combined with high temperature (16°C), plasma cortisol levels were elevated in the cyclic 1:5 h at 85%:50% DO group and fixed 50% DO group compared to the control (85% DO) group at day 10 but not at later time points. The intestinal barrier function was clearly disturbed in the 50% DO group; TER was reduced in both intestinal regions concomitant with increased paracellular permeability in the distal region. Conclusions This study reveals that adverse environmental conditions (low water flow, low DO levels at low and high temperature), that can occur in sea cages, elicits primary and secondary stress responses in Atlantic salmon post smolts. The intestinal barrier function was significantly affected by prolonged hypoxic stress even when no primary stress response was observed. This suggests that intestinal barrier function is a good experimental marker for evaluation of chronic stress and that it can be a valuable tool to study the impact of various husbandry conditions on health and welfare of farmed Atlantic salmon. PMID:21062437

  12. Salmon Patch

    MedlinePlus

    ... the head. Salmon patches are different from port-wine stains (discussed as a separate topic) in that ... difference between a salmon patch and a port-wine stain. In the past, port-wine stains and ...

  13. Amplification of European Little Ice Age by sea ice-ocean-atmosphere feedbacks

    NASA Astrophysics Data System (ADS)

    Lehner, Flavio; Born, Andreas; Raible, Christoph C.; Stocker, Thomas F.

    2013-04-01

    The transition from the Medieval Climate Anomaly (~950-1250 AD) to the Little Ice Age (~1400-1700 AD) is believed to have been driven by an interplay of external forcing and climate system-internal variability. While the hemispheric signal seems to have been dominated by solar irradiance and volcanic eruptions, the understanding of mechanisms shaping the climate on continental scale is less robust. Examining an ensemble of transient model simulations as well as a new type of sensitivity experiments with artificial sea ice growth, we identify a sea ice-ocean-atmosphere feedback mechanism that amplifies the Little Ice Age cooling in the North Atlantic-European region and produces the temperature pattern expected from reconstructions. Initiated by increasing negative forcing, the Arctic sea ice substantially expands at the beginning of the Little Ice Age. The excess of sea ice is exported to the subpolar North Atlantic, where it melts, thereby weakening convection of the ocean. As a consequence, northward ocean heat transport is reduced, reinforcing the expansion of the sea ice and the cooling of the Northern Hemisphere. In the Nordic Seas, sea surface height anomalies cause the oceanic recirculation to strengthen at the expense of the warm Barents Sea inflow, thereby further reinforcing sea ice growth in the Barents Sea. The absent ocean-atmosphere heat flux in the Barents Sea results in an amplified cooling over Northern Europe. The positive nature of this feedback mechanism enables sea ice to remain in an expanded state for decades to centuries and explain sustained cold periods over Europe such as the Little Ice Age. Support for the feedback mechanism comes from recent proxy reconstructions around the Nordic Seas.

  14. Experimental susceptibility of European sea bass and Senegalese sole to different betanodavirus isolates.

    PubMed

    Souto, S; Lopez-Jimena, B; Alonso, M C; García-Rosado, E; Bandín, I

    2015-05-15

    The susceptibility of juvenile European sea bass and Senegalese sole to three VNNV isolates (a reassortant RGNNV/SJNNV, as well as the parental RGNNV and SJNNV genotypes) has been evaluated by challenges using two inoculation ways (bath and intramuscular injection). The results demonstrate that these two fish species are susceptible to all the VNNV isolates tested. In European sea bass, RGNNV caused the highest cumulative mortality, reaching maximum values of viral RNA and titres. Although the SJNNV isolate did not provoke mortality or clinical signs of disease in this fish species, viral production in survivor fish was determined; on the other hand the reassortant isolate did cause mortality and clinical signs of disease, although less evident than those recorded after RGNNV infection. These results suggest that the changes suffered by the SJNNV RNA2 segment of the reassortant isolate, compared to the parental SJNNV, may have involved host-specificity and/or virulence determinants for European sea bass. Regarding Senegalese sole, although the three isolates caused 100% mortality, the reassortant strain provoked the most acute symptoms, and more quickly, especially in the bath challenge. This was also the isolate showing less difference between the number of RNA copies and viral titre, reaching the highest titres of infective viral particles in nervous tissue of infected animals. The RGNNV isolate produced the lowest values of infective viral particles. All these results suggest that the RGNNV and the reassortant isolates are the most suited for infecting European sea bass and Senegalese sole, respectively. PMID:25770892

  15. Evidence for an autumn downstream migration of Atlantic salmon Salmo salar (Linnaeus) and brown trout Salmo trutta (Linnaeus) parr to the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Taal, Imre; Kesler, Martin; Saks, Lauri; Rohtla, Mehis; Verliin, Aare; Svirgsden, Roland; Jürgens, Kristiina; Vetemaa, Markus; Saat, Toomas

    2014-06-01

    In the eastern Baltic rivers, anadromous salmonid parr are known to smoltify and migrate to the sea from March until June, depending on latitude, climate and hydrological conditions. In this study, we present the first records of autumn descent of brown trout Salmo trutta and Atlantic salmon Salmo salar from the Baltic Sea Basin. Otolith microchemistry analyses revealed that these individuals hatched in freshwater and had migrated to the brackish water shortly prior to capture. The fish were collected in 2006, 2008, 2009 and 2013 from Eru Bay (surface salinity 4.5-6.5 ‰), Gulf of Finland. This relatively wide temporal range of observations indicates that the autumn descent of anadromous salmonids is not a random event. These results imply that autumn descent needs more consideration in the context of the effective stock management, assessment and restoration of Baltic salmonid populations and their habitats.

  16. New perspectives on sea use management: initial findings from European experience with marine spatial planning.

    PubMed

    Douvere, Fanny; Ehler, Charles N

    2009-01-01

    Increased development pressures on the marine environment and the potential for multiple use conflicts, arising as a result of the current expansion of offshore wind energy, fishing and aquaculture, dredging, mineral extraction, shipping, and the need to meet international and national commitments to biodiversity conservation, have led to increased interest in sea use planning with particular emphasis on marine spatial planning. Several European countries, on their own initiative or driven by the European Union's Marine Strategy and Maritime Policy, the Bergen Declaration of the North Sea Conference, and the EU Recommendation on Integrated Coastal Zone Management, have taken global leadership in implementing marine spatial planning. Belgium, The Netherlands, and Germany in the North Sea, and the United Kingdom in the Irish Sea, have already completed preliminary sea use plans and zoning proposals for marine areas within their national jurisdictions. This paper discusses the nature and context of marine spatial planning, the international legal and policy framework, and the increasing need for marine spatial planning in Europe. In addition, the authors review briefly three marine spatial planning initiatives in the North Sea and conclude with some initial lessons learned from these experiences. PMID:18786758

  17. An European historical reconstruction of sea surface dynamics (waves and storm surge) for coastal impact studies

    NASA Astrophysics Data System (ADS)

    Menendez, Melisa; Perez, Jorge; Cid, Alba; Castanedo, Sonia; Losada, Inigo; Medina, Raul; Mendez, Fernando

    2015-04-01

    Despite their outstanding relevance in coastal processes, a study of the sea surface dynamics due to atmospheric wind and pressure variations are rather limited in comparison with the mean sea level rise. Data of waves and surges along the European region are scarce and in-homogeneous, not only in terms of spatial coverage but also in terms of temporal coverage. This study presents two databases focused on a historical reconstruction of: (i) the wind-generated waves (GOW) and (ii) the meteorological sea level component (GOS). The GOW and GOS datasets cover the whole European coast (North Atlantic, North Sea, Baltic Sea, Mediterranean Sea and Black Sea) at high-spatial resolution from 1979 to present. The meteorological sea level component (storm surge) has been generated by the Regional Ocean Model System (ROMS). To take into account non-linear interactions between tides and surges, both dynamics were simulated jointly. Final results of meteorological component of sea level were obtained by subtracting the astronomical tide from the simulated sea surface. The model was set-up for Europe using an orthogonal grid, with a horizontal resolution ranging between 3.5 to 11 km. A spatial domain of approximately 5 km was used for the Black Sea. Local coastal waves can be the integrated result of the ocean surface over a large region of influence. GOW-Europe is designed from a multigrid approach based on the overlapping of two-way nested domains. The coarser spatial resolution along the European coast of GOW is 15 km. The generation and propagation of the sea surface waves of GOW-Europe are simulated with the model WAVEWATCH III v4.18. Effects of non-linear wave-wave interactions, whitecapping and depth-induced refraction are considered in the propagation model. In order to validate GOW and GOS over Europe with available observations, an exhaustive comparison with in-situ and remote measurements was developed. In-situ buoys and tide-gauges are used to compare hourly time series of surge sea level component and waves (significant wave height, period and direction) at coastal locations. Altimeter observations are also considered for a spatial validation of surge and wave heights. Results obtained from this validation process show a general good agreement with observations for the European region. Finally, the hourly time series of surge and wave climate along the European coast grid-points are analyzed. Historical changes in the waves and storm surge provide a useful information for coastal impact studies since coastal flooding, beach erosion, coastal structures and physical damages in ecosystems can be affected by long-term changes in wave climate and sea levels. Reguero, B. G., Menéndez, M., Méndez, F. J. Mínguez, R. Losada, I. J. (2012). A Global Ocean Wave (GOW) calibrated reanalysis from 1948 onwards. Coastal Engineering, 65, 38-55. Cid, A., Castanedo, S., Abascal, A. J., Menéndez, M., & Medina, R. (2014). A high resolution hindcast of the meteorological sea level component for Southern Europe: the GOS dataset. Climate Dynamics, 1-18.

  18. Space-time cluster analysis of sea lice infestation (Caligus clemensi and Lepeophtheirus salmonis) on wild juvenile Pacific salmon in the Broughton Archipelago of Canada.

    PubMed

    Patanasatienkul, Thitiwan; Sanchez, Javier; Rees, Erin E; Pfeiffer, Dirk; Revie, Crawford W

    2015-06-15

    Sea lice infestation levels on wild chum and pink salmon in the Broughton Archipelago region are known to vary spatially and temporally; however, the locations of areas associated with a high infestation level had not been investigated yet. In the present study, the multivariate spatial scan statistic based on a Poisson model was used to assess spatial clustering of elevated sea lice (Caligus clemensi and Lepeophtheirus salmonis) infestation levels on wild chum and pink salmon sampled between March and July of 2004 to 2012 in the Broughton Archipelago and Knight Inlet regions of British Columbia, Canada. Three covariates, seine type (beach and purse seining), fish size, and year effect, were used to provide adjustment within the analyses. The analyses were carried out across the five months/datasets and between two fish species to assess the consistency of the identified clusters. Sea lice stages were explored separately for the early life stages (non-motile) and the late life stages of sea lice (motile). Spatial patterns in fish migration were also explored using monthly plots showing the average number of each fish species captured per sampling site. The results revealed three clusters for non-motile C. clemensi, two clusters for non-motile L. salmonis, and one cluster for the motile stage in each of the sea lice species. In general, the location and timing of clusters detected for both fish species were similar. Early in the season, the clusters of elevated sea lice infestation levels on wild fish are detected in areas closer to the rivers, with decreasing relative risks as the season progresses. Clusters were detected further from the estuaries later in the season, accompanied by increasing relative risks. In addition, the plots for fish migration exhibit similar patterns for both fish species in that, as expected, the juveniles move from the rivers toward the open ocean as the season progresses The identification of space-time clustering of infestation on wild fish from this study can help in targeting investigations of factors associated with these infestations and thereby support the development of more effective sea lice control measures. PMID:25869117

  19. Geological maps of the European seas - the EMODNET-Geology project.

    NASA Astrophysics Data System (ADS)

    Stevenson, Alan

    2014-05-01

    To support its objectives to achieve Good Environmental Status in Europe's seas by 2020, the European Commission established the European Marine Observation and Data Network (EMODNET) to assemble existing but fragmented and inaccessible marine data and to create interoperable, contiguous and publicly available information layers which encompass whole marine basins. EMODNET is a network of existing and developing European observation systems linked by a data management structure covering all European coastal waters, shelf seas and surrounding ocean basins. The marine departments of the European Geological Surveys form the basis of a partnership that implements the EMODNET-Geology project, part of a suite of EMODNET studies that also cover bathymetry, marine chemistry, marine biology, seabed habitats, physics and human activities in the marine environment. The EMODnet-Geology project will deliver integrated geological map products through the One Geology-Europe portal. EMODNET-Geology will have a distributed map service with each of the work packages delivering a specified layer that include seafloor geology, seabed sediments, mineral resources and geological events such as submarine slides and earthquakes. Further information about the EMODNET project can be found at: http://www.emodnet.eu/

  20. SeaDataNet Pan-European infrastructure for Ocean & Marine Data Management

    NASA Astrophysics Data System (ADS)

    Manzella, G. M.; Maillard, C.; Maudire, G.; Schaap, D.; Rickards, L.; Nast, F.; Balopoulos, E.; Mikhailov, N.; Vladymyrov, V.; Pissierssens, P.; Schlitzer, R.; Beckers, J. M.; Barale, V.

    2007-12-01

    SEADATANET is developing a Pan-European data management infrastructure to insure access to a large number of marine environmental data (i.e. temperature, salinity current, sea level, chemical, physical and biological properties), safeguard and long term archiving. Data are derived from many different sensors installed on board of research vessels, satellite and the various platforms of the marine observing system. SeaDataNet allows to have information on real time and archived marine environmental data collected at a pan-european level, through directories on marine environmental data and projects. SeaDataNet allows the access to the most comprehensive multidisciplinary sets of marine in-situ and remote sensing data, from about 40 laboratories, through user friendly tools. The data selection and access is operated through the Common Data Index (CDI), XML files compliant with ISO standards and unified dictionaries. Technical Developments carried out by SeaDataNet includes: A library of Standards - Meta-data standards, compliant with ISO 19115, for communication and interoperability between the data platforms. Software of interoperable on line system - Interconnection of distributed data centres by interfacing adapted communication technology tools. Off-Line Data Management software - software representing the minimum equipment of all the data centres is developed by AWI "Ocean Data View (ODV)". Training, Education and Capacity Building - Training 'on the job' is carried out by IOC-Unesco in Ostende. SeaDataNet Virtual Educational Centre internet portal provides basic tools for informal education

  1. Heritability of cortisol response to confinement stress in European sea bass dicentrarchus labrax

    PubMed Central

    2012-01-01

    Background In fish, the most studied production traits in terms of heritability are body weight or growth, stress or disease resistance, while heritability of cortisol levels, widely used as a measure of response to stress, is less studied. In this study, we have estimated heritabilities of two growth traits (body weight and length) and of cortisol response to confinement stress in the European sea bass. Findings The F1 progeny analysed (n?=?922) belonged to a small effective breeding population with contributions from an unbalanced family structure of just 10 males and 2 females. Heritability values ranged from 0.54 (0.21) for body weight to 0.65 (0.22) for standard body length and were low for cortisol response i.e. 0.08 (0.06). Genetic correlations were positive (0.94) between standard body length and body weight and negative between cortisol and body weight and between cortisol and standard body length (?0.60 and ?0.55, respectively). Conclusion This study confirms that in European sea bass, heritability of growth-related traits is high and that selection on such traits has potential. However, heritability of cortisol response to stress is low in European sea bass and since it is known to vary greatly among species, further studies are necessary to understand the reasons for these differences. PMID:22520515

  2. The main characteristics, problems, and prospects for Western European coastal seas.

    PubMed

    Dauvin, Jean-Claude

    2008-01-01

    Located to the far West of Western Europe, France has a western maritime coastal zone of more than 3800 km, which is widely influenced by the North-eastern Atlantic. The English Channel, an epi-continental shallow sea with very strong tides, runs along 650 km of the French coast and 1100 km of the English coast. It is also a bio-geographical crossroad encompassing a much wider range of ecological conditions than other European seas. France's Atlantic coast north of the Gironde estuary is a succession of rocky and sandy shorelines, including a sizeable intertidal zone, a wide continental shelf, and two major estuaries (Loire and Gironde). South of the Gironde, the 260 km of coastline is low, sandy and straight, with a narrowing continental shelf further on South due to the presence of the Cape Breton canyon in the bathyal and abyssal zones. Interface between the continental and oceanic systems, these bordering seas--North Sea, English Channel and Atlantic Ocean--have been the subject of many recent research programmes (the European Mast-FLUXMANCHE and INTERREG programmes; the national coastal environment programme and the LITEAU programme in France), designed to improve comprehension of the functions, production, and dynamics of these seas as well as their future evolution. Given the many conflicting practices in these littoral zones, integrated coastal zone management appears to be essential in order to cope with both natural phenomena, such as the infilling of estuarine zones, cliff erosion, and rising sea levels, and chronic anthropogenic pressures, such as new harbour installations (container dikes, marinas), sea aggregate extraction for human constructions, and offshore wind mill farms. This article provides as complete an overview as possible of the research projects on these bordering seas, both those that have recently been accomplished and those that are currently in progress, in order to highlight the main characteristics of these ecosystems and to underline the future challenges for European marine research in terms of the integrated coastal zone management of these highly significant coastal zones. PMID:18061212

  3. Changes in physiological parameters and feeding behaviour of Atlantic salmon Salmo salar infected with sea lice Lepeophtheirus salmonis.

    PubMed

    Dawson, L H; Pike, A W; Houlihan, D F; McVicar, A H

    1999-01-29

    Atlantic salmon Salmo salar L. artificially infected with salmon lice Lepeophtheirus salmonis (Krøyer 1837) recovered from detrimental physiological changes and skin damage induced by preadult lice as the parasites matured. Growth rates of Atlantic salmon remained unaffected by lice infection, but food consumption decreased with increasing feeding and movement of the lice prior to and post-mating, correlating with the appearance of head erosions and detrimental changes in physiological integrity. Food consumption of the fish increased as the lice moulted to the adult stage and gravid female lice settled in a posterior location on the fish, subsequently reducing the impact of infection and allowing recovery of the skin damage. However, the impact of preadults was limited, as the decrease in food consumption of fish at 21 d post-infection had no effect on either the specific growth rate or condition factor of the fish. Furthermore, the intensity of lice infections at each of the sample days was not correlated with food consumption, specific growth rate or any of the haematological or physiological parameters measured, either before or after infection, indicating that lice intensity was independent of social dominance/subordinance. This work has provided the first evidence that infected fish can recover from the detrimental changes caused by lice infection, even when they are still infected with lice. If fish can survive the preadult stage of lice, then the mortal impact of lice infections is greatly reduced. PMID:10092971

  4. Validation of an ensemble modelling system for climate projections for the northwest European shelf seas

    NASA Astrophysics Data System (ADS)

    Tinker, Jonathan; Lowe, Jason; Holt, Jason; Pardaens, Anne; Wiltshire, Andy

    2015-11-01

    The aim of this study was to evaluate the performance of a modelling system used to represent the northwest European shelf seas. Variants of the coupled atmosphere-ocean global climate model, HadCM3, were run under conditions of historically varying concentrations of greenhouse gases and other radiatively active constituents. The atmospheric simulation for the shelf sea region and its surrounds was downscaled to finer spatial scales using a regional climate model (HadRM3); these simulations were then used to drive a river routing scheme (TRIP). Together, these provide the atmospheric, oceanic and riverine boundary conditions to drive the shelf seas model POLCOMS. Additionally, a shelf seas simulation was driven by the ERA-40 reanalysis in place of HadCM3. We compared the modelling systems output against a sea surface temperature satellite analysis product, a quality controlled ocean profile dataset and values of volume transport through particular ocean sections from the literature. In addition to assessing model drift with a pre-industrial control simulation the modelling system was evaluated against observations and the reanalysis driven simulation. We concluded that the modelling system provided an excellent (good) representation of the spatial patterns of temperature (salinity). It provided a good representation of the mean temperature climate, and a sufficient representation of the mean salinity and water column structure climate. The representation of the interannual variability was sufficient, while the overall shelf-wide circulation was qualitatively good. From this wide range of metrics we judged the modelling system fit for the purpose of providing centennial climate projections for the northwest European shelf seas.

  5. Using EUNIS habitat classification for benthic mapping in European seas: present concerns and future needs.

    PubMed

    Galparsoro, Ibon; Connor, David W; Borja, Angel; Aish, Annabelle; Amorim, Patricia; Bajjouk, Touria; Chambers, Caroline; Coggan, Roger; Dirberg, Guillaume; Ellwood, Helen; Evans, Douglas; Goodin, Kathleen L; Grehan, Anthony; Haldin, Jannica; Howell, Kerry; Jenkins, Chris; Michez, Noëmie; Mo, Giulia; Buhl-Mortensen, Pål; Pearce, Bryony; Populus, Jacques; Salomidi, Maria; Sánchez, Francisco; Serrano, Alberto; Shumchenia, Emily; Tempera, Fernando; Vasquez, Mickaël

    2012-12-01

    The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europe's seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification. PMID:23117202

  6. Using EUNIS habitat classification for benthic mapping in European seas: present concerns and future needs.

    TOXLINE Toxicology Bibliographic Information

    Galparsoro I; Connor DW; Borja A; Aish A; Amorim P; Bajjouk T; Chambers C; Coggan R; Dirberg G; Ellwood H; Evans D; Goodin KL; Grehan A; Haldin J; Howell K; Jenkins C; Michez N; Mo G; Buhl-Mortensen P; Pearce B; Populus J; Salomidi M; Sánchez F; Serrano A; Shumchenia E; Tempera F; Vasquez M

    2012-12-01

    The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europe's seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification.

  7. Synthesis of knowledge on marine biodiversity in European Seas: from census to sustainable management.

    PubMed

    Narayanaswamy, Bhavani E; Coll, Marta; Danovaro, Roberto; Davidson, Keith; Ojaveer, Henn; Renaud, Paul E

    2013-01-01

    The recently completed European Census of Marine Life, conducted within the framework of the global Census of Marine Life programme (2000-2010), markedly enhanced our understanding of marine biodiversity in European Seas, its importance within ecological systems, and the implications for human use. Here we undertake a synthesis of present knowledge of biodiversity in European Seas and identify remaining challenges that prevent sustainable management of marine biodiversity in one of the most exploited continents of the globe. Our analysis demonstrates that changes in faunal standing stock with depth depends on the size of the fauna, with macrofaunal abundance only declining with increasing water depth below 1000 m, whilst there was no obvious decrease in meiofauna with increasing depth. Species richness was highly variable for both deep water macro- and meio- fauna along latitudinal and longitudinal gradients. Nematode biodiversity decreased from the Atlantic into the Mediterranean whilst latitudinal related biodiversity patterns were similar for both faunal groups investigated, suggesting that the same environmental drivers were influencing the fauna. While climate change and habitat degradation are the most frequently implicated stressors affecting biodiversity throughout European Seas, quantitative understanding, both at individual and cumulative/synergistic level, of their influences are often lacking. Full identification and quantification of species, in even a single marine habitat, remains a distant goal, as we lack integrated data-sets to quantify these. While the importance of safeguarding marine biodiversity is recognised by policy makers, the lack of advanced understanding of species diversity and of a full survey of any single habitat raises huge challenges in quantifying change, and facilitating/prioritising habitat/ecosystem protection. Our study highlights a pressing requirement for more complete biodiversity surveys to be undertaken within contrasting habitats, together with investigations in biodiversity-ecosystem functioning links and identification of separate and synergistic/cumulative human-induced impacts on biodiversity. PMID:23527045

  8. Synthesis of Knowledge on Marine Biodiversity in European Seas: From Census to Sustainable Management

    PubMed Central

    Narayanaswamy, Bhavani E.

    2013-01-01

    The recently completed European Census of Marine Life, conducted within the framework of the global Census of Marine Life programme (2000–2010), markedly enhanced our understanding of marine biodiversity in European Seas, its importance within ecological systems, and the implications for human use. Here we undertake a synthesis of present knowledge of biodiversity in European Seas and identify remaining challenges that prevent sustainable management of marine biodiversity in one of the most exploited continents of the globe. Our analysis demonstrates that changes in faunal standing stock with depth depends on the size of the fauna, with macrofaunal abundance only declining with increasing water depth below 1000 m, whilst there was no obvious decrease in meiofauna with increasing depth. Species richness was highly variable for both deep water macro- and meio- fauna along latitudinal and longitudinal gradients. Nematode biodiversity decreased from the Atlantic into the Mediterranean whilst latitudinal related biodiversity patterns were similar for both faunal groups investigated, suggesting that the same environmental drivers were influencing the fauna. While climate change and habitat degradation are the most frequently implicated stressors affecting biodiversity throughout European Seas, quantitative understanding, both at individual and cumulative/synergistic level, of their influences are often lacking. Full identification and quantification of species, in even a single marine habitat, remains a distant goal, as we lack integrated data-sets to quantify these. While the importance of safeguarding marine biodiversity is recognised by policy makers, the lack of advanced understanding of species diversity and of a full survey of any single habitat raises huge challenges in quantifying change, and facilitating/prioritising habitat/ecosystem protection. Our study highlights a pressing requirement for more complete biodiversity surveys to be undertaken within contrasting habitats, together with investigations in biodiversity-ecosystem functioning links and identification of separate and synergistic/cumulative human-induced impacts on biodiversity. PMID:23527045

  9. THE FOUR NATIONS OF SALMON WORLD

    EPA Science Inventory

    The four nations of Salmon World have existed for 10,000 years. Since the end of the last Ice Age, salmon established naturally substantial populations and prospered in four large regions of the earth: (1) the European side of the North Atlantic; (2) the North American side of...

  10. SALMON: A WORLD AND HISTORICAL PERSPECTIVE

    EPA Science Inventory

    The four nations of Salmon World have existed for 10,000 years. Since the end of the last Ice Age, salmon established naturally substantial populations and prospered in four large regions of the earth: (1) the European side of the North Atlantic; (2) the North American side of...

  11. WILDERNESS SOCIETY'S SALMON STATUS DATA FOR CA, ID, OR, AND WA

    EPA Science Inventory

    The fish status layers show the historic distribution of freshwater habitat and current status of ten different species of anadromous fish: spring/summer chinook, fall chinook, winter chinook, sockeye salmon, chum salmon, coho salmon, pink salmon, sea-run cutthroat, summer steel...

  12. A comprehensive inventory of ship traffic exhaust emissions in the European sea areas in 2011

    NASA Astrophysics Data System (ADS)

    Jalkanen, J.-P.; Johansson, L.; Kukkonen, J.

    2016-01-01

    Emissions originating from ship traffic in European sea areas were modelled using the Ship Traffic Emission Assessment Model (STEAM), which uses Automatic Identification System data to describe ship traffic activity. We have estimated the emissions from ship traffic in the whole of Europe in 2011. We report the emission totals, the seasonal variation, the geographical distribution of emissions, and their disaggregation between various ship types and flag states. The total ship emissions of CO2, NOx, SOx, CO, and PM2.5 in Europe for year 2011 were estimated to be 121, 3.0, 1.2, 0.2, and 0.2 million tons, respectively. The emissions of CO2 from the Baltic Sea were evaluated to be more than a half (55 %) of the emissions of the North Sea shipping; the combined contribution of these two sea regions was almost as high (88 %) as the total emissions from ships in the Mediterranean. As expected, the shipping emissions of SOx were significantly lower in the SOx Emission Control Areas, compared with the corresponding values in the Mediterranean. Shipping in the Mediterranean Sea is responsible for 40 and 49 % of the European ship emitted CO2 and SOx emissions, respectively. In particular, this study reported significantly smaller emissions of NOx, SOx, and CO for shipping in the Mediterranean than the EMEP inventory; however, the reported PM2.5 emissions were in a fairly good agreement with the corresponding values reported by EMEP. The vessels registered to all EU member states are responsible for 55 % of the total CO2 emitted by ships in the study area. The vessels under the flags of convenience were responsible for 25 % of the total CO2 emissions.

  13. A comprehensive inventory of ship traffic exhaust emissions in the European sea areas in 2011

    NASA Astrophysics Data System (ADS)

    Jalkanen, J.-P.; Johansson, L.; Kukkonen, J.

    2015-03-01

    Emissions originated from ship traffic in European sea areas were modelled using the Ship Traffic Emission Assessment Model (STEAM), which uses Automatic Identification System data to describe ship traffic activity. We have estimated the emissions from ship traffic in the whole of Europe in 2011. We report the emission totals, the seasonal variation, the geographical distribution of emissions, and their disaggregation between various ship types and flag states. The total ship emissions of CO2, NOx, SOx, CO and PM2.5 in Europe for year 2011 were estimated to be 131, 2.9, 1.2, 0.2 and 0.3 million tons, respectively. The emissions of CO2 from Baltic Sea were evaluated to be more than a half (58%) of the emissions of the North Sea shipping; the combined contribution of these two sea regions was almost as high (96%) as the total emissions from ships in the Mediterranean. As expected, the shipping emissions of SOx were significantly lower in the SOx Emission Control Areas, compared with the corresponding values in the Mediterranean. Shipping in the Mediterranean Sea is responsible for 39 and 49% of the European ship emitted CO2 and SOx emissions, respectively. In particular, this study reported significantly smaller emissions of NOx, SOx and CO for shipping in the Mediterranean than the EMEP inventory; however, the reported PM2.5 emissions were in a fairly good agreement with the corresponding values reported by EMEP. The vessels registered to all EU member states are responsible for 55% of the total CO2 emitted by ships in the study area. The vessels under the flags of convenience were responsible for 25% of the total CO2 emissions.

  14. SeaDataNet: Pan-European infrastructure for ocean and marine data management

    NASA Astrophysics Data System (ADS)

    Fichaut, M.; Schaap, D.; Maudire, G.; Manzella, G. M. R.

    2012-04-01

    The overall objective of the SeaDataNet project is the upgrade the present SeaDataNet infrastructure into an operationally robust and state-of-the-art Pan-European infrastructure for providing up-to-date and high quality access to ocean and marine metadata, data and data products originating from data acquisition activities by all engaged coastal states, by setting, adopting and promoting common data management standards and by realising technical and semantic interoperability with other relevant data management systems and initiatives on behalf of science, environmental management, policy making, and economy. SeaDataNet is undertaken by the National Oceanographic Data Centres (NODCs), and marine information services of major research institutes, from 31 coastal states bordering the European seas, and also includes Satellite Data Centres, expert modelling centres and the international organisations IOC, ICES and EU-JRC in its network. Its 40 data centres are highly skilled and have been actively engaged in data management for many years and have the essential capabilities and facilities for data quality control, long term stewardship, retrieval and distribution. SeaDataNet undertakes activities to achieve data access and data products services that meet requirements of end-users and intermediate user communities, such as GMES Marine Core Services (e.g. MyOcean), establishing SeaDataNet as the core data management component of the EMODNet infrastructure and contributing on behalf of Europe to global portal initiatives, such as the IOC/IODE - Ocean Data Portal (ODP), and GEOSS. Moreover it aims to achieve INSPIRE compliance and to contribute to the INSPIRE process for developing implementing rules for oceanography. • As part of the SeaDataNet upgrading and capacity building, training courses will be organised aiming at data managers and technicians at the data centres. For the data managers it is important, that they learn to work with the upgraded common SeaDataNet formats and procedures and software tools for preparing and updating metadata, processing and quality control of data, and presentation of data in viewing services, and for production of data products. • SeaDataNet maintains and operates several discovery services with overviews of marine organisations in Europe and their engagement in marine research projects, managing large datasets, and data acquisition by research vessels and monitoring programmes for the European seas and global oceans: o European Directory of Marine Environmental Data (EDMED) (at present > 4300 entries from more than 600 data holding centres in Europe) is a comprehensive reference to the marine data and sample collections held within Europe providing marine scientists, engineers and policy makers with a simple discovery mechanism. It covers all marine environmental disciplines. This needs regular maintenance. o European Directory of Marine Environmental Research Projects (EDMERP) (at present > 2200 entries from more than 300 organisations in Europe) gives an overview of research projects relating to the marine environment, that are relevant in the context of data sets and data acquisition activities ( cruises, in situ monitoring networks, ..) that are covered in SeaDataNet. This needs regular updating, following activities by dataholding institutes for preparing metadata references for EDMED, EDIOS, CSR and CDI. o Cruise Summary Reports (CSR) directory (at present > 43000 entries) provides a coarse-grained inventory for tracking oceanographic data collected by research vessels. o European Directory of Oceanographic Observing Systems (EDIOS) (at present > 10000 entries) is an initiative of EuroGOOS and gives an overview of the ocean measuring and monitoring systems operated by European countries. • European Directory of Marine Organisations (EDMO) (at present > 2000 entries) contains the contact information and activity profiles for the organisations whose data and activities are described by the discovery services. • Common Vocabularies (at present > 120000 terms in > 100 lists), covering a broad spectrum of ocean and marine disciplines. The common terms are used to mark up metadata, data and data products in a consistent and coherent way. Governance is regulated by an international board. • Common Data Index (CDI) data discovery and access service: SeaDataNet provides online unified access to distributed datasets via its portal website to the vast resources of marine and ocean datasets, managed by all the connected distributed data centres. The Common Data Index (CDI) service is the key Discovery and Delivery service. It enables users to have a detailed insight of the availability and geographical distribution of marine data, archived at the connected data centres, and it provides the means for downloading datasets in common formats via a transaction mechanism.

  15. Geo-Seas: delivering harmonised marine geoscience data on a European scale

    NASA Astrophysics Data System (ADS)

    Glaves, Helen; Schaap, Dick

    2013-04-01

    A large amount of both raw and interpreted marine geoscience data is held by an array of European organisations but its discovery and re-use can be very difficult. The data is stored in a variety of different formats and a range of different nomenclatures, scales and co-ordinate systems are used at the organisational, national and international level. This lack of standardisation hinders the user's ability to locate and access these datasets or to use them in an integrated way. The Geo-Seas project, an EU funded Framework 7 initiative, has addressed these barriers to the re-use of marine geological and geophysical data through the development of an on-line data discovery and access service (http://www.geo-seas.eu). It allows the end user to identify, evaluate and download a range of standardised marine geoscience data sets from 26 federated data centres across 17 European maritime countries. The dedicated portal, which currently provides access to more than 100,000 datasets, has been developed by adopting and adapting the existing technologies, standards and methodologies developed by the SeaDataNet project for the management and delivery of oceanographic data. Through the re-use of this pre-existing architecture including the associated common standards and vocabularies a joint infrastructure for both marine geoscientific and oceanographic data has been created which supports the development of multidisciplinary ocean science. The Geo-Seas project has also brought together and incorporated the metadata services developed by previous EU-funded projects such as EUSeaSed and SEISCAN. The formats of this legacy metadata have not only been used as the basis for developing the Geo-Seas metadatabase but it has also lead to these pre-existing metadata catalogues being upgraded to current international standards. The Geo-Seas initiative has lead to a major improvement in the availability of standardised marine geoscientific data throughout Europe allowing end users better access to marine geoscience data and interpretations for a range of applications. The delivery of these harmonised raw and interpreted data is also contributing to the development of a more multidisciplinary approach to marine research through increased interoperability with data types from other domains within the marine environment. This approach is also leading to the development of collaborative links with other European projects and initiatives as well as with the wider marine geoscientific and oceanographic communities including projects and organisations in both the USA and Australia.

  16. EMODNet Bathymetry - building and providing a high resolution digital bathymetry for European seas

    NASA Astrophysics Data System (ADS)

    Schaap, Dick M. A.

    2015-04-01

    Access to marine data is a key issue for the implementation of the EU Marine Strategy Framework Directive (MSFD). The EU communication 'Marine Knowledge 2020' underpins the importance of data availability and harmonising access to marine data from different sources. The European Marine Observation and Data Network (EMODnet) is a long term marine data initiative from the European Commission Directorate-General for Maritime Affairs and Fisheries (DG MARE) underpinning the Marine Knowledge 2020 strategy. EMODnet is a consortium of organisations assembling European marine data, data products and metadata from diverse sources in a uniform way. The main purpose of EMODnet is to unlock fragmented and hidden marine data resources and to make these available to individuals and organisations (public and private), and to facilitate investment in sustainable coastal and offshore activities through improved access to quality-assured, standardised and harmonised marine data which are interoperable and free of restrictions on use. The EMODnet data infrastructure is developed through a stepwise approach in three major phases. Currently EMODnet is in the 2nd phase of development with seven sub-portals in operation that provide access to marine data from the following themes: bathymetry, geology, physics, chemistry, biology, seabed habitats and human activities. EMODnet development is a dynamic process so new data, products and functionality are added regularly while portals are continuesly improved to make the service more fit for purpose and user friendly with the help of users and stakeholders. The EMODnet Bathymetry project develops and publishes Digital Terrain Models (DTM) for the European seas. These are produced from survey and aggregated data sets, that are indexed with metadata by adopting the SeaDataNet Common Data Index (CDI) data discovery and access service and the SeaDataNet Sextant data products catalogue service. The new EMODnet DTM will have a resolution of 1/8 arcminute * 1/8 arcminute and will cover all European sea regions. Use is made of available and gathered surveys and already more than 10.000 surveys have been indexed by 24 European data providers and originating from more than 120 organisations. Also use is made of composite DTMs as generated and maintained by several data providers for their areas of interest. Already 44 composite DTMs are included in the Sextant data products catalogue. For areas without coverage use is made of the latest global DTM of GEBCO who is partner in the EMODnet Bathymetry project. In return GEBCO integrates the EMODnet DTM to achieve an enriched and better result. The catalogue services and the generated EMODnet can be queried and browsed at the dedicated EMODnet Bathymetry portal which also provides a versatile DTM viewing service with many relevant map layers and functions for retrieving. Activities are underway for further refinement following user feedback. The EMODnet DTM is publicly available for downloading in various formats. The presentation will highlight key details of EMODnet Bathymetry project, its portal and views on the new EMODNet Digital Bathymetry for European seas as to be released early 2015.

  17. Application of the CARLIT index along a biogeographical gradient in the Alboran Sea (European Coast).

    PubMed

    Bermejo, Ricardo; de la Fuente, Gina; Vergara, Juan J; Hernández, Ignacio

    2013-07-15

    An index, based on littoral communities assemblages (CARLIT), was applied to assess the ecological status of Northwestern Mediterranean coastal waters, following the requirements of the European Water Framework Directive. The biogeographical particularities of the Alboran Sea suggested a reassessment of this index, and that was the main objective of this work. Due to these biogeographical particularities, two regions were proposed in the studied region, with new reference conditions for each region. Subsequently, by means of a multivariate analysis, littoral community abundances and the CARLIT index were compared with factors related to geomorphology, biogeography and anthropogenic pressures. Overall, the biogeographical component determined the distribution of littoral communities. In contrast, the ecological status yielded by the index only was significantly related to anthropogenic pressures. The results pointed out that the reassessment of the CARLIT index was suitable to evaluate the ecological status of the Alboran Sea. PMID:23673205

  18. Pile-Driving Noise Impairs Antipredator Behavior of the European Sea Bass Dicentrarchus labrax.

    PubMed

    Everley, Kirsty A; Radford, Andrew N; Simpson, Stephen D

    2016-01-01

    In an increasingly industrialized world, man-made noise is changing the underwater acoustic environment. The effects of anthropogenic noise on marine ecosystems are not yet fully understood despite important implications for science and policy, in particular with respect to investment in offshore renewable energy. In this study, a traditional looming-stimulus experimental setup was used to investigate the acute effects of pile-driving noise on the antipredator response of European sea bass (Dicentrarchus labrax). Playback of pile-driving noise was found to impair significantly the startle response of individuals, which potentially translates to an increased likelihood of being captured by predators in natural conditions. PMID:26610969

  19. Modelling of European hake nurseries in the Mediterranean Sea: An ecological niche approach

    NASA Astrophysics Data System (ADS)

    Druon, Jean-Noël; Fiorentino, Fabio; Murenu, Matteo; Knittweis, Leyla; Colloca, Francesco; Osio, Chato; Mérigot, Bastien; Garofalo, Germana; Mannini, Alessandro; Jadaud, Angélique; Sbrana, Mario; Scarcella, Giuseppe; Tserpes, George; Peristeraki, Panagiota; Carlucci, Roberto; Heikkonen, Jukka

    2015-01-01

    An ecological niche modelling (ENM) approach was developed to model the suitable habitat for the 0-group European hake, Merluccius merluccius L., 1758, in the Mediterranean Sea. The ENM was built combining knowledge on biological traits of hake recruits (e.g. growth, settlement, mobility and feeding strategy) with patterns of selected ecological variables (chlorophyll-a fronts and concentration, bottom depth, sea bottom current and temperature) to highlight favourable nursery habitats. The results show that hake nurseries require stable bottom temperature (11.8-15.0 °C), low bottom currents (<0.034 m s-1) and a frequent occurrence of productive fronts in low chlorophyll-a areas (0.1-0.9 mg m-3) to support a successful recruitment. These conditions mostly occur recurrently in outer shelf and shelf break areas. The prediction explains the relative balance between biotic and abiotic drivers of hake recruitment in the Mediterranean Sea and the primary role of unfavourable environmental conditions on low recruitment in specific years (i.e. 2011). The ENM outputs particularly agree spatially with biomass data of recruits, although processes such as fishing and natural mortality are not accounted for. The seasonal mapping of suitable habitats provides information on potential nurseries and recruitment carrying capacity which are relevant for spatial fisheries management of hake in the Mediterranean Sea.

  20. Tides, sea-level rise and tidal power extraction on the European shelf

    NASA Astrophysics Data System (ADS)

    Ward, Sophie L.; Green, J. A. Mattias; Pelling, Holly E.

    2012-08-01

    An established numerical tidal model has been used to investigate the impact of various sea-level rise (SLR) scenarios, as well as SLR in combination with large-scale tidal power plants on European shelf tidal dynamics. Even moderate and realistic levels of future SLR are shown to have significant impacts on the tidal dynamics of the area. These changes are further enhanced when SLR and tidal power plants are considered in combination, resulting in changes to tidal amplitudes, currents and associated tidal dissipation and bed shear stresses. Sea-level rise is the dominant influence on any far-field impacts, whereas tidal power plants are shown to have the prevailing influence over any changes close to the point of energy extraction. The spatial extent of the impacts of energy extraction is shown to be affected by the sea level when more than one tidal power plant in the Irish Sea was considered. Different ways to implement SLR in the model are also discussed and shown to be of great significance for the response of the tides.

  1. EMODNet Hydrography - Seabed Mapping - Developing a higher resolution digital bathymetry for the European seas

    NASA Astrophysics Data System (ADS)

    Schaap, Dick M. A.; Moussat, Eric

    2013-04-01

    In December 2007 the European Parliament and Council adopted the Marine Strategy Framework Directive (MSFD) which aims to achieve environmentally healthy marine waters by 2020. This Directive includes an initiative for an overarching European Marine Observation and Data Network (EMODNet). The EMODNet Hydrography - Seabed Mapping projects made good progress in developing the EMODNet Hydrography portal to provide overview and access to available bathymetric survey datasets and to generate an harmonised digital bathymetry for Europe's sea basins. Up till end 2012 more than 8400 bathymetric survey datasets, managed by 14 data centres from 9 countries and originated from 118 institutes, have been gathered and populated in the EMODNet Hydrography Data Discovery and Access service, adopting SeaDataNet standards. These datasets have been used as input for analysing and generating the EMODNet digital terrain model (DTM), so far for the following sea basins: • the Greater North Sea, including the Kattegat • the English Channel and Celtic Seas • Western and Central Mediterranean Sea and Ionian Sea • Bay of Biscay, Iberian coast and North-East Atlantic • Adriatic Sea • Aegean - Levantine Sea (Eastern Mediterranean). • Azores - Madeira EEZ The Hydrography Viewing service gives users wide functionality for viewing and downloading the EMODNet digital bathymetry: • water depth in gridded form on a DTM grid of a quarter a minute of longitude and latitude • option to view QC parameters of individual DTM cells and references to source data • option to download DTM tiles in different formats: ESRI ASCII, XYZ, CSV, NetCDF (CF), GeoTiff and SD for Fledermaus 3 D viewer software • option for users to create their Personal Layer and to upload multibeam survey ASCII datasets for automatic processing into personal DTMs following the EMODNet standards The NetCDF (CF) DTM files are fit for use in a special 3D Viewer software package which is based on the existing open source NASA World Wind JSK application. It has been developed in the frame of the EU Geo-Seas project (another sibling of SeaDataNet for marine geological and geophysical data) and is freely available. The 3D viewer also supports the ingestion of WMS overlay maps. The EMODNet consortium is actively seeking cooperation with Hydrographic Offices, research institutes, authorities and private organisations for additional data sets (single and multibeam surveys, sounding tracks, composite products) to contribute to an even better geographical coverage. These datasets will be used for upgrading and extending the EMODNet regional Digital Terrain Models (DTM). The datasets themselves are not distributed but described in the metadata service, giving clear information about the background survey data used for the DTM, their access restrictions, originators and distributors and facilitating requests by users to originators. This way the portal provides originators of bathymetric data sets an attractive shop window for promoting their data sets to potential users, without losing control. The EMODNet Hydrography Consortium consists of MARIS (NL), ATLIS (NL), IFREMER (FR), SHOM (FR), IEO (ES), GSI (IE), NERC-NOCS (UK), OGS (IT), HCMR (GR), and UNEP/GRID-Arendal (NO) with associate partners CNR-ISMAR (IT), OGS-RIMA (IT), IHPT (PT), and LNEG (PT). Website: http://www.emodnet-hydrography.eu

  2. 75 FR 32378 - Fisheries of the Exclusive Economic Zone off Alaska; Chinook Salmon Bycatch Data Collection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... Alaska; Chinook Salmon Bycatch Data Collection; Workshop for Industry Review of Data Forms AGENCY... Bering Sea pollock trawl industry on data forms for evaluating the Bering Sea Chinook salmon bycatch... knowledgeable about industry plans and operations for avoiding Chinook salmon bycatch. DATES: The...

  3. Piling underwater noise impact on migrating salmon fish during Lithuanian LNG terminal construction (Curonian Lagoon, Eastern Baltic Sea Coast).

    PubMed

    Bagočius, Donatas

    2015-03-15

    Development of human activities in the Klaipėda strait generates a wide spectrum of underwater noise. In the fall of 2013, at the liquid natural gas terminal construction site in the shallow Curonian Lagoon area, an assessment of possible negative impacts on migrating salmon fish caused by pile driving noise was made. It is well known that impact hammer pile driving generates pulses with extremely high underwater noise levels. The obtained results proved that the pile hammering into the lagoon bottom generated pulses with a sound exposure level of 218 dB re 1 μPa(2) s @1m thus posing a risk to the migrating fish. PMID:25599630

  4. Updating control of puberty in male European sea bass: A holistic approach.

    PubMed

    Carrillo, Manuel; Espigares, Felipe; Felip, Alicia; Escobar, Sebastian; Molés, Gregorio; Rodríguez, Rafael; Alvarado, Maria Victoria; Gómez, Ana; Zanuy, Silvia

    2015-09-15

    Puberty is the process by which an immature animal acquires the ability to reproduce for the first time; its onset occurs soon after sexual differentiation and is characterized by the beginning of gametogenesis in both sexes. Here we present new insights on when and how the onset of puberty occurs in male European sea bass, its dependence on reaching a critical size, and how it can be controlled by photoperiod, revealing the existence of a photolabile period with important applications in aquaculture. Regarding size, apparently only European sea bass above a certain size threshold attain the ability to carry out gametogenesis during their first year of life, while their smaller counterparts fail to do so. This could imply that fish need to achieve an optimal threshold of hormone production, particularly from the kisspeptin/Gnrh/Gth systems, in order to initiate and conclude puberty. However, a long-term restricted feeding regime during the second year of life did not prevent the onset of puberty, thus suggesting that the fish are able to maintain the reproductive function, even at the expense of other functions. Finally, the study of daily hormonal rhythms under different photoperiod regimes revealed the equivalence between their core values and those of seasonal rhythms, in such a way that the daily rhythms could be considered as the functional units of the seasonal rhythms. PMID:26172577

  5. The origins of Atlantic salmon (Salmo salar L.) recolonizing the River Mersey in northwest England.

    PubMed

    Ikediashi, Charles; Billington, Sam; Stevens, Jamie R

    2012-10-01

    By the 1950s, pollution had extirpated Atlantic salmon in the river Mersey in northwest England. During the 1970s, an extensive restoration program began and in 2001, an adult salmon was caught ascending the river. Subsequently, a fish trap was installed and additional adults are now routinely sampled. In this study, we have genotyped 138 adults and one juvenile salmon at 14 microsatellite loci from across this time period (2001-2011). We have used assignment analysis with a recently compiled pan-European microsatellite baseline to identify their most probable region of origin. Fish entering the Mersey appear to originate from multiple sources, with the greatest proportion (45-60%, dependent on methodology) assigning to rivers in the geographical region just north of the Mersey, which includes Northwest England and the Solway Firth. Substantial numbers also appear to originate from rivers in western Scotland, and from rivers in Wales and Southwest England; nonetheless, the number of fish originating from proximal rivers to the west of the Mersey was lower than expected. Our results suggest that the majority of salmon sampled in the Mersey are straying in a southerly direction, in accordance with the predominantly clockwise gyre present in the eastern Irish Sea. Our findings highlight the complementary roles of improving water quality and in-river navigability in restoring salmon to a river and underlines further the potential benefits of restoration over stocking as a long-term solution to declining fish stocks. PMID:23145338

  6. ["Non-aging" pearl oyster and aging salmon (about lack of basis for production of medicines based on European pearl oyster Margaritifera margaritifera)].

    PubMed

    Popov, I Iu

    2009-01-01

    The article focuses on disproof of the claim by Valery Ziuganov, that pearl oyster infection prolongs the lifespan of salmon and that pearl oyster can be used as a source of medicine. His activity on the production of medicine pretending to care cancer and senescence based on the gills of salmon infected by pearl oyster is blamed. The data on pearl oyster and salmon biology are presented: Atlantic salmon survives after spawning irrespectively of oyster infection. The problem of shady medicines production is discussed. It was shown that even Academic editions and formal attributes of the belonging to scientific community do not provide a necessary barrier to frauds in this field. Adaptationist program popularity contributes such a situation, because it provides "grounds" for any speculation concerning advantages of any biological process. PMID:20405726

  7. Effects of parasites from salmon farms on productivity of wild salmon

    PubMed Central

    Krkošek, Martin; Connors, Brendan M.; Morton, Alexandra; Lewis, Mark A.; Dill, Lawrence M.; Hilborn, Ray

    2011-01-01

    The ecological risks of salmon aquaculture have motivated changes to management and policy designed to protect wild salmon populations and habitats in several countries. In Canada, much attention has focused on outbreaks of parasitic copepods, sea lice (Lepeophtheirus salmonis), on farmed and wild salmon in the Broughton Archipelago, British Columbia. Several recent studies have reached contradictory conclusions on whether the spread of lice from salmon farms affects the productivity of sympatric wild salmon populations. We analyzed recently available sea lice data on farms and spawner–recruit data for pink (Oncorhynchus gorbuscha) and coho (Oncorhynchus kisutch) salmon populations in the Broughton Archipelago and nearby regions where farms are not present. Our results show that sea lice abundance on farms is negatively associated with productivity of both pink and coho salmon in the Broughton Archipelago. These results reconcile the contradictory findings of previous studies and suggest that management and policy measures designed to protect wild salmon from sea lice should yield conservation and fishery benefits. PMID:21873246

  8. European sea bass genome and its variation provide insights into adaptation to euryhalinity and speciation.

    PubMed

    Tine, Mbaye; Kuhl, Heiner; Gagnaire, Pierre-Alexandre; Louro, Bruno; Desmarais, Erick; Martins, Rute S T; Hecht, Jochen; Knaust, Florian; Belkhir, Khalid; Klages, Sven; Dieterich, Roland; Stueber, Kurt; Piferrer, Francesc; Guinand, Bruno; Bierne, Nicolas; Volckaert, Filip A M; Bargelloni, Luca; Power, Deborah M; Bonhomme, François; Canario, Adelino V M; Reinhardt, Richard

    2014-01-01

    The European sea bass (Dicentrarchus labrax) is a temperate-zone euryhaline teleost of prime importance for aquaculture and fisheries. This species is subdivided into two naturally hybridizing lineages, one inhabiting the north-eastern Atlantic Ocean and the other the Mediterranean and Black seas. Here we provide a high-quality chromosome-scale assembly of its genome that shows a high degree of synteny with the more highly derived teleosts. We find expansions of gene families specifically associated with ion and water regulation, highlighting adaptation to variation in salinity. We further generate a genome-wide variation map through RAD-sequencing of Atlantic and Mediterranean populations. We show that variation in local recombination rates strongly influences the genomic landscape of diversity within and differentiation between lineages. Comparing predictions of alternative demographic models to the joint allele-frequency spectrum indicates that genomic islands of differentiation between sea bass lineages were generated by varying rates of introgression across the genome following a period of geographical isolation. PMID:25534655

  9. European sea bass genome and its variation provide insights into adaptation to euryhalinity and speciation

    PubMed Central

    Tine, Mbaye; Kuhl, Heiner; Gagnaire, Pierre-Alexandre; Louro, Bruno; Desmarais, Erick; Martins, Rute S.T.; Hecht, Jochen; Knaust, Florian; Belkhir, Khalid; Klages, Sven; Dieterich, Roland; Stueber, Kurt; Piferrer, Francesc; Guinand, Bruno; Bierne, Nicolas; Volckaert, Filip A. M.; Bargelloni, Luca; Power, Deborah M.; Bonhomme, François; Canario, Adelino V. M.; Reinhardt, Richard

    2014-01-01

    The European sea bass (Dicentrarchus labrax) is a temperate-zone euryhaline teleost of prime importance for aquaculture and fisheries. This species is subdivided into two naturally hybridizing lineages, one inhabiting the north-eastern Atlantic Ocean and the other the Mediterranean and Black seas. Here we provide a high-quality chromosome-scale assembly of its genome that shows a high degree of synteny with the more highly derived teleosts. We find expansions of gene families specifically associated with ion and water regulation, highlighting adaptation to variation in salinity. We further generate a genome-wide variation map through RAD-sequencing of Atlantic and Mediterranean populations. We show that variation in local recombination rates strongly influences the genomic landscape of diversity within and differentiation between lineages. Comparing predictions of alternative demographic models to the joint allele-frequency spectrum indicates that genomic islands of differentiation between sea bass lineages were generated by varying rates of introgression across the genome following a period of geographical isolation. PMID:25534655

  10. Differential response of continental stock complexes of Atlantic salmon (Salmo salar) to the Atlantic Multidecadal Oscillation

    NASA Astrophysics Data System (ADS)

    Friedland, Kevin D.; Shank, Burton V.; Todd, Christopher D.; McGinnity, Philip; Nye, Janet A.

    2014-05-01

    Atlantic salmon, Salmo salar, in the North Atlantic are managed as a set of population complexes distributed in North America and Europe. In recent years, these complexes have experienced reduced marine survival and many populations within the complexes are at risk, especially those at the southern ends of the species amphi-Atlantic range. Atlantic salmon is an anadromous fish dividing its life history between residence in freshwater and the marine environment. The freshwater portion of the life history includes spawning and the rearing of juveniles where in-river production has tended to be relatively stable, whereas the first year at sea, termed the post-smolt year, is characterized by more variable rates of mortality. Although their habitats are widely separated geographically along the North Atlantic seaboards, strong recruitment coherence exists between North American and European stock complexes. This recruitment coherence is correlated with ocean temperature variation associated with the Atlantic Multidecadal Oscillation (AMO). The North Atlantic Oscillation (NAO) appears to be relatively unimportant as a driver of salmon abundance. The mechanism determining the link between AMO-related thermal variation and abundance appears to differ fundamentally for the two continental stock groupings. Whereas ocean climate variability during the first springtime months of juvenile salmon migration to sea appears to be important to the survival of North American stocks, summer climate variation appears to be central to adult recruitment variation for European stocks. This contrast in seasonal effects appears to be related to the varying roles of predation pressure and size-related mortality on the continental stock complexes. The anticipated warming due to global climate change will impose thermal conditions on salmon populations outside historical context and challenge the ability of many populations to persist.

  11. Competition between Asian pink salmon (Oncorhynchus gorbuscha) and Alaskan sockeye salmon (O. nerka) in the North Pacific Ocean

    USGS Publications Warehouse

    Ruggerone, G.T.; Zimmermann, M.; Myers, K.W.; Nielsen, J.L.; Rogers, D.E.

    2003-01-01

    The importance of interspecific competition as a mechanism regulating population abundance in offshore marine communities is largely unknown. We evaluated offshore competition between Asian pink salmon and Bristol Bay (Alaska) sockeye salmon, which intermingle in the North Pacific Ocean and Bering Sea, using the unique biennial abundance cycle of Asian pink salmon from 1955 to 2000. Sockeye salmon growth during the second and third growing seasons at sea, as determined by scale measurements, declined significantly in odd-numbered years, corresponding to years when Asian pink salmon are most abundant. Bristol Bay sockeye salmon do not interact with Asian pink salmon during their first summer and fall seasons and no difference in first year scale growth was detected. The interaction with odd-year pink salmon led to significantly smaller size at age of adult sockeye salmon, especially among younger female salmon. Examination of sockeye salmon smolt to adult survival rates during 1977-97 indicated that smolts entering the ocean during even-numbered years and interacting with abundant odd-year pink salmon during the following year experienced 26% (age-2 smolt) to 45% (age-1 smolt) lower survival compared with smolts migrating during odd-numbered years. Adult sockeye salmon returning to Bristol Bay from even-year smolt migrations were 22% less abundant (reduced by 5.9 million fish per year) compared with returns from odd-year migrations. The greatest reduction in adult returns occurred among adults spending 2 compared with 3 years at sea. Our new evidence for interspecific competition highlights the need for multispecies, international management of salmon production, including salmon released from hatcheries into the ocean.

  12. The impact of future sea-level rise on the European Shelf tides

    NASA Astrophysics Data System (ADS)

    Pickering, M. D.; Wells, N. C.; Horsburgh, K. J.; Green, J. A. M.

    2012-03-01

    This paper investigates the effect of future sea-level rise (SLR) on the tides of the northwest European Continental Shelf. The European shelf tide is dominated by semidiurnal constituents. This study therefore focuses primarily on the changes in the M2 tidal constituent and the spring and neap tidal conditions. The validated operational Dutch Continental Shelf Model is run for the present day sea-level as well as 2 and 10 m SLR scenarios. The M2 tidal amplitude responds to SLR in a spatially non-uniform manner, with substantial amplitude increases and decreases in both scenarios. The M2 tidal response is non-linear between 2 and 10 m with respect to SLR, particularly in the North Sea. Under the 2 m SLR scenario the M2 constituent is particularly responsive in the resonant areas of the Bristol Channel and Gulf of St. Malo (with large amplitude decreases) and in the southeastern German Bight and Dutch Wadden Sea (with large amplitude increases). Changes in the spring tide are generally greater still than those in the M2 or neap tides. With 2 m SLR the spring tidal range increases up to 35 cm at Cuxhaven and decreases up to -49 cm at St. Malo. Additionally the changes in the shallow water tides are larger than expected. With SLR the depth, wave speed and wave length (tidal resonance characteristics) are increased causing changes in near resonant areas. In expansive shallow areas SLR causes reduced energy dissipation by bottom friction. Combined these mechanisms result in the migration of the amphidromes and complex patterns of non-linear change in the tide with SLR. Despite the significant uncertainty associated with the rate of SLR over the next century, substantial alterations to tidal characteristics can be expected under a high end SLR scenario. Contrary to existing studies this paper highlights the importance of considering the modification of the tides by future SLR. These substantial future changes in the tides could have wide reaching implications; including for example, correctly calculating design level requirements for flood defences, the availability of tidal renewable energy and dredging requirements.

  13. Chl a trends in European seas estimated using ocean-colour products

    NASA Astrophysics Data System (ADS)

    Coppini, G.; Lyubarstev, V.; Pinardi, N.; Colella, S.; Santoleri, R.; Christiansen, T.

    2012-03-01

    Ocean-colour remote-sensing products have been used to estimate Chl a trends in European seas. This work aims to develop a new indicator based on ocean-colour data for the European Environment Agency (EEA). The new indicator, called CSI023(+), produced from satellite ocean-colour products from the MyOcean Marine Core Service (www.myocean.eu) has been defined and calculated. CSI023 (+) is intended to complement the EEA CSI023 (Core Set of Indicators n.23) indicator for eutrophication, which is based on chlorophyll a (Chl a) in-situ observations. Validation of ocean-colour products has been carried out through comparison with observations of the Eionet EEA database, and we believe that such validation should continue in the future, perhaps with a dedicated data-collection exercise. Ocean colour has a much higher spatial and temporal resolution than the in-situ observations. The ocean-colour observations, however, are based on indirect measurements of the optical properties of the ocean, which are transformed to Chl a using an appropriate algorithm. This algorithm can either be a global algorithm that reproduces the average global Chl a concentrations well or one that is adjusted to specific regional conditions. In our analysis we have used both global and regional (adjusted to specific regional Mediterranean conditions) ocean-colour products, but the results highlight the fact that regional products produced with regional algorithms are recommended for the future. This work proposes a methodology for analysing trends comparable to the method EEA uses for its CSI23 indicator. Analysis has revealed the potential of ocean colour as a CSI023(+) indicator: large-scale, and in some cases even local-scale, changes appear to be captured by the satellite images even though in general the ocean-colour products underestimate the Chl a values. CSI023(+) shows, in the period 1998-2009, decreasing Chl a concentrations throughout the Black Sea, in the Eastern Mediterranean, in the southern part of the Western Mediterranean, in the English Channel and in the north part of the North Sea, whereas large areas with increasing trends are observed in the Bay of Biscay, in the North-East Atlantic regions of Ireland and the UK, in the northern part of the North Sea, in the Kattegat and in the Baltic. Specific analysis has been performed in the Mediterranean and the Black Sea: we first defined Chl a areas and then calculated the CSI023(+) for each of the Chl a areas. This last analysis reveals that about 80 % of Chl a areas do not show significant trends; increasing significant Chl a trends were detected in 3 Chl a areas in the Black Sea and 32 Chl a areas in the Mediterranean. Decreasing significant trends were detected in 6 Chl a areas in the Mediterranean and 2 Chl a areas in the Black Sea.

  14. Characterization of the annual regulation of reproductive and immune parameters on the testis of European sea bass.

    PubMed

    Valero, Yulema; Sánchez-Hernández, Miriam; García-Alcázar, Alicia; García-Ayala, Alfonsa; Cuesta, Alberto; Chaves-Pozo, Elena

    2015-10-01

    The European sea bass, Dicentrarchus labrax L., is a seasonal gonochoristic species, the males of which are generally mature during their second year of life. It has been demonstrated that cytokines and immune cells play a key role in the testicular development. This reproductive-immune interaction might be very important in the sea bass since several pathogens are able to colonise the gonad and persist in this tissue, altering further reproductive functions and spreading disease. This study aims to investigate the reproductive cycle of 1-year European sea bass males by analysing cell proliferation and apoptosis and the expression profile of some reproductive and immune-related genes in the testis, as well as the serum sex steroid levels. Our data demonstrate that, in 1-year-old European sea bass males, the testis undergoes the spermatogenesis process and that the reproductive and immune parameters analysed varied during the reproductive cycle. In the testis, the highest proliferative rates were recorded at the spermatogenesis stage, while the highest apoptotic rates were recorded at the spawning stage. We have also analysed, for the first time in European sea bass males, the serum levels of 17β-estradiol (E2) and dihydrotestosterone and the gene expression profile of the enzymes implied in their production, determining that at least E2 might be involved in the regulation of the reproductive cycle. Some immune relevant genes, including cytokines, lymphocyte receptors, and anti-viral and anti-bacterial molecules were detected in the testis of naïve European sea bass specimens, and their expression profile was related to the stages of the reproductive cycle, suggesting an important role for the defence of the reproductive tissues. PMID:25896883

  15. The spatial data infrastructure for the European Seas Observatory Network (ESONET)

    NASA Astrophysics Data System (ADS)

    Huber, Robert; Diepenbroek, Michael

    2010-05-01

    ESONET is a Multidisciplinary European Network of Excellence (NoE) in which scientists and engineers from 50 partners and 14 countries cooperate in building the infrastructure for a lasting integration of research and development in deep sea observatories in Europe. This NoE aims to develop strong links between regional nodes of a European network of sub sea observatories and to promote multidiciplinarity and transnationality within each node. Essential for these goals is the provision of an effective data and knowledge infrastructure for both, management and archiving of observatory data as well as knowledge and data sharing among network participants. The ESONET data infrastructure roughly consists of four major components: data policies a common agreement on the data management procedures and prerequisites, data acquisition technologies serve to collect data directly from ESONET observatories, data archives care for long term data management of collected ESONET data and data integration and portal tools which ensure harmonisation of collected data and allow access to the data in a common way. Most critical for ESONET was the development of a spatial data infrastructure (SDI) by using standardised protocols to directly access observatory data in its spatial and temporal context. The ESONET SDI provides means to either access data in quasi real time or harvest locally stored data in order to transfer it to a long term data archive. ESONET SDI largely builds upon the OGC Sensor Web Enablement (SWE) suite of standards. Among those, the Sensor Observation Service (SOS), the Observations & Measurements (O&M), Sensor Markup Language (SensorML) are especially important for the integration of observatory data as well as for the contribution of ESONET data to GEOSS.

  16. Dietary carbohydrate and lipid source affect cholesterol metabolism of European sea bass (Dicentrarchus labrax) juveniles.

    PubMed

    Castro, Carolina; Corraze, Geneviève; Pérez-Jiménez, Amalia; Larroquet, Laurence; Cluzeaud, Marianne; Panserat, Stéphane; Oliva-Teles, Aires

    2015-10-28

    Plant feedstuffs (PF) are rich in carbohydrates, which may interact with lipid metabolism. Thus, when considering dietary replacement of fishery by-products with PF, knowledge is needed on how dietary lipid source (LS) and carbohydrates affect lipid metabolism and other metabolic pathways. For that purpose, a 73-d growth trial was performed with European sea bass juveniles (IBW 74 g) fed four diets differing in LS (fish oil (FO) or a blend of vegetable oils (VO)) and carbohydrate content (0 % (CH-) or 20 % (CH+) gelatinised starch). At the end of the trial no differences among diets were observed on growth and feed utilisation. Protein efficiency ratio was, however, higher in the CH+ groups. Muscle and liver fatty acid profiles reflected the dietary LS. Dietary carbohydrate promoted higher plasma cholesterol and phospholipids (PL), whole-body and hepatic (mainly 16 : 0) lipids and increased muscular and hepatic glycogen. Except for PL, which were higher in the FO groups, no major alterations between FO and VO groups were observed on plasma metabolites (glucose, TAG, cholesterol, PL), liver and muscle glycogen, and lipid and cholesterol contents. Activities of glucose-6-phosphate dehydrogenase and malic enzyme - lipogenesis-related enzymes - increased with carbohydrate intake. Hepatic expression of genes involved in cholesterol metabolism was up-regulated with carbohydrate (HMGCR and CYP3A27) and VO (HMGCR and CYP51A1) intake. No dietary regulation of long-chain PUFA biosynthesis at the transcriptional level was observed. Overall, very few interactions between dietary carbohydrates and LS were observed. However, important insights on the direct relation between dietary carbohydrate and the cholesterol biosynthetic pathway in European sea bass were demonstrated. PMID:26306559

  17. First evidence of European eels exiting the Mediterranean Sea during their spawning migration.

    PubMed

    Amilhat, Elsa; Aarestrup, Kim; Faliex, Elisabeth; Simon, Gaël; Westerberg, Håkan; Righton, David

    2016-01-01

    The migration route and the spawning site of the European eel Anguilla anguilla are still uncertain. It has been suggested that the Mediterranean eel stock does not contribute to spawning because there is no evidence of eels leaving the Mediterranean Sea. To test this hypothesis, we equipped eight female silver eels from the south of France with pop-up satellite tags during escapement from coastal waters. Once in deeper water, the eels quickly established diel vertical migration (DVM) between the upper and lower mesopelagic zone. Five tagged eels were taken by predators within the Mediterranean, but two eels reached the Atlantic Ocean after six months and at distances greater than 2000 km from release. These eels ceased their DVM while they negotiated the Gibraltar Strait, and remained in deep water until they reached the Atlantic Ocean, when they recommenced DVM. Our results are the first to show that eels from Mediterranean can cross the Strait of Gibraltar and continue their migration into the Atlantic Ocean. This finding suggests that Mediterranean countries, as for other EU states, have an important role to play in contributing to conservation efforts for the recovery of the European eel stock. PMID:26906289

  18. Implementing the European SEA Directive: the Member States' margin of discretion

    SciTech Connect

    Risse, Nathalie; Crowley, Michel; Vincke, Philippe; Waaub, Jean-Philippe

    2003-07-01

    Directive 2001/42/EC of the European Parliament and of the Council of 27 June 2001 on the assessment of the effects of certain plans and programmes on the environment was officialised in July 2001. It establishes a basic framework for the assessment of the effects of certain plans and programmes on the environment, which should be adopted by the Member States of the European Union. In accordance with the principle of subsidiarity, the responsibility of developing a detailed procedure is left to the Member States. Within this context, this paper aims to assist the Member States with decisions concerning the implementation of a strategic environmental assessment (SEA) process conforming to the Directive by defining briefly some operational issues related to the Member State's discretionary margin and by analysing their consequences regarding the objectives stated by the Directive (in terms of protection of the environment, contribution to the integration of environmental considerations into the preparation and adoption of plans and programmes, and contribution to more transparent decision-making)

  19. First evidence of European eels exiting the Mediterranean Sea during their spawning migration

    PubMed Central

    Amilhat, Elsa; Aarestrup, Kim; Faliex, Elisabeth; Simon, Gaël; Westerberg, Håkan; Righton, David

    2016-01-01

    The migration route and the spawning site of the European eel Anguilla anguilla are still uncertain. It has been suggested that the Mediterranean eel stock does not contribute to spawning because there is no evidence of eels leaving the Mediterranean Sea. To test this hypothesis, we equipped eight female silver eels from the south of France with pop-up satellite tags during escapement from coastal waters. Once in deeper water, the eels quickly established diel vertical migration (DVM) between the upper and lower mesopelagic zone. Five tagged eels were taken by predators within the Mediterranean, but two eels reached the Atlantic Ocean after six months and at distances greater than 2000 km from release. These eels ceased their DVM while they negotiated the Gibraltar Strait, and remained in deep water until they reached the Atlantic Ocean, when they recommenced DVM. Our results are the first to show that eels from Mediterranean can cross the Strait of Gibraltar and continue their migration into the Atlantic Ocean. This finding suggests that Mediterranean countries, as for other EU states, have an important role to play in contributing to conservation efforts for the recovery of the European eel stock. PMID:26906289

  20. Cessation of a salmon decline with control of parasites.

    PubMed

    Peacock, Stephanie J; Krkosek, Martin; Proboszcz, Stan; Orr, Craig; Lewis, Mark A

    2013-04-01

    The resilience of coastal social-ecological systems may depend on adaptive responses to aquaculture disease outbreaks that can threaten wild and farm fish. A nine-year study of parasitic sea lice (Lepeophtheirus salmonis) and pink salmon (Oncorhynchus gorbuscha) from Pacific Canada indicates that adaptive changes in parasite management on salmon farms have yielded positive conservation outcomes. After four years of sea lice epizootics and wild salmon population decline, parasiticide application on salmon farms was adapted to the timing of wild salmon migrations. Winter treatment of farm fish with parasiticides, prior to the out-migration of wild juvenile salmon, has reduced epizootics of wild salmon without significantly increasing the annual number of treatments. Levels of parasites on wild juvenile salmon significantly influence the growth rate of affected salmon populations, suggesting that these changes in management have had positive outcomes for wild salmon populations. These adaptive changes have not occurred through formal adaptive management, but rather, through multi-stakeholder processes arising from a contentious scientific and public debate. Despite the apparent success of parasite control on salmon farms in the study region, there remain concerns about the long-term sustainability of this approach because of the unknown ecological effects of parasticides and the potential for parasite resistance to chemical treatments. PMID:23734489

  1. Evaluation of the impact of polyethylene microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae.

    PubMed

    Mazurais, D; Ernande, B; Quazuguel, P; Severe, A; Huelvan, C; Madec, L; Mouchel, O; Soudant, P; Robbens, J; Huvet, A; Zambonino-Infante, J

    2015-12-01

    Microplastics are present in marine habitats worldwide and may be ingested by low trophic organisms such as fish larvae, with uncertain physiological consequences. The present study aims at assessing the impact of polyethylene (PE 10-45 μM) microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae. Fish were fed an inert diet including 0, 10(4) and 10(5) fluorescent microbeads per gram from 7 until 43 days post-hatching (dph). Microbeads were detected in the gastrointestinal tract in all fish fed diet incorporating PE. Our data revealed an efficient elimination of PE beads from the gut since no fluorescent was observed in the larvae after 48 h depuration. While the mortality rate increased significantly with the amount of microbeads scored per larvae at 14 and 20 dph, only ingestion of the highest concentration slightly impacted mortality rates. Larval growth and inflammatory response through Interleukine-1-beta (IL-1β) gene expression were not found to be affected while cytochrome-P450-1A1 (cyp1a1) expression level was significantly positively correlated with the number of microbeads scored per larva at 20 dph. Overall, these results suggest that ingestion of PE microbeads had limited impact on sea bass larvae possibly due to their high potential of egestion. PMID:26412109

  2. A polygenic hypothesis for sex determination in the European sea bass Dicentrarchus labrax.

    PubMed

    Vandeputte, Marc; Dupont-Nivet, Mathilde; Chavanne, Hervé; Chatain, Béatrice

    2007-06-01

    Polygenic sex determination, although suspected in several species, is thought to be evolutionarily unstable and has been proven in very few cases. In the European sea bass, temperature is known to influence the sex ratio. We set up a factorial mating, producing 5.893 individuals from 253 full-sib families, all reared in a single batch to avoid any between-families environmental effects. The proportion of females in the offspring was 18.3%, with a large variation between families. Interpreting sex as a threshold trait, the heritability estimate was 0.62 +/- 0.12. The observed distribution of family sex ratios was in accordance with a polygenic model or with a four-sex-factors system with environmental variance and could not be explained by any genetic model without environmental variance. We showed that there was a positive genetic correlation between weight and sex (r(A) = 0.50 +/- 0.09), apart from the phenotypic sex dimorphism in favor of females. This supports the hypothesis that a minimum size is required for sea bass juveniles to differentiate as females. An evolution of sex ratio by frequency-dependent selection is expected during the domestication process of Dicentrarchus labrax populations, raising concern about the release of such fish in the wild. PMID:17435246

  3. SeaDataNet II - EMODNet - building a pan-European infrastructure for marine and ocean data management

    NASA Astrophysics Data System (ADS)

    Schaap, Dick M. A.; Fichaut, Michele

    2014-05-01

    The second phase of the project SeaDataNet is well underway since October 2011 and is making good progress. The main objective is to improve operations and to progress towards an efficient data management infrastructure able to handle the diversity and large volume of data collected via research cruises and monitoring activities in European marine waters and global oceans. The SeaDataNet infrastructure comprises a network of interconnected data centres and a central SeaDataNet portal. The portal provides users a unified and transparent overview of the metadata and controlled access to the large collections of data sets, managed by the interconnected data centres, and the various SeaDataNet standards and tools,. Recently the 1st Innovation Cycle has been completed, including upgrading of the CDI Data Discovery and Access service to ISO 19139 and making it fully INSPIRE compliant. The extensive SeaDataNet Vocabularies have been upgraded too and implemented for all SeaDataNet European metadata directories. SeaDataNet is setting and governing marine data standards, and exploring and establishing interoperability solutions to connect to other e-infrastructures on the basis of standards of ISO (19115, 19139), OGC (WMS, WFS, CS-W and SWE), and OpenSearch. The population of directories has also increased considerably in cooperation and involvement in associated EU projects and initiatives. SeaDataNet now gives overview and access to more than 1.4 million data sets for physical oceanography, chemistry, geology, geophysics, bathymetry and biology from more than 90 connected data centres from 30 countries riparian to European seas. Access to marine data is also a key issue for the implementation of the EU Marine Strategy Framework Directive (MSFD). The EU communication 'Marine Knowledge 2020' underpins the importance of data availability and harmonising access to marine data from different sources. SeaDataNet qualified itself for leading the data management component of the EMODNet (European Marine Observation and Data Network) that is promoted in the EU Communication. In the past 4 years EMODNet portals have been initiated for marine data themes: digital bathymetry, chemistry, physical oceanography, geology, biology, and seabed habitat mapping. These portals are now being expanded to all European seas in successor projects, which started mid 2013 from EU DG MARE. EMODNet encourages more data providers to come forward for data sharing and participating in the process of making complete overviews and homogeneous data products. The EMODNet Bathymetry project is very illustrative for the synergy with SeaDataNet and added value of generating public data products. The project develops and publishes Digital Terrain Models (DTM) for the European seas. These are produced from survey and aggregated data sets. The portal provides a versatile DTM viewing service with many relevant map layers and functions for retrieving. A further refinement is taking place in the new phase. The presentation will give information on present services of the SeaDataNet infrastructure and services, highlight key achievements in SeaDataNet II so far, and give further insights in the EMODNet Bathymetry progress.

  4. Salmon's Laws.

    ERIC Educational Resources Information Center

    Shannon, Thomas A.

    1994-01-01

    Presents Paul Salmon's old-fashioned, common-sense guidelines for success in practical school administration. The maxims advise on problem ownership; the value of selective neglect; the importance of empowerment, enthusiasm, and effective communication; and the need for positive reinforcement, cultivation of support, and good relations with media,…

  5. Diva software, a tool for European regional seas and Ocean climatologies production

    NASA Astrophysics Data System (ADS)

    Ouberdous, M.; Troupin, C.; Barth, A.; Alvera-Azcàrate, A.; Beckers, J.-M.

    2012-04-01

    Diva (Data-Interpolating Variational Analysis) is a software based on a method designed to perform data-gridding (or analysis) tasks, with the assets of taking into account the intrinsic nature of oceanographic data, i.e., the uncertainty on the in situ measurements and the anisotropy due to advection and irregular coastlines and topography. The Variational Inverse Method (VIM, Brasseur et al., 1996) implemented in Diva consists in minimizing a variational principle which accounts for the differences between the observations and the reconstructed field, the influence of the gradients and variability of the reconstructed field. The resolution of the numerical problem is based on finite-element method, which allows a great numerical efficiency and the consideration of complicated contours. Along with the analysis, Diva provides also error fields (Brankart and Brasseur, 1998; Rixen et al., 2000) based on the data coverage and noise. Diva is used for the production of climatologies in the pan-European network SeaDataNet. SeaDataNet is connecting the existing marine data centres of more than 30 countries and set up a data management infrastructure consisting of a standardized distributed system. The consortium has elaborated integrated products, using common procedures and methods. Among these, it uses the Diva software as reference tool for climatologies computation for various European regional seas, the Atlantic and the global ocean. During the first phase of the SeaDataNet project, a number of additional tools were developed to make easier the climatologies production for the users. Among these tools: the advection constraint during the field reconstruction through the specification of a velocity field on a regular grid, forcing the analysis to align with the velocity vectors; the Generalized Cross Validation for the determination of analysis parameters (signal-to-noise ratio); the creation of contours at selected depths; the detection of possible outliers; the hydrostatic constraint for eliminating the potential hydrostatic instabilities arisen from the combined analysis of temperature and salinity data in several horizontal planes independently; the specification of a variable correlation length over the domain, allowing one to consider different scales of interest according to the location; the computation of the error field based on the real correlation function of the considered data; the generation of semi-normed reference fields. Collaboration with Diva users (marine data centres) permitted the identification of a variety of problems that can occur in the Diva analysis due to numerical computations and/or data types (i.e. negative concentrations for certain data sets of bio-chemical and nutrient data). To solve these problems, new options were designed and implemented additional for Diva computation algorithms. Among these new options the user has the possibility to: avoid negative values performing analyses based on transformed data (i.e. anamorphosis transformation), avoid unrealistic and/or negative concentrations due to small number of data using semi-normed reference field generated with data sets from other layers, to perform a layer analysis, filter vertically the background (mean data) or reference fields for vertical field coherence. Diva analysis tools and options, as well as Climatologies validation tools will be presented, with a demonstration of efficiency of the new Diva options using bio-chemical and physical data, through samples of climatologies for different regions of the Mediterranean sea.

  6. Potential use of the invasive European green crab (Carcinus maenas) as an ingredient in Atlantic Salmon (Salmo salar) diets; a preliminary analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atlantic salmon (Salmo salar) is an important cultured carnivorous species with wide comsumer acceptance. With the finite supply of available fishmeal and fish oil available for aquafeeds, research on and utilization of alternative protein and lipid sources is expandingWe examined the nutritional p...

  7. LPXRFa peptide system in the European sea bass: A molecular and immunohistochemical approach.

    PubMed

    Paullada-Salmerón, José A; Cowan, Mairi; Aliaga-Guerrero, María; Gómez, Ana; Zanuy, Silvia; Mañanos, Evaristo; Muñoz-Cueto, José A

    2016-01-01

    Gonadotropin-inhibitory hormone (GnIH) is a neuropeptide that suppresses reproduction in birds and mammals by inhibiting GnRH and gonadotropin secretion. GnIH orthologs with a C-terminal LPXRFamide (LPXRFa) motif have been identified in teleost fish. Although recent work also suggests its role in fish reproduction, studies are scarce and controversial, and have mainly focused on cyprinids. In this work we cloned a full-length cDNA encoding an LPXRFa precursor in the European sea bass, Dicentrarchus labrax. In contrast to other teleosts, the sea bass LPXRFa precursor contains only two putative RFamide peptides, termed sbLPXRFa1 and sbLPXRFa2. sblpxrfa transcripts were expressed predominantly in the olfactory bulbs/telencephalon, diencephalon, midbrain tegmentum, retina, and gonads. We also developed a specific antiserum against sbLPXRFa2, which revealed sbLPXRFa-immunoreactive (ir) perikarya in the olfactory bulbs-terminal nerve, ventral telencephalon, caudal preoptic area, dorsal mesencephalic tegmentum, and rostral rhombencephalon. These sbLPXRFa-ir cells profusely innervated the preoptic area, hypothalamus, optic tectum, semicircular torus, and caudal midbrain tegmentum, but conspicuous projections also reached the olfactory bulbs, ventral/dorsal telencephalon, habenula, ventral thalamus, pretectum, rostral midbrain tegmentum, posterior tuberculum, reticular formation, and viscerosensory lobe. The retina, pineal, vascular sac, and pituitary were also targets of sbLPXRFa-ir cells. In the pituitary, this innervation was observed close to follicle-stimulating hormone (FSH), luteinizing hormone (LH) and growth hormone (GH) cells. Tract-tracing retrograde labeling suggests that telencephalic and preoptic sbLPXRFa cells might represent the source of pituitary innervation. The immunohistochemical distribution of sbLPXRFa cells and fibers suggest that LPXRFa peptides might be involved in some functions as well as reproduction, such as feeding, growth, and behavior. PMID:26105807

  8. Behavioural Stress Responses Predict Environmental Perception in European Sea Bass (Dicentrarchus labrax)

    PubMed Central

    Millot, Sandie; Cerqueira, Marco; Castanheira, Maria-Filipa; Øverli, Øyvind; Oliveira, Rui F.; Martins, Catarina I. M.

    2014-01-01

    Individual variation in the response to environmental challenges depends partly on innate reaction norms, partly on experience-based cognitive/emotional evaluations that individuals make of the situation. The goal of this study was to investigate whether pre-existing differences in behaviour predict the outcome of such assessment of environmental cues, using a conditioned place preference/avoidance (CPP/CPA) paradigm. A comparative vertebrate model (European sea bass, Dicentrarchus labrax) was used, and ninety juvenile individuals were initially screened for behavioural reactivity using a net restraining test. Thereafter each individual was tested in a choice tank using net chasing as aversive stimulus or exposure to familiar conspecifics as appetitive stimulus in the preferred or non preferred side respectively (called hereafter stimulation side). Locomotor behaviour (i.e. time spent, distance travelled and swimming speed in each tank side) of each individual was recorded and analysed with video software. The results showed that fish which were previously exposed to appetitive stimulus increased significantly the time spent on the stimulation side, while aversive stimulus led to a strong decrease in time spent on the stimulation side. Moreover, this study showed clearly that proactive fish were characterised by a stronger preference for the social stimulus and when placed in a putative aversive environment showed a lower physiological stress responses than reactive fish. In conclusion, this study showed for the first time in sea bass, that the CPP/CPA paradigm can be used to assess the valence (positive vs. negative) that fish attribute to different stimuli and that individual behavioural traits is predictive of how stimuli are perceived and thus of the magnitude of preference or avoidance behaviour. PMID:25264870

  9. Influence of temperature, oxygen and salinity on the metabolism of the European sea bass

    NASA Astrophysics Data System (ADS)

    Claireaux, G.; Lagardère, J.-P.

    1999-09-01

    Standard (SMR) and routine (RMR) metabolic rates of groups (4 to 5 individuals) of European sea bass ( Dicentrarchus labrax) were measured at combinations of the following factors: temperature (10, 15, 20 and 25°C), oxygenation level (air saturation to 1.5 mg dm -3) and salinity (30, 20, 10 and 5‰). The influence of these environmental conditions on fish metabolic demand was then analysed through ANOVA. At 10, 15, 20 and 25°C, standard metabolic rates were 36, 65, 89, and 91 mg O 2 kg -1 h -1, respectively, while routine oxygen consumptions covered most of the metabolic range accessible. Osmoregulatory costs are linked to metabolic activity through ventilation. This relationship was highlighted by the observed interaction between environmental salinity and temperature. We were, however, unable to detect interactions between salinity and routine metabolic rate, or between salinity and oxygenation level. In order to delineate more precisely the restrictions imposed by water oxygenation on fish metabolic performance we determined the limiting oxygen concentration curves at each experimental temperature. We followed up by modelling the bass active metabolic rate (AMR) and metabolic scope (MS) as functions of both ambient temperature and oxygenation. These mathematical models allowed the characterisation of the controlling and limiting effects of water temperature and oxygen content on the metabolic capacity of the species. Thus, AMR at 10, 15 and 20°C were estimated at 65, 160 and 360 mg O 2 kg -1 h -1, respectively. However, at higher temperature (25°C) AMR dropped slightly (to 340 mg O 2 kg -1 h -1). Bass MS increased by a factor of 9 between 10 and 20°C, but diminished at higher temperatures. The present study contributes to our current understanding of the influences of environmental factors on the metabolism of sea bass and provides a bioenergetic basis for a study of how environmental constraints govern the spatial and temporal distribution pattern of this species.

  10. The Relationship between Phytoplankton Distribution and Water Column Characteristics in North West European Shelf Sea Waters

    PubMed Central

    Davidson, Keith; Bolch, Christopher J. S.; Brand, Tim D.; Narayanaswamy, Bhavani E.

    2012-01-01

    Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the “Ellett Line” cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN∶DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN∶DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of growth at most stations and depths. PMID:22479533

  11. Potential impacts of climate change on the primary production of regional seas: A comparative analysis of five European seas

    NASA Astrophysics Data System (ADS)

    Holt, Jason; Schrum, Corinna; Cannaby, Heather; Daewel, Ute; Allen, Icarus; Artioli, Yuri; Bopp, Laurent; Butenschon, Momme; Fach, Bettina A.; Harle, James; Pushpadas, Dhanya; Salihoglu, Baris; Wakelin, Sarah

    2016-01-01

    Regional seas are potentially highly vulnerable to climate change, yet are the most directly societally important regions of the marine environment. The combination of widely varying conditions of mixing, forcing, geography (coastline and bathymetry) and exposure to the open-ocean makes these seas subject to a wide range of physical processes that mediates how large scale climate change impacts on these seas' ecosystems. In this paper we explore the response of five regional sea areas to potential future climate change, acting via atmospheric, oceanic and terrestrial vectors. These include the Barents Sea, Black Sea, Baltic Sea, North Sea, Celtic Seas, and are contrasted with a region of the Northeast Atlantic. Our aim is to elucidate the controlling dynamical processes and how these vary between and within these seas. We focus on primary production and consider the potential climatic impacts on: long term changes in elemental budgets, seasonal and mesoscale processes that control phytoplankton's exposure to light and nutrients, and briefly direct temperature response. We draw examples from the MEECE FP7 project and five regional model systems each using a common global Earth System Model as forcing. We consider a common analysis approach, and additional sensitivity experiments. Comparing projections for the end of the 21st century with mean present day conditions, these simulations generally show an increase in seasonal and permanent stratification (where present). However, the first order (low- and mid-latitude) effect in the open ocean projections of increased permanent stratification leading to reduced nutrient levels, and so to reduced primary production, is largely absent, except in the NE Atlantic. Even in the two highly stratified, deep water seas we consider (Black and Baltic Seas) the increase in stratification is not seen as a first order control on primary production. Instead, results show a highly heterogeneous picture of positive and negative change arising from complex combinations of multiple physical drivers, including changes in mixing, circulation and temperature, which act both locally and non-locally through advection.

  12. Tenacibaculum dicentrarchi sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from European sea bass.

    PubMed

    Piñeiro-Vidal, Maximino; Gijón, Daniel; Zarza, Carles; Santos, Ysabel

    2012-02-01

    A novel Gram-stain-negative rod-shaped gliding bacterial strain, designated 35/09(T), was isolated from diseased European sea bass (Dicentrarchus labrax L.) in Spain. Colonies were pale-yellow-pigmented with uneven edges and did not adhere to the agar. The DNA G+C content of the isolate was 31.3 mol%. 16S rRNA gene sequence analysis indicated affiliation to the genus Tenacibaculum (family Flavobacteriaceae, phylum 'Bacteroidetes'). Sequence similarities between the isolate and type strains of other members of the genus were 93.1-97.3 %. The major fatty acids (>5 % of the total fatty acids) were iso-C(15 : 0) (24.8 %), iso-C(15 : 0) 3-OH (18.0 %), anteiso-C(15 : 0) (8.1 %), C(15 : 1)ω6c (6.9 %) and iso-C(15 : 1) (6.2 %). Genotypic and phenotypic data indicate that strain 35/09(T) should be classified as a representative of a novel species in the genus Tenacibaculum, for which the name Tenacibaculum dicentrarchi sp. nov. is proposed; the type strain is 35/09(T) ( = CECT 7612(T) = NCIMB 14598(T)). PMID:21460137

  13. Intercomparison of carbonate chemistry measurements on a cruise in northwestern European shelf seas

    NASA Astrophysics Data System (ADS)

    Ribas-Ribas, M.; Rérolle, V. M. C.; Bakker, D. C. E.; Kitidis, V.; Lee, G. A.; Brown, I.; Achterberg, E. P.; Tyrrell, T.

    2014-02-01

    Four carbonate system variables were measured in surface waters during a cruise traversing northwestern European shelf seas in the summer of 2011. High resolution surface water data were collected for partial pressure of carbon dioxide (pCO2; using two independent instruments) and pHT, in addition to discrete measurements of total alkalinity and dissolved inorganic carbon. We thus overdetermined the carbonate system (four measured variables, two degrees of freedom) which allowed us to evaluate the level of agreement between the variables. Calculations of carbonate system variables from other measurements generally compared well (Pearson's correlation coefficient always ≳ 0.94; mean residuals similar to the respective uncertainties of the calculations) with direct observations of the same variables. We therefore conclude that the four independent datasets of carbonate chemistry variables were all of high quality, and as a result that this dataset is suitable to be used for the evaluation of ocean acidification impacts and for carbon was observed in the difference between the pCO2; values obtained by the two independent analytical pCO2; systems, and this was partly attributed to irregular seawater flows to the equilibrator and partly to biological activity inside the seawater supply and one of the equilibrators. We discuss how these issues can be addressed to improve carbonate chemistry data quality on research cruises.

  14. Multivariate approach to gill pathology in European sea bass after experimental exposure to cadmium and terbuthylazine.

    PubMed

    Manera, Maurizio; Sayyaf Dezfuli, Bahram; DePasquale, Joseph A; Giari, Luisa

    2016-07-01

    The combined use of guided quantitative expert analysis and of multivariate exploratory data analysis is reported as a robust, sensitive and sufficiently specific approach to study European sea bass gill secondary lamellar pathology after exposure to incremental doses of cadmium and terbuthylazine up to 48h. The following elementary pathological findings were considered: "epithelial lifting", "epithelial shrinkage", "epithelial swelling", "pillar cells coarctation", "pillar cells detachment", "channels fusion", "chloride cells swelling", and "chloride cells invasion". The relative spatial extension was determined according to exposure class and data were analyzed by means of canonical correspondence analysis (CCA), linear discriminant analysis (LDA) and canonical variates analysis (CVA). Histologically and ultrastructurally, cellular shrinkage/coarctation prevailed in cadmium exposed lamellae, whereas cellular swelling and epithelial lifting were predominant in terbuthylazine exposed lamellae compared to unexposed fish. Both CCA and CVA permit a good graphical data grouping according to exposure classes by means of the convex hull minimum polygons. This also reveals exposure dose and time gradients in CCA plot. Accordingly, epithelial swelling and epithelial shrinkage were comparatively associated to higher exposure time, whereas epithelial shrinkage and pillar cells coarctation were comparatively associated to higher exposure dose. LDA with only "epithelial shrinkage", "epithelial swelling" and "pillar cells coarctation" in the model classified correctly 87.5% of the cross-validated cases. A possible pathogenetic relationship between the discriminant elementary lesions and the toxic mode of action at the cellular level of both cadmium and terbuthylazine is also discussed. PMID:27057996

  15. Discovering Alaska's Salmon: A Children's Activity Book.

    ERIC Educational Resources Information Center

    Devaney, Laurel

    This children's activity book helps students discover Alaska's salmon. Information is provided about salmon and where they live. The salmon life cycle and food chains are also discussed. Different kinds of salmon such as Chum Salmon, Chinook Salmon, Coho Salmon, Sockeye Salmon, and Pink Salmon are introduced, and various activities on salmon are

  16. Discovering Alaska's Salmon: A Children's Activity Book.

    ERIC Educational Resources Information Center

    Devaney, Laurel

    This children's activity book helps students discover Alaska's salmon. Information is provided about salmon and where they live. The salmon life cycle and food chains are also discussed. Different kinds of salmon such as Chum Salmon, Chinook Salmon, Coho Salmon, Sockeye Salmon, and Pink Salmon are introduced, and various activities on salmon are…

  17. Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.

    USGS Publications Warehouse

    Garver, Kyle A.; Marty, Gary D.; Cockburn, Sarah N.; Richard, Jon; Hawley, Laura M.; Müller, Anita; Thompson, Rachel L.; Purcell, Maureen K.; Saksida, Sonja M.

    2016-01-01

    A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon.

  18. Estrogen-induced yolk precursors in European sea bass, Dicentrarchus labrax: Status and perspectives on multiplicity and functioning of vitellogenins.

    PubMed

    Yilmaz, Ozlem; Prat, Francisco; Ibañez, Antonio José; Amano, Haruna; Koksoy, Sadi; Sullivan, Craig V

    2015-09-15

    The estrogen-inducible egg yolk precursor, vitellogenin, of the European sea bass (Dicentrarchus labrax) has received considerable scientific attention by virtue of its central importance in determination of oocyte growth and egg quality in this important aquaculture species. However, the multiplicity of vitellogenins in the sea bass has only recently been examined. Recent cloning and homology analyses have revealed that the sea bass possesses the three forms of vitellogenin, VtgAa, VtgAb and VtgC, reported to occur in some other highly evolved teleosts. Progress has been made in assessing the relative abundance and special structural features of the three Vtgs and their likely roles in oocyte maturation and embryonic nutrition. This report discusses these findings in the context of our prior knowledge of vitellogenesis in this species and of the latest advances in our understanding of the evolution and function of multiple Vtgs in acanthomorph fishes. PMID:25637672

  19. Deep sea corals and carbonate mounds of the nw european margin: a biogeochemical perspective

    NASA Astrophysics Data System (ADS)

    Kiriakoulakis, K.; White, M.; Bett, B.; Wolff, G. A.

    2003-04-01

    The deep-sea, scleractinian, reef-forming coral Lophelia pertusa is widespread along the NW European Continental Margin and its presence has been documented since the 19th century. However little is known about its ecology, biochemistry and particularly its relationship with the carbonate mounds it is often associated with. The characterisation of particulate organic matter (POM), which fuels the Lophelia pertusa ecosystems and the sediments on and around the coral/mound sites, may potentially shed light on the biogeochemical processes of the deep water coral (DWC) ecosystems. In this study, POM (20--40 m above bottom) and sediments have been collected from five mound/coral sites along the European Continental Slope (water depth ˜500--1000 m) with distinct oceanographic and sedimentological conditions, (Darwin, Logachev, Pelagia, Hovland and Belgica Mounds located around the Rockall Trough and Porcupine Seabight). Coral densities and mound sizes, shapes and conditions vary significantly from site to site. POM at these sites are significantly different, particularly with respect to the lipid concentrations relative to organic carbon, which are much higher at the Darwin Mounds (N.Rockall Trough; ˜1000m depth) than the rest of the sites (46.63 -- 225.11 mg g-1 and 0.49 -- 14.21 mg g-1 respectively). Polyunsaturated fatty acids (PUFAs), which are used as proxies of labile organic matter are also abundant at the Darwin Mounds, indicating that POM is 'fresh'. Scanning electron microscopy carried out on filtered material from this area confirms this. These mounds are affected by a branch of the poleward slope current, which, in combination with enhanced Ekman downwelling, could transport appreciable amounts of high quality organic matter to the depth that they are found. Lipid (including PUFAs) concentrations at the Pelagia Mounds (SE Rockall Trough; ˜700 m) although lower than at the Darwin Mounds are higher than at the other sites. This location is also influenced by a poleward slope current. In contrast, at the Logachev (S.Rockall Bank; ˜500--700 m), Hovland (N.Porcupine Seabight; ˜600--900 m) and Belgica (S. Porcupine Seabight; ˜700--900 m) Mounds the combination of tidal, and backwater geostrophic bottom currents probably results in entrapment and/or recirculation of organic material, with important consequences on its lability/freshness. Initial results on the sediments from four of the above sites show a significant correlation (R^2 = 0.87) between sedimentary total organic carbon (TOC) and carbonate content (0--10 cm depth integrated values). This may indicate a direct relationship between carbonate and organic matter, perhaps via microbial activity, which is often suggested as the main driving force for mound genesis.

  20. Impact of the European Russia drought in 2010 on the Caspian Sea level

    NASA Astrophysics Data System (ADS)

    Arpe, K.; Leroy, S. A. G.; Lahijani, H.; Khan, V.

    2011-08-01

    The hydrological budgets of the Volga basin (VB) and the Caspian Sea (CS) have been established. The components of the water balance for the CS were calculated for the period 1993 to 2010 with emphasis on summer 2010 when a severe drought developed over European Russia. A drop in precipitation over the VB in July 2010 occurs simultaneously with a decrease in evaporation for the same area, an increase of evaporation over the CS itself and a drop of the Caspian Sea Level (CSL). The drop in the precipitation over the VB cannot have led to an instantaneous drop of the CSL because the precipitated water needs some months to reach the CS. The delay is estimated to be 1 to 3 months for excessive precipitation in summer, longer for other cases. However, the evaporation over the CS itself is considered to be responsible for a simultaneous drop of the CSL from July to September 2010. The impact on the CSL from the precipitation deficit over the VB occurs in the months following the drought. The water deficit from July to September 2010 calculated from the anomalous precipitation minus evaporation over the VB would decrease the CSL by 22 cm, of which only 2 cm had been observed until end of September (observed Volga River discharge anomaly), 7 cm from October to the end of 2010 and another 5 cm to the end of May 2011. From October 2010 to February 2011 excessive precipitation occurred over the Volga basin, equivalent to an increase of the CSL of 7 cm which might just compensate the 7 cm of the remaining deficit from the summer drought. A deficit of water took however already place in the months before July 2010. In previous studies the precipitation over the VB has been identified as the main cause for CSL changes, but here from a 10 cm drop from beginning of July to end of September, 6 cm can be directly assigned to the enhanced evaporation over the CS itself and 2 cm due to reduced precipitation over the CS. Further periods with strong changes of the CSL are investigated as well which provide some estimates concerning the accuracy of the analysis data. The investigation was possible due to the new ECMWF interim reanalysis data which are used to provide data also for sensitive quantities like surface evaporation and precipitation. The comparison with independent data and the consistency between such data for calculating the water budget over the CS gives a high confidence in the quality of the data used. This investigation provides some scope for making forecasts of the CSL few months ahead to allow for mitigating societal impacts.

  1. Impact of the European Russia drought in 2010 on the Caspian Sea level

    NASA Astrophysics Data System (ADS)

    Arpe, K.; Leroy, S. A. G.; Lahijani, H.; Khan, V.

    2012-01-01

    The hydrological budgets of the Volga basin (VB) and the Caspian Sea (CS) have been analysed. The components of the water balance for the CS were calculated for the period 1993 to 2010 with emphasis on summer 2010 when a severe drought developed over European Russia. A drop in precipitation over the VB in July 2010 occurs simultaneously with a decrease in evaporation for the same area, an increase of evaporation over the CS itself and a drop of the Caspian Sea level (CSL). The drop in the precipitation over the VB cannot lead to an instantaneous drop of the CSL because the precipitated water needs some months to reach the CS. The delay is estimated here to be 1 to 3 months for excessive precipitation in summer, longer for deficient precipitation and for winter cases. However, the evaporation over the CS itself is considered to be responsible for a simultaneous drop of the CSL from July to September 2010. The impact on the CSL from the precipitation deficit over the VB occurs in the months following the drought. The water deficit from July to September 2010 calculated from the anomalous precipitation minus evaporation over the VB would decrease the CSL by 22 cm, of which only 2 cm had been observed until the end of September (observed Volga River discharge anomaly). So the remaining drop of 20 cm can be expected in the months to follow if no other anomalies happen. In previous studies the precipitation over the VB has been identified as the main cause for CSL changes, but here from a 10 cm drop from beginning of July to end of September, 6 cm can be directly assigned to the enhanced evaporation over the CS itself and 2 cm due to reduced precipitation over the CS. Further periods with strong changes of the CSL are also investigated, which provide some estimates concerning the accuracy of the analysis data. The investigation was possible due to the new ECMWF interim reanalysis data which are used to provide data also for sensitive quantities like surface evaporation and precipitation. The comparison with independent data and the consistency between such data for calculating the water budget over the CS gives a high confidence in the quality of the data used. This investigation provides some scope for making forecasts of the CSL few months ahead to allow for mitigating societal impacts.

  2. Intercomparison of carbonate chemistry measurements on a cruise in northwestern European shelf seas

    NASA Astrophysics Data System (ADS)

    Ribas-Ribas, M.; Rérolle, V. M. C.; Bakker, D. C. E.; Kitidis, V.; Lee, G. A.; Brown, I.; Achterberg, E. P.; Hardman-Mountford, N. J.; Tyrrell, T.

    2014-08-01

    Four carbonate system variables were measured in surface waters during a cruise aimed at investigating ocean acidification impacts traversing northwestern European shelf seas in the summer of 2011. High-resolution surface water data were collected for partial pressure of carbon dioxide (pCO2; using two independent instruments) and pH using the total pH scale (pHT), in addition to discrete measurements of total alkalinity and dissolved inorganic carbon. We thus overdetermined the carbonate system (four measured variables, two degrees of freedom), which allowed us to evaluate the level of agreement between the variables on a cruise whose main aim was not intercomparison, and thus where conditions were more representative of normal working conditions. Calculations of carbonate system variables from other measurements generally compared well with direct observations of the same variables (Pearson's correlation coefficient always greater than or equal to 0.94; mean residuals were similar to the respective accuracies of the measurements). We therefore conclude that four of the independent data sets of carbonate chemistry variables were of high quality. A diurnal cycle with a maximum amplitude of 41 μatm was observed in the difference between the pCO2 values obtained by the two independent analytical pCO2 systems, and this was partly attributed to irregular seawater flows to the equilibrator and partly to biological activity inside the seawater supply and one of the equilibrators. We discuss how these issues can be addressed to improve carbonate chemistry data quality on future research cruises.

  3. Osmoregulatory response to low salinities in the European sea bass embryos: a multi-site approach.

    PubMed

    Sucré, Elliott; Bossus, Maryline; Bodinier, Charlotte; Boulo, Viviane; Charmantier, Guy; Charmantier-Daures, Mireille; Cucchi, Patricia

    2013-01-01

    Embryonic osmoregulation effected by embryonic ionocytes in the European sea bass Dicentrarchus labrax has been studied at several sites, including the yolk sac membrane, the first gill slits and the gut ionocytes. D. labrax embryos, spawned in seawater (SW) (39 ‰), were exposed to dilute seawater (DSW) (5 ‰) during 48 h, from stage 10 pairs of somites (10S) to hatching time (HT). Control embryos originating from the same spawn were maintained in SW. Both SW and DSW embryos were examined after 24- and 48-h exposure. Nanoosmometric measurements of the embryonic fluids osmolality suggest that late embryos are confronted with the variations in external salinity and that they were able to slightly regulate their osmolality. Immunolocalization of Na⁺/K⁺ ATPase, NKCC and CFTR has shown that DSW-exposed embryos can limit ion losses due to compensatory physiological mechanisms. CFTR and NKCC were not observed in DSW embryos in the yolk sac ionocytes and in the tegumentary ionocytes of the gill slits. The quantification of mRNA indicated that NKA, NKCC1 and CFTR transcript levels increased from stage 10S to stage HT. At stage HT, following 48 h of DSW- or SW-exposure, different responses were observed according to salinity. These results, when compared to those obtained in D. labrax juveniles and adults long-term exposed to fresh water (FW), show that in embryos the physiological response following a short-term DSW exposure is different. The mechanisms of hyper-osmoregulation observed in D. labrax embryos, although not fully efficient, allow their survival for several days in DSW. PMID:22752053

  4. European sea bass gill pathology after exposure to cadmium and terbuthylazine: expert versus fractal analysis.

    PubMed

    Manera, M; Giari, L; Depasquale, J A; Dezfuli, B S

    2016-03-01

    The objective of this study was to compare expert versus fractal analysis as new methods to evaluate branchial lamellar pathology in European sea bass Dicentrarchus labrax (Linnaeus, 1758) experimentally exposed to cadmium and to terbuthylazine. In particular, guided expert quantitative and fractal analysis were performed on selected images from semithin sections to test possible differences according to exposure class (unexposed, cadmium exposed, or terbuthylazine exposed) and the discrimination power of the two methods. With respect to guided expert quantitative analysis, the following elementary pathological features were assessed according to pre-determined cover classes: 'epithelial lifting', 'epithelial shrinkage', 'epithelial swelling', 'pillar cells coarctation', 'pillar cells detachment', 'channels fusion', 'chloride cells swelling' and 'chloride cells invasion'. Considering fractal analysis, DB (box dimension), DM (mass dimension), Dx¯ (mean fractal dimension) as fractal dimensions and lacunarity from DM and Dx¯ scan types were calculated both from the outlined and skeletonized (one pixel wide lines) images. Despite significant differences among experimental classes, only expert analysis provided good discrimination with correct classification of 91.7 % of the original cases, and of 87.5 % of the cross-validated cases, with a sensitivity of 95.45 % and 91.3 %, respectively, and a specificity of 75 % in both cases. Guided expert quantitative analysis appears to be a reliable method to objectively characterize fish gill pathology and may represent a powerful tool in environmental biomonitoring to ensure proper standardization and reproducibility. Though fractal analysis did not equal the discrimination power of the expert method, it certainly warrants further study to evaluate local variations in complexity or possible multiple scaling rules. PMID:26469527

  5. Individual variation and repeatability in aerobic and anaerobic swimming performance of European sea bass, Dicentrarchus labrax.

    PubMed

    Marras, S; Claireaux, G; McKenzie, D J; Nelson, J A

    2010-01-01

    Studies of inter-individual variation in fish swimming performance may provide insight into how selection has influenced diversity in phenotypic traits. We investigated individual variation and short-term repeatability of individual swimming performance by wild European sea bass in a constant acceleration test (CAT). Fish were challenged with four consecutive CATs with 5 min rest between trials. We measured maximum anaerobic speed at exhaustion (U(CAT)), gait transition speed from steady aerobic to unsteady anaerobic swimming (U(gt)), routine metabolic rate (RMR), post-CAT maximum metabolic rate (MMR), aerobic scope and recovery time from the CATs. Fish achieved significantly higher speeds during the first CAT (U(CAT)=170 cm s(-1)), and had much more inter-individual variation in performance (coefficient of variation, CV=18.43%) than in the subsequent three tests (U(CAT)=134 cm s(-1); CV=7.3%), which were very repeatable among individuals. The individual variation in U(CAT) in the first trial could be accounted for almost exclusively by variation in anaerobic burst-and-coast performance beyond U(gt). The U(gt) itself varied substantially between individuals (CV=11.4%), but was significantly repeatable across all four trials. Individual RMR and MMR varied considerably, but the rank order of post-CAT MMR was highly repeatable. Recovery rate from the four CATs was highly variable and correlated positively with the first U(CAT) (longer recovery for higher speeds) but negatively with RMR and aerobic scope (shorter recovery for higher RMR and aerobic scope). This large variation in individual performance coupled with the strong correlations between some of the studied variables may reflect divergent selection favouring alternative strategies for foraging and avoiding predation. PMID:20008358

  6. Salmon, Mississippi Fact Sheet

    SciTech Connect

    2010-01-04

    The Salmon, Mississippi, Site, also called the Tatum Dome Test Site, is a 1,470-acre tract of land in Lamar County, Mississippi, 21 miles southwest of Hattiesburg. The nearest town is Purvis, about 10 miles east of the site. The site is in a forested region known as the long-leaf pine belt of the Gulf Coastal Plain. Elevations in the area range from about 240 to 350 feet above sea level. The site overlies a salt formation called the Tatum Salt Dome. Land around the Salmon site has residential, industrial, and commercial use, although no one lives within the boundary of the site itself. The U.S. Atomic Energy Commission, a predecessor agency of the U.S. Department of Energy (DOE), and the U.S. Department of Defense conducted two underground nuclear tests at the site under the designation of Project Dribble, part of a larger program known as the Vela Uniform program. Two gas explosive tests, designated Project Miracle Play, were also conducted at the site.

  7. Calcitonin Salmon Injection

    MedlinePlus

    Calcitonin salmon injection is used to treat osteoporosis in postmenopausal women. Osteoporosis is a disease that causes bones to weaken and break more easily. Calcitonin salmon injection is also used to ...

  8. Antimicrobial response is increased in the testis of European sea bass, but not in gilthead seabream, upon nodavirus infection.

    PubMed

    Valero, Yulema; García-Alcázar, Alicia; Esteban, M Ángeles; Cuesta, Alberto; Chaves-Pozo, Elena

    2015-05-01

    Antimicrobial peptides (AMPs) have a crucial role in the fish innate immune response, being considered a fundamental component of the first line of defence against pathogens. Moreover, AMPs have not been studied in the fish gonad since this is used by some pathogens as a vehicle or a reservoir to be transmitted to the progeny, as occurs with nodavirus (VNNV), which shows vertical transmission through the gonad and/or gonadal fluids, but no study has looked into the gonad of infected fish. In this framework, we have characterized the antimicrobial response triggered by VNNV in the testis of European sea bass, a very susceptible species of the virus, and in the gilthead seabream, which acts as a reservoir, both in vivo and in vitro, and compared with that present in the serum and brain (target tissue of VNNV). First, our data show a great antiviral response in the brain of gilthead seabream and in the gonad of European sea bass. In addition, for the first time, our results demonstrate that the antimicrobial activities (complement, lysozyme and bactericidal) and the expression of AMP genes such as complement factor 3 (c3), lysozyme (lyz), hepcidin (hamp), dicentracin (dic), piscidin (pis) or β-defensin (bdef) in the gonad of both species are very different, but generally activated in the European sea bass, probably related with the differences of susceptibility upon VNNV infection, and even differs to the brain response. Furthermore, the in vitro data suggest that some AMPs are locally regulated playing a local immune response in the gonad, while others are more dependent of the systemic immune system. Data are discussed in the light to ascertain their potential role in viral clearance by the gonad to avoid vertical transmission. PMID:25707600

  9. Eustatic and climatic control on the Upper Muschelkalk Sea (late Anisian/Ladinian) in the Central European Basin

    NASA Astrophysics Data System (ADS)

    Franz, M.; Kaiser, S. I.; Fischer, J.; Heunisch, C.; Kustatscher, E.; Luppold, F. W.; Berner, U.; Röhling, H.-G.

    2015-12-01

    The Upper Muschelkalk in the Central European Basin (CEB) is a key example of eustatic and climatic controls on inland seas. The late Anisian rapid transgression from Tethyan waters culminated in a large semi-enclosed inland sea stretching across the CEB. Subsequently, the slow but successive retreat in the early Ladinian resulted in a small remnant sea. The pronounced stratal pattern architectures are translated into a framework of 3rd- and 4th-order T-R sequences. The latest Illyrian 3rd-order maximum flooding surface corresponds to maximum abundances of carbonates and marine phytoplankton. An euryhaline marine ecology is indicated by prasinophycean algae dominating over acritarchs and δ18OP values of 18.9-22.4‰ VSMOW corresponding to Tethyan references. During the 3rd-order regressive phase successive freshening up to hyposaline conditions is indicated by up to 3‰ depleted δ18OP values, shifts to more radiogenic 87Sr/86Sr ratios and maximum abundances of terrestrial palynomorphs. Likewise, 4th-order T-R sequences are constrained by commutated stratal pattern architectures, palynofacies and geochemistry. The favourable correlation of middle Triassic 3rd-order sequences of Tethyan and peri-Tethyan basins demonstrate the principle control of circum-Tethyan eustatic cycles. 4th-order sequences are evident and, although not yet correlatable in detail, indicate 106-year scale eustatic cycles which may be attributed to glacioeustatic sea-level changes. The subordinated control of arid to semiarid low latitude and semihumid to humid temperate mid latitude climates affected the Upper Muschelkalk Sea in particular during 4th-order sea-level lowstands. Substantial fresh water input from Scandinavian sources caused temporal stratification leading to stagnant bottom waters and/or sediments as indicated by palynofacies and U/Th and Ni/Co redox indices. The herein reconstructed middle Triassic zonal climates are in agreement to previously published Late Triassic zonal climates.

  10. The pineal complex of the European sea bass (Dicentrarchus labrax): I. histological, immunohistochemical and qPCR study.

    PubMed

    Herrera-Pérez, P; Servili, A; Rendón, M C; Sánchez-Vázquez, F J; Falcón, J; Muñoz-Cueto, J A

    2011-04-01

    The pineal organ of fish is a photosensory and neuroendocrine epithalamic structure that plays a key role in the temporal organisation of physiological and behavioural processes. In this study performed in the European sea bass, Dicentrarchus labrax, we provided an in-depth description of the macroscopic and microscopic anatomy of the pineal organ and identified the presence of photoreceptor and presumed melatonin-producing cells using histological and immunohistochemical techniques. In addition, we analysed in the pineal the day-night expression (using quantitative real-time PCR) of two key enzymes in the melatonin-synthesising pathway; arylalkylamine-N-acetyltransferase 2 (AANAT2) and hydroxyindole-O-methyltransferase (HIOMT). The pineal complex of sea bass consisted of a narrow and short pineal stalk that adopts a vertical disposition, a small-sized pineal end vesicle firmly attached to the skull by connective tissue, a parapineal organ and a convoluted dorsal sac. Immunohistochemical study showed the presence of abundant serotonin-positive cells. Cone opsin-like and rod opsin-like photoreceptor cells were also evidenced in the pineal stalk and vesicle. Both Aanat2 and Hiomt were expressed in sea bass pineal organ. Aanat2 exhibited higher nocturnal transcript levels, while no significant day-night differences were found for Hiomt. These results, together with ongoing studies analysing neural and neurohormonal outputs from the pineal organ of sea bass, provide the basic framework to understand the transduction integration of light stimulus in this relevant species for marine aquaculture. PMID:21310229

  11. Regulation of natural killer enhancing factor (NKEF) genes in teleost fish, gilthead seabream and European sea bass.

    PubMed

    Esteban, Mara A; Chaves-Pozo, Elena; Arizcun, Marta; Meseguer, Jos; Cuesta, Alberto

    2013-10-01

    Peroxiredoxins (Prx) are a family of antioxidant proteins also involved in inflammation and innate immunity. Prx1 and Prx2 are also known as natural killer enhancing factor (NKEF)-A and NKEF-B, respectively, by their ability to prime the mammalian NK-cells activity. In teleost fish, NKEF genes have been isolated but their regulation has been scarcely evaluated. We have identified orthologues of the NKEF-A and NKEF-B genes in the teleost European sea bass (Dicentrarchus labrax) which showed constitutive expression and wide distribution in their tissues. In vitro, the gilthead seabream (Sparus aurata) and sea bass NKEFs were slightly up-regulated in head-kidney leucocytes after stimulation with unmethylated CpG oligodeoxynucleotides, poly I:C or pathogenic bacteria. In vivo, seabream and sea bass infection with nodavirus up-regulated the expression of NKEF genes in the brain (target tissue for nodavirus) and head-kidney at different infection times. Although further studies are necessary to ascertain their role as antioxidant proteins and in the immune response in teleost fish, our results suggest a primary role of seabream and sea bass NKEFs in the innate immune response against bacterial and viral agents. PMID:23511025

  12. It's a Salmon's Life!

    ERIC Educational Resources Information Center

    French, M. Jenice; Skochdopole, Laura Downey

    1998-01-01

    Describes an integrated science unit to help preservice teachers gain confidence in their abilities to learn and teach science. The teachers role played being salmon as they learned about the salmon's life cycle and the difficulties salmon encounter. The unit introduced the use of investigative activities that begin with questions and end with…

  13. Adaptive strategies and life history characteristics in a warming climate: salmon in the Arctic?

    USGS Publications Warehouse

    Nielsen, Jennifer L.; Ruggerone, Gregory T.; Zimmerman, Christian E.

    2013-01-01

    In the warming Arctic, aquatic habitats are in flux and salmon are exploring their options. Adult Pacific salmon, including sockeye (Oncorhynchus nerka), coho (O. kisutch), Chinook (O. tshawytscha), pink (O. gorbuscha) and chum (O. keta) have been captured throughout the Arctic. Pink and chum salmon are the most common species found in the Arctic today. These species are less dependent on freshwater habitats as juveniles and grow quickly in marine habitats. Putative spawning populations are rare in the North American Arctic and limited to pink salmon in drainages north of Point Hope, Alaska, chum salmon spawning rivers draining to the northwestern Beaufort Sea, and small populations of chum and pink salmon in Canada’s Mackenzie River. Pacific salmon have colonized several large river basins draining to the Kara, Laptev and East Siberian seas in the Russian Arctic. These populations probably developed from hatchery supplementation efforts in the 1960’s. Hundreds of populations of Arctic Atlantic salmon (Salmo salar) are found in Russia, Norway and Finland. Atlantic salmon have extended their range eastward as far as the Kara Sea in central Russian. A small native population of Atlantic salmon is found in Canada’s Ungava Bay. The northern tip of Quebec seems to be an Atlantic salmon migration barrier for other North American stocks. Compatibility between life history requirements and ecological conditions are prerequisite for salmon colonizing Arctic habitats. Broad-scale predictive models of climate change in the Arctic give little information about feedback processes contributing to local conditions, especially in freshwater systems. This paper reviews the recent history of salmon in the Arctic and explores various patterns of climate change that may influence range expansions and future sustainability of salmon in Arctic habitats. A summary of the research needs that will allow informed expectation of further Arctic colonization by salmon is given.

  14. Disease Resistance in Atlantic Salmon (Salmo salar): Coinfection of the Intracellular Bacterial Pathogen Piscirickettsia salmonis and the Sea Louse Caligus rogercresseyi

    PubMed Central

    Lhorente, Jean Paul; Gallardo, José A.; Villanueva, Beatriz; Carabaño, María J.; Neira, Roberto

    2014-01-01

    Background Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1) coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2) coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. Methodology In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI) of P. salmonis (primary pathogen) or coinfection with C. rogercresseyi (secondary pathogen). Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish). Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. Main Findings C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545). Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23±0.07; h2LC = 0.17±0.08; h2HC = 0.24±0.07). A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99±0.01) but not between the single and coinfection treatments (rg SI-LC = −0.14±0.33; rg SI-HC = 0.32±0.34). Conclusions/Significance C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future research on salmon farming, selective breeding and conservation. PMID:24736323

  15. A global assessment of salmon aquaculture impacts on wild salmonids.

    PubMed

    Ford, Jennifer S; Myers, Ransom A

    2008-02-01

    Since the late 1980s, wild salmon catch and abundance have declined dramatically in the North Atlantic and in much of the northeastern Pacific south of Alaska. In these areas, there has been a concomitant increase in the production of farmed salmon. Previous studies have shown negative impacts on wild salmonids, but these results have been difficult to translate into predictions of change in wild population survival and abundance. We compared marine survival of salmonids in areas with salmon farming to adjacent areas without farms in Scotland, Ireland, Atlantic Canada, and Pacific Canada to estimate changes in marine survival concurrent with the growth of salmon aquaculture. Through a meta-analysis of existing data, we show a reduction in survival or abundance of Atlantic salmon; sea trout; and pink, chum, and coho salmon in association with increased production of farmed salmon. In many cases, these reductions in survival or abundance are greater than 50%. Meta-analytic estimates of the mean effect are significant and negative, suggesting that salmon farming has reduced survival of wild salmon and trout in many populations and countries. PMID:18271629

  16. Phytoplankton invasions: comments on the validity of categorizing the non-indigenous dinoflagellates and diatoms in European seas.

    PubMed

    Gómez, Fernando

    2008-04-01

    The validity of categorizing the diatoms and dinoflagellates reported in the literature as non-indigenous phytoplankton in the European Seas was investigated. Species that are synonymous are often included as separate species (Gessnerium mochimaensis=Alexandrium monilatum, Gymnodinium nagasakiense=Karenia mikimotoi, Pleurosigma simonsenii=P. planctonicum), while other species names are synonyms of cosmopolitan taxa (Prorocentrum redfieldii=P. triestinum, Pseliodinium vaubanii=Gyrodinium falcatum, Gonyaulax grindleyi=Protoceratium reticulatum, Asterionella japonica=Asterionellopsis glacialis). Epithets of an exotic etymology (i.e. japonica, sinensis, indica) imply that a cosmopolitan species may be non-indigenous, and several taxa are even considered as non-indigenous in their type locality (Alexandrium tamarense and A. pseudogoniaulax). The records of Alexandrium monilatum, A. leei and Corethron criophilum are doubtful. Cold or warm-water species expand their geographical ranges or increase their abundances to detectable levels during cooling (Coscinodiscus wailesii) or warming periods (Chaetoceros coarctatus, Proboscia indica, Pyrodinium bahamense). These are a few examples of marginal dispersal associated with climatic events instead of species introductions from remote areas. The number of non-indigenous phytoplankton species in European Seas has thus been excessively inflated. PMID:18295804

  17. SeaDataNet : Pan-European infrastructure for marine and ocean data management - Project objectives, structure and components

    NASA Astrophysics Data System (ADS)

    Maudire, G.; Maillard, C.; Fichaut, M.; Manzella, G.; Schaap, D. M. A.

    2009-04-01

    SeaDataNet : Pan-European infrastructure for marine and ocean data management Project objectives, structure and components G. Maudire (1), C. Maillard (1), G. Manzella (2), M. Fichaut (1), D.M.A. Schaap (3), E. Iona (4) and the SeaDataNet consortium. (1) IFREMER, Brest, France (Gilbert.Maudire@ifremer.fr), (2) ENEA, La Spezia, Italy, (3) Mariene Informatie Service 'MARIS', Voorburg, The Netherlands, (4) Hellenic Centre for Marine Research-HCMR, Anavyssos, Greece. Since a large part of the earth population lives near the oceans or carries on activities directly or indirectly linked to the seas (fishery and aquaculture, exploitation of sea bottom resources, international shipping, tourism), knowledge of oceans is of primary importance for security and economy. However, observation and monitoring of the oceans remains difficult and expensive even if real improvements have been achieved using research vessels and submersibles, satellites and automatic observatories like buoys, floats and seafloor observatories transmitting directly to the shore using global transmission systems. More than 600 governmental or private organizations are active in observation of seas bordering Europe, but European oceanographic data are fragmented, not always validated and not always easily accessible. That highlights the need of international collaboration to tend toward a comprehensive view of ocean mechanisms, resources and changes. SeaDataNet is an Integrated research Infrastructure Initiative (I3) in European Union Framework Program 6 (2006 - 2011) to provide the data management system adapted both to the fragmented observation systems and to the users need for an integrated access to data, meta-data, products and services. Its major objectives are to: - encourage long-term archiving at national level to secure ocean data taking into account that all the observations made in the variable oceanic environment can never be remade if they are lost; - promote best practices for data management, taking benefits of the development of international initiatives and standards on data quality insurance, data descriptions (metadata and common vocabulary) and interoperability. Software tools are developed or adapted accordingly to support these practices and the adoption of standards; - establish online services to facilitate data discovery, data requests, data visualisation and data download for the users; - process data sets of reference like ocean climatologies at a regional basin scale to provide comprehensive data sets Sustainability of the provided services is researched by a balance between the activities mostly undertaken at National level by the National Oceanographic data centres or some thematic data centres and the effort done at the Pan-European level by the project. The SeaDataNet consortium brings now together a unique group of 49 partners from major oceanographic institutes of 35 countries. Taking in account that valuable work on ocean data management must be done at basin level, most of countries bordering Black Sea, Mediterranean Sea, North-East Atlantic, North Sea, Baltic Sea and Artic Sea are part of the project. Capacity building of consortium members is necessary to meet project objectives and a comprehensive training program is conducted both for data management and for IT technologies which are necessary to establish such a distributed system: databases management, XML language, web portal and services, GIS technologies. SeaDataNet Partners: IFREMER (France), MARIS (Netherlands), HCMR/HNODC (Greece), ULg (Belgium), OGS (Italy),NERC/BODC (UK), BSH/DOD (Germany), SMHI (Sweden), IEO (Spain), RIHMI/WDC (Russia), IOC (International), ENEA (Italy), INGV (Italy), METU (Turkey), CLS (France), AWI (Germany), IMR (Norway), NERI (Denmark), ICES (International), EC-DG JRC (International), MI (Ireland), IHPT (Portugal), RIKZ (Netherlands), RBINS/MUMM (Belgium), VLIZ (Belgium), MRI (Iceland), FIMR (Finland ), IMGW (Poland), MSI (Estonia), IAE/UL (Latvia), CMR (Lithuania), SIO/RAS (Russia), MHI/DMIST (Ukraine), IO/BAS (Bulgaria), NIMRD (Romania), TSU (Georgia), INRH (Morocco), IOF (Croatia), PUT (Albania), NIB (Slovenia), UoM (Malta), OC/UCY (Cyprus), IOLR (Israel), NCSR/NCMS (Lebanon), CNR-ISAC (Italy), ISMAL (Algeria), INSTM (Tunisia)

  18. Productivity, facies and stable-isotope records of OAE2 (Cenomanian - Turonian) in the NW European epicontinental sea: from the English Chalk to North Sea black shales

    NASA Astrophysics Data System (ADS)

    Jarvis, Ian; Olde, Kate; Trabucho-Alexandre, João; Gröcke, Darren

    2013-04-01

    The Late Cretaceous (100.5 - 66.0 Ma) provides perhaps the best example of how the Earth System may function under long-term extreme greenhouse conditions. Rapidly rising global temperatures indicate that we are heading 'back to the Cretaceous' within a few hundred years, so a better understanding of this time interval is essential. The beginning of the Late Cretaceous was characterized by a period of rapidly rising eustatic sea level, the Cenomanian transgression, which flooded continental margins and established large areas of new epicontinental sea that accumulated thick sequences of pelagic and hemipelagic carbonate (chalk). Highest global temperatures were reached during the early part of the Turonian Stage (93.9 - 89.8 Ma). This period of dramatic palaeoenvironmental change was accompanied by one the largest perturbations of the global carbon cycle in the Mesozoic: Oceanic Anoxic Event 2 (OAE2), which was characterized by a 500 kyr episode of oceanic anoxia, widespread black shale deposition, biotic turnover, and a large global positive carbon stable-isotope excursion (2 - 6 ‰ ∂13C) recorded in marine carbonates and both marine and terrestrial organic matter. The Cenomanian-Turonian boundary interval exposed at Eastbourne, southern England, has become established as a European reference section for OAE2. Here, and elsewhere in Europe, the base of the ∂13C excursion is coincident with a marked facies change from rhythmically bedded grey chalks and marls, to a >8 m thick package of dark greenish-grey marl - the Plenus Marl. The termination of OAE2 occurs 6 m above, in a package of pale-yellow-weathering nodular chalks with prominent marl seams. Sediments are organic lean (<0.2 wt% TOC) and bioturbated throughout, and although a case can be made for periodic oxygen depletion in bottom waters, there is no evidence here of marine surface- or bottom-water anoxia. The Plenus Marl displays a distinctive succession of 8 beds that can be correlated throughout southern England and northern France, and the formation is widely developed in the North Sea Basin where it forms an important lithostratigraphic and geophysical marker. In contrast to southern England, the Plenus Marl of the North Sea (Blodøks Formation of the Norwegian sector) consists of a succession with laminated black shales yielding TOC >10 wt%. The onshore equivalent in eastern England (the Black Band) is similarly organic-rich, as are comparable sections in northern Germany (e.g. Wunstorf), indicating likely fully anoxic episodes within some NW European basins. The exact stratigraphic equivalence between the onshore Plenus Marl, North Sea black shales and the Black Band remains controversial. Here, we compare the lithofacies, sedimentology, elemental and stable-isotope records, and palynology of Upper Cenomanian - Lower Turonian sections in southern England to those from a central North Sea cored reference well that includes a 6 m package with laminated black shales (Plenus Marl). Factors influencing carbonate and organic matter ∂13C trends in the records will be considered in the context of the palaeoceanographic and palaeoclimatic events that accompanied eustatic sea-level change, culminating in OAE2 and the subsequent global climatic optimum. The effects of diagenesis on the stable-isotope records will be discussed.

  19. Development of an oligo DNA microarray for the European sea bass and its application to expression profiling of jaw deformity

    PubMed Central

    2010-01-01

    Background The European sea bass (Dicentrarchus labrax) is a marine fish of great importance for fisheries and aquaculture. Functional genomics offers the possibility to discover the molecular mechanisms underlying productive traits in farmed fish, and a step towards the application of marker assisted selection methods in this species. To this end, we report here on the development of an oligo DNA microarray for D. labrax. Results A database consisting of 19,048 unique transcripts was constructed, of which 12,008 (63%) could be annotated by similarity and 4,692 received a GO functional annotation. Two non-overlapping 60mer probes were designed for each unique transcript and in-situ synthesized on glass slides using Agilent SurePrint™ technology. Probe design was positively completed for 19,035 target clusters; the oligo microarray was then applied to profile gene expression in mandibles and whole-heads of fish affected by prognathism, a skeletal malformation that strongly affects sea bass production. Statistical analysis identified 242 transcripts that are significantly down-regulated in deformed individuals compared to normal fish, with a significant enrichment in genes related to nervous system development and functioning. A set of genes spanning a wide dynamic range in gene expression level were selected for quantitative RT-PCR validation. Fold change correlation between microarray and qPCR data was always significant. Conclusions The microarray platform developed for the European sea bass has a high level of flexibility, reliability, and reproducibility. Despite the well known limitations in achieving a proper functional annotation in non-model species, sufficient information was obtained to identify biological processes that are significantly enriched among differentially expressed genes. New insights were obtained on putative mechanisms involved on mandibular prognathism, suggesting that bone/nervous system development might play a role in this phenomenon. PMID:20525278

  20. Qualitative assessment of the diet of European eel larvae in the Sargasso Sea resolved by DNA barcoding.

    PubMed

    Riemann, Lasse; Alfredsson, Hanna; Hansen, Michael M; Als, Thomas D; Nielsen, Torkel G; Munk, Peter; Aarestrup, Kim; Maes, Gregory E; Sparholt, Henrik; Petersen, Michael I; Bachler, Mirjam; Castonguay, Martin

    2010-12-23

    European eels (Anguilla anguilla) undertake spawning migrations of more than 5000 km from continental Europe and North Africa to frontal zones in the Sargasso Sea. Subsequently, the larval offspring are advected by large-scale eastward ocean currents towards continental waters. However, the Sargasso Sea is oligotrophic, with generally low plankton biomass, and the feeding biology of eel larvae has so far remained a mystery, hampering understanding of this peculiar life history. DNA barcoding of gut contents of 61 genetically identified A. anguilla larvae caught in the Sargasso Sea showed that even the smallest larvae feed on a striking variety of plankton organisms, and that gelatinous zooplankton is of fundamental dietary importance. Hence, the specific plankton composition seems essential for eel larval feeding and growth, suggesting a linkage between eel survival and regional plankton productivity. These novel insights into the prey of Atlantic eels may furthermore facilitate eel larval rearing in aquaculture, which ultimately may replace the unsustainable use of wild-caught glass eels. PMID:20573615

  1. Leptin receptor gene in the European sea bass (Dicentrarchus labrax): Cloning, phylogeny, tissue distribution and neuroanatomical organization.

    PubMed

    Escobar, Sebastián; Rocha, Ana; Felip, Alicia; Carrillo, Manuel; Zanuy, Silvia; Kah, Olivier; Servili, Arianna

    2016-04-01

    In this study, we report the cloning of three transcripts for leptin receptor in the European sea bass, a marine teleost of economic interest. The two shortest variants, generated by different splice sites, encode all functional extracellular and intracellular domains but missed the transmembrane domain. The resulting proteins are therefore potential soluble binding proteins for leptin. The longest transcript (3605bp), termed sblepr, includes all the essential domains for binding and transduction of the signal. Thus, it is proposed as the ortholog for the human LEPR gene, the main responsible for leptin signaling. Phylogenetic analysis shows the sblepr clustered within the teleost leptin receptor group in 100% of the bootstrap replicates. The neuroanatomical localization of sblepr expressing cells has been assessed by in situ hybridization in brains of sea bass of both sexes during their first sexual maturation. At histological level, the distribution pattern of sblepr expressing cells in the brain shows no clear differences regarding sex or reproductive season. Transcripts of the sblepr have a widespread distribution throughout the forebrain and midbrain until the caudal portion of the hypothalamus. A high hybridization signal is detected in the telencephalon, preoptic area, medial basal and caudal hypothalamus and in the pituitary gland. In a more caudal region, sblepr expressing cells are identified in the longitudinal torus. The expression pattern observed for sblepr suggests that in sea bass, leptin is very likely to be involved in the control of food intake, energy reserves and reproduction. PMID:26979276

  2. Qualitative assessment of the diet of European eel larvae in the Sargasso Sea resolved by DNA barcoding

    PubMed Central

    Riemann, Lasse; Alfredsson, Hanna; Hansen, Michael M.; Als, Thomas D.; Nielsen, Torkel G.; Munk, Peter; Aarestrup, Kim; Maes, Gregory E.; Sparholt, Henrik; Petersen, Michael I.; Bachler, Mirjam; Castonguay, Martin

    2010-01-01

    European eels (Anguilla anguilla) undertake spawning migrations of more than 5000 km from continental Europe and North Africa to frontal zones in the Sargasso Sea. Subsequently, the larval offspring are advected by large-scale eastward ocean currents towards continental waters. However, the Sargasso Sea is oligotrophic, with generally low plankton biomass, and the feeding biology of eel larvae has so far remained a mystery, hampering understanding of this peculiar life history. DNA barcoding of gut contents of 61 genetically identified A. anguilla larvae caught in the Sargasso Sea showed that even the smallest larvae feed on a striking variety of plankton organisms, and that gelatinous zooplankton is of fundamental dietary importance. Hence, the specific plankton composition seems essential for eel larval feeding and growth, suggesting a linkage between eel survival and regional plankton productivity. These novel insights into the prey of Atlantic eels may furthermore facilitate eel larval rearing in aquaculture, which ultimately may replace the unsustainable use of wild-caught glass eels. PMID:20573615

  3. Distribution and persistence of the anti sea-lice drug teflubenzuron in wild fauna and sediments around a salmon farm, following a standard treatment.

    PubMed

    Samuelsen, Ole B; Lunestad, Bjørn T; Hannisdal, Rita; Bannister, Raymond; Olsen, Siri; Tjensvoll, Tore; Farestveit, Eva; Ervik, Arne

    2015-03-01

    The salmon louse (Lepeoptheirus salmonis) is a challenge in the farming of Atlantic salmon (Salmo salar). To treat an infestation, different insecticides are used like the orally administered chitin synthetase inhibitor teflubenzuron. The concentrations and distribution of teflubenzuron were measured in water, organic particles, marine sediment and biota caught in the vicinity of a fish farm following a standard medication. Low concentrations were found in water samples whereas the organic waste from the farm, collected by sediment traps had concentrations higher than the medicated feed. Most of the organic waste was distributed to the bottom close to the farm but organic particles containing teflubenzuron were collected 1100 m from the farm. The sediment under the farm consisted of 5 to 10% organic material and therefore the concentration of teflubenzuron was much lower than in the organic waste. Teflubenzuron was persistent in the sediment with a stipulated halflife of 170 days. Sediment consuming polychaetes had high but decreasing concentrations of teflubenzuron throughout the experimental period, reflecting the decrease of teflubenzuron in the sediment. During medication most wild fauna contained teflubenzuron residues and where polychaetes and saith had highest concentrations. Eight months later only polychaetes and some crustaceans contained drug residues. What dosages that induce mortality in various crustaceans following short or long-term exposure is not known but the results indicate that the concentrations in defined individuals of king crab, shrimp, squat lobster and Norway lobster were high enough shortly after medication to induce mortality if moulting was imminent. Considering food safety, saith and the brown meat of crustaceans contained at first sampling concentrations of teflubenzuron higher than the MRL-value set for Atlantic salmon. The concentrations were, however, moderate and the amount of saith fillet or brown meat of crustaceans to be consumed in order to exceed ADI is relatively large. PMID:25474168

  4. European weather sensitivity to Barents-Kara sea-ice variability

    NASA Astrophysics Data System (ADS)

    Ruggieri, Paolo; Buizza, Roberto; Visconti, Guido

    2015-04-01

    The rapid decline of sea-ice cover in the Arctic has recently instilled great interest in the atmospheric dynamics community, who has been trying to understand the links between this region and the extra-tropical circulation. One of the aspects that has attracted attention has been the so-called Arctic Amplification mechanism linked to the sea ice variability over the Barents and Kara seas (B-K). In this work, we investigate this link and show that changes in the tropospheric circulation over the Euro-Atlantic sector can be associated with sea ice variability in B-K. The links between the local response in the surroundings of the B-K seas, expressed in terms of temperature and pressure anomalies, and atmospheric regimes in the North Atlantic, identified with a low-level jet index and a blocking index, are investigated looking at 16 years of winter weather reanalyses. It is found that cooling over Western Europe can be caused, or at least enhanced, by the atmosphere dynamics response to low B-K sea ice conditions. Reanalyses of the 100 hPa heat flux and of the intensity of the stratospheric polar vortex suggest that a two-way coupling troposphere-stratosphere is one of the key physical mechanisms linking the B-K seas and the Euro-Atlantic variability. Years with low ice cover are found to be associated with enhanced high-latitude blocking activity in the North Atlantic, with increased occurrence of low-latitude jet events that induce cold-air advection over Europe. In this framework, blocking events can be interpreted both as the cause and the consequence of the intense coupling between the lower and the upper atmosphere by means of vertical propagation of planetary waves. The impact of B-K sea ice variability over Europe thus appears to be associated with a positive feedback between high latitude blocking and changes in the stratospheric circulation. Although the variability of early winter B-K sea ice is probably only one of factors driving the coupling, we speculate that it has a potential role in the predictability of a class of severe events in Europe.

  5. Indirect benefits for female salmon from mating with brown trout.

    PubMed

    Castillo, Ana G F; Beall, Edward; Morán, Paloma; Martinez, Jose L; Garcia-Vazquez, Eva

    2010-01-01

    By genetic analysis of 1625 samples from 10 south European rivers, we have found that Atlantic salmon Salmo salar hybridize with sympatric brown trout S. trutta in the wild and provide the female in most heterospecific crosses. Hybrids exhibit reduced fertility and could be considered a wasted reproductive effort by salmon females. In 7 experiments involving salmon females, large brown trout males, and small salmon male sneakers, reproductive success of Atlantic salmon females mating with brown trout males was not significantly different from that of 5 experiments of females mating with conspecific males because small Atlantic salmon sneakers fertilized most ova (mean 93%) in salmon x trout matings. Although egg retention tended to be higher in heterospecific than in conspecific crosses (mean 5.7% vs. 20.5% respectively), mean offspring survival was 24.4% and 30.3%, respectively (t = 1.5 x 10(-8), not significant). Brown trout males taking on a courting role may benefit late-maturing females in absence or scarcity of anadromous salmon males because they play a protective role against disturbances from other fishes (including cannibal sneakers). PMID:20453033

  6. SeaDataNet - Pan-European infrastructure for marine and ocean data management: Unified access to distributed data sets

    NASA Astrophysics Data System (ADS)

    Schaap, D. M. A.; Maudire, G.

    2009-04-01

    SeaDataNet is an Integrated research Infrastructure Initiative (I3) in EU FP6 (2006 - 2011) to provide the data management system adapted both to the fragmented observation system and the users need for an integrated access to data, meta-data, products and services. Therefore SeaDataNet insures the long term archiving of the large number of multidisciplinary data (i.e. temperature, salinity current, sea level, chemical, physical and biological properties) collected by many different sensors installed on board of research vessels, satellite and the various platforms of the marine observing system. The SeaDataNet project started in 2006, but builds upon earlier data management infrastructure projects, undertaken over a period of 20 years by an expanding network of oceanographic data centres from the countries around all European seas. Its predecessor project Sea-Search had a strict focus on metadata. SeaDataNet maintains significant interest in the further development of the metadata infrastructure, but its primary objective is the provision of easy data access and generic data products. SeaDataNet is a distributed infrastructure that provides transnational access to marine data, meta-data, products and services through 40 interconnected Trans National Data Access Platforms (TAP) from 35 countries around the Black Sea, Mediterranean, North East Atlantic, North Sea, Baltic and Arctic regions. These include: National Oceanographic Data Centres (NODC's) Satellite Data Centres. Furthermore the SeaDataNet consortium comprises a number of expert modelling centres, SME's experts in IT, and 3 international bodies (ICES, IOC and JRC). Planning: The SeaDataNet project is delivering and operating the infrastructure in 3 versions: Version 0: maintenance and further development of the metadata systems developed by the Sea-Search project plus the development of a new metadata system for indexing and accessing to individual data objects managed by the SeaDataNet data centres. This is known as the Common Data Index (CDI) V0 system Version 1: harmonisation and upgrading of the metadatabases through adoption of the ISO 19115 metadata standard and provision of transparent data access and download services from all partner data centres through upgrading the Common Data Index and deployment of a data object delivery service. Version 2: adding data product services and OGC compliant viewing services and further virtualisation of data access. SeaDataNet Version 0: The SeaDataNet portal has been set up at http://www.seadatanet.org and it provides a platform for all SeaDataNet services and standards as well as background information about the project and its partners. It includes discovery services via the following catalogues: CSR - Cruise Summary Reports of research vessels; EDIOS - Locations and details of monitoring stations and networks / programmes; EDMED - High level inventory of Marine Environmental Data sets collected and managed by research institutes and organisations; EDMERP - Marine Environmental Research Projects ; EDMO - Marine Organisations. These catalogues are interrelated, where possible, to facilitate cross searching and context searching. These catalogues connect to the Common Data Index (CDI). Common Data Index (CDI) The CDI gives detailed insight in available datasets at partners databases and paves the way to direct online data access or direct online requests for data access / data delivery. The CDI V0 metadatabase contains more than 340.000 individual data entries from 36 CDI partners from 29 countries across Europe, covering a broad scope and range of data, held by these organisations. For purposes of standardisation and international exchange the ISO19115 metadata standard has been adopted. The CDI format is defined as a dedicated subset of this standard. A CDI XML format supports the exchange between CDI-partners and the central CDI manager, and ensures interoperability with other systems and networks. CDI XML entries are generated by participating data centres, directly from their databases. CDI-partners can make use of dedicated SeaDataNet Tools to generate CDI XML files automatically. Approach for SeaDataNet V1 and V2: The approach for SeaDataNet V1 and V2, which is in line with the INSPIRE Directive, comprises the following services: Discovery services = Metadata directories Security services = Authentication, Authorization & Accounting (AAA) Delivery services = Data access & downloading of datasets Viewing services = Visualisation of metadata, data and data products Product services = Generic and standard products Monitoring services = Statistics on usage and performance of the system Maintenance services = Updating of metadata by SeaDataNet partners The services will be operated over a distributed network of interconnected Data Centres accessed through a central Portal. In addition to service access the portal will provide information on data management standards, tools and protocols. The architecture has been designed to provide a coherent system based on V1 services, whilst leaving the pathway open for later extension with V2 services. For the implementation, a range of technical components have been defined. Some are already operational with the remainder in the final stages of development and testing. These make use of recent web technologies, and also comprise Java components, to provide multi-platform support and syntactic interoperability. To facilitate sharing of resources and interoperability, SeaDataNet has adopted SOAP Web Service technology. The SeaDataNet architecture and components have been designed to handle all kinds of oceanographic and marine environmental data including both in-situ measurements and remote sensing observations. The V1 technical development is ready and the V1 system is now being implemented and adopted by all participating data centres in SeaDataNet. Interoperability: Interoperability is the key to distributed data management system success and it is achieved in SeaDataNet V1 by: Using common quality control protocols and flag scale Using controlled vocabularies from a single source that have been developed using international content governance Adopting the ISO 19115 metadata standard for all metadata directories Providing XML Validation Services to quality control the metadata maintenance, including field content verification based on Schematron. Providing standard metadata entry tools Using harmonised Data Transport Formats (NetCDF, ODV ASCII and MedAtlas ASCII) for data sets delivery Adopting of OGC standards for mapping and viewing services Using SOAP Web Services in the SeaDataNet architecture SeaDataNet V1 Delivery Services: An important objective of the V1 system is to provide transparent access to the distributed data sets via a unique user interface at the SeaDataNet portal and download service. In the SeaDataNet V1 architecture the Common Data Index (CDI) V1 provides the link between discovery and delivery. The CDI user interface enables users to have a detailed insight of the availability and geographical distribution of marine data, archived at the connected data centres, and it provides the means for downloading data sets in common formats via a transaction mechanism. The SeaDataNet portal provides registered users access to these distributed data sets via the CDI V1 Directory and a shopping basket mechanism. This allows registered users to locate data of interest and submit their data requests. The requests are forwarded automatically from the portal to the relevant SeaDataNet data centres. This process is controlled via the Request Status Manager (RSM) Web Service at the portal and a Download Manager (DM) java software module, implemented at each of the data centres. The RSM also enables registered users to check regularly the status of their requests and download data sets, after access has been granted. Data centres can follow all transactions for their data sets online and can handle requests which require their consent. The actual delivery of data sets is done between the user and the selected data centre. The CDI V1 system is now being populated by all participating data centres in SeaDataNet, thereby phasing out CDI V0. 0.1 SeaDataNet Partners: IFREMER (France), MARIS (Netherlands), HCMR/HNODC (Greece), ULg (Belgium), OGS (Italy), NERC/BODC (UK), BSH/DOD (Germany), SMHI (Sweden), IEO (Spain), RIHMI/WDC (Russia), IOC (International), ENEA (Italy), INGV (Italy), METU (Turkey), CLS (France), AWI (Germany), IMR (Norway), NERI (Denmark), ICES (International), EC-DG JRC (International), MI (Ireland), IHPT (Portugal), RIKZ (Netherlands), RBINS/MUMM (Belgium), VLIZ (Belgium), MRI (Iceland), FIMR (Finland ), IMGW (Poland), MSI (Estonia), IAE/UL (Latvia), CMR (Lithuania), SIO/RAS (Russia), MHI/DMIST (Ukraine), IO/BAS (Bulgaria), NIMRD (Romania), TSU (Georgia), INRH (Morocco), IOF (Croatia), PUT (Albania), NIB (Slovenia), UoM (Malta), OC/UCY (Cyprus), IOLR (Israel), NCSR/NCMS (Lebanon), CNR-ISAC (Italy), ISMAL (Algeria), INSTM (Tunisia)

  7. A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas: The PERSEUS experience.

    PubMed

    Crise, A; Kaberi, H; Ruiz, J; Zatsepin, A; Arashkevich, E; Giani, M; Karageorgis, A P; Prieto, L; Pantazi, M; Gonzalez-Fernandez, D; Ribera d'Alcalà, M; Tornero, V; Vassilopoulou, V; Durrieu de Madron, X; Guieu, C; Puig, P; Zenetos, A; Andral, B; Angel, D; Altukhov, D; Ayata, S D; Aktan, Y; Balcıoğlu, E; Benedetti, F; Bouchoucha, M; Buia, M-C; Cadiou, J-F; Canals, M; Chakroun, M; Christou, E; Christidis, M G; Civitarese, G; Coatu, V; Corsini-Foka, M; Cozzi, S; Deidun, A; Dell'Aquila, A; Dogrammatzi, A; Dumitrache, C; Edelist, D; Ettahiri, O; Fonda-Umani, S; Gana, S; Galgani, F; Gasparini, S; Giannakourou, A; Gomoiu, M-T; Gubanova, A; Gücü, A-C; Gürses, Ö; Hanke, G; Hatzianestis, I; Herut, B; Hone, R; Huertas, E; Irisson, J-O; İşinibilir, M; Jimenez, J A; Kalogirou, S; Kapiris, K; Karamfilov, V; Kavadas, S; Keskin, Ç; Kideyş, A E; Kocak, M; Kondylatos, G; Kontogiannis, C; Kosyan, R; Koubbi, P; Kušpilić, G; La Ferla, R; Langone, L; Laroche, S; Lazar, L; Lefkaditou, E; Lemeshko, I E; Machias, A; Malej, A; Mazzocchi, M-G; Medinets, V; Mihalopoulos, N; Miserocchi, S; Moncheva, S; Mukhanov, V; Oaie, G; Oros, A; Öztürk, A A; Öztürk, B; Panayotova, M; Prospathopoulos, A; Radu, G; Raykov, V; Reglero, P; Reygondeau, G; Rougeron, N; Salihoglu, B; Sanchez-Vidal, A; Sannino, G; Santinelli, C; Secrieru, D; Shapiro, G; Simboura, N; Shiganova, T; Sprovieri, M; Stefanova, K; Streftaris, N; Tirelli, V; Tom, M; Topaloğlu, B; Topçu, N E; Tsagarakis, K; Tsangaris, C; Tserpes, G; Tuğrul, S; Uysal, Z; Vasile, D; Violaki, K; Xu, J; Yüksek, A; Papathanassiou, E

    2015-06-15

    PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. PMID:25892079

  8. Photoperiodic Modulation of Circadian Clock and Reproductive Axis Gene Expression in the Pre-Pubertal European Sea Bass Brain

    PubMed Central

    Martins, Rute S. T.; Gomez, Ana; Zanuy, Silvia; Carrillo, Manuel; Canário, Adelino V. M.

    2015-01-01

    The acquisition of reproductive competence requires the activation of the brain-pituitary-gonad (BPG) axis, which in most vertebrates, including fishes, is initiated by changes in photoperiod. In the European sea bass long-term exposure to continuous light (LL) alters the rhythm of reproductive hormones, delays spermatogenesis and reduces the incidence of precocious males. In contrast, an early shift from long to short photoperiod (AP) accelerates spermatogenesis. However, how photoperiod affects key genes in the brain to trigger the onset of puberty is still largely unknown. Here, we investigated if the integration of the light stimulus by clock proteins is sufficient to activate key genes that trigger the BPG axis in the European sea bass. We found that the clock genes clock, npas2, bmal1 and the BPG genes gnrh, kiss and kissr share conserved transcription factor frameworks in their promoters, suggesting co-regulation. Other gene promoters of the BGP axis were also predicted to be co-regulated by the same frameworks. Co-regulation was confirmed through gene expression analysis of brains from males exposed to LL or AP photoperiod compared to natural conditions: LL fish had suppressed gnrh1, kiss2, galr1b and esr1, while AP fish had stimulated npas2, gnrh1, gnrh2, kiss2, kiss1rb and galr1b compared to NP. It is concluded that fish exposed to different photoperiods present significant expression differences in some clock and reproductive axis related genes well before the first detectable endocrine and morphological responses of the BPG axis. PMID:26641263

  9. Effect of two sulfur-containing amino acids, taurine and hypotaurine in European sea bass (Dicentrarchus labrax) sperm cryopreservation.

    PubMed

    Martínez-Páramo, S; Diogo, P; Dinis, M T; Soares, F; Sarasquete, C; Cabrita, E

    2013-06-01

    In the present work, taurine and hypotaurine were evaluated as potential additives to improve European sea bass (Dicentrarchus labrax) sperm quality after cryopreservation. For cryopreservation, three different extenders were used: control extender (NAM), supplemented with 1mM taurine or supplemented with 1mM hypotaurine, all of them containing 10% Me₂SO as cryoprotectant. To evaluate sperm quality of fresh and thawed sperm, motility (CASA: computer assisted sperm analysis), viability (SYBR Green/propidium iodide), lipid peroxidation (malondialdehyde level), protein oxidation (carbonyl content), glutathione peroxidase, glutathione reductase and superoxide dismutase activities and DNA fragmentation (comet assay) were quantified. The result demonstrated that 1 mM hypotaurine supplemented extender increased total motility (30.1 ± 3.2%), and that 1 mM taurine extender produced higher velocity (18.1 ± 2.6 μm/s) and linearity (46.0 ± 4.8%) than the control extender (21.8 ± 3.2%, 15.5 ± 1.3 μm/s, 41.8 ± 2.4%, respectively). Cell viability, lipid peroxidation and protein oxidation were not statistically different between treatments. Similar results were obtained for glutathione peroxidase and superoxide dismutase activities. Only glutathione reductase showed differential activity before and after freezing, increasing its activity in thawed sperm. Regarding the comet assay results, taurine and hypotaurine significantly reduced DNA fragmentation (52.8 ± 0.9% and 51.8 ± 0.9%, respectively) in comparison to the control (55.7 ± 0.8%). In conclusion, for European sea bass sperm cryopreservation, extenders supplemented with 1 mM taurine and 1 mM hypotaurine improved some parameters of sperm quality after thawing, resulting in better motility and lower DNA damage than the control, two very important factors related to fertilization success. PMID:23583301

  10. 76 FR 42099 - Fisheries of the Exclusive Economic Zone Off Alaska; Chinook Salmon Bycatch Management in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ...NMFS proposes to implement the Chinook Salmon Economic Data Report Program to evaluate the effectiveness of Chinook salmon bycatch management measures for the Bering Sea pollock fishery that were implemented under Amendment 91 to the Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area (FMP). The data collected for this program would be submitted by......

  11. 77 FR 5389 - Fisheries of the Exclusive Economic Zone Off Alaska; Chinook Salmon Bycatch Management in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ...NMFS issues a final rule to implement the Chinook Salmon Economic Data Report Program, which will evaluate the effectiveness of Chinook salmon bycatch management measures for the Bering Sea pollock fishery that were implemented under Amendment 91 to the Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area (FMP). Members of the American Fisheries Act......

  12. Transcription of T cell-related genes in teleost fish, and the European sea bass (Dicentrarchus labrax) as a model.

    PubMed

    Boschi, I; Randelli, E; Buonocore, F; Casani, D; Bernini, C; Fausto, A M; Scapigliati, G

    2011-11-01

    In recent years the cloning of genes coding for immuno-regulatory peptides, as well as the sequencing of genomes, provided fish immunologists with a growing amount of information on nucleotide sequences. Research is now also addressed in investigating the functional immunology counterpart of nucleotide sequence transcripts in various fish species. In this respect, studies on functional immunology of T cell activities are still at their beginning, and much work is needed to investigate T cell responses in teleost fish species. In this review we summarise the current knowledge on the group of genes coding for main T cell-related peptides in fish, and the expression levels of these genes in organs and tissues. Particular attention is paid to European sea bass (Dicentrarchus labrax), a marine species in which some information on functional immunology has been obtained, and we reassume here the expression of some T cell-related genes in basal conditions. In addition, we provide original data showing that T cells purified from the intestinal mucosa of sea bass with a specific mAb, express transcripts for TRβ, TRγ, CD8α, and RAG-1, thus showing similarities with intra-epithelial leucocytes of mammals. PMID:20950688

  13. SJNNV down-regulates RGNNV replication in European sea bass by the induction of the type I interferon system.

    PubMed

    Carballo, Carlos; Garcia-Rosado, Esther; Borrego, Juan J; Alonso, M Carmen

    2016-01-01

    European sea bass is highly susceptible to the betanodavirus RGNNV genotype, although the SJNNV genotype has also been detected in this fish species. The coexistence of both genotypes may affect the replication of both viruses by viral interaction or by stimulation of the host antiviral defense system in which the IFN I system plays a key role. IFN I triggers the transcription of interferon-stimulated genes, including Mx genes, whose expression has been used as a reporter of IFN I activity. The present study evaluated the effect of a primary exposure to an SJNNV isolate on a subsequent RGNNV infection and analyzed the role of the IFN I system in controlling VNNV infections in sea bass using different in vivo approaches. VNNV infection and Mx transcription were comparatively evaluated after single infections, superinfection (SJ+RG) and co-infection (poly I:C+RG). The single RGNNV infection resulted in a 24% survival rate, whereas the previous SJNNV or poly I:C inoculation increased the survival rate up to 96 and 100%, respectively. RGNNV replication in superinfection was reduced compared with RGNNV replication after a single inoculation. Mx transcription analysis shows differential induction of the IFN I system by both isolates. SJNNV was a potent Mx inducer, whereas RGNNV induced lower Mx transcription and did not interfere with the IFN I system triggered by SJNNV or poly I:C. This study demonstrates that an antiviral state exists after SJNNV and poly I:C injection, suggesting that the IFN I system plays an important role against VNNV infections in sea bass. PMID:26743933

  14. Salmon River Fish Hatchery: Home Base for Released Salmon

    Salmon that have been reared and released at the NY State Salmon River Fish Hatchery imprint on the Hatchery waters, often returning to visit the Hatchery after they are released. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this dim...

  15. Salmon River Fish Hatchery: Home Base for Released Salmon

    Salmon that have been reared and released at the NY State Salmon River Fish Hatchery imprint on the Hatchery waters, often returning to visit the Hatchery after they are released. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this diminish...

  16. USGS Releases Atlantic Salmon at the Salmon River Fish Hatchery

    USGS scientists (L to R) Ross Abbett and Rich Chiavelli watch as hundreds of salmon swim into troughs at the NY State Salmon River Fish Hatchery. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this diminished Lake Ontario fish population, e...

  17. A case study on bio-optical and radiometric quantities in northwest European shelf seas

    NASA Astrophysics Data System (ADS)

    Garaba, Shungu; Zielinski, Oliver

    2013-04-01

    Colour of seawater has become an integral tool in understanding surface marine ecosystems and processes. Additionally, operational oceanographic observatories are becoming more prominent these days while at the same time hyperspectral radiometric sensors are becoming increasingly affordable. This has driven a wide spread use of these hyperspectral sensors to measure reflectance above the water surface from stationary and mobile platforms alike. As enormous amounts of data are produced and favourably processed in real-time, effective quality control procedures become more than just supporting tools, but a crucial prerequisite for trustworthy and manageable information. Here, we use bio-geophysical and hyperspectral radiometric measurements from German Bight (GB), North Sea (NS), Inner Seas (ISS), Irish Sea (IS) and Celtic Sea (CS) to identify and establish relationships between colour producing agents (CPAs) and perceived colour of seawater. In order to obtain valid optical measurements, meteorological and sunglint contamination were mitigated using state-of-the-art quality control protocols. The remote sensing reflectance measured is transformed into discrete Forel-Ule numerical indices (FUI), 1 (indigo-blue, oligotrophic) to 21 (cola brown, hyper-eutrophic). We present a novel approach of estimating which of the three main CPAs of seawater control perceived colour of seawater. Our bio-optical models for estimating FUI for measured CPAs; chlorophyll (Chl-a), coloured dissolved organic material (CDOM) and suspended particulate material (SPM) had correlation coefficients, R² (GB = 0.98, NS = 0.23, ISS=0.99, IS=0.63, CS = 0.16). It was also observed that salinity can be estimated from coloured dissolved organic matter with good accuracy, R² (GB = 0.94, NS = 0.44, ISS=0.90, IS=0.85, CS = 0.51). We show that ocean colour products i.e. reflectance and perceived colour of seawater can be used to infer, with good accuracy, environmental parameters e.g. Chl-a, CDOM, SPM, salinity and Secchi depth of the investigated waters providing an effective and affordable tool for operational marine observations. Improved and extensive field investigations are required to further enhance the sensitivity/accuracy of such region specific bio-optical models.

  18. Saving the Salmon

    ERIC Educational Resources Information Center

    Sprangers, Donald

    2004-01-01

    In November 2000, wild Atlantic salmon were placed under the protection of the Endangered Species Act of 1973. Washington Academy (WA) in Maine has played an integral role in the education and restoration of this species. Efforts to restore the salmon's dwindling population, enhance critical habitat areas, and educate and inform the public require

  19. Saving the Salmon

    ERIC Educational Resources Information Center

    Sprangers, Donald

    2004-01-01

    In November 2000, wild Atlantic salmon were placed under the protection of the Endangered Species Act of 1973. Washington Academy (WA) in Maine has played an integral role in the education and restoration of this species. Efforts to restore the salmon's dwindling population, enhance critical habitat areas, and educate and inform the public require…

  20. Yearling Atlantic Salmon

    A new, sophisticated fish rearing facility in Cortland, N.Y. will help restore Atlantic salmon, bloater, and lake herring to Lake Ontario, strengthening the local ecosystem and economy. To restore the population, young Atlantic salmon are reared at the USGS Tunison Laboratory of Aquaitic Science&nb...

  1. Young Atlantic Salmon

    These two-day old Atlantic salmon were hatched at the USGS Tunison Lab and will eventually be released in Lake Ontario tributaries. A new, sophisticated fish rearing facility in Cortland, N.Y. will help restore Atlantic salmon, bloater, and lake herring to Lake Ontario, strengthening the local...

  2. Salmon-Filled Tanks

    Specialized tanks at the USGS Tunison Lab hold young Atlantic salmon until they are released in Lake Ontario tributaries. A new, sophisticated fish rearing facility in Cortland, N.Y. will help restore Atlantic salmon, bloater, and lake herring to Lake Ontario, strengthening the local ecosystem and ...

  3. Young Atlantic Salmon

    These two-day old Atlantic salmon were hatched at the USGS Tunison Lab and will eventually be released in Lake Ontario tributaries. A new, sophisticated fish rearing facility in Cortland, N.Y. will help restore Atlantic salmon, bloater, and lake herring to Lake Ontario, strengthening the local ecos...

  4. Gene expression patterns during the larval development of European sea bass (dicentrarchus labrax) by microarray analysis.

    PubMed

    Darias, M J; Zambonino-Infante, J L; Hugot, K; Cahu, C L; Mazurais, D

    2008-01-01

    During the larval period, marine teleosts undergo very fast growth and dramatic changes in morphology, metabolism, and behavior to accomplish their metamorphosis into juvenile fish. Regulation of gene expression is widely thought to be a key mechanism underlying the management of the biological processes required for harmonious development over this phase of life. To provide an overall analysis of gene expression in the whole body during sea bass larval development, we monitored the expression of 6,626 distinct genes at 10 different points in time between 7 and 43 days post-hatching (dph) by using heterologous hybridization of a rainbow trout cDNA microarray. The differentially expressed genes (n = 485) could be grouped into two categories: genes that were generally up-expressed early, between 7 and 23 dph, and genes up-expressed between 25 and 43 dph. Interestingly, among the genes regulated during the larval period, those related to organogenesis, energy pathways, biosynthesis, and digestion were over-represented compared with total set of analyzed genes. We discuss the quantitative regulation of whole-body contents of these specific transcripts with regard to the ontogenesis and maturation of essential functions that take place over larval development. Our study is the first utilization of a transcriptomic approach in sea bass and reveals dynamic changes in gene expression patterns in relation to marine finfish larval development. PMID:18246396

  5. Arm regeneration frequency in eight species of ophiuroidea (Echinodermata) from European sea areas

    NASA Astrophysics Data System (ADS)

    Sköld, Mattias; Rosenberg, Rutger

    1996-06-01

    Eight ophiuroid species, six from the northern Kattegat-eastern Skagerrak and three from the northern Adriatic Sea, were examined for regeneration of arms. The species were separated into groups based upon mode of feeding and habitat. Comparison between groups collected in the northern Kattegat-eastern Skagerrak showed that infaunal suspension- and deposit-feeding species ( Amphiura filiformis and A. chiajei) had significantly more scars per arm (mean number 0.78) than epibenthic suspension feeders ( Ophiothrix fragilis and Ophiocomina nigra, 0.29) or epibenthic carnivores and deposit feeders ( Ophiura ophiura and O. albida, 0.13). Spatial variation in arm regeneration incidence was found between sampling sites in the northern Kattegat-eastern Skagerrak for Amphiura filiformis and in the northern Adriatic Sea for Ophiothrix quinquemaculata. The ash-free dry weight (AFDW) and nitrogen (N) contents were measured in arms of six species of brittle-stars from the northern Kattegat-eastern Skagerrak. Differences between species were found, with highest concentrations of AFDW and N in Amphiura filiformis, intermediate in A. chiajei, Ophiocomina nigra and Ophiothrix fragilis, and lowest in Ophiura ophiura and O. albida. As the infaunal suspension- and deposit-feeding brittle-stars ( Amphiura spp.) had the highest proportions of damaged arms and highest AFDW and N contents in their arms in this comparison, it is suggested that selective cropping of arms by demersal fish is the main cause of arm damage on Amphiura spp. in this area.

  6. Potential impact of tidal power plants and future sea-level rise on the dynamics of the European Shelf

    NASA Astrophysics Data System (ADS)

    Green, Mattias; Pelling, Holly

    2010-05-01

    Tidal power is a potential renewable energy source internationally, although financial and technical limitations to tidal power have been addressed. There is also a dynamical aspect of the extraction of tidal energy from shallow shelf seas: what will happen with the tidal dynamics on the shelf if energy is extracted at point sources? The tidal currents and the dissipation of tidal energy control the location of shelf sea fronts and thereby the seasonal stratification. Any change in the tides may thus have far-reaching implications for the biogeochemical and physical systems on the shelf, e.g. primary production, draw-down of atmospheric CO2, and sediment transport. Here we suggest ways to implement tidal power plants in dynamic tidal models, and we investigate how the tidal dynamics of the European shelf changes if we extract large amounts of tidal energy during both present and future climate-change scenarios. With a 1 m future sea-level rise the results show significantly modified tidal amplitudes with up to 20% in certain areas, and the effects may reach the global ocean. These changes are attributed to modifications of the resonant properties of the ocean, which induce a shift in the location of the amphidromic points. During present day conditions the addition of a large-scale Severn barrage induces amplitude changes of 10-20% of the regional tide in several locations. Significant changes can be found at locations far from the barrage itself, i.e. on the Northwest coast of Scotland and in the English Channel, again due to movement of the amphidromic points. However, the back effects on the open ocean tides from tidal power plants are negligible. The combination of a 1 m sea-level rise and a Severn barrage show even larger modifications with effects at large distances from the shelf and the power plant itself. The conclusion is that care must be taken in the implementation of tidal power plants to ensure that the full impact of the power extraction is understood and quantified.

  7. Patterns of co-variability among California Current chinook salmon, coho salmon, Dungeness crab, and physical oceanographic conditions

    NASA Astrophysics Data System (ADS)

    Botsford, L. W.; Lawrence, C. A.

    One of the primary motivations for the GLOBEC NEP program was the apparent inverse relationship between the increase in salmon populations in the Gulf of Alaska since the mid-1970s and concurrent declines in salmon populations in the California Current. The increase in abundance of some salmon species in the Gulf of Alaska can be plausibly explained based on mechanisms involving changes in physical structure, biological productivity, and salmon survival. To assess concurrent changes in salmon populations in the California Current and their possible physical and biological bases we examined temporal and spatial patterns of co-variability between biological variables and physical descriptors along the coasts of Washington, Oregon and California, from 1950 to 1990. The biological variables were catch records of coho salmon, chinook salmon and an ecologically related species, Dungeness crab. The physical variables were sea surface temperature, sea surface height (SSH) and the upwelling index (UWI). We found that while California Current coho salmon declined uniformly in the mid-1970s, consistent with the proposed inverse relationship, chinook salmon did not. All three species appear to be driven by the dominant mode of co-variability in the three physical variables, an indicator of warm/cool water conditions, but in different ways. In general, warm conditions have a negative effect on salmon at the age of ocean entry and spawning return, and Dungeness crab during the larval stage, while cool conditions have a positive effect. Differences in spatio-temporal variability between the two salmon species suggest they may respond to ocean conditions differently: coho salmon vary synchronously along the coast on annual time scales, while chinook salmon vary on slightly longer time scales in a specific spatial pattern. Dungeness crab vary on 10-year time scales, synchronously along the coast, except for the most southern areas (central California) where populations collapsed in the late 1950s. The dominant, warm/cool mode of physical co-variability, which drives these populations regionally, is related to basin-scale indices; it appeared to follow these indices in the 1950s and 1975-1990, but differs from them1960-1975, in ways that may be biologically important.

  8. European Sea Bass (Dicentrarchus labrax) Immune Status and Disease Resistance Are Impaired by Arginine Dietary Supplementation

    PubMed Central

    Azeredo, Rita; Pérez-Sánchez, Jaume; Sitjà-Bobadilla, Ariadna; Fouz, Belén; Tort, Lluis; Aragão, Cláudia; Oliva-Teles, Aires; Costas, Benjamín

    2015-01-01

    Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated immune parameters and immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed immune status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy. PMID:26447480

  9. Decadal reanalysis of biogeochemical indicators and fluxes in the North West European shelf-sea ecosystem

    NASA Astrophysics Data System (ADS)

    Ciavatta, S.; Kay, S.; Saux-Picart, S.; Butenschön, M.; Allen, J. I.

    2016-03-01

    This paper presents the first decadal reanalysis simulation of the biogeochemistry of the North West European shelf, along with a full evaluation of its skill, confidence, and value. An error-characterized satellite product for chlorophyll was assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The results showed that the reanalysis improved the model simulation of assimilated chlorophyll in 60% of the study region. Model validation metrics showed that the reanalysis had skill in matching a large data set of in situ observations for 10 ecosystem variables. Spearman rank correlations were significant and higher than 0.7 for physical-chemical variables (temperature, salinity, and oxygen), ˜0.6 for chlorophyll and nutrients (phosphate, nitrate, and silicate), and significant, though lower in value, for partial pressure of dissolved carbon dioxide (˜0.4). The reanalysis captured the magnitude of pH and ammonia observations, but not their variability. The value of the reanalysis for assessing environmental status and variability has been exemplified in two case studies. The first shows that between 325,000 and 365,000 km2 of shelf bottom waters were vulnerable to oxygen deficiency potentially threatening bottom fishes and benthos. The second application confirmed that the shelf is a net sink of atmospheric carbon dioxide, but the total amount of uptake varies between 36 and 46 Tg C yr-1 at a 90% confidence level. These results indicate that the reanalysis output data set can inform the management of the North West European shelf ecosystem, in relation to eutrophication, fishery, and variability of the carbon cycle.

  10. Environmental factors affecting thyroid function of wild sea bass (Dicentrarchuslabrax) from European coasts.

    PubMed

    Schnitzler, Joseph G; Klaren, Peter H M; Bouquegneau, Jean-Marie; Das, Krishna

    2012-05-01

    Thyroid functional status of wild fish in relation with the contamination of their environment deserves further investigation. We here applied a multi-level approach of thyroid function assessment in 87 wild sea bass collected near several estuaries: namely the Scheldt, the Seine, the Loire, the Charente and the Gironde. Thyroxine (T(4)) and triiodothyronine (T(3)) concentrations in muscle were analyzed by radioimmunoassay. The activity of hepatic enzymes involved in extrathyroidal pathways of thyroid hormone metabolism, viz. deiodination, glucuronidation and sulfatation were analyzed. Last, follicle diameter and epithelial cell heights were measured. We observed changes that are predicted to lead to an increased conversion of T(4)-T(3) and lowered thyroid hormone excretion. The changes in the metabolic pathways of thyroid hormones can be interpreted as a pathway to maintain thyroid hormone homeostasis. From all compounds tested, the higher chlorinated PCBs seemed to be the most implicated in this perturbation. PMID:22169207

  11. Nodavirus Colonizes and Replicates in the Testis of Gilthead Seabream and European Sea Bass Modulating Its Immune and Reproductive Functions

    PubMed Central

    Valero, Yulema; Arizcun, Marta; Esteban, M. Ángeles; Bandín, Isabel; Olveira, José G.; Patel, Sonal; Cuesta, Alberto; Chaves-Pozo, Elena

    2015-01-01

    Viruses are threatening pathogens for fish aquaculture. Some of them are transmitted through gonad fluids or gametes as occurs with nervous necrosis virus (NNV). In order to be transmitted through the gonad, the virus should colonize and replicate inside some cell types of this tissue and avoid the subsequent immune response locally. However, whether NNV colonizes the gonad, the cell types that are infected, and how the immune response in the gonad is regulated has never been studied. We have demonstrated for the first time the presence and localization of NNV into the testis after an experimental infection in the European sea bass (Dicentrarchus labrax), and in the gilthead seabream (Sparus aurata), a very susceptible and an asymptomatic host fish species, respectively. Thus, we localized in the testis viral RNA in both species using in situ PCR and viral proteins in gilthead seabream by immunohistochemistry, suggesting that males might also transmit the virus. In addition, we were able to isolate infective particles from the testis of both species demonstrating that NNV colonizes and replicates into the testis of both species. Blood contamination of the tissues sampled was discarded by completely fish bleeding, furthermore the in situ PCR and immunocytochemistry techniques never showed staining in blood vessels or cells. Moreover, we also determined how the immune and reproductive functions are affected comparing the effects in the testis with those found in the brain, the main target tissue of the virus. Interestingly, NNV triggered the immune response in the European sea bass but not in the gilthead seabream testis. Regarding reproductive functions, NNV infection alters 17β-estradiol and 11-ketotestosterone production and the potential sensitivity of brain and testis to these hormones, whereas there is no disruption of testicular functions according to several reproductive parameters. Moreover, we have also studied the NNV infection of the testis in vitro to assess local responses. Our in vitro results show that the changes observed on the expression of immune and reproductive genes in the testis of both species are different to those observed upon in vivo infections in most of the cases. PMID:26691348

  12. The influence of ocean acidification on nitrogen regeneration and nitrous oxide production in the North-West European shelf sea

    NASA Astrophysics Data System (ADS)

    Clark, D. R.; Brown, I. J.; Rees, A. P.; Somerfield, P. J.; Miller, P. I.

    2014-02-01

    The assimilation and regeneration of dissolved inorganic nitrogen, and the concentration of N2O, was investigated at stations located in the NW European shelf sea during June/July 2011. These observational measurements within the photic zone demonstrated the simultaneous regeneration and assimilation of NH4+, NO2- and NO3-. NH4+ was assimilated at 1.82-49.12 nmol N L-1 h-1 and regenerated at 3.46-14.60 nmol N L-1 h-1; NO2- was assimilated at 0-2.08 nmol N L-1 h-1 and regenerated at 0.01-1.85 nmol N L-1 h-1; NO3- was assimilated at 0.67-18.75 nmol N L-1 h-1 and regenerated at 0.05-28.97 nmol N L-1 h-1. Observations implied that these processes were closely coupled at the regional scale and nitrogen recycling played an important role in sustaining phytoplankton growth during the summer. The [N2O], measured in water column profiles, was 10.13 ± 1.11 nmol L-1 and did not strongly diverge from atmospheric equilibrium indicating that sampled marine regions where neither a strong source nor sink of N2O to the atmosphere. Multivariate analysis of data describing water column biogeochemistry and its links to N-cycling activity failed to explain the observed variance in rates of N-regeneration and N-assimilation, possibly due to the limited number of process rate observations. In the surface waters of 5 further stations, Ocean Acidification (OA) bioassay experiments were conducted to investigate the response of NH4+ oxidising and regenerating organisms to simulated OA conditions, including the implications for [N2O]. Multivariate analysis was undertaken which considered the complete bioassay dataset of measured variables describing changes in N-regeneration rate, [N2O] and the biogeochemical composition of seawater. While anticipating biogeochemical differences between locations, we aimed to test the hypothesis that the underlying mechanism through which pelagic N-regeneration responded to simulated OA conditions was independent of location and that a mechanistic understanding of how NH4+ oxidation, NH4+ regeneration and N2O production responded to OA could be developed. Results indicated that N-regeneration process responses to OA treatments were location specific; no mechanistic understanding of how N-regeneration processes respond to OA in the surface ocean of the NW European shelf sea could be developed.

  13. The influence of ocean acidification on nitrogen regeneration and nitrous oxide production in the northwest European shelf sea

    NASA Astrophysics Data System (ADS)

    Clark, D. R.; Brown, I. J.; Rees, A. P.; Somerfield, P. J.; Miller, P. I.

    2014-09-01

    The assimilation and regeneration of dissolved inorganic nitrogen, and the concentration of N2O, was investigated at stations located in the NW European shelf sea during June/July 2011. These observational measurements within the photic zone demonstrated the simultaneous regeneration and assimilation of NH4+, NO2- and NO3-. NH4+ was assimilated at 1.82-49.12 nmol N L-1 h-1 and regenerated at 3.46-14.60 nmol N L-1 h-1; NO2- was assimilated at 0-2.08 nmol N L-1 h-1 and regenerated at 0.01-1.85 nmol N L-1 h-1; NO3- was assimilated at 0.67-18.75 nmol N L-1 h-1 and regenerated at 0.05-28.97 nmol N L-1 h-1. Observations implied that these processes were closely coupled at the regional scale and that nitrogen recycling played an important role in sustaining phytoplankton growth during the summer. The [N2O], measured in water column profiles, was 10.13 ± 1.11 nmol L-1 and did not strongly diverge from atmospheric equilibrium indicating that sampled marine regions were neither a strong source nor sink of N2O to the atmosphere. Multivariate analysis of data describing water column biogeochemistry and its links to N-cycling activity failed to explain the observed variance in rates of N-regeneration and N-assimilation, possibly due to the limited number of process rate observations. In the surface waters of five further stations, ocean acidification (OA) bioassay experiments were conducted to investigate the response of NH4+ oxidising and regenerating organisms to simulated OA conditions, including the implications for [N2O]. Multivariate analysis was undertaken which considered the complete bioassay data set of measured variables describing changes in N-regeneration rate, [N2O] and the biogeochemical composition of seawater. While anticipating biogeochemical differences between locations, we aimed to test the hypothesis that the underlying mechanism through which pelagic N-regeneration responded to simulated OA conditions was independent of location. Our objective was to develop a mechanistic understanding of how NH4+ regeneration, NH4+ oxidation and N2O production responded to OA. Results indicated that N-regeneration process responses to OA treatments were location specific; no mechanistic understanding of how N-regeneration processes respond to OA in the surface ocean of the NW European shelf sea could be developed.

  14. Marine litter distribution and density in European seas, from the shelves to deep basins.

    PubMed

    Pham, Christopher K; Ramirez-Llodra, Eva; Alt, Claudia H S; Amaro, Teresa; Bergmann, Melanie; Canals, Miquel; Company, Joan B; Davies, Jaime; Duineveld, Gerard; Galgani, François; Howell, Kerry L; Huvenne, Veerle A I; Isidro, Eduardo; Jones, Daniel O B; Lastras, Galderic; Morato, Telmo; Gomes-Pereira, José Nuno; Purser, Autun; Stewart, Heather; Tojeira, Inês; Tubau, Xavier; Van Rooij, David; Tyler, Paul A

    2014-01-01

    Anthropogenic litter is present in all marine habitats, from beaches to the most remote points in the oceans. On the seafloor, marine litter, particularly plastic, can accumulate in high densities with deleterious consequences for its inhabitants. Yet, because of the high cost involved with sampling the seafloor, no large-scale assessment of distribution patterns was available to date. Here, we present data on litter distribution and density collected during 588 video and trawl surveys across 32 sites in European waters. We found litter to be present in the deepest areas and at locations as remote from land as the Charlie-Gibbs Fracture Zone across the Mid-Atlantic Ridge. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Plastic was the most prevalent litter item found on the seafloor. Litter from fishing activities (derelict fishing lines and nets) was particularly common on seamounts, banks, mounds and ocean ridges. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments. PMID:24788771

  15. Relationships among Traits of Aerobic and Anaerobic Swimming Performance in Individual European Sea Bass Dicentrarchus labrax

    PubMed Central

    Marras, Stefano; Killen, Shaun S.; Domenici, Paolo; Claireaux, Guy; McKenzie, David J.

    2013-01-01

    Teleost fishes exhibit wide and temporally stable inter-individual variation in a suite of aerobic and anaerobic locomotor traits. One mechanism that could allow such variation to persist within populations is the presence of tradeoffs between aerobic and anaerobic performance, such that individuals with a high capacity for one type of performance have a reduced capacity for the other. We investigated this possibility in European seabass Dicentrarchuslabrax, each measured for a battery of indicators of maximum locomotor performance. Aerobic traits comprised active metabolic rate, aerobic scope for activity, maximum aerobic swimming speed, and stride length, using a constant acceleration test. Anaerobic traits comprised maximum speed during an escape response, maximum sprint speed, and maximum anaerobic burst speed during constant acceleration. The data provided evidence of significant variation in performance among individuals, but there was no evidence of any trade-offs among any traits of aerobic versus anaerobic swimming performance. Furthermore, the anaerobic traits were not correlated significantly among each other, despite relying on the same muscular structures. Thus, the variation observed may reflect trade-offs with other morphological, physiological or behavioural traits. PMID:24019879

  16. Marine Litter Distribution and Density in European Seas, from the Shelves to Deep Basins

    PubMed Central

    Pham, Christopher K.; Ramirez-Llodra, Eva; Alt, Claudia H. S.; Amaro, Teresa; Bergmann, Melanie; Canals, Miquel; Company, Joan B.; Davies, Jaime; Duineveld, Gerard; Galgani, François; Howell, Kerry L.; Huvenne, Veerle A. I.; Isidro, Eduardo; Jones, Daniel O. B.; Lastras, Galderic; Morato, Telmo; Gomes-Pereira, José Nuno; Purser, Autun; Stewart, Heather; Tojeira, Inês; Tubau, Xavier; Van Rooij, David; Tyler, Paul A.

    2014-01-01

    Anthropogenic litter is present in all marine habitats, from beaches to the most remote points in the oceans. On the seafloor, marine litter, particularly plastic, can accumulate in high densities with deleterious consequences for its inhabitants. Yet, because of the high cost involved with sampling the seafloor, no large-scale assessment of distribution patterns was available to date. Here, we present data on litter distribution and density collected during 588 video and trawl surveys across 32 sites in European waters. We found litter to be present in the deepest areas and at locations as remote from land as the Charlie-Gibbs Fracture Zone across the Mid-Atlantic Ridge. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Plastic was the most prevalent litter item found on the seafloor. Litter from fishing activities (derelict fishing lines and nets) was particularly common on seamounts, banks, mounds and ocean ridges. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments. PMID:24788771

  17. A radiation hybrid map of the European sea bass (Dicentrarchus labrax) based on 1581 markers: Synteny analysis with model fish genomes.

    PubMed

    Guyon, Richard; Senger, Fabrice; Rakotomanga, Michaelle; Sadequi, Naoual; Volckaert, Filip A M; Hitte, Christophe; Galibert, Francis

    2010-10-01

    The selective breeding of fish for aquaculture purposes requires the understanding of the genetic basis of traits such as growth, behaviour, resistance to pathogens and sex determinism. Access to well-developed genomic resources is a prerequisite to improve the knowledge of these traits. Having this aim in mind, a radiation hybrid (RH) panel of European sea bass (Dicentrarchus labrax) was constructed from splenocytes irradiated at 3000 rad, allowing the construction of a 1581 marker RH map. A total of 1440 gene markers providing ~4400 anchors with the genomes of three-spined stickleback, medaka, pufferfish and zebrafish, helped establish synteny relationships with these model species. The identification of Conserved Segments Ordered (CSO) between sea bass and model species allows the anticipation of the position of any sea bass gene from its location in model genomes. Synteny relationships between sea bass and gilthead seabream were addressed by mapping 37 orthologous markers. The sea bass genetic linkage map was integrated in the RH map through the mapping of 141 microsatellites. We are thus able to present the first complete gene map of sea bass. It will facilitate linkage studies and the identification of candidate genes and Quantitative Trait Loci (QTL). The RH map further positions sea bass as a genetic and evolutionary model of Perciformes and supports their ongoing aquaculture expansion. PMID:20659549

  18. Chemical residues and biochemical responses in wild and cultured European sea bass (Dicentrarchus labrax L.)

    SciTech Connect

    Fernandes, Denise; Porte, Cinta . E-mail: cpvqam@cid.csic.es; Bebianno, Maria Joao

    2007-02-15

    Cultured and wild sea bass (Dicentrarchus labrax) from the Arade Estuary were sampled in summer and winter and the degree of exposure to metals and polycyclic aromatic hydrocarbons (PAHs) assessed, together with some biochemical responses against those and other pollutants. The highest levels of copper (up to 997 {mu}g g{sup -1} dry weight) and cadmium (up to 4.22 {mu}g g{sup -1} dry weight) were detected in the liver and kidney of cultured specimens, whereas the highest exposure to PAHs was observed in wild fish. Significant alterations in some biochemical markers were detected and associated to pollutant exposure. Thus, metallothionein concentrations were higher in the tissues of cultured fish and positively correlated with metal residues. The activity 7-ethoxyresorufin O-deethylase ranged from 28 pmol/min/mg protein in cultured fish to 83 pmol/min/mg protein in wild fish collected near a marina area. Cultured fish and wild fish from the marina area had depressed acetylcholinesterase in muscle tissue and a parasitic infection in the gonads. The obtained results support the usefulness of the combined use of chemical and biochemical markers to assess the impact of anthropogenic pollutants in both wild and cultured fish.

  19. Transcription expression of immune-related genes from Caligus rogercresseyi evidences host-dependent patterns on Atlantic and coho salmon.

    PubMed

    Vera-Bizama, Fredy; Valenzuela-Muñoz, Valentina; Gonçalves, Ana Teresa; Marambio, Jorge Pino; Hawes, Christopher; Wadsworth, Simon; Gallardo-Escárate, Cristian

    2015-12-01

    The transcriptomic response of the sea louse Caligus rogercresseyi during the infestation on Atlantic salmon (Salmo salar) and coho salmon (Oncorhynchus kisutch) was evaluated using 27 genes related to immune response, antioxidant system and secretome. Results showed early responses of TLR/IMD signaling pathway in sea lice infesting Atlantic salmon. Overall, genes associated with oxidative stress responses were upregulated in both host species. This pattern suggests that reactive oxygen species emitted by the host as a response to the infestation, could modulate the sea louse antioxidant system. Secretome-related transcripts evidenced upregulation of trypsins and serpins, mainly associated to Atlantic salmon than coho salmon. Interestingly, cathepsins and trypsin2 were downregulated at 7 days post-infection (dpi) in coho salmon. The principal component analysis revealed an inverse time-dependent pattern based on the different responses of C. rogercresseyi infecting both salmon species. Here, Atlantic salmon strongly modulates the transcriptome responses at earlier infection stages; meanwhile coho salmon reveals a less marked modulation, increasing the transcription activity during the infection process. This study evidences transcriptome differences between two salmon host species and provides pivotal knowledge towards elaborating future control strategies. PMID:26492996

  20. Historical growth of Bristol Bay and Yukon River, Alaska chum salmon (Oncorhynchus keta) in relation to climate and inter- and intraspecific competition

    NASA Astrophysics Data System (ADS)

    Agler, Beverly A.; Ruggerone, Gregory T.; Wilson, Lorna I.; Mueter, Franz J.

    2013-10-01

    We examined Bristol Bay and Yukon River adult chum salmon scales to determine whether climate variability, such as changes in sea surface temperature and climate indices, and high pink and Asian chum salmon abundance reduced chum salmon growth. Annual marine growth increments for 1965-2006 were estimated from scale growth measurements and were modeled as a function of potential explanatory variables using a generalized least squares regression approach. First-year growth of salmon originating from Bristol Bay and the Yukon River showed increased growth in association with higher regional ocean temperatures and was negatively affected by wind mixing and ice cover. Third-year growth was lower when Asian chum salmon were more abundant. Contrary to our hypothesis, warmer large-scale sea surface temperatures in the Gulf of Alaska were also associated with reduced third-year growth. Negative effects of high abundances of Russian pink salmon on third-year growth provided some evidence for interspecific interactions, but the effects were smaller than the effects of Asian chum salmon abundance and Gulf of Alaska sea surface temperature. Although the relative effects of Asian chum salmon and sea surface temperature on the growth of Yukon and Bristol Bay chum salmon were difficult to untangle, we found consistent evidence that high abundances of Asian chum salmon contributed to a reduction in the growth of western Alaska chum salmon.

  1. Temporal profile of brain and pituitary GnRHs, GnRH-R and gonadotropin mRNA expression and content during early development in European sea bass (Dicentrarchus labrax L.).

    PubMed

    Moles, G; Carrillo, M; Mañanós, E; Mylonas, C C; Zanuy, S

    2007-01-01

    A likely endocrine control mechanism for sexual differentiation in size-graded populations of European sea bass (Dicentrarchus labrax) is proposed by evaluating the brain expression and pituitary content of two forms of gonadotropin-releasing hormone (GnRH), namely sea bream (sbGnRH) and salmon (sGnRH), the pituitary expression of one subtype of GnRH receptor (dlGnRH-R-2A) and the three gonadotropin (GtH) subunits, namely glycoprotein alpha (GPalpha), follicle-stimulating hormone beta (FSHbeta) and luteinizing hormone beta (LHbeta), as well as the pituitary and plasma LH levels between 50 and 300 days post-hatching (dph). Four gradings were conducted between 2 and 8 months after hatching, resulting in a population of large and small individuals, having 96.5% females (female-dominant population) and 69.2% males (male-dominant population), respectively, after the last grading. The onset of gonadal differentiation was different in the two sexes, and coincided with a peak of expression of sbGnRH or sGnRH. Furthermore, the expression of these GnRHs was correlated with the expression of dlGnRH-R-2A. Sex-related differences in the brain and pituitary content of sbGnRH were also found at the time of sexual differentiation. Moreover, the observed sexual dimorphism at the transcriptional or synthesis level of these GnRH forms suggests that a different neuro-hormonal regulation is operating according to sex. At the onset of sex differentiation, FSHbeta transcriptional activity reached maximal values, which were maintained until the completion of the process. The present study suggests a role for sbGnRH, sGnRH and the dlGnRH-R-2A during gonadal differentiation, possibly through enhancement of FSHbeta gene expression. In males, a different endocrine regulation seems to exist also during spermiogenesis and spermiation, when gene transcription, peptide synthesis and release of LH are of greater importance. PMID:16962597

  2. Genetic Inactivation of European Sea Bass (Dicentrarchus labrax L.) Eggs Using UV-Irradiation: Observations and Perspectives

    PubMed Central

    Colléter, Julie; Penman, David J.; Lallement, Stéphane; Fauvel, Christian; Hanebrekke, Tanja; Osvik, Renate D.; Eilertsen, Hans C.; D’Cotta, Helena; Chatain, Béatrice; Peruzzi, Stefano

    2014-01-01

    Androgenesis is a form of uniparental reproduction leading to progenies inheriting only the paternal set of chromosomes. It has been achieved with variable success in a number of freshwater species and can be attained by artificial fertilization of genetically inactivated eggs following exposure to gamma (γ), X-ray or UV irradiation (haploid androgenesis) and by restoration of diploidy by suppression of mitosis using a pressure or thermal shock. The conditions for the genetic inactivation of the maternal genome in the European sea bass (Dicentrarchus labrax L.) were explored using different combinations of UV irradiation levels and durations. UV treatments significantly affected embryo survival and generated a wide range of developmental abnormalities. Despite the wide range of UV doses tested (from 7.2 to 720 mJ.cm−2), only one dose (60 mJ.cm−2.min−1 with 1 min irradiation) resulted in a small percentage (14%) of haploid larvae at hatching in the initial trials as verified by flow cytometry. Microsatellite marker analyses of three further batches of larvae produced by using this UV treatment showed a majority of larvae with variable levels of paternal and maternal contributions and only one larva displaying pure paternal inheritance. The results are discussed also in the context of an assessment of the UV-absorbance characteristics of egg extracts in this species that revealed the presence of gadusol, a compound structurally related to mycosporine-like amino acids (MAAs) with known UV-screening properties. PMID:25329931

  3. Effects of salinity and sea salt type on egg activation, fertilization, buoyancy and early embryology of European eel, Anguilla anguilla.

    PubMed

    Sørensen, Sune Riis; Butts, Ian Anthony Ernest; Munk, Peter; Tomkiewicz, Jonna

    2016-02-01

    Improper activation and swelling of in vitro produced eggs of European eel, Anguilla anguilla, has been shown to negatively affect embryonic development and hatching. We investigated this phenomenon by examining the effects of salinity and sea salt type on egg dimensions, cell cleavage patterns and egg buoyancy. Egg diameter after activation, using natural seawater adjusted to different salinities, varied among female eels, but no consistent pattern emerged. Activation salinities between 30-40 practical salinity unit (psu) produced higher quality eggs and generally larger egg diameters. Chorion diameters reached maximal values of 1642 ± 8 μm at 35 psu. A positive relationship was found between egg neutral buoyancy and activation salinity. Nine salt types were investigated as activation and incubation media. Five of these types induced a substantial perivitelline space (PVS), leading to large egg sizes, while the remaining four salt types resulted in smaller eggs. All salt types except NaCl treatments led to high fertilization rates and had no effect on fertilization success as well as egg neutral buoyancies at 7 h post-fertilization. The study points to the importance of considering ionic composition of the media when rearing fish eggs and further studies are encouraged. PMID:25707438

  4. Dietary carbohydrate and lipid sources affect differently the oxidative status of European sea bass (Dicentrarchus labrax) juveniles.

    PubMed

    Castro, Carolina; Peréz-Jiménez, Amalia; Coutinho, Filipe; Díaz-Rosales, Patricia; Serra, Cláudia Alexandra Dos Reis; Panserat, Stéphane; Corraze, Geneviève; Peres, Helena; Oliva-Teles, Aires

    2015-11-28

    This study aimed to evaluate the effects of dietary lipid source and carbohydrate content on the oxidative status of European sea bass (Dicentrarchus labrax) juveniles. For that purpose, four diets were formulated with fish oil (FO) and vegetable oils (VO) as the lipid source and with 20 or 0 % gelatinised starch as the carbohydrate source, in a 2×2 factorial design. Liver and intestine antioxidant enzyme activities (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD)), hepatic and intestinal lipid peroxidation (LPO), as well as hepatic oxidative stress index (OSI), were measured in fish fed the experimental diets for 73 d (n 9 fish/diet). Carbohydrate-rich diets promoted a decrease in hepatic LPO and OSI, whereas the lipid source induced no changes. Inversely, dietary lipid source, but not dietary carbohydrate concentration, affected LPO in the intestine. Lower intestinal LPO was observed in VO groups. Enzymes responsive to dietary treatments were GR, G6PD and CAT in the liver and GR and GPX in the intestine. Dietary carbohydrate induced GR and G6PD activities and depressed CAT activity in the liver. GPX and GR activities were increased in the intestine of fish fed VO diets. Overall, effects of diet composition on oxidative status were tissue-related: the liver and intestine were strongly responsive to dietary carbohydrates and lipid sources, respectively. Furthermore, different metabolic routes were more active to deal with the oxidative stress in the two organs studied. PMID:26365262

  5. Associations between piscine reovirus infection and life history traits in wild-caught Atlantic salmon Salmo salar L. in Norway.

    PubMed

    Garseth, Ase Helen; Biering, Eirik; Aunsmo, Arnfinn

    2013-10-01

    Piscine Reovirus (PRV), the putative causative agent of heart and skeletal muscle inflammation (HSMI), is widely distributed in both farmed and wild Atlantic salmon (Salmo salar L.) in Norway. While HSMI is a common and commercially important disease in farmed Atlantic salmon, the presence of PRV has so far not been associated with HSMI related lesions in wild salmon. Factors associated with PRV-infection were investigated in returning Atlantic salmon captured in Norwegian rivers. A multilevel mixed-effect logistic regression model confirmed clustering within rivers and demonstrated that PRV-infection is associated with life-history, sex, catch-year and body length as a proxy for sea-age. Escaped farmed salmon (odds ratio/OR: 7.32, p<0.001) and hatchery-reared salmon (OR: 1.69 p=0.073) have higher odds of being PRV-infected than wild Atlantic salmon. Male salmon have double odds of being PRV infected compared to female salmon (OR: 2.11, p<0.001). Odds of being PRV-infected increased with body-length measured as decimetres (OR: 1.20, p=0.004). Since body length and sea-age are correlated (r=0.85 p<0.001), body length serves as a proxy for sea-age, meaning that spending more years in sea increases the odds of being PRV-infected. PMID:23906390

  6. SeaDataNet II - Second phase of developments for the pan-European infrastructure for marine and ocean data management

    NASA Astrophysics Data System (ADS)

    Schaap, Dick M. A.; Fichaut, Michele

    2013-04-01

    The second phase of the project SeaDataNet started on October 2011 for another 4 years with the aim to upgrade the SeaDataNet infrastructure built during previous years. The numbers of the project are quite impressive: 59 institutions from 35 different countries are involved. In particular, 45 data centers are sharing human and financial resources in a common efforts to sustain an operationally robust and state-of-the-art Pan-European infrastructure for providing up-to-date and high quality access to ocean and marine metadata, data and data products. The main objective of SeaDataNet II is to improve operations and to progress towards an efficient data management infrastructure able to handle the diversity and large volume of data collected via the Pan-European oceanographic fleet and the new observation systems, both in real-time and delayed mode. The infrastructure is based on a semi-distributed system that incorporates and enhance the existing NODCs network. SeaDataNet aims at serving users from science, environmental management, policy making, and economical sectors. Better integrated data systems are vital for these users to achieve improved scientific research and results, to support marine environmental and integrated coastal zone management, to establish indicators of Good Environmental Status for sea basins, and to support offshore industry developments, shipping, fisheries, and other economic activities. The recent EU communication "MARINE KNOWLEDGE 2020 - marine data and observation for smart and sustainable growth" states that the creation of marine knowledge begins with observation of the seas and oceans. In addition, directives, policies, science programmes require reporting of the state of the seas and oceans in an integrated pan-European manner: of particular note are INSPIRE, MSFD, WISE-Marine and GMES Marine Core Service. These underpin the importance of a well functioning marine and ocean data management infrastructure. SeaDataNet is now one of the major players in informatics in oceanography and collaborative relationships have been created with other EU and non EU projects. In particular SeaDataNet has recognised roles in the continuous serving of common vocabularies, the provision of tools for data management, as well as giving access to metadata, data sets and data products of importance for society. The SeaDataNet infrastructure comprises a network of interconnected data centres and a central SeaDataNet portal. The portal provides users not only background information about SeaDataNet and the various SeaDataNet standards and tools, but also a unified and transparent overview of the metadata and controlled access to the large collections of data sets, managed by the interconnected data centres. The presentation will give information on present services of the SeaDataNet infrastructure and services, and highlight a number of key achievements in SeaDataNet II so far.

  7. Physiological mechanism of homing migration in Pacific salmon from behavioral to molecular biological approaches.

    PubMed

    Ueda, Hiroshi

    2011-01-15

    The amazing abilities of Pacific salmon to migrate long distances from the ocean to their natal streams for spawning have been investigated intensively since 1950's, but there are still many mysteries because of difficulties to follow their whole life cycle and to wait their sole reproductive timing for several years. In my laboratory, we have tried to clarify physiological mechanisms of homing migration in Pacific salmon, using four anadromous Pacific salmon (pink, Oncorhynchus gorbuscha; chum, Oncorhynchus keta; sockeye, Oncorhynchus nerka; masu, Oncorhynchus masou) in the north Pacific Ocean as well as two lacustrine salmon (sockeye and masu) in Lake Toya and Lake Shikotsu, Hokkaido, Japan, where the lakes serve as a model "ocean". Three different approaches from behavioral to molecular biological researches have been conducted using these model fish. First, the homing behaviors of adult chum salmon from the Bering Sea to Hokkaido as well as lacustrine sockeye and masu salmon in Lake Toya were examined by means of physiological biotelemetry techniques, and revealed that salmon can navigate in open water using different sensory systems. Second, the hormone profiles in the brain-pituitary-gonadal (BPG) axis were investigated in chum salmon and lacustrine sockeye salmon during their homing migration by means of hormone specific time-resolved fluoroimmunoassay (TR-FIA) systems, and clarified that salmon gonadotropin-releasing hormone (sGnRH) plays leading roles on homing migration. Third, the olfactory functions of salmon were studied by means of electrophysiological, behavioral, and molecular biological techniques, and made clear that olfactory discriminating ability of natal stream odors. These results have discussed with the evolutional aspects of four Pacific salmon, sexual differences in homing profiles, and the possibility of dissolved free amino acids (DFAA) as natal stream odors for salmon. PMID:20144612

  8. SeaDataNet - Pan-European infrastructure for marine and ocean data management: Unified access to distributed data sets (www.seadatanet.org)

    NASA Astrophysics Data System (ADS)

    Schaap, Dick M. A.; Maudire, Gilbert

    2010-05-01

    SeaDataNet is a leading infrastructure in Europe for marine & ocean data management. It is actively operating and further developing a Pan-European infrastructure for managing, indexing and providing access to ocean and marine data sets and data products, acquired via research cruises and other observational activities, in situ and remote sensing. The basis of SeaDataNet is interconnecting 40 National Oceanographic Data Centres and Marine Data Centers from 35 countries around European seas into a distributed network of data resources with common standards for metadata, vocabularies, data transport formats, quality control methods and flags, and access. Thereby most of the NODC's operate and/or are developing national networks to other institutes in their countries to ensure national coverage and long-term stewardship of available data sets. The majority of data managed by SeaDataNet partners concerns physical oceanography, marine chemistry, hydrography, and a substantial volume of marine biology and geology and geophysics. These are partly owned by the partner institutes themselves and for a major part also owned by other organizations from their countries. The SeaDataNet infrastructure is implemented with support of the EU via the EU FP6 SeaDataNet project to provide the Pan-European data management system adapted both to the fragmented observation system and the users need for an integrated access to data, meta-data, products and services. The SeaDataNet project has a duration of 5 years and started in 2006, but builds upon earlier data management infrastructure projects, undertaken over a period of 20 years by an expanding network of oceanographic data centres from the countries around all European seas. Its predecessor project Sea-Search had a strict focus on metadata. SeaDataNet maintains significant interest in the further development of the metadata infrastructure, extending its services with the provision of easy data access and generic data products. Version 1 of its infrastructure upgrade was launched in April 2008 and is now well underway to include all 40 data centres at V1 level. It comprises the network of 40 interconnected data centres (NODCs) and a central SeaDataNet portal. V1 provides users a unified and transparent overview of the metadata and controlled access to the large collections of data sets, that are managed at these data centres. The SeaDataNet V1 infrastructure comprises the following middleware services: • Discovery services = Metadata directories and User interfaces • Vocabulary services = Common vocabularies and Governance • Security services = Authentication, Authorization & Accounting • Delivery services = Requesting and Downloading of data sets • Viewing services = Mapping of metadata • Monitoring services = Statistics on system usage and performance and Registration of data requests and transactions • Maintenance services = Entry and updating of metadata by data centres Also good progress is being made with extending the SeaDataNet infrastructure with V2 services: • Viewing services = Quick views and Visualisation of data and data products • Product services = Generic and standard products • Exchange services = transformation of SeaDataNet portal CDI output to INSPIRE compliance As a basis for the V1 services, common standards have been defined for metadata and data formats, common vocabularies, quality flags, and quality control methods, based on international standards, such as ISO 19115, OGC, NetCDF (CF), ODV, best practices from IOC and ICES, and following INSPIRE developments. An important objective of the SeaDataNet V1 infrastructure is to provide transparent access to the distributed data sets via a unique user interface and download service. In the SeaDataNet V1 architecture the Common Data Index (CDI) V1 metadata service provides the link between discovery and delivery of data sets. The CDI user interface enables users to have a detailed insight of the availability and geographical distribution of marine data, archived at the connected data centres. It provides sufficient information to allow the user to assess the data relevance. Moreover the CDI user interface provides the means for downloading data sets in common formats via a transaction mechanism. The SeaDataNet portal provides registered users access to these distributed data sets via the CDI V1 Directory and a shopping basket mechanism. This allows registered users to locate data of interest and submit their data requests. The requests are forwarded automatically from the portal to the relevant SeaDataNet data centres. This process is controlled via the Request Status Manager (RSM) Web Service at the portal and a Download Manager (DM) java software module, implemented at each of the data centres. The RSM also enables registered users to check regularly the status of their requests and download data sets, after access has been granted. Data centres can follow all transactions for their data sets online and can handle requests which require their consent. The actual delivery of data sets is done between the user and the selected data centre. Very good progress is being made with connecting all SeaDataNet data centres and their data sets to the CDI V1 system. At present the CDI V1 system provides users functionality to discover and download more than 500.000 data sets, a number which is steadily increasing. The SeaDataNet architecture provides a coherent system of the various V1 services and inclusion of the V2 services. For the implementation, a range of technical components have been defined and developed. These make use of recent web technologies, and also comprise Java components, to provide multi-platform support and syntactic interoperability. To facilitate sharing of resources and interoperability, SeaDataNet has adopted the technology of SOAP Web services for various communication tasks. The SeaDataNet architecture has been designed as a multi-disciplinary system from the beginning. It is able to support a wide variety of data types and to serve several sector communities. SeaDataNet is willing to share its technologies and expertise, to spread and expand its approach, and to build bridges to other well established infrastructures in the marine domain. Therefore SeaDataNet has developed a strategy of seeking active cooperation on a national scale with other data holding organisations via its NODC networks and on an international scale with other European and international data management initiatives and networks. This is done with the objective to achieve a wider coverage of data sources and an overall interoperability between data infrastructures in the marine and ocean domains. Recent examples are e.g. the EU FP7 projects Geo-Seas for geology and geophysical data sets, UpgradeBlackSeaScene for a Black Sea data management infrastructure, CaspInfo for a Caspian Sea data management infrastructure, the EU EMODNET pilot projects, for hydrographic, chemical, and biological data sets. All projects are adopting the SeaDataNet standards and extending its services. Also active cooperation takes place with EuroGOOS and MyOcean in the domain of real-time and delayed mode metocean monitoring data. SeaDataNet Partners: IFREMER (France), MARIS (Netherlands), HCMR/HNODC (Greece), ULg (Belgium), OGS (Italy), NERC/BODC (UK), BSH/DOD (Germany), SMHI (Sweden), IEO (Spain), RIHMI/WDC (Russia), IOC (International), ENEA (Italy), INGV (Italy), METU (Turkey), CLS (France), AWI (Germany), IMR (Norway), NERI (Denmark), ICES (International), EC-DG JRC (International), MI (Ireland), IHPT (Portugal), RIKZ (Netherlands), RBINS/MUMM (Belgium), VLIZ (Belgium), MRI (Iceland), FIMR (Finland ), IMGW (Poland), MSI (Estonia), IAE/UL (Latvia), CMR (Lithuania), SIO/RAS (Russia), MHI/DMIST (Ukraine), IO/BAS (Bulgaria), NIMRD (Romania), TSU (Georgia), INRH (Morocco), IOF (Croatia), PUT (Albania), NIB (Slovenia), UoM (Malta), OC/UCY (Cyprus), IOLR (Israel), NCSR/NCMS (Lebanon), CNR-ISAC (Italy), ISMAL (Algeria), INSTM (Tunisia)

  9. PACIFIC SALMON: LESSONS LEARNED FOR RECOVERING ATLANTIC SALMON

    EPA Science Inventory

    n evaluation of the history of efforts to reverse the long-term decline of Pacific Salmon provides instructive policy lessons for recovering Atlantic Salmon. From California to southern British Columbia, wild runs of Pacific salmon have universally declined and many have disappe...

  10. GEO-MOTION: A fresh approach to land, water and sea level changes in a European habitat

    NASA Astrophysics Data System (ADS)

    Cloetingh, S.; Geo-Motion Consortium, T.; GEO-MOTION Consortium

    2003-04-01

    The present state and behaviour of the Shallow Earth System is a consequence of processes on a wide range of time scales. These include the long term tectonic effects on uplift, subsidence and river systems, residual effects of the ice ages on crustal movement and geochemistry, natural climate to environmental changes over recent millennia and up to the present, and the powerful anthropogenic impacts of the last century. If we are to understand the present state of the system, to predict its future and to engineer our use of it, this spectrum of processes, operating concurrently but on different time scales, needs to be better understood. The challenge to the Geosciences is to describe the state of the system, to monitor its changes, to forecast its evolution and, in collaboration with others, to evaluate modes of sustainable use by human society. Land, water and sea level changes can seriously affect the sustainability of ecological and human habitats in Europe. When sea water or surface water levels rise, or land subsides, the risk of flooding increases, directly inflicting on local ecosystems and human habitats. The effects on society are widely known as many of the affected areas in Europe are densely populated and the financial loss foreseen is tremendous. On the other hand, declining water levels and uplift may lead to a higher risk of desertification. These changes are caused by both natural processes and human activities, but the absolute and relative contributions of each of these processes are still little understood. Only very recently, the impact of processes located in the underlying subsurface of intraplate areas has been recognized in the coastal realm, leading to the newly coined term ‘Environmental Earth System Dynamics’. The members of the Geo-Motion consortium have joined forces in order to create a fully integrated pan-European research infrastructure (a virtual scientific centre) on a hitherto not existing scale. It runs monitoring programs including satellite, surface and borehole monitoring instruments. It integrates large scale and excellent geo-mechanical, geo-chemical and geo-biological laboratory facilities. Based on existing structures and data sets it develops a new geo data infrastructure containing historical data on global and regional changes in combination with the vulnerability of natural and human habitats. Most significant milestones are a large scale and excellent know-how base on geo-motion modelling and simulation, as well as on risk and impact assessment. The development of a foresight and assessment competency represents a long-term strategic scientific objective for the consortium. It is vital that it is also promoted in education, which will be done through the development of a European School for Predictive Geoscience, in which parallel masters programmes will be offered by the university partners based on their pooled expertise. The national geoscience surveys play a key role in delivering the outputs of research into the public, policy and industrial domains.

  11. Expression profiles of sex differentiation-related genes during ontogenesis in the European sea bass acclimated to two different temperatures.

    PubMed

    Blázquez, Mercedes; Navarro-Martín, Laia; Piferrer, Francesc

    2009-11-15

    The European sea bass is a teleost fish that lacks sex chromosomes and for which temperature influences sex ratios. However, correlation between temperature, developmental stage at a given age and sex-specific gene expression is hampered by the lack of sex markers. To study this correlation, fish were exposed to feminizing (15 degrees C) or masculinizing temperature (21 degrees C) from 0-120 days post fertilization, throughout the thermosensitive period (TSP). Aromatase (cyp19a1a), 11beta-hydroxylase (cyp11b), androgen receptor (arb) and estrogen receptors (era, erb1 and erb2) were assessed by qPCR prior and during sex differentiation. Canonical discriminant analysis (CDA), with length--as proxy for developmental stage--and cyp19a1a expression as predictors, was validated and used to reliably assign gonadal sex to fish sampled within and outside the TSP. Differences in cyp19a1a and cyp11b expression could be detected 1-month before the first signs of histological sex differentiation. Cyp19a1a and cyp11b were significantly higher in future females and males, respectively, and revealed as robust molecular markers to predict future ovarian and testicular differentiation. In contrast, no association between phenotypic sex and arb, era, erb1 and erb2 expression was found, suggesting that these genes do not contribute to the differentiation of a particular sex. The CDA-based approach implemented here could be used to sex undifferentiated animals in species where genetic sex cannot be known owing to the lack of simple sex determining systems, as it is the case of many fish and reptiles with or without temperature-dependent sex determination, and provide a useful tool to relate gene expression and phenotypic sex. PMID:19338052

  12. Application of data assimilation for improved operational water level forecasting on the northwest European shelf and North Sea

    NASA Astrophysics Data System (ADS)

    Zijl, Firmijn; Sumihar, Julius; Verlaan, Martin

    2015-12-01

    For the Netherlands, accurate water level forecasting in the coastal region is crucial, since large areas of the land lie below sea level. During storm surges, detailed and timely water level forecasts provided by an operational storm surge forecasting system are necessary to support, for example, the decision to close the movable storm surge barriers in the Eastern Scheldt and the Rotterdam Waterway. In the past years, a new generation operational tide-surge model (Dutch Continental Shelf Model version 6) has been developed covering the northwest European continental shelf. In a previous study, a large effort has been put in representing relevant physical phenomena in this process model as well as reducing parameter uncertainty over a wide area. While this has resulted in very accurate water level representation (root-mean-square error (RMSE) ˜7-8 cm), during severe storm surges, the errors in the meteorological model forcing are generally non-negligible and can cause forecast errors of several decimetres. By integrating operationally available observational data in the forecast model by means of real-time data assimilation, the errors in the meteorological forcing are prevented from propagating to the hydrodynamic tide-surge model forecasts. This paper discusses the development of a computationally efficient steady-state Kalman filter to enhance the predictive quality for the shorter lead times by improving the system state at the start of the forecast. Besides evaluating the model quality against shelf-wide tide gauge observations for a year-long hindcast simulation, the predictive value of the Kalman filter is determined by comparing the forecast quality for various lead time intervals against the model without a steady-state Kalman filter. This shows that, even though the process model has a water level representation that is substantially better than that of other comparable operational models of this scale, substantial improvements in predictive quality in the first few hours are possible in an actual operational setting.

  13. Phytoplankton responses and associated carbon cycling during shipboard carbonate chemistry manipulation experiments conducted around Northwest European shelf seas

    NASA Astrophysics Data System (ADS)

    Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.

    2014-09-01

    The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which may reflect community/environment-specific responses or inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series (n = 8) of short-term (2-4 days) multi-level (≥4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically separated experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterised by a suppression of net growth for small-sized cells (<10 μm), were observed in the majority of the experiments, irrespective of natural or manipulated nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasise how biogeochemical feedbacks may be altered in the future ocean.

  14. Carbon cycling and phytoplankton responses within highly-replicated shipboard carbonate chemistry manipulation experiments conducted around Northwest European Shelf Seas

    NASA Astrophysics Data System (ADS)

    Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.

    2014-03-01

    The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which in part likely reflects inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series of highly replicated (n = 8), short term (2-4 days) multi-level (≥ 4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically different experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterized by a suppression of net growth for small sized cells (< 10 μm), were observed in the majority of the experiments, irrespective of nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasize how biological-chemical feedbacks may be altered in the future ocean.

  15. Comparative pathogenicity study of ten different betanodavirus strains in experimentally infected European sea bass, Dicentrarchus labrax (L.).

    PubMed

    Vendramin, N; Toffan, A; Mancin, M; Cappellozza, E; Panzarin, V; Bovo, G; Cattoli, G; Capua, I; Terregino, C

    2014-04-01

    Viral encephalopathy and retinopathy (VER), otherwise known as viral nervous necrosis (VNN), is a severe pathological condition caused by RNA viruses belonging to the Nodaviridae family, genus Betanodavirus. The disease, described in more than 50 fish species worldwide, is considered as the most serious viral threat affecting marine farmed species in the Mediterranean region, thus representing one of the bottlenecks for further development of the aquaculture industry. To date, four different genotypes have been identified, namely red-spotted grouper nervous necrosis virus (RGNNV), striped jack nervous necrosis virus (SJNNV), tiger puffer nervous necrosis virus and barfin flounder nervous necrosis virus, with the RGNNV genotype appearing as the most widespread in the Mediterranean region, although SJNNV-type strains and reassortant viruses have also been reported. The existence of these genetically different strains could be the reason for the differences in mortality observed in the field. However, very little experimental data are available on the pathogenicity of these viruses in farmed fish. Therefore, in this study, the pathogenicity of 10 isolates has been assessed with an in vivo trial. The investigation was conducted using the European sea bass, the first target fish species for the disease in the Mediterranean basin. Naive fish were challenged by immersion and clinical signs and mortality were recorded for 68 days; furthermore, samples collected at selected time points were analysed to evaluate the development of the infection. Finally, survivors were weighed to estimate the growth reduction. The statistically supported results obtained in this study demonstrated different pathogenicity patterns, underlined the potential risk represented by different strains in the transmission of the infection to highly susceptible species and highlighted the indirect damage caused by a clinical outbreak of VER/VNN. PMID:23662921

  16. Integrated decision support tools for Puget Sound salmon recovery planning

    EPA Science Inventory

    We developed a set of tools to provide decision support for community-based salmon recovery planning in Salish Sea watersheds. Here we describe how these tools are being integrated and applied in collaboration with Puget Sound tribes and community stakeholders to address restora...

  17. First detection, isolation and molecular characterization of infectious salmon anaemia virus associated with clinical disease in farmed Atlantic salmon (Salmo salar) in Chile

    PubMed Central

    Godoy, Marcos G; Aedo, Alejandra; Kibenge, Molly JT; Groman, David B; Yason, Carmencita V; Grothusen, Horts; Lisperguer, Angelica; Calbucura, Marlene; Avendaño, Fernando; Imilán, Marcelo; Jarpa, Miguel; Kibenge, Frederick SB

    2008-01-01

    Background Infectious salmon anaemia (ISA) is a viral disease of marine-farmed Atlantic salmon (Salmo salar) caused by ISA virus (ISAV), which belongs to the genus Isavirus, family Orthomyxoviridae. The virus is considered to be carried by marine wild fish and for over 25 years has caused major disease outbreaks in marine-farmed Atlantic salmon in the Northern hemisphere. In the Southern hemisphere, ISAV was first detected in Chile in 1999 in marine-farmed Coho salmon (Oncorhynchus kisutch). In contrast to the classical presentation of ISA in Atlantic salmon, the presence of ISAV in Chile until now has only been associated with a clinical condition called Icterus Syndrome in Coho salmon and virus isolation has not always been possible. During the winter of 2007, unexplained mortalities were registered in market-size Atlantic salmon in a grow-out site located in Chiloé in Region X of Chile. We report here the diagnostic findings of the first significant clinical outbreak of ISA in marine-farmed Atlantic salmon in Chile and the first characterization of the ISAV isolated from the affected fish. Results In mid-June 2007, an Atlantic salmon marine farm site located in central Chiloé Island in Region X of Chile registered a sudden increase in mortality following recovery from an outbreak of Pisciricketsiosis, which rose to a cumulative mortality of 13.6% by harvest time. Based on the clinical signs and lesions in the affected fish, and laboratory tests performed on the fish tissues, a confirmatory diagnosis of ISA was made; the first time ISA in its classical presentation and for the first time affecting farmed Atlantic salmon in Chile. Rapid sequencing of the virus-specific RT-PCR products amplified from the fish tissues identified the virus to belong to the European genotype (Genotype I) of the highly polymorphic region (HPR) group HPR 7b, but with an 11-amino acid insert in the fusion glycoprotein, and ability to cause cytopathic effects (CPE) in CHSE-214 cell line, characteristics which make it distinct from common European Genotype ISAV isolates from Europe and North America. Conclusion In conclusion, the present work constitutes the first report of a case of ISA in farmed Atlantic salmon in Chile. The clinical signs and lesions are consistent with the classical descriptions of the disease in marine-farmed Atlantic salmon in the Northern hemisphere. The outbreak was caused by ISAV of European genotype (or Genotype I) of HPR 7b but distinct from common European Genotype ISAV isolates. PMID:18680586

  18. Dynamics of air-sea CO2 fluxes in the northwestern European shelf based on voluntary observing ship and satellite observations

    NASA Astrophysics Data System (ADS)

    Marrec, P.; Cariou, T.; Macé, E.; Morin, P.; Salt, L. A.; Vernet, M.; Taylor, B.; Paxman, K.; Bozec, Y.

    2015-09-01

    From January 2011 to December 2013, we constructed a comprehensive pCO2 data set based on voluntary observing ship (VOS) measurements in the western English Channel (WEC). We subsequently estimated surface pCO2 and air-sea CO2 fluxes in northwestern European continental shelf waters using multiple linear regressions (MLRs) from remotely sensed sea surface temperature (SST), chlorophyll a concentration (Chl a), wind speed (WND), photosynthetically active radiation (PAR) and modeled mixed layer depth (MLD). We developed specific MLRs for the seasonally stratified northern WEC (nWEC) and the permanently well-mixed southern WEC (sWEC) and calculated surface pCO2 with uncertainties of 17 and 16 μatm, respectively. We extrapolated the relationships obtained for the WEC based on the 2011-2013 data set (1) temporally over a decade and (2) spatially in the adjacent Celtic and Irish seas (CS and IS), two regions which exhibit hydrographical and biogeochemical characteristics similar to those of WEC waters. We validated these extrapolations with pCO2 data from the SOCAT and LDEO databases and obtained good agreement between modeled and observed data. On an annual scale, seasonally stratified systems acted as a sink of CO2 from the atmosphere of -0.6 ± 0.3, -0.9 ± 0.3 and -0.5 ± 0.3 mol C m-2 yr-1 in the northern Celtic Sea, southern Celtic sea and nWEC, respectively, whereas permanently well-mixed systems acted as source of CO2 to the atmosphere of 0.2 ± 0.2 and 0.3 ± 0.2 mol C m-2 yr-1 in the sWEC and IS, respectively. Air-sea CO2 fluxes showed important inter-annual variability resulting in significant differences in the intensity and/or direction of annual fluxes. We scaled the mean annual fluxes over these provinces for the last decade and obtained the first annual average uptake of -1.11 ± 0.32 Tg C yr-1 for this part of the northwestern European continental shelf. Our study showed that combining VOS data with satellite observations can be a powerful tool to estimate and extrapolate air-sea CO2 fluxes in sparsely sampled area.

  19. Metabolism of the polycyclic musk galaxolide and its interference with endogenous and xenobiotic metabolizing enzymes in the European sea bass (Dicentrarchus labrax).

    PubMed

    Fernandes, Denise; Dimastrogiovanni, Giorgio; Blázquez, Mercedes; Porte, Cinta

    2013-03-01

    This study investigates the metabolism and mode of action of galaxolide (HHCB) in the European sea bass -Dicentrarchus labrax- following a single intraperitoneal injection of 50 mg HHCB/kg body weight. In addition, a group of fish was injected with 50 mg/kg of ketoconazole (KCZ), a fungicide that is known to interfere with different Cyp isoenzymes. HHCB was actively metabolised by sea bass and acted as a weak inhibitor of the synthesis of oxyandrogens in gonads of male fish. Both, HHCB and a hydroxylated metabolite were detected in bile. The fungicide ketoconazole was a strong inhibitor of Cyp11β and Cyp3a-catalyzed activities. The work contributes to the better understanding of the impact of synthetic musks on fish and proposes the determination of HHCB and/or its hydroxylated metabolite in bile as a tool to assess environmental exposure in wild fish. PMID:23274450

  20. Cytokine expression in head-kidney leucocytes of European sea bass (Dicentrarchus labrax L.) after incubation with the probiotic Vagococcus fluvialis L-21.

    PubMed

    Román, L; Real, F; Padilla, D; El Aamri, F; Déniz, S; Grasso, V; Acosta, F

    2013-10-01

    The European sea bass (Dicentrarchus labrax L.) is one of the most extensively farmed marine fish in the Mediterranean sea. Under the high-density condition, common in aquaculture, the infectious diseases can cause significant economic losses. Probiotics are presented as an alternative to antibiotics for the control of aquaculture diseases. This study used real-time PCR to investigate in vitro the dynamic of expression of immune-related genes in sea bass after incubation with live and inactivated (heat and Uv-light) probiotic Vagoccus fluvialis L-21 at different times (T1, T12, T24, T48). The immune associated genes, interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin 10 (IL-10), TumourTumour necrosis factor- (TNF-), ciclo-oxigenase-2 (COX-2), caspase-3 (Casp-3) and Mx were studied in head-kidney (HK) leucocytes of sea bass after incubation with the probiotic strain. Transcript of proinflammatory cytokines (IL-1, TNF-, COX-2) was highly up-regulated after 1 h of incubation with the probiotic strain V. fluvialis L-21. We found statistically significant difference in pick of expression of TNF-, after 1 h of incubation with Uv-light inactivated probiotic strain. The COX-2 expression was highly up-regulated at all times studied, with the exception of 12 and 24 h post incubation for the Uv-light inactivated bacteria. Transcript of IL-10 and Casp-3 showed the higher statistically significant differences of expression after 48 h post incubation with live bacteria. In the contrast, sea bass HK leucocytes expressed Mx at 12 and 48 h without statistically differences among treatments. Our results suggest that V. fluvialis L-21 is able to stimulate in vitro some immune-related genes associated with the early inflammatory response. Future studies in vivo are necessary to clarify this process in sea bass. PMID:23927874

  1. A second look at mitochondrial DNA variability in European anchovy (Engraulis encrasicolus): assessing models of population structure and the Black Sea isolation hypothesis.

    PubMed

    Grant, W Stewart

    2005-11-01

    Genetic architectures of marine fishes are generally shallow because of the large potential for gene flow in the sea. European anchovy, however, are unusual among small pelagic fishes in showing large differences among sub-basins and in harbouring two mtDNA phylogroups ('A' & 'B'), representing 1.1-1.85 million years of separation. Here the mtDNA RFLP dataset of Magoulas et al. [1996, Mol. Biol. Evol. 13: 178-190] is re-examined to assess population models accounting for this subdivided population structure and to evaluate the zoogeographical origins of the two major phylogroups. Haplotype and nucleotide diversities are highest in the Ionian Sea and lowest in the Aegean and Black seas. However, this gradient is absent when 'A' and 'B' haplotypes are examined separately. Neither the self-sustaining nor the basin population models adequately describe anchovy population behaviour. Tests for neutrality, mismatch and nested clade analyses are concordant in depicting recent expansions of both phylogroups. Unimodel mismatch distributions and haplotype coalescences dating to the last (Eemian) interglacial ('B') and the Weichselian pleniglacial period ('A') indicate separate colonizations of the Mediterranean Basin. Phylogroup 'A' is unlikely to have arisen through continuous long-term isolation in the Black Sea because of climate extremes from displaced subpolar weather systems during the ice ages. Ancestors of both groups appear to have colonized the Mediterranean from the Atlantic in the late Pleistocene. Hence, zoogeographic models of anchovy in the Mediterranean must also include the eastern (and possibly southern) Atlantic. PMID:16247701

  2. Velocity model of the crust and upper mantle at the southern margin of the East European Craton (Azov Sea-Crimea-Black Sea area), DOBRE-2 & DOBRE'99 transect

    NASA Astrophysics Data System (ADS)

    Starostenko, Vitaly; Janik, Tomasz; Stephenson, Randell; Gryn, Dmytro; Tolkunov, Anatoliy; Czuba, Wojciech; Środa, Piotr; Sydorenko, Grigoriy; Lysynchuk, Dmytro; Omelchenko, Victor; Grad, Marek; Guterch, Aleksander; Kolomiyets, Katerina; Thybo, Hans; Dannowski, Anke; Flűh, Ernst R.; Legostaeva, Olga

    2013-04-01

    The southern part of the eastern European continental landmass consists mainly of a thick platform of Vendian and younger sediments overlying Precambrian basement, part of the East European Craton (EEC). The Scythian Platform (SP) lies between the EEC and the (mainly Alpine) deformed belt running from Dobrudja (Romania) to Crimea (Ukraine) and the Greater Caucasus (Russia), along the northern margin of the Black Sea. Hard constraints on the Palaeozoic history on the SP are very sparse and little is known of its crustal structure in this area. The poster presents the seismic results of a multidisciplinary project that fills some of this gap. The project is called DOBRE-2 (as it forms a prolongation of the successful DOBRE project executed in 1999-2001). The main objectives of DOBRE-2 were to elucidate the deep-seated structure of the lithosphere and geodynamic setting of the shelf zones of the Azov and Black seas and the Crimean peninsula and to study the deep controls on the structure of basement and sedimentary cover. DOBRE-2 traverses a number of major faults and suture zones separating the EEC from the SP, the Crimean Mountains, and the Black Sea depression. Significant hydrocarbon reserves occur in the basins traversed by DOBRE-2. Deep seismic reflection profiling (30 second, Vibroseis) has been completed on a 100-km segment of the profile on the Azov massif (part of the Ukrainian Shield) as well as a 47-km segment in Crimea. These are complemented by refraction profiling on the shelf zones of the Azov (~53 km) and Black (~160 km) seas and coincident near-vertical (CDP) in the Black Sea, using a combination of onshore seismograph stations, ocean-bottom seismometers, onshore explosive energy sources (6 shot points), as well as ship-borne seismic acquisition. We present a 2-D seismic velocity model (Vp in the crust, depth to the Moho and depth to the intracrustal reflectors) along (~780 km) the DOBRE-2 & DOBRE'99 transect. Our model extends the model published for the DOBRE'99 profile (The DOBREfraction'99 Working Group, 2003) to the southwest. The Moho dips in this direction, from a depth of 40 km below the Azov Sea to ~47 km, below Crimea. A short segment of a reflector interpreted to represent Moho was detected at a depth of ~37 km in the Black Sea part of the profile. We also present a comparison of the DOBRE-2 velocity model with an interpretation of a coincident CDP profile.

  3. Linking oceanic food webs to coastal production and growth rates of Pacific salmon ( Oncorhynchus spp.), using models on three scales

    NASA Astrophysics Data System (ADS)

    Aydin, Kerim Y.; McFarlane, Gordon A.; King, Jacquelynne R.; Megrey, Bernard A.; Myers, Katherine W.

    2005-03-01

    Three independent modeling methodsa nutrient-phytoplankton-zooplankton (NPZ) model (NEMURO), a food web model (Ecopath/Ecosim), and a bioenergetics model for pink salmon ( Oncorhynchus gorbuscha)were linked to examine the relationship between seasonal zooplankton dynamics and annual food web productive potential for Pacific salmon feeding and growing in the Alaskan subarctic gyre ecosystem. The linked approach shows the importance of seasonal and ontogenetic prey switching for zooplanktivorous pink salmon, and illustrates the critical role played by lipid-rich forage species, especially the gonatid squid Berryteuthis anonychus, in connecting zooplankton to upper trophic level production in the subarctic North Pacific. The results highlight the need to uncover natural mechanisms responsible for accelerated late winter and early spring growth of salmon, especially with respect to climate change and zooplankton bloom timing. Our results indicate that the best match between modeled and observed high-seas pink salmon growth requires the inclusion of two factors into bioenergetics models: (1) decreasing energetic foraging costs for salmon as zooplankton are concentrated by the spring shallowing of pelagic mixed-layer depth and (2) the ontogenetic switch of salmon diets from zooplankton to squid. Finally, we varied the timing and input levels of coastal salmon production to examine effects of density-dependent coastal processes on ocean feeding; coastal processes that place relatively minor limitations on salmon growth may delay the seasonal timing of ontogenetic diet shifts and thus have a magnified effect on overall salmon growth rates.

  4. Temporal patterns in adult salmon migration timing across southeast Alaska

    USGS Publications Warehouse

    Kovach, Ryan P.; Ellison, Stephen; Pyare, Sanjay; Tallmon, David

    2015-01-01

    Pacific salmon migration timing can drive population productivity, ecosystem dynamics, and human harvest. Nevertheless, little is known about long-term variation in salmon migration timing for multiple species across broad regions. We used long-term data for five Pacific salmon species throughout rapidly warming southeast Alaska to describe long-term changes in salmon migration timing, interannual phenological synchrony, relationships between climatic variation and migratory timing, and to test whether long-term changes in migration timing are related to glaciation in headwater streams. Temporal changes in the median date of salmon migration timing varied widely across species. Most sockeye populations are migrating later over time (11 of 14), but pink, chum, and especially coho populations are migrating earlier than they did historically (16 of 19 combined). Temporal trends in duration and interannual variation in migration timing were highly variable across species and populations. The greatest temporal shifts in the median date of migration timing were correlated with decreases in the duration of migration timing, suggestive of a loss of phenotypic variation due to natural selection. Pairwise interannual correlations in migration timing varied widely but were generally positive, providing evidence for weak region-wide phenological synchrony. This synchrony is likely a function of climatic variation, as interannual variation in migration timing was related to climatic phenomenon operating at large- (Pacific decadal oscillation), moderate- (sea surface temperature), and local-scales (precipitation). Surprisingly, the presence or the absence of glaciers within a watershed was unrelated to long-term shifts in phenology. Overall, there was extensive heterogeneity in long-term patterns of migration timing throughout this climatically and geographically complex region, highlighting that future climatic change will likely have widely divergent impacts on salmon migration timing. Although salmon phenological diversity will complicate future predictions of migration timing, this variation likely acts as a major contributor to population and ecosystem resiliency in southeast Alaska.

  5. Temporal patterns in adult salmon migration timing across southeast Alaska.

    PubMed

    Kovach, Ryan P; Ellison, Stephen C; Pyare, Sanjay; Tallmon, David A

    2015-05-01

    Pacific salmon migration timing can drive population productivity, ecosystem dynamics, and human harvest. Nevertheless, little is known about long-term variation in salmon migration timing for multiple species across broad regions. We used long-term data for five Pacific salmon species throughout rapidly warming southeast Alaska to describe long-term changes in salmon migration timing, interannual phenological synchrony, relationships between climatic variation and migratory timing, and to test whether long-term changes in migration timing are related to glaciation in headwater streams. Temporal changes in the median date of salmon migration timing varied widely across species. Most sockeye populations are migrating later over time (11 of 14), but pink, chum, and especially coho populations are migrating earlier than they did historically (16 of 19 combined). Temporal trends in duration and interannual variation in migration timing were highly variable across species and populations. The greatest temporal shifts in the median date of migration timing were correlated with decreases in the duration of migration timing, suggestive of a loss of phenotypic variation due to natural selection. Pairwise interannual correlations in migration timing varied widely but were generally positive, providing evidence for weak region-wide phenological synchrony. This synchrony is likely a function of climatic variation, as interannual variation in migration timing was related to climatic phenomenon operating at large- (Pacific decadal oscillation), moderate- (sea surface temperature), and local-scales (precipitation). Surprisingly, the presence or the absence of glaciers within a watershed was unrelated to long-term shifts in phenology. Overall, there was extensive heterogeneity in long-term patterns of migration timing throughout this climatically and geographically complex region, highlighting that future climatic change will likely have widely divergent impacts on salmon migration timing. Although salmon phenological diversity will complicate future predictions of migration timing, this variation likely acts as a major contributor to population and ecosystem resiliency in southeast Alaska. PMID:25482609

  6. Effects of dietary concentrated mannan oligosaccharides supplementation on growth, gut mucosal immune system and liver lipid metabolism of European sea bass (Dicentrarchus labrax) juveniles.

    PubMed

    Torrecillas, Silvia; Montero, Daniel; Caballero, Maria José; Robaina, Lidia; Zamorano, Maria Jesús; Sweetman, John; Izquierdo, Marisol

    2015-02-01

    The study assesses the effects of dietary concentrated mannan oligosaccharides (cMOS) on fish performance, biochemical composition, tissue fatty acid profiles, liver and posterior gut morphology and gen expression of selected parameters involved on the intestinal immune response and liver lipid metabolism of European sea bass (Dicentrarchus labrax). For that purpose, specimens of 20 g were fed during 8 weeks at 0 and 1.6 g kg(-1) dietary cMOS of inclusion in a commercial sea bass diet. Dietary cMOS enhanced fish length, specific and relative growth without affecting tissue proximate composition. However, cMOS supplementation altered especially liver and muscle fatty acid profiles by reducing levels of those fatty acids that are preferential substrates for β-oxidation in spite of a preferential retention of long chain polyunsaturated fatty acids (LC-PUFA), such as 20:4n-6 or 22:5n-6, in relation to the down-regulation of delta 6/5 desaturase gene expression found in liver. Besides, dietary cMOS supplementation reduced posterior gut intestinal folds width and induced changes on the gene expression level of certain immune-related genes mainly by down regulating transforming growth factor β (TGFβ) and up-regulating immunoglobulin (Ig), major histocompatibility complex class II (MHCII), T cell receptor β (TCRβ) and Caspase 3 (Casp-3). Thus, dietary cMOS inclusion at 0.16% promoted European sea bass specific growth rate and length, stimulated selected cellular GALT-associated parameters and affected lipid metabolism in muscle and liver pointing to a higher LC-PUFA accumulation and promoted β-oxidation. PMID:25447638

  7. Monitoring the impact of litter in large vertebrates in the Mediterranean Sea within the European Marine Strategy Framework Directive (MSFD): constraints, specificities and recommendations.

    PubMed

    Galgani, F; Claro, F; Depledge, M; Fossi, C

    2014-09-01

    In its decision (2010/477/EU) relating to the European Marine Strategy Framework Directive (MSFD, 2008/56/EC), the European Commission identified the following points as focuses for monitoring: (i) 10.1.1: Trends in the amount, source and composition of litter washed ashore and/or deposited on coastlines, (ii) 10.1.2: Trends in the amount and composition of litter in the water column and accumulation on the sea floor, (iii) 10.1.3: Trends in the amount, distribution and composition of micro-particles (mainly microplastics), and (iv) 10.2.1: Trends in the amount and composition of litter ingested by marine animals. Monitoring the impacts of litter will be considered further in 2014. At that time, the strategy will be discussed in the context of the Mediterranean Sea, providing information on constraints, protocols, existing harm and research needed to support monitoring efforts. The definition of targets and acceptable levels of harm must take all factors into account, whether entanglement, ingestion, the transport and release of pollutants, the transport of alien species and socio-economic impacts. It must also reflect on the practical deployment of "ingestion" measures (10.2.1). The analysis of existing data will reveal the potential and suitability of some higher trophic level organisms (fish, turtles, birds and mammals) for monitoring the adverse effects of litter. Sea turtles appear to be useful indicator species, but the definition of an ecological quality objective is still needed, as well as research on alternative potential indicator species. PMID:24612883

  8. The European Fixed point Open Ocean Observatory network (FixO3): Multidisciplinary observations from the air-sea interface to the deep seafloor

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard; Cristini, Luisa; Alexiou, Sofia

    2015-04-01

    The Fixed point Open Ocean Observatory network (FixO3, http://www.fixo3.eu/ ) integrates 23 European open ocean fixed point observatories and improves access to these infrastructures for the broader community. These provide multidisciplinary observations in all parts of the oceans from the air-sea interface to the deep seafloor. Started in September 2013 with a budget of 7 Million Euros over 4 years, the project has 29 partners drawn from academia, research institutions and SME's coordinated by the National Oceanography Centre, UK. Here we present the programme's achievements in the 18 months and the activities of the 12 Work Packages which have the objectives to: • integrate and harmonise the current procedures and processes • offer free access to observatory infrastructures to those who do not have such access, and free and open data services and products • innovate and enhance the current capability for multidisciplinary in situ ocean observation Open ocean observation is a high priority for European marine and maritime activities. FixO3 provides important data and services to address the Marine Strategy Framework Directive and in support of the European Integrated Maritime Policy. FixO3 provides a strong integrated framework of open ocean facilities in the Atlantic from the Arctic to the Antarctic and throughout the Mediterranean, enabling an integrated, regional and multidisciplinary approach to understand natural and anthropogenic change in the ocean.

  9. Dynamics of air-sea CO2 fluxes in the North-West European Shelf based on Voluntary Observing Ship (VOS) and satellite observations

    NASA Astrophysics Data System (ADS)

    Marrec, P.; Cariou, T.; Macé, E.; Morin, P.; Salt, L. A.; Vernet, M.; Taylor, B.; Paxman, K.; Bozec, Y.

    2015-04-01

    From January 2011 to December 2013, we constructed a comprehensive pCO2 dataset based on voluntary observing ship (VOS) measurements in the Western English Channel (WEC). We subsequently estimated surface pCO2 and air-sea CO2 fluxes in north-west European continental shelf waters using multiple linear regressions (MLRs) from remotely sensed sea surface temperature (SST), chlorophyll a concentration (Chl a), the gas transfer velocity coefficient (K), photosynthetically active radiation (PAR) and modeled mixed layer depth (MLD). We developed specific MLRs for the seasonally stratified northern WEC (nWEC) and the permanently well-mixed southern WEC (sWEC) and calculated surface pCO2 with relative uncertainties of 17 and 16 μatm, respectively. We extrapolated the relationships obtained for the WEC based on the 2011-2013 dataset (1) temporally over a decade and (2) spatially in the adjacent Celtic and Irish Seas (CS and IS), two regions which exhibit hydrographical and biogeochemical characteristics similar to those of WEC waters. We validated these extrapolations with pCO2 data from the SOCAT database and obtained relatively robust results with an average precision of 4 ± 22 μatm in the seasonally stratified nWEC and the southern and northern CS (sCS and nCS), but less promising results in the permanently well-mixed sWEC, IS and Cap Lizard (CL) waters. On an annual scale, seasonally stratified systems acted as a sink of CO2 from the atmosphere of -0.4, -0.9 and -0.4 mol C m-2 year-1 in the nCS, sCS and nWEC, respectively, whereas, permanently well-mixed systems acted as source of CO2 to the atmosphere of 0.2, 0.4 and 0.4 mol C m-2 year-1 in the sWEC, CL and IS, respectively. Air-sea CO2 fluxes showed important inter-annual variability resulting in significant differences in the intensity and/or direction of annual fluxes. We scaled the mean annual fluxes over six provinces for the last decade and obtained the first annual average uptake of -0.95 Tg C year-1 for this part of the north-western European continental shelf. Our study showed that combining VOS data with satellite observations can be a powerful tool to estimate and extrapolate air-sea CO2 fluxes in sparsely sampled area.

  10. Comparison of bio-physical marine products from SeaWiFS, MODIS and a bio-optical model with in situ measurements from Northern European waters

    NASA Astrophysics Data System (ADS)

    Blondeau-Patissier, D.; Tilstone, G. H.; Martinez-Vicente, V.; Moore, G. F.

    2004-09-01

    In this paper, we compare bio-physical marine products from SeaWiFS, MODIS and a novel bio-optical absorption model with in situ measurements of chlorophyll-a (Chla) concentrations, total suspended material (TSM) concentrations, normalized water-leaving radiances (nLw) and absorption coefficients of coloured dissolved organic matter (aCDOM), total particulate (atotal) and phytoplankton (aphy) for 26 satellite match-ups in three Northern European seas. Cruises were undertaken in 2002 and 2003 in phytoplankton dominated open ocean waters of the Celtic Sea and optically complex waters of the Western English Channel (WEC) and North Sea. For all environments, Chla concentrations varied from 0.4 to 7.8 mg m-3, TSM from 0.2 to 6.0 mg l-1 and aCDOM at 440 nm from 0.02 to 0.30 m-1. SeaWiFS OC4v4, with the Remote Sensing Data Analysis Service (RSDAS) atmospheric correction for turbid waters, showed the most accurate retrieval of in situ Chla (RMS = 0.24; n = 26), followed by MODIS chlor_a_3 (RMS = 0.40; n = 26). This suggested that improving the atmospheric correction over optically complex waters results in more accurate Chla concentrations compared to those obtained using more complicated Chla algorithms. We found that the SeaWiFS OC4v4 and the MODIS chlor_a_2 switching band ratio algorithms, which mainly use longer wavebands than 443 nm, were less affected by CDOM. They were both more accurate than chlor_MODIS in the higher CDOM waters of the North Sea. Compared to MODIS the absorption model was better at retrieving atotal (RMS = 0.39; n = 78) and aCDOM (RMS = 0.79; n = 12) in all study areas and TSM in the WEC (RMS = 0.04; n = 10) but it underestimated Chla concentrations (RMS = 0.45; n = 26). The results are discussed in terms of atmospheric correction, sensor characteristics and the functioning and performance of Chla algorithms. This paper was presented at the Institute of Physics Meeting on Underwater Optics held during Photonex 03 at Warwick, UK, in October 2003. Four companion papers from this conference were published in Journal of Optics A: Pure and Applied Optics, volume 6, issue 7 (July 2004), on pages 684, 690, 698 and 703.

  11. Fitness reduction and potential extinction of wild populations of Atlantic salmon, Salmo salar, as a result of interactions with escaped farm salmon.

    PubMed Central

    McGinnity, Philip; Prodöhl, Paulo; Ferguson, Andy; Hynes, Rosaleen; Maoiléidigh, Niall O; Baker, Natalie; Cotter, Deirdre; O'Hea, Brendan; Cooke, Declan; Rogan, Ger; Taggart, John; Cross, Tom

    2003-01-01

    The high level of escapes from Atlantic salmon farms, up to two million fishes per year in the North Atlantic, has raised concern about the potential impact on wild populations. We report on a two-generation experiment examining the estimated lifetime successes, relative to wild natives, of farm, F(1) and F(2) hybrids and BC(1) backcrosses to wild and farm salmon. Offspring of farm and "hybrids" (i.e. all F(1), F(2) and BC(1) groups) showed reduced survival compared with wild salmon but grew faster as juveniles and displaced wild parr, which as a group were significantly smaller. Where suitable habitat for these emigrant parr is absent, this competition would result in reduced wild smolt production. In the experimental conditions, where emigrants survived downstream, the relative estimated lifetime success ranged from 2% (farm) to 89% (BC(1) wild) of that of wild salmon, indicating additive genetic variation for survival. Wild salmon primarily returned to fresh water after one sea winter (1SW) but farm and 'hybrids' produced proportionately more 2SW salmon. However, lower overall survival means that this would result in reduced recruitment despite increased 2SW fecundity. We thus demonstrate that interaction of farm with wild salmon results in lowered fitness, with repeated escapes causing cumulative fitness depression and potentially an extinction vortex in vulnerable populations. PMID:14667333

  12. Relative resistance of Pacific salmon to infectious salmon anaemia virus

    USGS Publications Warehouse

    Rolland, J.B.; Winton, J.R.

    2003-01-01

    Infectious salmon anaemia (ISA) is a major disease of Atlantic salmon, Salmo salar, caused by an orthomyxovirus (ISAV). Increases in global aqua culture and the international movement of fish made it important to determine if Pacific salmon are at risk. Steelhead trout, Oncorhynchus mykiss, and chum, O. keta, Chinook, O. tshawytscha, coho, O. kisutch, and Atlantic salmon were injected intraperitoneally with a high, medium, or low dose of a Norwegian strain of ISAV. In a second challenge, the same species, except chum salmon, were injected with a high dose of either a Canadian or the Norwegian strain. Average cumulative mortality of Atlantic salmon in trial 1 was 12% in the high dose group, 20% in the medium dose group and 16% in the low dose group. The average cumulative mortality of Atlantic salmon in trial 2 was 98%. No signs typical of ISA and no ISAV-related mortality occurred among any of the groups of Oncorhynchus spp. in either experiment, although ISAV was reisolated from some fish sampled at intervals post-challenge. The results indicate that while Oncorhynchus spp. are quite resistant to ISAV relative to Atlantic salmon, the potential for ISAV to adapt to Oncorhynchus spp. should not be ignored.

  13. SALMON 2100 PROJECT: LIKELY SCENARIOS FOR WILD SALMON

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and British Columbia. The Project does not support o...

  14. Seasonal marine growth of Bristol Bay sockeye salmon (Oncorhynchus nerka) in relation to competition with Asian pink salmon (O. gorbuscho) and the 1977 ocean regime shift

    USGS Publications Warehouse

    Ruggerone, G.T.; Farley, E.; Nielsen, J.; Hagen, P.

    2005-01-01

    Recent research demonstrated significantly lower growth and survival of Bristol Bay sockeye salmon (Oncorhynchus nerka) during odd-numbered years of their second or third years at sea (1975, 1977, etc.), a trend that was opposite that of Asian pink salmon (O. gorbuscha) abundance. Here we evaluated seasonal growth trends of Kvichak and Egegik river sockeye salmon (Bristol Bay stocks) during even- and odd-numbered years at sea by measuring scale circuli increments within each growth zone of each major salmon age group between 1955 and 2000. First year scale growth was not significantly different between odd- and even-numbered years, but peak growth of age-2. smolts was significantly higher than age-1. smolts. Total second and third year scale growth of salmon was significantly lower during odd- than during even-numbered years. However, reduced scale growth in odd-numbered years began after peak growth in spring and continued through summer and fall even though most pink salmon had left the high seas by late July (10-18% growth reduction in odd vs. even years). The alternating odd and even year growth pattern was consistent before and after the 1977 ocean regime shift. During 1977-2000, when salmon abundance was relatively great, sockeye salmon growth was high during specific seasons compared with that during 1955-1976, that is to say, immediately after entry to Bristol Bay, after peak growth in the first year, during the middle of the second growing season, and during spring of the third season. Growth after the spring peak in the third year at sea was relatively low during 1977-2000. We hypothesize that high consumption rates of prey by pink salmon during spring through mid-July of odd-numbered years, coupled with declining zooplankton biomass during summer and potentially cyclic abundances of squid and other prey, contributed to reduced prey availability and therefore reduced growth of Bristol Bay sockeye salmon during late spring through fall of odd-numbered years.

  15. Multiple vitellogenins and product yolk proteins in European sea bass (Dicentrarchus labrax): Molecular characterization, quantification in plasma, liver and ovary, and maturational proteolysis.

    PubMed

    Yilmaz, Ozlem; Prat, Francisco; Ibáñez, A Jose; Köksoy, Sadi; Amano, Haruna; Sullivan, Craig V

    2016-01-01

    Three complete vitellogenin (Vtg) polypeptides of European sea bass (Dicentrarchus labrax), an acanthomorph teleost spawning pelagic eggs in seawater, were deduced from cDNA and identified as VtgAa, VtgAb and VtgC based on current Vtg nomenclature and phylogeny. Label free quantitative mass spectrometry verified the presence of the three sea bass Vtgs or their product yolk proteins (YPs) in liver, plasma and ovary of postvitellogenic females. As evidenced by normalized spectral counts, VtgAb-derived protein was 2- to 5-fold more abundant, depending on sample type, than for VtgAa, while VtgC-derived protein was less abundant, albeit only 3-fold lower than for VtgAb in the ovary. Western blotting with Vtg type-specific antisera raised against corresponding gray mullet (Mugil cephalus) lipovitellins (Lvs) detected all three types of sea bass Vtg in the blood plasma of gravid females and/or estrogenized males and showed that all three forms of sea bass Lv undergo limited partial degradation during oocyte maturation. The comparatively high levels of VtgC-derived YPs in fully-grown oocytes and the maturational proteolysis of all three types of Lv differ from what has been reported for other teleosts spawning pelagic eggs in seawater but are similar to recent findings for two species of North American Moronidae, the striped bass (Morone saxatilis) and white perch (Morone americana), which spawn pelagic and demersal eggs, respectively in fresh water. Together with the high Vtg sequence homologies and virtually identical structural features of each type of Vtg between species, these findings indicate that the moronid multiple Vtg systems do not substantially vary with reproductive environment. PMID:26643259

  16. The Impact of Escaped Farmed Atlantic Salmon (Salmo salar L.) on Catch Statistics in Scotland

    PubMed Central

    Green, Darren M.; Penman, David J.; Migaud, Herve; Bron, James E.; Taggart, John B.; McAndrew, Brendan J.

    2012-01-01

    In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L.) may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed) and sea trout (Salmo trutta L.). This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible. PMID:22970132

  17. The impact of escaped farmed Atlantic salmon (Salmo salar L.) on catch statistics in Scotland.

    PubMed

    Green, Darren M; Penman, David J; Migaud, Herve; Bron, James E; Taggart, John B; McAndrew, Brendan J

    2012-01-01

    In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L.) may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed) and sea trout (Salmo trutta L.). This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible. PMID:22970132

  18. Dietary Mannan Oligosaccharides: Counteracting the Side Effects of Soybean Meal Oil Inclusion on European Sea Bass (Dicentrarchus labrax) Gut Health and Skin Mucosa Mucus Production?

    PubMed Central

    Torrecillas, Silvia; Montero, Daniel; Caballero, Maria José; Pittman, Karin A.; Custódio, Marco; Campo, Aurora; Sweetman, John; Izquierdo, Marisol

    2015-01-01

    The main objective of this study was to assess the effects of 4 g kg−1 dietary mannan oligosaccharides (MOS) inclusion in soybean oil (SBO)- and fish oil (FO)-based diets on the gut health and skin mucosa mucus production of European sea bass juveniles after 8 weeks of feeding. Dietary MOS, regardless of the oil source, promoted growth. The intestinal somatic index was not affected, however dietary SBO reduced the intestinal fold length, while dietary MOS increased it. The dietary oil source fed produced changes on the posterior intestine fatty acid profiles irrespective of MOS dietary supplementation. SBO down-regulated the gene expression of TCRβ, COX2, IL-1β, TNFα, IL-8, IL-6, IL-10, TGFβ, and Ig and up-regulated MHCII. MOS supplementation up-regulated the expression of MHCI, CD4, COX2, TNFα, and Ig when included in FO-based diets. However, there was a minor up-regulating effect on these genes when MOS was supplemented in the SBO-based diet. Both dietary oil sources and MOS affected mean mucous cell areas within the posterior gut, however the addition of MOS to a SBO diet increased the mucous cell size over the values shown in FO fed fish. Dietary SBO also trends to reduce mucous cell density in the anterior gut relative to FO, suggesting a lower overall mucosal secretion. There are no effects of dietary oil or MOS in the skin mucosal patterns. Complete replacement of FO by SBO, modified the gut fatty acid profile, altered posterior gut-associated immune system (GALT)-related gene expression and gut mucous cells patterns, induced shorter intestinal folds and tended to reduce European sea bass growth. However, when combined with MOS, the harmful effects of SBO appear to be partially balanced by moderating the down-regulation of certain GALT-related genes involved in the functioning of gut mucous barrier and increasing posterior gut mucous cell diffusion rates, thus helping to preserve immune homeostasis. This denotes the importance of a balanced dietary n–3/n–6 ratio for an appropriate GALT-immune response against MOS in European sea bass juveniles. PMID:26300883

  19. Consequences of changing sea-ice cover for primary and secondary producers in the European Arctic shelf seas: Timing, quantity, and quality

    NASA Astrophysics Data System (ADS)

    Leu, E.; Søreide, J. E.; Hessen, D. O.; Falk-Petersen, S.; Berge, J.

    2011-07-01

    The Arctic ice cover poses severe limitations on the productive period of marine autotrophs that form the base of the marine food web. Sea-ice algae begin to grow in early spring within and underneath the ice, producing a substantial biomass despite very low light intensities. Pelagic algal blooms, in contrast, normally occur after ice breakup, at high latitudes as late as July-September. The timing of these blooms is crucial for the quantity and quality of primary and secondary production, and therefore for the transfer of energy and matter to higher trophic levels. Recent findings from Rijpfjorden, north-eastern Svalbard indicate that ice algae, rather than pelagic algae, trigger the reproduction of Arctic zooplankton around Svalbard. The key herbivore in Arctic shelf seas, the copepod Calanus glacialis, timed its seasonal migration, foraging, and reproduction to the ice algal bloom, which preceded the pelagic algal bloom by two months. The growth of this secondary producer’s offspring, however, was dependent on the later bloom of phytoplankton and higher sea-water temperatures. In 2007, reproduction and growth of C. glacialis and the primary production regime matched perfectly. The persistent ice cover in summer 2008, however, led to a mismatch between the pelagic algal bloom and the growth of the new copepod generation, resulting in a fivefold lower biomass of C. glacialis in August 2008 compared to 2007. The initiation of the ice algal bloom is mainly determined by the solar angle, whereas the pelagic algal bloom requires more light and is therefore governed to a larger degree by ice thinning and the unpredictable ice breakup. We conclude that both a too early as well as a too late ice breakup can cause a mismatch between primary and secondary producers, with negative consequences for the entire lipid-based Arctic marine food web.

  20. Does salmon brain produce insulin?

    PubMed

    Plisetskaya, E M; Bondareva, V M; Duan, C; Duguay, S J

    1993-07-01

    To address the question whether fish brain can produce insulin, pink salmon (Oncorhynchus gorbusha) brains were extracted and processed according to the procedure developed for purification of pancreatic insulin (Rusakov and Bondareva, 1979). Biological and immunological activity of the resulting material was evaluated respectively by a cartilage sulfation assay and by radioimmunoassay homologous for salmon insulin. Preparations from salmon brain stimulated the [35S]sulfate uptake into salmon branchial cartilage with a potency comparable to pure mammalian or salmon insulins but lower than that of mammalian insulin-like growth factor (IGF-I). In contrast, only trace amounts of radioimmunoreactive insulin could be detected by homologous radioimmunoassay. To determine whether insulin mRNA was present in salmon brain, primers specific for salmon proinsulin and salmon prepro-IGF-I were designed to amplify corresponding cDNA regions by reverse transcriptase-PCR. Insulin mRNA was found only in the endocrine pancreas (Brockmann body) while IGF-I mRNA was detected in the brain, liver, and the Brockmann body. Our results suggest that in fish pancreatic-type insulin is most likely produced only in the endocrine pancreas and then transported to the brain through blood/cerebrospinal fluid system. However, it does not exclude a possibility that some yet unknown insulin-like substances may be expressed in the neural system of ectotherm vertebrates. PMID:8405893

  1. MAINE ATLANTIC SALMON HABITAT - GENERAL

    EPA Science Inventory

    ASDENN00 describes, at 1:24,000 scale, important Atlantic salmon habitat of the Dennys River in Maine. The coverage was developed from field surveys conducted on the Dennys River in Maine by staff of the Atlantic Salmon Authority and U.S. Fish and Wildlife Service. This survey wa...

  2. Biodiesel from Waste Salmon Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmon oils separated from salmon processing waste and hydrolysate and their derived methyl esters were analyzed and compared with corn oil and its methyl ester. These materials were characterized for their fatty acid profiles, viscosity, volatility, thermal properties, low temperature properties, o...

  3. New York State Salmon River Fish Hatchery

    USGS scientists release young Atlantic salmon into Lake Ontario tributaries near the New York State Department of Environmental Conservation's Salmon River Fish Hatchery in Altmar, N.Y. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this di...

  4. WILD SALMON RESTORATION: IS IT WORTH IT?

    EPA Science Inventory

    Salmon are categorized biologically into two groups: Pacific salmon and Atlantic salmon. Atlantic salmon are found on both sides of the North Atlantic Ocean, but have declined precipitously compared to the size of runs prior to the 1700s. The largest (though small by historic ...

  5. A comparative review on European-farmed finfish RNA viruses and their vaccines.

    PubMed

    Gomez-Casado, E; Estepa, A; Coll, J M

    2011-03-24

    The diseases causing the highest ecological and socio-economical impacts in European farmed finfish are produced by RNA viruses. Salmon, trout, sea bream, sea bass, carp and turbot, suffer viral nervous necrosis produced by betanodaviruses (VNNV), infectious pancreatic necrosis produced by aquabirnaviruses (IPNV), viral haemorrhagic septicemia (VHSV) and infectious haematopoietic necrosis (IHNV) produced by novirhabdoviruses, spring viremia of carp produced by vesicular-like rhabdoviruses (SVCV), salmon pancreas disease and trout sleeping disease produced by alphaviruses (SAV) and infectious salmon anaemia produced by isaviruses (ISAV). There are not yet any effective treatments other than destroying all fish in infected farms, avoiding fish movements to and from infected areas and, in some particular cases, vaccination. The comparative study of the molecular characteristics of those RNA viruses and the state of knowledge of their vaccines, point to the development of new DNA vaccines for some RNA viruses, design of new mass delivery methods, maternal transfer of immunity, more extensive crossprotection studies between genotypes, use of safer all-fish plasmid control elements and study of DNA plasmid distribution after vaccination, as some of the major gaps that need urgent filling. In addition, to obtain similar protection levels to those produced by viral infections in survivors, live attenuated and/or some oil-adjuvanted inactivated virus vaccines, molecular adjuvants and/or other viral components (dsRNA or viral proteins interfering with fish defences), might have to be included in new DNA vaccine formulations. Furthermore, to be approved by the corresponding European authorities, fish viral DNA vaccines would also require the study of the persistence in fish of the introduced DNA, their possible impact to the aquatic environment and the acceptance of potential consumers. PMID:21320546

  6. Effect of an experimental oil spill on vertebral bone tissue quality in European sea bass (Dicentrarchus labrax L.).

    PubMed

    Danion, Morgane; Deschamps, Marie-Hélène; Thomas-Guyon, Hélène; Bado-Nilles, Anne; Le Floch, Stéphane; Quentel, Claire; Sire, Jean-Yves

    2011-10-01

    In order to identify biomarkers of oil pollution in fish we tested the effects of an experimental Light Cycle Oil (LCO) exposure on vertebral bone of sea bass, Dicentrarchus labrax L. A total of 60 adult fish were acclimated for fifteen days, then twenty were collected as controls (Day 0) while 40 were exposed to a soluble fraction of LCO (1136 ng L(-1) of ten Polycyclic Aromatic Hydrocarbons, PAHs) for seven days. Twenty of them were sampled at the end of the exposure period and the twenty last after a recovery period of fourteen days in clean seawater. Vertebral abnormalities were counted and bone mineralization, total bone area and bone density profiles were established for several post-cranial and caudal vertebrae. In sea bass, seven days of LCO exposure did not affect the frequency and severity of the vertebral abnormalities. No significant differences were observed in bone density and bone repartition (parameters of bone area profiles) between unexposed (Day 0), exposed (D7) and decontaminated (D21) fish. In contrast, bone mineralization of the vertebrae decreased in contaminated sea bass, but in a reversible way, which confirms a previous study in trout showing that this parameter is an early stress indicator. Our results suggest that vertebral bone mineralization could be used as a biomarker of PAH pollution in sea bass. It would be interesting to check this new biomarker in other teleost species exposed to various xenobiotics. PMID:21831432

  7. Growth evaluation of atlantic salmon (Salmo salar) raised in seawater or freshwater and fed either fishmeal based on marine-free diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A forty week feeding study was conducted with Atlantic salmon (Salmo salar) smolts in two recirculating aquaculture systems. Twelve salmon (average initial weight 117 g; initial density 9.4 kg/m3) were stocked per tank. Two identical systems were used and contained either freshwater (0 ppt) or sea...

  8. Telemetry link for an automatic salmon migration monitor

    NASA Technical Reports Server (NTRS)

    Baldwin, H. A.; Freyman, R. W.

    1973-01-01

    The antenna and transmitter described in this report were designed for integration into the remote acoustic assessment system for detection of sockeye salmon in the Bristol Bay region of the Bering Sea. The assessment system configuration consists of an upward directed sonar buoy anchored 150 ft below the surface and attached by cable to a spar buoy tethered some 300 ft laterally. The spar buoy contains a telemetry transmitter, power supply, data processing electronics, an antenna and a beacon light.

  9. Swimming speeds and buoyancy compensation of migrating adult chum salmon Oncorhynchus keta revealed by speed/depth/acceleration data logger.

    PubMed

    Tanaka, H; Takagi, Y; Naito, Y

    2001-11-01

    Although the homing migration of Pacific salmon is well documented, the swimming behaviour of the returning salmon has been poorly described, principally as a result of the difficulties encountered in monitoring salmon behaviour in the sea. The present study describes the use of a recently developed electronic data logger to obtain simultaneous recordings of the swimming speed, depth, fin-beating activity and body angle of free-ranging chum salmon Oncorhynchus keta during their homing migration in coastal waters. Chum salmon migrated horizontally at speeds of 1.5-3.0 km h(-1). The gross horizontal distance salmon moved during total recording periods were 1.24- to 19.0-fold greater than the net distance from the release site to the retrieval points. It is suggested that homing salmon did not drift passively but swam actively to the spawning grounds. Salmon preferred the surface water, but also made frequent vertical migrations. The travelled depth of each salmon ranged from 0.36 to 0.64 km per hour. Salmon descended at faster rates and steeper angles than they ascended. Both tailbeat frequency and tail thrust were higher during the ascent than the descent phase. These results suggest that chum salmon spent more energy during the ascent than the descent phase. Profiles of descent rate assumed an arched shape with respect to a change in hydrostatic pressure, while ascent rate increased with decreasing depth. High tailbeat frequencies were found during the course of ascent, which suggests that the salmon did not regulate the volume of air in the swim bladder during short-term vertical migrations. PMID:11807107

  10. Modulation of the Expression of Components of the Stress Response by Dietary Arachidonic Acid in European Sea Bass (Dicentrarchus labrax) Larvae.

    PubMed

    Montero, Daniel; Terova, Genciana; Rimoldi, Simona; Betancor, Mónica B; Atalah, Eyad; Torrecillas, Silvia; Caballero, María J; Zamorano, María J; Izquierdo, Marisol

    2015-10-01

    This study reports for the first time on European sea bass, Dicentrarchus labrax (L.), larvae, the effect of different levels of dietary arachidonic acid (ARA; 20:4n-6) on the expression of genes related to the fish stress response. Copies of mRNA from genes related to steroidogenesis [StAR (steroidogenic acute regulatory protein), c-Fos, and CYP11β (11β-hydroxylase gene)], glucocorticoid receptor complex [GR (glucocorticoid receptor) and HSP (heat shock proteins) 70 and 90) and antioxidative stress (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase] were quantified. Eighteen day-old larvae were fed for 14 days with three experimental diets with increasing levels of ARA (0.3, 0.6 and 1.2% d.w.) and similar levels of docosahexaenoic (22:6n-3) and eicosapentaenoic (20:5n-3) acids (5 and 3%, respectively). The quantification of stress-related genes transcripts was conducted by One-Step TaqMan real time RT-PCR with the standard curve method (absolute quantification). Increase dietary levels of ARA induced a significantly (p < 0.05) down-regulation of genes related to cortisol synthesis, such as StAR and CYP11β and up-regulated genes related to glucocorticoid receptor complex, such as HSP70 and GR. No effects were observed on antioxidant enzymes gene expression. These results revealed the regulatory role of dietary ARA on the expression of stress-related genes in European sea bass larvae. PMID:26233819

  11. Effects of fish oil replacement by vegetable oil blend on digestive enzymes and tissue histomorphology of European sea bass (Dicentrarchus labrax) juveniles.

    PubMed

    Castro, Carolina; Couto, Ana; Pérez-Jiménez, Amalia; Serra, Cláudia R; Díaz-Rosales, Patricia; Fernandes, Rui; Corraze, Geneviève; Panserat, Stéphane; Oliva-Teles, Aires

    2016-02-01

    The impact of replacing circa 70 % fish oil (FO) by a vegetable oil (VO) blend (rapeseed, linseed, palm oils; 20:50:30) in diets for European sea bass juveniles (IBW 96 ± 0.8 g) was evaluated in terms of activities of digestive enzymes (amylase, lipase, alkaline phosphatase, trypsin and total alkaline proteases) in the anterior (AI) and posterior (PI) intestine and tissue morphology (pyloric caeca-PC, AI, PI, distal intestine-DI and liver). For that purpose, fish were fed the experimental diets for 36 days and then liver and intestine were sampled at 2, 6 and 24 h after the last meal. Alkaline protease characterization was also done in AI and PI at 6 h post-feeding. Dietary VO promoted higher alkaline phosphatase activity at 2 h post-feeding in the AI and at all sampling points in the PI. Total alkaline protease activity was higher at 6 h post-feeding in the PI of fish fed the FO diet. Identical number of bands was observed in zymograms of alkaline proteases of fish fed both diets. No alterations in the histomorphology of PC, AI, PI or DI were noticed in fish fed the VO diets, while in the liver a tendency towards increased hepatocyte vacuolization due to lipid accumulation was observed. Overall, and with the exception of a higher intestine alkaline phosphatase activity, 70 % FO replacement by a VO blend in diets for European sea bass resulted in no distinctive alterations on the postprandial pattern of digestive enzyme activities and intestine histomorphology. PMID:26364216

  12. First report on toxicity assessment of the Lessepsian migrant pufferfish Lagocephalus sceleratus (Gmelin, 1789) from European waters (Aegean Sea, Greece).

    PubMed

    Katikou, Panagiota; Georgantelis, Dimitrios; Sinouris, Nikolaos; Petsi, Anastasia; Fotaras, Theodoros

    2009-07-01

    According to the current European Union legislative requirements (Regulation 853/2004/EC; Regulation 854/2004/EC, poisonous fish of the family Tetraodontidae and products derived from them must not be placed on the European markets. Following the increased publicity regarding the presence of the pufferfish species Lagocephalus sceleratus in Greek waters, this study was undertaken in order to confirm its toxicity and assess the risk of poisoning in case of accidental consumption. Acidic extracts from tissues of L. sceleratus specimens of different sizes were examined by means of the official mouse bioassay for tetrodotoxin, while some of the extracts were also tested for the presence of Paralytic Shellfish Poisoning (PSP) toxins with a commercial ELISA kit. Toxicity in mice, with symptomatology indicative of tetrodotoxin, was confirmed in a number of samples and indicated a correlation with fish size. Toxicity of certain tissues (liver, gonads, gastrointestinal tract) in larger individuals, expressed as microg/g tetrodotoxin equivalents, was largely above levels required to cause death in human adults. On the other hand, all tested extracts provided a positive reaction in the ELISA test for PSP toxins. This constitutes the first report for presence of toxicity in L. sceleratus caught in European coastal waters. PMID:19303896

  13. Tropical Atlantic Sea Surface Temperature Forcing of Quasi-Decadal Climate Variability over the North Atlantic-European Region.

    NASA Astrophysics Data System (ADS)

    Terray, L.; Cassou, C.

    2002-11-01

    Effects of Atlantic sea surface temperature (SST) anomalies on the North Atlantic low-frequency atmospheric variability are examined by analyzing two ensembles of integrations of the ARPEGE general circulation model (GCM) forced with differently configured observed SSTs and sea ice extents (SIE) over the 1948-98 period. An attempt is made to separate the forced atmospheric response from internal atmospheric variability by using a signal-to-noise maximizing empirical orthogonal function (EOF) analysis. This method yields an estimate of the most detectable common forced response given the knowledge of internal variability provided by the ensemble. Applying the algorithm to North Atlantic atmospheric model data leads to an atmospheric response associated with a tripole pattern in North Atlantic SSTs. The spatial structure of the forced response, which is most consistent in winter, shows a dipole pattern in mean sea level pressure projecting onto the North Atlantic Oscillation. Examination of other atmospheric variables shows a very coherent signal with a quasi-barotropic signature. Additional atmospheric integrations with idealized SST anomaly patterns demonstrate the primary role of the tropical North Atlantic SST anomalies in generating the forced response. The physical mechanism involves related changes in tropical convection, Hadley circulation, and the modulation of the stationary and transient planetary-scale waves by the low-frequency variability in subtropical winds induced by the persistent tropical circulation anomalies.

  14. Validation of stir bar sorptive extraction for the determination of 24 priority substances from the European Water Framework Directive in estuarine and sea water.

    PubMed

    Huertas, Cristina; Morillo, José; Usero, José; Gracia-Manarillo, Ignacio

    2007-05-15

    This paper describes the validation of a method for the determination of 24 priority substances from the European Framework Directive in estuarine and sea water using the new extraction technique known as stir bar sorptive extraction (SBSE), followed by thermal desorption using capillary gas chromatography-mass spectrometry. We studied linearity, detection and quantitation limits and accuracy (which includes determination of trueness and precision). Using the lack-of-fit method we tested linearity in the 0-200ngL(-1) range for all the priority substances. The detection and quantification limits were less than 5 and 10ngL(-1), respectively, for most of the compounds studied. Precision was assessed by variance analysis (ANOVA) and relative standard values of less than 10% were obtained for repeatability and less than 15% for intermediate precision. The recovery percentages in spiked estuarine and sea water were close to 100%. Finally, for quality control of the method (stability of precision and accuracy through time), we developed a method for calculating Shewhart control charts based on the information obtained in the validation process. PMID:19071738

  15. Atmospheric-induced variability of hydrological and biogeochemical signatures in the NW Alboran Sea. Consequences for the spawning and nursery habitats of European anchovy

    NASA Astrophysics Data System (ADS)

    Macías, D.; Catalán, I. A.; Solé, J.; Morales-Nin, B.; Ruiz, J.

    2011-12-01

    The north-western Alboran Sea is a highly dynamic region in which the hydrological processes are mainly controlled by the entrance of the Atlantic Jet (AJ) through the Strait of Gibraltar. The biological patterns of the area are also related to this variability in which atmospheric pressure distributions and wind intensity and direction play major roles. In this work, we studied how changes in atmospheric forcing (from high atmospheric pressure over the Mediterranean to low atmospheric pressure) induced alterations in the physical and biogeochemical environment by re-activating coastal upwelling on the Spanish shore. The nursery area of European anchovy ( Engraulis encrasicolus) in the NW Alboran Sea, confirmed to be the very coastal band around Malaga Bay, did not show any drastic change in its biogeochemical characteristics, indicating that this coastal region is somewhat isolated from the rest of the basin. Our data also suggests that anchovy distribution is tightly coupled to the presence of microzooplankton rather than mesozooplankton. Finally, we use detailed physical and biological information to evaluate a hydrological-biogeochemical coupled model with a specific hydrological configuration to represent the Alboran basin. This model is able to reproduce the general circulation patterns in the region forced by the AJ movements only including two variable external forcings; atmospheric pressure over the western Mediterranean and realistic wind fields.

  16. Influence of titanium dioxide nanoparticles on 2,3,7,8-tetrachlorodibenzo-p-dioxin bioconcentration and toxicity in the marine fish European sea bass (Dicentrarchus labrax).

    PubMed

    Torre, Camilla Della; Buonocore, Francesco; Frenzilli, Giada; Corsolini, Simonetta; Brunelli, Andrea; Guidi, Patrizia; Kocan, Anton; Mariottini, Michela; Mottola, Filomena; Nigro, Marco; Pozo, Karla; Randelli, Elisa; Vannuccini, Maria Luisa; Picchietti, Simona; Santonastaso, Marianna; Scarcelli, Vittoria; Focardi, Silvano; Marcomini, Antonio; Rocco, Lucia; Scapigliati, Giuseppe; Corsi, Ilaria

    2015-01-01

    The present study investigated the influence of nano-TiO(2) (1 mg L(-1)) on 2,3,7,8-tetrachlorodibenzo-p-dioxin(2,3,7,8-TCDD) (46 pg L(-1)) bioconcentration and toxicity in the European sea bass (Dicentrarchus labrax) during 7 days in vivo exposure. A multimarkers approach was applied in different organs: detoxification in liver; innate immunity and pro-inflammatory response and adaptive immunity in gills and spleen; genotoxicity in peripheral erythrocytes and muscle. Bioconcentration of 2,3,7,8-TCDD in presence of nano-TiO2 was investigated in liver, skin and muscle as well as interaction between nano-TiO2 and organic pollutants in artificial sea water (ASW). Nano-TiO2 negatively influenced immune response induced by 2,3,7,8-TCDD in spleen but not in gills and reduced the DNA damage induced by 2,3,7,8-TCDD in erythrocytes. nano-TiO2 did not interfere with 2,3,7,8-TCDD detoxification and bioconcentration according to the observed no interaction of the nano-TiO2 with organic pollutants in ASW. PMID:25463713

  17. Finnish salmon resistant to Gyrodactylus salaris: a long-term study at fish farms.

    PubMed

    Rintamäki-Kinnunen, P; Valtonen, E T

    1996-07-01

    The occurrence of Gyrodactylus salaris on Baltic salmon (Salmo salar), sea trout (S. trutta m. trutta) and brown trout (S. trutta m. lacustris) was examined from 1984 to 1993 at 4 fish farms (A, B, C and D) that produce smolts for stocking in northern Finland. No G. salaris was found on the sea or brown trout, but it did occur on salmon for 6-7 years at farms B, C and D, the prevalences of infection being 9.5%, 17.7% and 8.8% for salmon yearlings and smolts during that time, respectively, but less than 1.2% for fingerlings at farms B and C. Only brood stock salmon were infected at farm A in 4 years. The abundances of G. salaris increased during the second winter of each year class and were highest in the spring before stocking. The combination of variables farm, water temperature, age of fish and other ectoparasites did not suffice to explain the occurrence of G. salaris when studied by step-wise logistic regression analysis. It is suggested that other irregular factors at the farm, such as a change in the water intake system, transfers of fish to the farm and the keeping of wild fish at the farm are also important. The present extensive data strongly support previous suggestions that the Baltic salmon is more resistant to G. salaris than salmon migrating into the Atlantic Ocean. PMID:8894763

  18. Effect of gas-transfer-velocity parameterization choice on CO2 air-sea fluxes in the North Atlantic and European Arctic

    NASA Astrophysics Data System (ADS)

    Wróbel, I.; Piskozub, J.

    2015-11-01

    The ocean sink is an important part of the anthropogenic CO2 budget. Because the terrestrial biosphere is usually treated as a residual, understanding the uncertainties the net flux into the ocean sink is crucial for understanding the global carbon cycle. One of the sources of uncertainty is the parameterization of CO2 gas transfer velocity. We used a recently developed software tool, FluxEngine, to calculate monthly net carbon air-sea flux for the extratropical North Atlantic, European Arctic as well as global values (or comparison) using several available parameterizations of gas transfer velocity of different dependence of wind speed, both quadratic and cubic. The aim of the study is to constrain the uncertainty caused by the choice of parameterization in the North Atlantic, a large sink of CO2 and a region with good measurement coverage, characterized by strong winds. We show that this uncertainty is smaller in the North Atlantic and in the Arctic than globally, within 5 % in the North Atlantic and 4 % in the European Arctic, comparing to 9 % for the World Ocean when restricted to functions with quadratic wind dependence and respectively 42, 40 and 67 % for all studied parameterizations. We propose an explanation of this smaller uncertainty due to the combination of higher than global average wind speeds in the North Atlantic and lack of seasonal changes in the flux direction in most of the region. We also compare the available pCO2 climatologies (Takahashi and SOCAT) pCO2 discrepancy in annual flux values of 8 % in the North Atlantic and 19 % in the European Arctic. The seasonal flux changes in the Arctic have inverse seasonal change in both climatologies, caused most probably by insufficient data coverage, especially in winter.

  19. The exceptional surface turbidity of the North-West European shelf seas during the stormy 2013-2014 winter: Consequences for the initiation of the phytoplankton blooms?

    NASA Astrophysics Data System (ADS)

    Gohin, F.; Bryère, P.; Griffiths, J. W.

    2015-08-01

    A succession of storms during the winter 2013-2014 enhanced the resuspension of sediments in the surface waters of the North-West European shelf seas. The effects of waves on satellite-derived non-algal SPM (Suspended Particulate Matters) are discussed for the January 2008-March 2014 period. A simple statistical model relating locally SPM to tidal intensity and waves helps us analyse the main characteristics of the winter 2013-2014. The exceptional run of storms observed in this stormy and rainy winter has resulted in the highest SPM concentration in the Celtic Sea and the Bay of Biscay ever observed by remote-sensing during the 1998-2014 period. Despite the lower clarity of the surface waters over a large part of the continental shelf during the first days of March 2014, blooms occurred early off the coast of Southern Brittany (Bay of Biscay) and later in April, as usual, in the Celtic Sea. Off the coast of southern Brittany, a region of freshwater influence, the lower clarity of the waters was counterbalanced by stronger haline stratification, due to high river discharges, enabling the initiation of blooms in late winter when the solar irradiance is sufficient; which was the case in March 2014 with 7 sunny days in a row just after the last storm. As a consequence, we can postulate that a possible increase in the intensity of waves occurring from December to early March, along with a possible scenario of global change, would not restrict the productive period in the Bay of Biscay. However an extension of the period of storms later in March would delay the timing of the blooms as observed in March 2008 in most of the investigated area.

  20. Influence of season and site location on European cultured sea bass parasites in Corsican fish farms using indicator species analysis (IndVal).

    PubMed

    Antonelli, Laetitia; Foata, Joséphine; Quilichini, Yann; Marchand, Bernard

    2016-02-01

    The parasites of 536 European sea bass, Dicentrarchus labrax, were studied between January 2012 and December 2013 in six Corsican fish farms. The indicator value (IndVal) method, which combines measures of fidelity and specificity, has been used in this study. Because of its resilience to changes in abundance, IndVal is a particularly effective tool for ecological bioindicator. The IndVal method showed how season can influence the occurrence of parasite species in cultured sea bass and also identified parasites as bioindicators relative to fish farm location. The combination of specificity and fidelity highlighted several parasite species as significant indicators. A randomization test identified five parasite species as having a significant indicator value for season (the monogenean Diplectanum aequans; the copepods Lernanthropus kroyeri and Caligus minimus; the isopod Ceratothoa oestroides, and the myxosporidian Ceratomyxa labracis). If gills parasites are compared, they can be seen to be indicator species for two different seasons. The only Monogenea species D. aequans had fidelity and specificity more pronounced in winter, whereas both copepod species and the Isopoda revealed highest rates of infestation corresponding with an increase of water temperature. Four species have a significant indicator value for site location (D. aequans, L. kroyeri, C. minimus, and C. oestroides). The fact that the farm 6 was isolated on the east coast of Corsica may not have allowed the parasite to infect other farms. The presence of copepods on a single farm can also be explained according to salinity variations. Data for species composition and infection levels should help to improve the monitoring and management of parasitism in cultured sea bass populations. PMID:26446088

  1. Growth and feeding patterns of European anchovy ( Engraulis encrasicolus) early life stages in the Aegean Sea (NE Mediterranean)

    NASA Astrophysics Data System (ADS)

    Catalán, Ignacio A.; Folkvord, Arild; Palomera, Isabel; Quílez-Badía, Gemma; Kallianoti, Fotini; Tselepides, Anastasios; Kallianotis, Argyris

    2010-01-01

    The objective of this work was to describe inter- and intra-annual variations in the environmental characteristics of the North-eastern Aegean Sea and to relate these changes to the egg and larval distributions, growth and feeding of larval anchovy ( Engraulis encrasicolus). Four cruises, two in July and two in September in 2003 and 2004 were performed. The distributions of eggs and larvae were associated with i) salinity fronts related to the Black Sea Water and ii) shallow areas of high productivity over the continental shelf, some of them with high riverine influence. The first published description of the anchovy larval diet in the Eastern Mediterranean was conducted in individuals ranging from 2.2 to 17 mm standard length. The number of non-empty guts was relatively high (between 20% and 30%), and the diet was described through 15 main items. The mean size of the prey increased with larval size, and was generally dominated by prey widths smaller than 80 μm (mainly the nauplii and copepodite stages of copepods). Small larvae positively selected copepod nauplii. As larvae grew, they shifted to larger copepod stages. At all sizes, larvae rejected abundant taxa like cladocerans. The average trophic level calculated for anchovy of all size ranges was 2.98 ± 0.16 (SE). Growth rates varied from 0.41 to 0.75 mm d -1, with the highest growth rates generally observed in September. Variability in the Black Sea Water influence and the recorded inter- and intra-annual changes in primary and secondary production, combined with marked changes in temperature over the first 20 m depth, are used to frame the discussion regarding the observed significant differences in growth rates in terms of both length and weight.

  2. Historical biogeography in a linear system: genetic variation of sea rocket (Cakile maritima) and sea holly (Eryngium maritimum) along European coasts.

    PubMed

    Clausing, G; Vickers, K; Kadereit, J W

    2000-11-01

    The exclusively coastal Cakile maritima and Eryngium maritimum represent a linear biogeographical system. Genetic variation among 25 individuals of C. maritima and 16 individuals of E. maritimum, from the coasts of Europe, North Africa and the Canary Islands, was analysed using random amplified polymorphic DNAs (RAPDs) and intersimple sequence repeats (ISSRs). Genetic distances (Dice) were calculated and used to investigate the correlation between genetic and geographical distances, to construct Neighbour Joining (NJ) trees, and to compare mean genetic distances between areas within and across species. Genetic distances and geographical distances measured along the coast are well correlated in Cakile and Eryngium. This implies that dispersal in both species is largely along the coast. The NJ analyses resulted in the recognition of Atlantic and Mediterranean clusters in both Cakile and Eryngium. The genetic distance between these two clusters is much larger in Eryngium (0. 285) than in Cakile (0.037). Mean genetic distances are substantially higher in the Mediterranean than in the Atlantic clusters in both species, and higher in Cakile than in Eryngium particularly in the Atlantic cluster. It is argued that all similarities and differences between the two species can be explained with the presumed distribution of the two species in the Würm glacial as reconstructed from their extant temperature requirements, the distribution of ice cover, permafrost, and sea surface temperatures in that period, and indirect fossil evidence. PMID:11091318

  3. SALMON 2100: THE FUTURE OF WILD PACIFIC SALMON

    EPA Science Inventory

    Many experts have concluded that wild salmon recovery efforts in western North America (especially California, Oregon, Washington, Idaho, and southern British Columbia), as earnest, expensive, and socially disruptive as they currently are, do not appear likely to sustain biologic...

  4. Canada-USA Salmon Shelf Survival Study, 2007-2008 Annual Report.

    SciTech Connect

    Trudel, Marc; Tucker, Strahan; Morris, John

    2009-03-09

    Historically, salmon stocks from the Columbia River and Snake River formed one of the most valuable fisheries on the west coast of North America. However, salmon and steelhead returns sharply declined during the 1980s and 1990s to reach nearly 1 million fish. Although several factors may be responsible for the decline of Columbia River salmon and steelhead, there is increasing evidence that these drastic declines were primarily attributable to persistently unfavorable ocean conditions. Hence, an understanding of the effects of ocean conditions on salmon production is required to forecast the return of salmon to the Columbia River basin and to assess the efficacy of mitigation measures such as flow regulation on salmon resources in this system. The Canadian Program on High Seas Salmon has been collecting juvenile salmon and oceanographic data off the west coast of British Columbia and Southeast Alaska since 1998 to assess the effects of ocean conditions on the distribution, migration, growth, and survival of Pacific salmon. Here, we present a summary of the work conducted as part of the Canada-USA Salmon Shelf Survival Study during the 2008 fiscal year and compare these results with those obtained from previous years. The working hypothesis of this research is that fast growth enhances the marine survival of salmon, either because fast growing fish quickly reach a size that is sufficient to successfully avoid predators, or because they accumulate enough energy reserves to better survive their first winter at sea, a period generally considered critical in the life cycle of salmon. Sea surface temperature decreased from FY05 to FY08, whereas, the summer biomass of phytoplankton increased steadily off the west coast of Vancouver Island from FY05 to FY08. As in FY07, zooplankton biomass was generally above average off the west coast of Vancouver Island in FY08. Interestingly, phytoplankton and zooplankton biomass were higher in FY08 than was expected from the observed nutrient concentration that year. This suggests nutrients were more effectively by phytoplankton in FY08. In addition, the abundance of lipid-rich northern copepods increased from FY05 to FY08, whereas lipid-poor southern copepods showed the opposite pattern, suggesting that growth conditions were more favorable to juvenile salmon in FY08 than in previous years. However, growth indices for juvenile coho salmon were near the 1998-2008 average, both off the west coast of Vancouver Island and Southeast Alaska, indicating that additional factors beside prey quality affect juvenile salmon growth in the marine environment. Catches of juvenile Chinook, sockeye and chum salmon off the west coast of Vancouver Island in June-July 2008 were the highest on record during summer since 1998, suggesting that early marine survival for the 2008 smolt year was high. Interestingly, the proportion of hatchery fish was high (80-100%) among the juvenile Columbia River Chinook salmon caught off the British Columbia coast during summer, suggest that relatively few wild Chinook salmon are produced in the Columbia River Chinook. In addition, we also recovered two coded-wire tagged juvenile Redfish Lake sockeye salmon in June 2008 off the west coast of British Columbia. As relatively few Redfish Lake sockeye smolts are tagged each year, this also suggests that early marine survival was high for these fish, and may result in a high return in 2009 if they mature at age three, or in 2010 if they mature at age four. To date, our research shows that different populations of Columbia River salmon move to different locations along the coastal zone where they establish their ocean feeding grounds and overwinter. We further show that ocean conditions experienced by juvenile Columbia River salmon vary among regions of the coast, with higher plankton productivity and temperatures off the west coast of Vancouver Island than in Southeast Alaska. Hence, different stocks of juvenile salmon originating from the Columbia River and Snake River are exposed to different ocean conditions and may respond differently to climate changes. In particular, our work shows that the growth and fat content of Chinook and coho salmon vary along different parts of the coast and among years. These growth differences appear to be associated with differences in prey quality rather than by a direct effect of temperature on salmon growth or prey quantity, indicating that changes in ocean conditions and circulation affect salmon production indirectly through changes in prey community composition and quality. Taken together, our analyses indicate that the relative survival of different stocks of salmon in the ocean will depend on where they migrate in the ocean, and that changes at the base of the food chain must be taken into consideration to understand the effects of ocean conditions on salmon growth, and hence, on salmon survival.

  5. Reproductive isolation, evolutionary distinctiveness and setting conservation priorities: The case of European lake whitefish and the endangered North Sea houting (Coregonus spp.)

    PubMed Central

    2008-01-01

    Background Adaptive radiation within fishes of the Coregonus lavaretus complex has created numerous morphs, posing significant challenges for taxonomy and conservation priorities. The highly endangered North Sea houting (C. oxyrhynchus; abbreviated NSH) has been considered a separate species from European lake whitefish (C. lavaretus; abbreviated ELW) due to morphological divergence and adaptation to oceanic salinities. However, its evolutionary and taxonomic status is controversial. We analysed microsatellite DNA polymorphism in nine populations from the Jutland Peninsula and the Baltic Sea, representing NSH (three populations, two of which are reintroduced) and ELW (six populations). The objectives were to: 1) analyse postglacial recolonization of whitefish in the region; 2) assess the evolutionary distinctiveness of NSH, and 3) apply several approaches for defining conservation units towards setting conservation priorities for NSH. Results Bayesian cluster analyses of genetic differentiation identified four major groups, corresponding to NSH and three groups of ELW (Western Jutland, Central Jutland, Baltic Sea). Estimates of historical migration rates indicated recolonization in a north-eastern direction, suggesting that all except the Baltic Sea population predominantly represent postglacial recolonization via the ancient Elbe River. Contemporary gene flow has not occurred between NSH and ELW, with a divergence time within the last 4,000 years suggested from coalescence methods. NSH showed interbreeding with ELW when brought into contact by stocking. Thus, reproductive isolation of NSH was not absolute, although possible interbreeding beyond the F1 level could not be resolved. Conclusion Fishes of the C. lavaretus complex in the Jutland Peninsula originate from the same recolonization event. NSH has evolved recently and its species status may be questioned due to incomplete reproductive isolation from ELW, but it was shown to merit consideration as an independent conservation unit. Yet, application of several approaches for defining conservation units generated mixed outcomes regarding its conservation priority. Within the total species complex, it remains one among many recently evolved unique forms. Its uniqueness and high conservation priority is more evident at a local geographical scale, where conservation efforts will also benefit populations of a number of other endangered species. PMID:18471278

  6. The Mediterranean Sea Regime Shift at the End of the 1980s, and Intriguing Parallelisms with Other European Basins

    PubMed Central

    Conversi, Alessandra; Fonda Umani, Serena; Peluso, Tiziana; Molinero, Juan Carlos; Santojanni, Alberto; Edwards, Martin

    2010-01-01

    Background Regime shifts are abrupt changes encompassing a multitude of physical properties and ecosystem variables, which lead to new regime conditions. Recent investigations focus on the changes in ecosystem diversity and functioning associated to such shifts. Of particular interest, because of the implication on climate drivers, are shifts that occur synchronously in separated basins. Principal Findings In this work we analyze and review long-term records of Mediterranean ecological and hydro-climate variables and find that all point to a synchronous change in the late 1980s. A quantitative synthesis of the literature (including observed oceanic data, models and satellite analyses) shows that these years mark a major change in Mediterranean hydrographic properties, surface circulation, and deep water convection (the Eastern Mediterranean Transient). We provide novel analyses that link local, regional and basin scale hydrological properties with two major indicators of large scale climate, the North Atlantic Oscillation index and the Northern Hemisphere Temperature index, suggesting that the Mediterranean shift is part of a large scale change in the Northern Hemisphere. We provide a simplified scheme of the different effects of climate vs. temperature on pelagic ecosystems. Conclusions Our results show that the Mediterranean Sea underwent a major change at the end of the 1980s that encompassed atmospheric, hydrological, and ecological systems, for which it can be considered a regime shift. We further provide evidence that the local hydrography is linked to the larger scale, northern hemisphere climate. These results suggest that the shifts that affected the North, Baltic, Black and Mediterranean (this work) Seas at the end of the 1980s, that have been so far only partly associated, are likely linked as part a northern hemisphere change. These findings bear wide implications for the development of climate change scenarios, as synchronous shifts may provide the key for distinguishing local (i.e., basin) anthropogenic drivers, such as eutrophication or fishing, from larger scale (hemispheric) climate drivers. PMID:20502704

  7. Maastrichtian-aged lithostratigraphic patterns in the European tethys: Implications for sea level change and end-Cretaceous extinction patterns

    SciTech Connect

    Ward, P.; Macleod, K.G. . Dept. of Geological Sciences)

    1992-01-01

    Thirteen Maastrichtian-aged stratigraphic sections from a variety of sites spanning the ancient Tethys ocean in Western and Eastern Europe and Northern Africa have been measured in this study. The similarity in lithologies between even geographically separated localities allows refined lithostratigraphic correlation; individual members first defined from Bay of Biscay sections can now be recognized through all sections. The sections are found in the Bay of Biscay and Basque region of France and Spain (Sopelana, Zumaya, Hendaye, Bidart, Tercis, Pamplona;) southern Spain (Caravaca, Agost); northern Africa (El Kef); and Eastern Europe (Georgia). All of the sections are dominated by limestones in the Lower Maastrichtian, and marls or limestone-marl rhythmites in the Upper Maastrichtian. A conspicuous, massive limestone, usually 10 to 15 m thick, is found in all sections at the top of the Lower Maastrichtian; it is invariably overlain by a thicker unit composed entirely of marl. The thick limestone contains the last body fossils of the genus Inoceramus, and occurs just beneath the first occurrence of foraminifera diagnostic of the Abathomphalus mayaroensis Zone of Late Maastrichtian age. The dramatic shift in lithology lies at or just beneath the boundary between the Lower and Upper Maastrichtian, and may have been caused by one of the most rapid and profound sea level changes of the Cretaceous Period. The sea-level change may be a causal factor in the mid-Maastrichtian extinction which affected the Inoceramidae and other mollusks, such as the rudistid bivalves and ammonites, and certainly is one of the dominant factors in forming the sequence of lithologies found in the Maastrichtian Stage of Tethys.

  8. Sustainable Fisheries Management: Pacific Salmon

    USGS Publications Warehouse

    Knudsen, E. Eric; Steward, C.R.; MacDonald, Donald; Williams, J.E.

    2000-01-01

    What has happened to the salmon resource in the Pacific Northwest? Who is responsible and what can be done to reverse the decline in salmon populations? The responsibly falls on everyone involved - fishermen, resource managers and concerned citizens alike - to take the steps necessary to ensure that salmon populations make a full recovery. This collection of papers examines the state of the salmon fisheries in the Pacific Northwest. They cover existing methods and supply model approaches for alternative solutions. The editors stress the importance of input from and cooperation with all parties involved to create a viable solution. Grass roots education and participation is the key to public support - and ultimately the success - of whatever management solutions are developed. A unique and valuable scientific publication, Sustainable Fisheries Management: Pacific Salmon clearly articulates the current state of the Pacific salmon resource, describes the key features of its management, and provides important guidance on how we can make the transition towards sustainable fisheries. The solutions presented in this book provide the basis of a strategy for sustainable fisheries, requiring society and governmental agencies to establish a shared vision, common policies, and a process for collaborative management.

  9. 78 FR 62616 - Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... Energy Regulatory Commission Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer of Exemption 1. By letter filed September 23, 2013, Salmon Creek Hydroelectric Company informed the Commission that they have changed its name to Salmon Creek Hydroelectric Company, LLC for...

  10. Declining wild salmon populations in relation to parasites from farm salmon.

    PubMed

    Krkosek, Martin; Ford, Jennifer S; Morton, Alexandra; Lele, Subhash; Myers, Ransom A; Lewis, Mark A

    2007-12-14

    Rather than benefiting wild fish, industrial aquaculture may contribute to declines in ocean fisheries and ecosystems. Farm salmon are commonly infected with salmon lice (Lepeophtheirus salmonis), which are native ectoparasitic copepods. We show that recurrent louse infestations of wild juvenile pink salmon (Oncorhynchus gorbuscha), all associated with salmon farms, have depressed wild pink salmon populations and placed them on a trajectory toward rapid local extinction. The louse-induced mortality of pink salmon is commonly over 80% and exceeds previous fishing mortality. If outbreaks continue, then local extinction is certain, and a 99% collapse in pink salmon population abundance is expected in four salmon generations. These results suggest that salmon farms can cause parasite outbreaks that erode the capacity of a coastal ecosystem to support wild salmon populations. PMID:18079401

  11. Physiological disturbances in Atlantic salmon exposed to crude oil

    SciTech Connect

    Gagnon, M.M.; Holdway, D.A.

    1995-12-31

    In Southern Australia, Atlantic salmon (Salmo salar) farming is undertaken in marine areas where extensive oil exploration, exploitation and transport are taking place. Pen-reared juvenile fish are at high risk of oil exposure through frequent small spills or major accidents. When exposed, commercial fisheries have to face million-dollar loses due to potential tainting of their stocks. In this study, juvenile Atlantic salmon were exposed to Bass Strait light crude oil in a fashion simulating an accidental oil spill at sea i.e. exposure to crude oil followed by a deputation period. Temporal trends in enzymatic bioindicators of exposure were investigated through exposure and deputation periods, as well as several biochemical and chemical measurements. The main objective of the study was to relate tainting with easily measured biological indicators of exposure to crude oil. Good correlations between bioindicators of exposure and tainting could assist fish farming industry to decide on the fate of fish stocks affected by oil taint.

  12. Temperature effects and genotype-temperature interactions on sex determination in the European sea bass (Dicentrarchus labrax L.).

    PubMed

    Saillant, Eric; Fostier, Alexis; Haffray, Pierrick; Menu, Bruno; Thimonier, Jacques; Chatain, Béatrice

    2002-04-01

    The effect of temperature on sex-ratios in 27 families of sea bass reared in the same tank from the fertilization stage onward was investigated. An excess of males (68%) was found in the groups that were reared at high temperature (mean +/- standard deviation: 20+/-1 degrees C) until they reached the mean size of 8.1 cm (Standard Length, 149 days post-fertilization [p.f.]). Masculinization was higher (89% of males) in the groups maintained at low temperature (13 degrees C), from fertilization to a mean length of 6.5 cm (346 days p.f.). Shifts from high to low temperature at 8.1cm and from low to high temperature at 6.5 cm had no consequence on the sex-ratio. The percentage of males showing intratesticular oocytes was higher at low temperature (63%) than at high temperature (36%), suggesting that these males may be sensitive fish that have been masculinized by environmental factors. Fish sampled in the groups reared at high (2,200 fish) and low (500 fish) temperature were genotyped on three microsatellite loci. This allowed them to be assigned to the breeders used in the crossing design, thus permitting an analysis of parental influence on sex-ratios. In groups reared at high temperature, both parents had a significant additive effect on the percentage of females, and the interaction between sire and dam was not significant. Genotype temperature interactions were also detected and their existence suggests the interesting possibility of selecting nonsensitive genotypes in breeding programs. PMID:11857484

  13. Effects of two oils and 16 pure polycyclic aromatic hydrocarbons on plasmatic immune parameters in the European sea bass, Dicentrarchus labrax (Linné).

    PubMed

    Bado-Nilles, A; Quentel, C; Thomas-Guyon, H; Le Floch, S

    2009-03-01

    The in vitro effects of polycyclic aromatic hydrocarbons (PAHs) on two plasmatic immune parameters, lysozyme concentration and haemolytic alternative complement activity, of the European sea bass, Dicentrarchus labrax, were tested using field (10(-7) and 10(-9) mg mL(-1)) and high concentrations (10(-3) and 10(-5) mg mL(-1)) observed during oil spills. Peripheral blood from 105 fish was collected, centrifuged at 1200 g, for 10 min, at 4 degrees C and three plasma pools, each of 35 fish, were constituted. Two oils (heavy fuel oil and light cycle oil) and 16 pure PAHs, selected on the basis of the American Environmental Protection Agency list (US EPA), were tested in vitro on the two humoral immune parameters. Only three pure PAHs (anthracene, chrysene and dibenz[a,h]anthracene) modulated lysozyme concentration. Acenaphthene, acenaphthylene, anthracene, benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, pyrene and light cycle oil modified the haemolytic alternative complement activity after 4h of incubation. This study investigates the direct effects of several PAHs on fish humoral immune functions and describes the haemolytic complement activity of fish as suitable biomarkers of oil pollution. PMID:19111921

  14. Scientists Release Altantic Salmon into Beaverdam Brook

    USGS Tunison Lab scientist Emily Waldt (right) assists Dan Bishop of the New York State Department of Environmental Conservation in releasing Atlantic salmon into Beaverdam Brook at the state's Salmon River Fish Hatchery. Thousands of young Atlantic salmon are being release...

  15. Atlantic Salmon Released into Beaverdam Brook

    USGS employee Marisa Lubeck releases the day's last young Atlantic salmon into Beaverdam Brook in Altmar, N.Y. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this diminished Lake Ontario fish population, extending the sport fishing season b...

  16. Effects of polyunsaturated fatty acids and prostaglandins on oocyte maturation in a marine teleost, the European sea bass (Dicentrarchus labrax).

    PubMed

    Sorbera, L A; Asturiano, J F; Carrillo, M; Zanuy, S

    2001-01-01

    The effects of the polyunsaturated fatty acids (PUFAs), arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and prostaglandins (PGs) on oocyte maturation were investigated in a marine teleost, the sea bass (Dicentrarchus labrax). Follicle-enclosed postvitellogenic, preovulatory oocytes were cultured in vitro and maturation was verified by assessing volume increase, lipid droplet coalescence, yolk clarification, and germinal vesicle migration and breakdown. Human chorionic gonadotropin was administered as the maturation-inducing gonadotropin (GTH) and was capable of inducing maturation in a time- and dose-dependent manner. Free AA induced maturation in a dose- and time-dependent manner and enhanced GTH-induced maturation, while EPA, DHA, and oleic acid were ineffective. Maturation induced by GTH was significantly suppressed by a phospholipase A(2) blocker, suggesting that mobilization of AA was involved in GTH-induced maturation. Moreover, EPA and DHA exhibited a significant, dose-dependent attenuation of GTH-induced maturation. Maturation induced by GTH was inhibited in the presence of a cyclooxygenase inhibitor, indomethacin, and this inhibition was reversed by addition of AA, PGE(2), or PGF(2alpha). PGE(2) and PGF(2alpha) alone were both effective stimulators of maturation, while PGE(1) and PGE(3) were ineffective. The effect of PUFAs on oocyte maturation in vitro were corroborated with studies in vivo. Oocytes were obtained from females fed a commercial, PUFA-enriched diet (RD) and maturational behavior was compared with oocytes from females fed a natural diet (ND) with a higher EPA content and n-3:n-6 ratio. Although no significant difference was observed in the rate of spontaneous oocyte maturation, a higher percentage of GTH-induced maturation and lower percentage of atresia were observed in RD oocytes. Moreover, while basal PGE production from oocytes from both groups was the same, RD oocytes produced significantly higher levels of PGE in the presence of hCG. The results from this study provide evidence for the participation of AA metabolism in GTH-induced oocyte maturation, and suggest that other PUFAs and PGs may play important roles in the induction of maturation in a marine teleost. PMID:11133697

  17. Evidence for geomagnetic imprinting as a homing mechanism in Pacific salmon.

    PubMed

    Putman, Nathan F; Lohmann, Kenneth J; Putman, Emily M; Quinn, Thomas P; Klimley, A Peter; Noakes, David L G

    2013-02-18

    In the final phase of their spawning migration, Pacific salmon use chemical cues to identify their home river, but how they navigate from the open ocean to the correct coastal area has remained enigmatic. To test the hypothesis that salmon imprint on the magnetic field that exists where they first enter the sea and later seek the same field upon return, we analyzed a 56-year fisheries data set on Fraser River sockeye salmon, which must detour around Vancouver Island to approach the river through either a northern or southern passageway. We found that the proportion of salmon using each route was predicted by geomagnetic field drift: the more the field at a passage entrance diverged from the field at the river mouth, the fewer fish used the passage. We also found that more fish used the northern passage in years with warmer sea surface temperature (presumably because fish were constrained to more northern latitudes). Field drift accounted for 16% of the variation in migratory route used, temperature 22%, and the interaction between these variables 28%. These results provide the first empirical evidence of geomagnetic imprinting in any species and imply that forecasting salmon movements is possible using geomagnetic models. PMID:23394828

  18. Unraveling the estrogen receptor (er) genes in Atlantic salmon (Salmo salar) reveals expression differences between the two adult life stages but little impact from polychlorinated biphenyl (PCB) load.

    PubMed

    Nikoleris, Lina; Hansson, Maria C

    2015-01-15

    Estrogen receptors (ers) not only are activated by hormones but also interact with many human-derived environmental contaminants. Here, we present evidence for four expressed er genes in Atlantic salmon cDNA - two more ers (erα2 and erβ2) than previously published. To determine if er gene expression differs between two adult life-stages we sampled 20 adult salmon from the feeding phase in the Baltic Sea and during migration in the River Mörrum, Sweden. Results show that all four er genes are present in the investigated tissues, except for erα2 not appearing in the spleen. Overall, a profile analysis reveals the erα1 gene to be the most highly expressed er gene in both female and male Baltic Sea salmon tissues, and also in female River Mörrum salmon. In contrast, this gene has the lowest gene expression level of the four er genes in male salmon from the River Mörrum. The erα2 gene is expressed at the lowest levels in both female/male Baltic Sea salmon and in female River Mörrum salmon. Statistical analyses indicate a significant and complex interaction where both sex and adult life stage can impact er gene expression. Regression analyses did not demonstrate any significant relationship between polychlorinated biphenyl (PCB) body burden and er gene expression level, suggesting that accumulated pollutants from the Baltic Sea may be deactivated inside the salmon's lipid tissues and have limited impact on er activity. This study is the first comprehensive analysis of four er gene expression levels in two wild salmon populations from two different adult life stages where information about PCB load is also available. PMID:25451980

  19. Interactive effect of high environmental ammonia and nutritional status on ecophysiological performance of European sea bass (Dicentrarchus labrax) acclimated to reduced seawater salinities.

    PubMed

    Sinha, Amit Kumar; Rasoloniriana, Rindra; Dasan, Antony Franklin; Pipralia, Nitin; Blust, Ronny; De Boeck, Gudrun

    2015-03-01

    We investigated the interactive effect of ammonia toxicity, salinity challenge and nutritional status on the ecophysiological performance of European sea bass (Dicentrarchus labrax). Fish were progressively acclimated to normal seawater (32ppt), to brackish water (20ppt and 10ppt) and to hyposaline water (2.5ppt). Following acclimation to different salinities for two weeks, fish were exposed to high environmental ammonia (HEA, 20mg/L ∼1.18mM representing 50% of 96h LC50 value for ammonia) for 12h, 48h, 84h and 180h, and were either fed (2% body weight) or fasted (unfed for 7 days prior to HEA exposure). Biochemical responses such as ammonia (Jamm) and urea excretion rate, plasma ammonia, urea and lactate, plasma ions (Na(+), Cl(-) and K(+)) and osmolality, muscle water content (MWC) and liver and muscle energy budget (glycogen, lipid and protein), as well as branchial Na(+)/K(+)-ATPase (NKA) and H(+)-ATPase activity, and branchial mRNA expression of NKA and Na(+)/K(+)/2Cl(-) co-transporter (NKCC1) were investigated in order to understand metabolic and ion- osmoregulatory consequences of the experimental conditions. During HEA, Jamm was inhibited in fasted fish at 10ppt, while fed fish were still able to excrete efficiently. At 2.5ppt, both feeding groups subjected to HEA experienced severe reductions and eventually a reversion in Jamm. Overall, the build-up of plasma ammonia in HEA exposed fed fish was much lower than fasted ones. Unlike fasted fish, fed fish acclimated to lower salinities (10ppt-2.5ppt) could maintain plasma osmolality, [Na(+)], [Cl(-)] and MWC during HEA exposure. Thus fed fish were able to sustain ion-osmotic homeostasis which was associated with a more pronounced up-regulation in NKA expression and activity. At 2.5ppt both feeding groups activated H(+)-ATPase. The expression of NKCC1 was down-regulated at lower salinities in both fed and fasted fish, but was upregulated within each salinity after a few days of HEA exposure. Though an increment in plasma lactate content and a decline in energy stores were noted for both feeding regimes, the effect was more severe in feed deprived fish. Overall, several different physiological processes were disturbed in fasted sea bass during HEA exposure while feeding alleviated adverse effects of high ammonia and salinity challenge. This suggests that low food availability can render fish more vulnerable to external ammonia, especially at reduced seawater salinities. PMID:25625520

  20. Infectious salmon anaemia virus (ISAV) mucosal infection in Atlantic salmon.

    PubMed

    Aamelfot, Maria; McBeath, Alastair; Christiansen, Debes H; Matejusova, Iveta; Falk, Knut

    2015-01-01

    All viruses infecting fish must cross the surface mucosal barrier to successfully enter a host. Infectious salmon anaemia virus (ISAV), the causative agent of the economically important infectious salmon anaemia (ISA) in Atlantic salmon, Salmo salar L., has been shown to use the gills as its entry point. However, other entry ports have not been investigated despite the expression of virus receptors on the surface of epithelial cells in the skin, the gastrointestinal (GI) tract and the conjunctiva. Here we investigate the ISAV mucosal infection in Atlantic salmon after experimental immersion (bath) challenge and in farmed fish collected from a confirmed outbreak of ISA in Norway. We show for the first time evidence of early replication in several mucosal surfaces in addition to the gills, including the pectoral fin, skin and GI tract suggesting several potential entry points for the virus. Initially, the infection is localized and primarily infecting epithelial cells, however at later stages it becomes systemic, infecting the endothelial cells lining the circulatory system. Viruses of low and high virulence used in the challenge revealed possible variation in virus progression during infection at the mucosal surfaces. PMID:26490835

  1. Ocean Carrying Capacity : Recovery Issues for Threatened and Endangered Snake River Salmon : Technical Report 6 of 11.

    SciTech Connect

    Lichatowich, Jim

    1993-06-01

    The northeast Pacific is comprised of four fishery production domains: The gulf of Alaska, a coastal downwelling zone, a coastal upwelling zone and a transition zone. Salmon from the Columbia River enter the sea in the upwelling zone. Marine survival of coho salmon in the Oregon Production Index area has been the subject of extensive study. Variability in marine survival of coho salmon appears to be determined in the first month at sea while the fish are still in local marine areas in the upwelling zone. There is stronger evidence that upwelling might influence vulnerability to predation. A broader ecosystem view which considers salmon as a member of a complex marine community offers additional insight and raises new questions regarding the marine mortality of salmon. The pelagic fish community in the upwelling zone has undergone dramatic change in the last 50 years. That change is consistent with the historical record, however, the system has not completed a full cycle of change (as it has in the past) since the stocks have been subjected to intense commercial and sport exploitation. Salmon seem to be responding to shifts in productivity in the coastal upwelling zone.

  2. Modulation of adrenocorticotrophin hormone (ACTH)-induced expression of stress-related genes by PUFA in inter-renal cells from European sea bass (Dicentrarchus labrax).

    PubMed

    Montero, Daniel; Terova, Genciana; Rimoldi, Simona; Tort, Lluis; Negrin, Davinia; Zamorano, Mara Jess; Izquierdo, Marisol

    2015-01-01

    Dietary fatty acids have been shown to exert a clear effect on the stress response, modulating the release of cortisol. The role of fatty acids on the expression of steroidogenic genes has been described in mammals, but little is known in fish. The effect of different fatty acids on the release of cortisol and expression of stress-related genes of European sea bass (Dicentrarchus labrax) head kidney, induced by a pulse of adenocorticotrophin hormone (ACTH), was studied. Tissue was maintained in superfusion with 60 min of incubation with EPA, DHA, arachidonic acid (ARA), linoleic acid or ?-linolenic acid (ALA) during 490 min. Cortisol was measured by RIA. The quantification of stress-related genes transcripts was conducted by One-Step TaqMan real-time RT-PCR. There was an effect of the type of fatty acid on the ACTH-induced release of cortisol, values from ALA treatment being elevated within all of the experimental period. The expression of some steroidogenic genes, such as the steroidogenic acute regulatory protein (StAR) and c-fos, were affected by fatty acids, ALA increasing the expression of StAR after 1 h of ACTH stimulation whereas DHA, ARA and ALA increased the expression of c-fos after 20 min. ARA increased expression of the 11?-hydroxylase gene. Expression of heat shock protein 70 (HSP70) was increased in all the experimental treatments except for ARA. Results corroborate previous studies of the effect of different fatty acids on the release of cortisol in marine fish and demonstrate that those effects are mediated by alteration of the expression of steroidogenic genes. PMID:26090096

  3. Expression of Kisspeptins and Kiss Receptors Suggests a Large Range of Functions for Kisspeptin Systems in the Brain of the European Sea Bass

    PubMed Central

    Escobar, Sebastián; Servili, Arianna; Espigares, Felipe; Gueguen, Marie-Madeleine; Brocal, Isabel; Felip, Alicia; Gómez, Ana; Carrillo, Manuel; Zanuy, Silvia; Kah, Olivier

    2013-01-01

    This study, conducted in the brain of a perciform fish, the European sea bass, aimed at raising antibodies against the precursor of the kisspeptins in order to map the kiss systems and to correlate the expression of kisspeptins, kiss1 and kiss2, with that of kisspeptin receptors (kiss-R1 and kiss-R2). Specific antibodies could be raised against the preprokiss2, but not the preoprokiss1. The data indicate that kiss2 neurons are mainly located in the hypothalamus and project widely to the subpallium and pallium, the preoptic region, the thalamus, the pretectal area, the optic tectum, the torus semicircularis, the mediobasal medial and caudal hypothalamus, and the neurohypophysis. These results were compared to the expression of kiss-R1 and kiss-R2 messengers, indicating a very good correlation between the wide distribution of Kiss2-positive fibers and that of kiss-R2 expressing cells. The expression of kiss-R1 messengers was more limited to the habenula, the ventral telencephalon and the proximal pars distalis of the pituitary. Attempts to characterize the phenotype of the numerous cells expressing kiss-R2 showed that neurons expressing tyrosine hydroxylase, neuropeptide Y and neuronal nitric oxide synthase are targets for kisspeptins, while GnRH1 neurons did not appear to express kiss-R1 or kiss-R2 messengers. In addition, a striking result was that all somatostatin-positive neurons expressed-kissR2. These data show that kisspeptins are likely to regulate a wide range of neuronal systems in the brain of teleosts. PMID:23894610

  4. Hypo-osmotic stress-induced physiological and ion-osmoregulatory responses in European sea bass (Dicentrarchus labrax) are modulated differentially by nutritional status.

    PubMed

    Sinha, Amit Kumar; Dasan, Antony Franklin; Rasoloniriana, Rindra; Pipralia, Nitin; Blust, Ronny; De Boeck, Gudrun

    2015-03-01

    We investigated the impact of nutritional status on the physiological, metabolic and ion-osmoregulatory performance of European sea bass (Dicentrarchus labrax) when acclimated to seawater (32 ppt), brackish water (20 and 10 ppt) and hyposaline water (2.5 ppt) for 2 weeks. Following acclimation to different salinities, fish were either fed or fasted (unfed for 14 days). Plasma osmolality, [Na(+)], [Cl(-)] and muscle water content were severely altered in fasted fish acclimated to 10 and 2.5 ppt in comparison to normal seawater-acclimated fish, suggesting ion regulation and acid-base balance disturbances. In contrast to feed-deprived fish, fed fish were able to avoid osmotic perturbation more effectively. This was accompanied by an increase in Na(+)/K(+)-ATPase expression and activity, transitory activation of H(+)-ATPase (only at 2.5 ppt) and down-regulation of Na(+)/K(+)/2Cl(-) gene expression. Ammonia excretion rate was inhibited to a larger extent in fasted fish acclimated to low salinities while fed fish were able to excrete efficiently. Consequently, the build-up of ammonia in the plasma of fed fish was relatively lower. Energy stores, especially glycogen and lipid, dropped in the fasted fish at low salinities and progression towards the anaerobic metabolic pathway became evident by an increase in plasma lactate level. Overall, the results indicate no osmotic stress in both feeding treatments within the salinity range of 32 to 20 ppt. However, at lower salinities (10-2.5 ppt) feed deprivation tends to reduce physiological, metabolic, ion-osmo-regulatory and molecular compensatory mechanisms and thus limits the fish's abilities to adapt to a hypo-osmotic environment. PMID:25483239

  5. Acceleration performance of individual European sea bass Dicentrarchus labrax measured with a sprint performance chamber: comparison with high-speed cinematography and correlates with ecological performance.

    PubMed

    Vandamm, Joshua P; Marras, Stefano; Claireaux, Guy; Handelsman, Corey A; Nelson, Jay A

    2012-01-01

    Locomotor performance can influence the ecological and evolutionary success of a species. For fish, favorable outcomes of predator-prey encounters are often presumably due to robust acceleration ability. Although escape-response or "fast-start" studies utilizing high-speed cinematography are prevalent, little is known about the contribution of relative acceleration performance to ecological or evolutionary success in a species. This dearth of knowledge may be due to the time-consuming nature of analyzing film, which imposes a practical limit on sample sizes. Herein, we present a high-throughput potential alternative for measuring fish acceleration performance using a sprint performance chamber (SPC). The acceleration performance of a large number of juvenile European sea bass (Dicentrarchus labrax) from two populations was analyzed. Animals from both hatchery and natural ontogenies were assessed, and animals of known acceleration ability had their ecological performance measured in a mesocosm environment. Individuals from one population also had their acceleration performance assessed by both high-speed cinematography and an SPC. Acceleration performance measured in an SPC was lower than that measured by classical high-speed video techniques. However, short-term repeatability and interindividual variation of acceleration performance were similar between the two techniques, and the SPC recorded higher sprint swimming velocities. Wild fish were quicker to accelerate in an SPC and had significantly greater accelerations than all groups of hatchery-raised fish. Acceleration performance had no significant effect on ecological performance (as assessed through animal growth and survival in the mesocosms). However, it is worth noting that wild animals did survive predation in the mesocosm better than farmed ones. Moreover, the hatchery-originated fish that survived the mesocosm experiment, when no predators were present, displayed significantly increased acceleration performance during their 6 mo in the mesocosm; this performance was found to be inversely proportional to growth rate. PMID:23099467

  6. Recurrent evolution of life history ecotypes in sockeye salmon: implications for conservation and future evolution

    PubMed Central

    Wood, Chris C; Bickham, John W; John Nelson, R; Foote, Chris J; Patton, John C

    2008-01-01

    We examine the evolutionary history and speculate about the evolutionary future of three basic life history ecotypes that contribute to the biocomplexity of sockeye salmon (Oncorhynchus nerka). The ‘recurrent evolution’ (RE) hypothesis claims that the sea/river ecotype is ancestral, a ‘straying’ form with poorly differentiated (meta)population structure, and that highly structured populations of lake-type sockeye and kokanee have evolved repeatedly in parallel adaptive radiations between recurrent glaciations of the Pleistocene Epoch. Basic premises of this hypothesis are consistent with new, independent evidence from recent surveys of genetic variation in mitochondrial and microsatellite DNA: (1) sockeye salmon are most closely related to pink (O. gorbuscha) and chum (O. keta) salmon with sea-type life histories; (2) the sockeye life history ecotypes exist as polyphyletic lineages within large drainages and geographic regions; (3) the sea/river ecotype exhibits less genetic differentiation among populations than the lake or kokanee ecotypes both within and among drainages; and (4) genetic diversity is typically higher in the sea/river ecotype than in the lake and kokanee ecotypes. Anthropogenic modification of estuarine habitat and intensive coastal fisheries have likely reduced and fragmented historic metapopulations of the sea/river ecotype, particularly in southern areas. In contrast, the kokanee ecotype appears to be favoured by marine fisheries and predicted changes in climate. PMID:25567627

  7. 2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, headworks overflow weir to center left, view to east - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  8. 1. Salmon Creek Diversion Dam, weir (to left), sand and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Salmon Creek Diversion Dam, weir (to left), sand and silt sluice gate (center), main canal headworks (to right), view to northwest - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  9. The vgll3 Locus Controls Age at Maturity in Wild and Domesticated Atlantic Salmon (Salmo salar L.) Males.

    PubMed

    Ayllon, Fernando; Kjærner-Semb, Erik; Furmanek, Tomasz; Wennevik, Vidar; Solberg, Monica F; Dahle, Geir; Taranger, Geir Lasse; Glover, Kevin A; Almén, Markus Sällman; Rubin, Carl J; Edvardsen, Rolf B; Wargelius, Anna

    2015-11-01

    Wild and domesticated Atlantic salmon males display large variation for sea age at sexual maturation, which varies between 1-5 years. Previous studies have uncovered a genetic predisposition for variation of age at maturity with moderate heritability, thus suggesting a polygenic or complex nature of this trait. The aim of this study was to identify associated genetic loci, genes and ultimately specific sequence variants conferring sea age at maturity in salmon. We performed a genome wide association study (GWAS) using a pool sequencing approach (20 individuals per river and phenotype) of male salmon returning to rivers as sexually mature either after one sea winter (2009) or three sea winters (2011) in six rivers in Norway. The study revealed one major selective sweep, which covered 76 significant SNPs in which 74 were found in a 370 kb region of chromosome 25. Genotyping other smolt year classes of wild and domesticated salmon confirmed this finding. Genotyping domesticated fish narrowed the haplotype region to four SNPs covering 2386 bp, containing the vgll3 gene, including two missense mutations explaining 33-36% phenotypic variation. A single locus was found to have a highly significant role in governing sea age at maturation in this species. The SNPs identified may be both used as markers to guide breeding for late maturity in salmon aquaculture and in monitoring programs of wild salmon. Interestingly, a SNP in proximity of the VGLL3 gene in humans (Homo sapiens), has previously been linked to age at puberty suggesting a conserved mechanism for timing of puberty in vertebrates. PMID:26551894

  10. The vgll3 Locus Controls Age at Maturity in Wild and Domesticated Atlantic Salmon (Salmo salar L.) Males

    PubMed Central

    Ayllon, Fernando; Kjærner-Semb, Erik; Furmanek, Tomasz; Wennevik, Vidar; Solberg, Monica F.; Dahle, Geir; Taranger, Geir Lasse; Glover, Kevin A.; Almén, Markus Sällman; Rubin, Carl J; Edvardsen, Rolf B.; Wargelius, Anna

    2015-01-01

    Wild and domesticated Atlantic salmon males display large variation for sea age at sexual maturation, which varies between 1–5 years. Previous studies have uncovered a genetic predisposition for variation of age at maturity with moderate heritability, thus suggesting a polygenic or complex nature of this trait. The aim of this study was to identify associated genetic loci, genes and ultimately specific sequence variants conferring sea age at maturity in salmon. We performed a genome wide association study (GWAS) using a pool sequencing approach (20 individuals per river and phenotype) of male salmon returning to rivers as sexually mature either after one sea winter (2009) or three sea winters (2011) in six rivers in Norway. The study revealed one major selective sweep, which covered 76 significant SNPs in which 74 were found in a 370 kb region of chromosome 25. Genotyping other smolt year classes of wild and domesticated salmon confirmed this finding. Genotyping domesticated fish narrowed the haplotype region to four SNPs covering 2386 bp, containing the vgll3 gene, including two missense mutations explaining 33–36% phenotypic variation. A single locus was found to have a highly significant role in governing sea age at maturation in this species. The SNPs identified may be both used as markers to guide breeding for late maturity in salmon aquaculture and in monitoring programs of wild salmon. Interestingly, a SNP in proximity of the VGLL3 gene in humans (Homo sapiens), has previously been linked to age at puberty suggesting a conserved mechanism for timing of puberty in vertebrates. PMID:26551894

  11. PNW WILD SALMON IN 2100: AN ALTERNATIVE FUTURES PERSPECTIVE ON SALMON RECOVERY

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project does not...

  12. WILD SALMON IN 2100: AN ALTERNATIVE FUTURES PERSPECTIVE ON SALMON RECOVERY - MAY 2006

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project does not...

  13. Vibrio viscosus in farmed Atlantic salmon Salmo salar in Scotland: field and experimental observations.

    PubMed

    Bruno, D W; Griffiths, J; Petrie, J; Hastings, T S

    1998-11-30

    Winter mortality occurred in market-sized (2 to 3 kg) Atlantic salmon Salmo salar reared in sea cages in Scottish waters. Many of the fish had skin ulcers. Internally prominent dark-brown petechiae or ecchymotic haemorrhage was observed. Splenomegaly was associated with congestion and widespread necrosis. A Vibrio sp. was isolated from internal organs. Biochemically isolates of the bacterium were similar to a previously described bacterium, Vibrio viscosus, recorded in a phenotypic study from farmed salmon in Norway. This work examines the occurrence of V. viscosus in marine-reared Atlantic salmon for the first time in Scottish waters. An experimental study reproduced the field observations and Koch's postulates were fulfilled. The histopathology associated with natural infection was compared with that in laboratory-infected fish. PMID:9891731

  14. Early marine growth in relation to marine-stage survival rates for Alaska sockeye salmon (Oncorhynchus nerka)

    USGS Publications Warehouse

    Farley, E.V., Jr.; Murphy, J.M.; Adkison, M.D.; Eisner, L.B.; Helle, J.H.; Moss, J.H.; Nielsen, J.

    2007-01-01

    We tested the hypothesis that larger juvenile sockeye salmon (Oncorhynchus nerka) in Bristol Bay, Alaska, have higher marine-stage survival rates than smaller juvenile salmon. We used scales from returning adults (33 years of data) and trawl samples of juveniles (n = 3572) collected along the eastern Bering Sea shelf during August through September 2000-02. The size of juvenile sockeye salmon mirrored indices of their marine-stage survival rate (e.g., smaller fish had lower indices of marine-stage survival rate). However, there was no relationship between the size of sockeye salmon after their first year at sea, as estimated from archived scales, and brood-year survival size was relatively uniform over the time series, possibly indicating size-selective mortality on smaller individuals during their marine residence. Variation in size, relative abundance, and marine-stage survival rate of juvenile sockeye salmon is likely related to ocean conditions affecting their early marine migratory pathways along the eastern Bering Sea shelf.

  15. The European-wide Geo-Seas data space for marine geological and geophysical data and its novel approach in Metadata, Data models and Semantics emerging from the case of Seismic data.

    NASA Astrophysics Data System (ADS)

    Diviacco, Paolo; Busato, Alessandro; Glaves, Helen M.; Schaap, Dick M. A.

    2013-04-01

    The Geo-Seas EU FP7 project aims at providing means to deliver and access integrated sets of primary marine geological and geophysical data. These are among the most important elements in the process of scientific and applied marine research, economic activities, and sustainable environmental management, at regional, European and global scales. Such data space requires an European-wide services infrastructure, standardised practices by the data repositories, and middleware so that end users can identify, locate and access the data they might be interested in. Being Geo-Seas a sibling of the SeaDataNet project, it adopts technologies developed within the latter, extending them and introducing new paradigms. Within this perspective a specific attention was reserved to Seismic data, due to its value in commercial use and scientific community positioning, on one hand, and to the difficulties in handling its file size on the other. To tackle these issues a novel approach was devised, that uses web based data-owner-side visualization facilities installed at each data provider premise. This overcomes the limitations of the common practices in data dissemination, where eventually the data is downloaded and used "off-line" at the end-user workstation. This solution is based on a seismic data visualization software that is strictly integrated with the GeoSeas (and SeaDataNet) project middleware and that therefore allows to perform consistent user authentications and requests handling across all domains and partners. Considering the large and ever increasing number of datasets made available within the project, and that deep examination of seismic data via the viewer could take time, it was devised to introduce a more efficient way to select useful hits within the Geo-Seas data space extending the already existent ISO19115-based SeaDataNet discovery mechanism (CDI). This has been achieved through the introduction of a "browsing" level linked to the CDI where further information on the seismic data is made available within O&M and SensorML documents. Information is entered using controlled vocabularies made available to the whole community of users and partners. The whole system have been tested successfully and is currently operational at a subset of all the Geo-Seas partners. We are currently planning to extend the paradigm to other domains that have similarities with Seismic data.

  16. Large scale modelling of salmon lice (Lepeophtheirus salmonis) infection pressure based on lice monitoring data from Norwegian salmonid farms.

    PubMed

    Kristoffersen, Anja B; Jimenez, Daniel; Viljugrein, Hildegunn; Grøntvedt, Randi; Stien, Audun; Jansen, Peder A

    2014-12-01

    Infection by parasitic sea lice is a substantial problem in industrial scale salmon farming. To control the problem, Norwegian salmonid farms are not permitted to exceed a threshold level of infection on their fish, and farms are required to monitor and report lice levels on a weekly basis to ensure compliance with the regulation. In the present study, we combine the monitoring data with a deterministic model for salmon lice population dynamics to estimate farm production of infectious lice stages. Furthermore, we use an empirical estimate of the relative risk of salmon lice transmission between farms, that depend on inter-farm distances, to estimate the external infection pressure at a farm site, i.e. the infection pressure from infective salmon lice of neighbouring farm origin. Finally, we test whether our estimates of infection pressure from neighbouring farms as well as internal within farm infection pressure, predicts subsequent development of infection in cohorts of farmed salmonids in their initial phase of marine production. We find that estimated external infection pressure is a main predictor of salmon lice population dynamics in newly stocked cohorts of salmonids. Our results emphasize the importance of keeping the production of infectious lice stages at low levels within local networks of salmon farms. Our model can easily be implemented for real time estimation of infection pressure at the national scale, utilizing the masses of data generated through the compulsory lice monitoring in salmon farms. The implementation of such a system should give the salmon industry greater predictability with respect to salmon lice infection levels, and aid the decision making process when the development of new farm sites are planned. PMID:25480132

  17. Comparison of genetic diversity in the recently founded Connecticut River Atlantic salmon population to that of its primary donor stock, Maine's Penobscot River

    USGS Publications Warehouse

    Spidle, A.P.; King, T.L.; Letcher, B.H.

    2004-01-01

    Anadromous Atlantic salmon returning to the Connecticut River (CR) from 1996 to 1999 were assayed for variability at nine microsatellite DNA loci. Heterozygosity and allele frequencies were compared to the anadromous Atlantic salmon returning to Maine's Penobscot River from 1998 to 2000. The Penobscot River was the primary source of the salmon used to found the previously extirpated population in the Connecticut River. While there were no significant differences in heterozygosity between the source population and the Connecticut River sea-run spawners, microsatellite allele frequencies were significantly different between the populations. Two techniques of estimating effective population size (Ne) suggested a healthy level of genetic variation in the Connecticut River population of anadromous Atlantic salmon. This is significant because the sea-run population is maintained almost entirely through hatchery production. Healthy ratios of Ne to N indicate that hatchery production has not resulted in excessive inbreeding to date. ?? 2003 Elsevier B.V. All rights reserved.

  18. THE SALMON 2100 PROJECT -- AN ALTERNATIVES FUTURES PERSPECTIVE ON PACIFIC NORTHWEST SALMON RECOVERY

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in the Pacific Northwest and California. Wild salmon recovery efforts in western North Americ...

  19. Infections by Renibacterium salmoninarum and Nanophyetus salmincola Chapin are associated with reduced growth of juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), in the Northeast Pacific Ocean.

    PubMed

    Sandell, T A; Teel, D J; Fisher, J; Beckman, B; Jacobson, K C

    2015-04-01

    We examined 1454 juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), captured in nearshore waters off the coasts of Washington and Oregon (USA) from 1999 to 2004 for infection by Renibacterium salmoninarum, Nanophyetus salmincola Chapin and skin metacercariae. The prevalence and intensities for each of these infections were established for both yearling and subyearling Chinook salmon. Two metrics of salmon growth, weight residuals and plasma levels of insulin-like growth factor-1, were determined for salmon infected with these pathogens/parasites, both individually and in combination, with uninfected fish used for comparison. Yearling Chinook salmon infected with R. salmoninarum had significantly reduced weight residuals. Chinook salmon infected with skin metacercariae alone did not have significantly reduced growth metrics. Dual infections were not associated with significantly more severe effects on the growth metrics than single infections; the number of triple infections was very low and precluded statistical comparison. Overall, these data suggest that infections by these organisms can be associated with reduced juvenile Chinook salmon growth. Because growth in the first year at sea has been linked to survival for some stocks of Chinook salmon, the infections may therefore play a role in regulating these populations in the Northeast Pacific Ocean. PMID:24720546

  20. Involvement of hormones in olfactory imprinting and homing in chum salmon.

    PubMed

    Ueda, Hiroshi; Nakamura, Shingo; Nakamura, Taro; Inada, Kaoru; Okubo, Takashi; Furukawa, Naohiro; Murakami, Reiichi; Tsuchida, Shigeo; Zohar, Yonathan; Konno, Kotaro; Watanabe, Masahiko

    2016-01-01

    The olfactory hypothesis for salmon imprinting and homing to their natal stream is well known, but the endocrine hormonal control mechanisms of olfactory memory formation in juveniles and retrieval in adults remain unclear. In brains of hatchery-reared underyearling juvenile chum salmon (Oncorhynchus keta), thyrotropin-releasing hormone gene expression increased immediately after release from a hatchery into the natal stream, and the expression of the essential NR1 subunit of the N-methyl-D-aspartate receptor increased during downstream migration. Gene expression of salmon gonadotropin-releasing hormone (sGnRH) and NR1 increased in the adult chum salmon brain during homing from the Bering Sea to the natal hatchery. Thyroid hormone treatment in juveniles enhanced NR1 gene activation, and GnRHa treatment in adults improved stream odour discrimination. Olfactory memory formation during juvenile downstream migration and retrieval during adult homing migration of chum salmon might be controlled by endocrine hormones and could be clarified using NR1 as a molecular marker. PMID:26879952

  1. Involvement of hormones in olfactory imprinting and homing in chum salmon

    PubMed Central

    Ueda, Hiroshi; Nakamura, Shingo; Nakamura, Taro; Inada, Kaoru; Okubo, Takashi; Furukawa, Naohiro; Murakami, Reiichi; Tsuchida, Shigeo; Zohar, Yonathan; Konno, Kotaro; Watanabe, Masahiko

    2016-01-01

    The olfactory hypothesis for salmon imprinting and homing to their natal stream is well known, but the endocrine hormonal control mechanisms of olfactory memory formation in juveniles and retrieval in adults remain unclear. In brains of hatchery-reared underyearling juvenile chum salmon (Oncorhynchus keta), thyrotropin-releasing hormone gene expression increased immediately after release from a hatchery into the natal stream, and the expression of the essential NR1 subunit of the N-methyl-D-aspartate receptor increased during downstream migration. Gene expression of salmon gonadotropin-releasing hormone (sGnRH) and NR1 increased in the adult chum salmon brain during homing from the Bering Sea to the natal hatchery. Thyroid hormone treatment in juveniles enhanced NR1 gene activation, and GnRHa treatment in adults improved stream odour discrimination. Olfactory memory formation during juvenile downstream migration and retrieval during adult homing migration of chum salmon might be controlled by endocrine hormones and could be clarified using NR1 as a molecular marker. PMID:26879952

  2. [Homozygous familial hypercholesterolaemia: Spanish adaptation of the position paper from the Consensus Panel on Familial Hypercholesterolaemia of the European Atherosclerosis Society. Consensus document of the Spanish Society of Arteriosclerosis (SEA) and Familial Hypercholesterolaemia Foundation (FHF)].

    PubMed

    Ascaso, Juan F; Mata, Pedro; Arbona, Cristina; Civeira, Fernando; Valdivielso, Pedro; Masana, Luis

    2015-01-01

    Homozygous familial hypercholesterolaemia (HoFH) is a rare life-threatening disease characterized by markedly elevated circulating levels of low-density lipoprotein cholesterol (LDL-C) and accelerated, premature atherosclerotic cardiovascular disease (ACVD). The Consensus Panel on Familial Hypercholesterolaemia of the European Atherosclerosis Society (EAS) has recently published a clinical guide to diagnose and manage HoFH (Eur Heart J. 2014;35:2146-57). Both the Spanish Society of Atherosclerosis (SEA) and Familial Hypercholesterolaemia Foundation (FHF) consider this European Consensus document of great value and utility. However, there are particularities in our country which advise to have a Spanish adaptation of the European HoFH document in order to approximate this clinical guide to our environment. In Spain, chronic treatment with statins, ezetimibe and resins (colesevelam) has a reduced contribution in the National Health System (NHS) and is one of the few European countries where LDL apheresis is included in the Basic Service Portfolio coverage. This Spanish document also includes clinical experience in the management of these patients in our country. The Drafting Committee emphasizes the need for early identification of HoFH patients, prompt referral to specialized units, and an early and appropriate treatment. These recommendations will provide a guidance for HoFH patient management in Spain. PMID:25757840

  3. Acoustic tracking of migrating salmon.

    PubMed

    Kupilik, Matthew J; Petersen, Todd

    2014-10-01

    Annual salmon migrations vary significantly in annual return numbers from year to year. In order to determine when a species' sustainable return size has been met, a method for counting and sizing the spawning animals is required. This project implements a probability hypothesis density tracker on data from a dual frequency identification sonar to automate the process of counting and sizing the fish crossing an insonified area. Data processing on the sonar data creates intensity images from which possible fish locations can be extracted using image processing. These locations become the input to the tracker. The probability hypothesis density tracker then solves the multiple target tracking problem and creates fish tracks from which length information is calculated using image segmentation. The algorithm is tested on data from the 2010 salmon run on the Kenai river in Alaska and compares favorably with statistical models from sub-sampling and manual measurements. PMID:25324076

  4. Asymmetric hybridization and introgression between pink salmon and chinook salmon in the Laurentian Great Lakes

    USGS Publications Warehouse

    Rosenfield, Jonathan A.; Todd, Thomas; Greil, Roger

    2000-01-01

    Among Pacific salmon collected in the St. Marys River, five natural hybrids of pink salmon Oncorhynchus gorbuscha and chinook salmon Oncorhynchus tshawytscha and one suspected backcross have been detected using morphologic, meristic, and color evidence. One allozyme (LDH, l-lactate dehydrogenase from muscle) and one nuclear DNA locus (growth hormone) for which species-specific fixed differences exist were analyzed to detect additional hybrids and to determine if introgression had occurred. Restriction fragment length polymorphism of mitochondrial DNA (mtDNA) was used to identify the maternal parent of each hybrid. Evidence of introgression was found among the five previously identified hybrids. All hybrid specimens had chinook salmon mtDNA, indicating that hybridization between chinook salmon and pink salmon in the St. Marys River is asymmetric and perhaps unidirectional. Ecological, physiological, and sexual selection forces may contribute to this asymmetric hybridization. Introgression between these highly differentiated species has implications for management, systematics, and conservation of Pacific salmon.

  5. The influence of the North Atlantic Oscillation on the sea-level around the northern European coasts reconsidered: the thermosteric effects.

    PubMed

    Tsimplis, M N; Shaw, A G P; Flather, R A; Woolf, D K

    2006-04-15

    The thermosteric contribution of the North Atlantic Oscillation (NAO) to the North Sea sea-level for the winter period is investigated. Satellite sea surface temperature as well as in situ measurements are used to define the sensitivity of winter water temperature to the NAO as well as to determine the trends in temperature. The sea surface temperature sensitivity to the NAO is about 0.85 degrees C per unit NAO, which results in thermosteric sea-level changes of about 1-2 cm per unit NAO. The sensitivity of sea surface temperatures to the NAO is strongly time-dependent. Model data from a two-dimensional hydrodynamic tide+surge model are used in combination with the estimated thermosteric anomalies to explain the observed sea-level changes and, in particular, the sensitivity of the datasets to the NAO variability. The agreement between the model and the observed data is improved by the inclusion of the thermosteric effect. PMID:16537143

  6. SALMON RECOVERY: LEARNING FROM SUCCESSES AND FAILURES

    EPA Science Inventory

    Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline of wild Pacific salmon. Of the Earth's four regions (i.e., Asian Far East, Atlantic Europe, eastern North America, and western North America) where salmon runs occurred originally, it...

  7. Scientists Release Altantic Salmon into Beaverdam Brook

    USGS Tunison Lab scientists Rich Chiavelli (left) and Emily Waldt (middle) hand a bucketful of young Atlantic salmon to Dan Bishop (right) of the New York State Department of Environmental Conservation for release into Beaverdam Brook at the state's Salmon River Fish Hatchery. Thousands of you...

  8. 150 YEARS OF SALMON RESTORATION: ASSORTED TRUTHS

    EPA Science Inventory

    Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline of wild Pacific salmon. Of the Earth's four regions (i.e., Asian Far East, Atlantic Europe, eastern North America, and western North America) where salmon runs originally occurred, it...

  9. Salmon Are Carefully Released Using Buckets

    Thousands of young Atlantic salmonare beingreleased into Salmon River in an effort to restore this diminished Lake Ontario fish population, extending the sport fishing season by at least two months in Oswego County, N.Y. Duringfall 2011 and spring 2012, U.S. Geological Survey scie...

  10. Salmon Are Carefully Released Using Buckets

    Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this diminished Lake Ontario fish population, extending the sport fishing season by at least two months in Oswego County, N.Y. During fall 2011 and spring 2012, U.S. Geological Survey scie...

  11. Salmon River Fish Hatchery in Altmar, N.Y.

    USGS scientists release young Atlantic salmon into Lake Ontario tributaries near the New York State Department of Environmental Conservation's Salmon River Fish Hatchery in Altmar, N.Y. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this di...

  12. THE FUTURE OF PACIFIC NORTHWEST SALMON: ANATOMY OF A CRISIS

    EPA Science Inventory

    Salmon are categorized biologically into two groups: Pacific salmon or Atlantic salmon. All seven species of Pacific salmon on both sides of the North Pacific Ocean have declined substantially from historic levels, but large runs still occur in northern British Columbia, Yukon,...

  13. Phylogenetic Evidence of Long Distance Dispersal and Transmission of Piscine Reovirus (PRV) between Farmed and Wild Atlantic Salmon

    PubMed Central

    Garseth, Åse Helen; Ekrem, Torbjørn; Biering, Eirik

    2013-01-01

    The extent and effect of disease interaction and pathogen exchange between wild and farmed fish populations is an ongoing debate and an area of research that is difficult to explore. The objective of this study was to investigate pathogen transmission between farmed and wild Atlantic salmon (Salmo salar L.) populations in Norway by means of molecular epidemiology. Piscine reovirus (PRV) was selected as the model organism as it is widely distributed in both farmed and wild Atlantic salmon in Norway, and because infection not necessarily will lead to mortality through development of disease. A matrix comprised of PRV protein coding sequences S1, S2 and S4 from wild, hatchery-reared and farmed Atlantic salmon in addition to one sea-trout (Salmo trutta L.) was examined. Phylogenetic analyses based on maximum likelihood and Bayesian inference indicate long distance transport of PRV and exchange of virus between populations. The results are discussed in the context of Atlantic salmon ecology and the structure of the Norwegian salmon industry. We conclude that the lack of a geographical pattern in the phylogenetic trees is caused by extensive exchange of PRV. In addition, the detailed topography of the trees indicates long distance transportation of PRV. Through its size, structure and infection status, the Atlantic salmon farming industry has the capacity to play a central role in both long distance transportation and transmission of pathogens. Despite extensive migration, wild salmon probably play a minor role as they are fewer in numbers, appear at lower densities and are less likely to be infected. An open question is the relationship between the PRV sequences found in marine fish and those originating from salmon. PMID:24349221

  14. Phylogenetic evidence of long distance dispersal and transmission of piscine reovirus (PRV) between farmed and wild Atlantic salmon.

    PubMed

    Garseth, Åse Helen; Ekrem, Torbjørn; Biering, Eirik

    2013-01-01

    The extent and effect of disease interaction and pathogen exchange between wild and farmed fish populations is an ongoing debate and an area of research that is difficult to explore. The objective of this study was to investigate pathogen transmission between farmed and wild Atlantic salmon (Salmo salar L.) populations in Norway by means of molecular epidemiology. Piscine reovirus (PRV) was selected as the model organism as it is widely distributed in both farmed and wild Atlantic salmon in Norway, and because infection not necessarily will lead to mortality through development of disease. A matrix comprised of PRV protein coding sequences S1, S2 and S4 from wild, hatchery-reared and farmed Atlantic salmon in addition to one sea-trout (Salmo trutta L.) was examined. Phylogenetic analyses based on maximum likelihood and Bayesian inference indicate long distance transport of PRV and exchange of virus between populations. The results are discussed in the context of Atlantic salmon ecology and the structure of the Norwegian salmon industry. We conclude that the lack of a geographical pattern in the phylogenetic trees is caused by extensive exchange of PRV. In addition, the detailed topography of the trees indicates long distance transportation of PRV. Through its size, structure and infection status, the Atlantic salmon farming industry has the capacity to play a central role in both long distance transportation and transmission of pathogens. Despite extensive migration, wild salmon probably play a minor role as they are fewer in numbers, appear at lower densities and are less likely to be infected. An open question is the relationship between the PRV sequences found in marine fish and those originating from salmon. PMID:24349221

  15. Using Agent-Based Modelling to Predict the Role of Wild Refugia in the Evolution of Resistance of Sea Lice to Chemotherapeutants.

    PubMed

    McEwan, Gregor F; Groner, Maya L; Fast, Mark D; Gettinby, George; Revie, Crawford W

    2015-01-01

    A major challenge for Atlantic salmon farming in the northern hemisphere is infestation by the sea louse parasite Lepeophtheirus salmonis. The most frequent method of controlling these sea louse infestations is through the use of chemical treatments. However, most major salmon farming areas have observed resistance to common chemotherapeutants. In terrestrial environments, many strategies employed to manage the evolution of resistance involve the use of refugia, where a portion of the population is left untreated to maintain susceptibility. While refugia have not been deliberately used in Atlantic salmon farming, wild salmon populations that migrate close to salmon farms may act as natural refugia. In this paper we describe an agent-based model that explores the influence of different sizes of wild salmon populations on resistance evolution in sea lice on a salmon farm. Using the model, we demonstrate that wild salmon populations can act as refugia that limit the evolution of resistance in the sea louse populations. Additionally, we demonstrate that an increase in the size of the population of wild salmon results in an increased effect in slowing the evolution of resistance. We explore the effect of a population fitness cost associated with resistance, finding that in some cases it substantially reduces the speed of evolution to chemical treatments. PMID:26485023

  16. Using Agent-Based Modelling to Predict the Role of Wild Refugia in the Evolution of Resistance of Sea Lice to Chemotherapeutants

    PubMed Central

    McEwan, Gregor F.; Groner, Maya L.; Fast, Mark D.; Revie, Crawford W.

    2015-01-01

    A major challenge for Atlantic salmon farming in the northern hemisphere is infestation by the sea louse parasite Lepeophtheirus salmonis. The most frequent method of controlling these sea louse infestations is through the use of chemical treatments. However, most major salmon farming areas have observed resistance to common chemotherapeutants. In terrestrial environments, many strategies employed to manage the evolution of resistance involve the use of refugia, where a portion of the population is left untreated to maintain susceptibility. While refugia have not been deliberately used in Atlantic salmon farming, wild salmon populations that migrate close to salmon farms may act as natural refugia. In this paper we describe an agent-based model that explores the influence of different sizes of wild salmon populations on resistance evolution in sea lice on a salmon farm. Using the model, we demonstrate that wild salmon populations can act as refugia that limit the evolution of resistance in the sea louse populations. Additionally, we demonstrate that an increase in the size of the population of wild salmon results in an increased effect in slowing the evolution of resistance. We explore the effect of a population fitness cost associated with resistance, finding that in some cases it substantially reduces the speed of evolution to chemical treatments. PMID:26485023

  17. The forebrain-midbrain acts as functional endocrine signaling pathway of Kiss2/Gnrh1 system controlling the gonadotroph activity in the teleost fish European sea bass (Dicentrarchus labrax).

    PubMed

    Espigares, Felipe; Carrillo, Manuel; Gómez, Ana; Zanuy, Silvia

    2015-03-01

    Some teleost species, including European sea bass, harbor two different kisspeptin coding genes: kiss1 and kiss2. Both genes are expressed in the brain, but their differential roles in the central control of fish reproduction are only beginning to be elucidated. In this study, we have examined the effects of intracerebroventricular injections of the highly active sea bass peptides Kiss1-15 and Kiss2-12 on spermiating male sea bass. Physiological saline, Kiss1-15, or Kiss2-12 was injected into the third ventricle. To establish the gene expression cascade involved in the action of kisspeptins, the expression of the two sea bass kisspeptin receptor genes (kiss1r and kiss2r) and the three sea bass Gnrh genes (gnrh1, gnrh2, and gnrh3) were analyzed in the forebrain-midbrain and the hypothalamus. In addition, the protein levels of hypothalamic and pituitary Gnrh1 were measured. Blood samples were collected at different times after injection to analyze the effects of kisspeptins on the release of gonadotropins (Lh and Fsh) and androgens (testosterone and 11-ketotestosterone). The present results provide the first evidence that the effects of Kiss2 on central regulation of reproductive function involve the neuroendocrine areas of the forebrain-midbrain in teleost fish. The marked effect of Kiss2 on kiss2r and gnrh1 expression in the forebrain-midbrain and on Gnrh1 release suggest that this neuronal system is involved in the neuroendocrine regulation of gonadotroph activity. This hypothesis was confirmed by a surge of plasma Lh in response to Kiss2, which presumably has a strong stimulatory effect on testosterone release, and thus on sperm quality parameters. PMID:25609835

  18. Nutritional Status as the Key Modulator of Antioxidant Responses Induced by High Environmental Ammonia and Salinity Stress in European Sea Bass (Dicentrarchus labrax)

    PubMed Central

    Zinta, Gaurav; Dasan, Antony Franklin; Rasoloniriana, Rindra; Asard, Han; Blust, Ronny; De Boeck, Gudrun

    2015-01-01

    Salinity fluctuation is one of the main factors affecting the overall fitness of marine fish. In addition, water borne ammonia may occur simultaneously with salinity stress. Additionally, under such stressful circumstances, fish may encounter food deprivation. The physiological and ion-osmo regulatory adaptive capacities to cope with all these stressors alone or in combination are extensively addressed in fish. To date, studies revealing the modulation of antioxidant potential as compensatory response to multiple stressors are rather lacking. Therefore, the present work evaluated the individual and combined effects of salinity challenge, ammonia toxicity and nutritional status on oxidative stress and antioxidant status in a marine teleost, European sea bass (Dicentrarchus labrax). Fish were acclimated to normal seawater (32 ppt), to brackish water (20 ppt and 10 ppt) and to hypo-saline water (2.5 ppt). Following acclimation to different salinities for two weeks, fish were exposed to high environmental ammonia (HEA, 20 mg/L representing 50% of 96h LC50 value for ammonia) for 12 h, 48 h, 84 h and 180 h, and were either fed (2% body weight) or fasted (unfed for 7 days prior to HEA exposure). Results show that in response to decreasing salinities, oxidative stress indices such as xanthine oxidase activity, levels of hydrogen peroxide (H2O2) and lipid peroxidation (malondialdehyde, MDA) increased in the hepatic tissue of fasted fish but remained unaffected in fed fish. HEA exposure at normal salinity (32 ppt) and at reduced salinities (20 ppt and 10 ppt) increased ammonia accumulation significantly (84 h–180 h) in both feeding regimes which was associated with an increment of H2O2 and MDA contents. Unlike in fasted fish, H2O2 and MDA levels in fed fish were restored to control levels (84 h–180 h); with a concomitant increase in superoxide dismutase (SOD), catalase (CAT), components of the glutathione redox cycle (reduced glutathione, glutathione peroxidase and glutathione reductase), ascorbate peroxidase (APX) activity and reduced ascorbate (ASC) content. On the contrary, fasted fish could not activate many of these protective systems and rely mainly on CAT and ASC dependent pathways as antioxidative sentinels. The present findings exemplify that in fed fish single factors and a combination of HEA exposure and reduced seawater salinities (upto 10 ppt) were insufficient to cause oxidative damage due to the highly competent antioxidant system compared to fasted fish. However, the impact of HEA exposure at a hypo-saline environment (2.5 ppt) also defied antioxidant defence system in fed fish, suggesting this combined factor is beyond the tolerance range for both feeding groups. Overall, our results indicate that the oxidative stress mediated by the experimental conditions were exacerbated during starvation, and also suggest that feed deprivation particularly at reduced seawater salinities can instigate fish more susceptible to ammonia toxicity. PMID:26241315

  19. Nutritional Status as the Key Modulator of Antioxidant Responses Induced by High Environmental Ammonia and Salinity Stress in European Sea Bass (Dicentrarchus labrax).

    PubMed

    Sinha, Amit Kumar; AbdElgawad, Hamada; Zinta, Gaurav; Dasan, Antony Franklin; Rasoloniriana, Rindra; Asard, Han; Blust, Ronny; De Boeck, Gudrun

    2015-01-01

    Salinity fluctuation is one of the main factors affecting the overall fitness of marine fish. In addition, water borne ammonia may occur simultaneously with salinity stress. Additionally, under such stressful circumstances, fish may encounter food deprivation. The physiological and ion-osmo regulatory adaptive capacities to cope with all these stressors alone or in combination are extensively addressed in fish. To date, studies revealing the modulation of antioxidant potential as compensatory response to multiple stressors are rather lacking. Therefore, the present work evaluated the individual and combined effects of salinity challenge, ammonia toxicity and nutritional status on oxidative stress and antioxidant status in a marine teleost, European sea bass (Dicentrarchus labrax). Fish were acclimated to normal seawater (32 ppt), to brackish water (20 ppt and 10 ppt) and to hypo-saline water (2.5 ppt). Following acclimation to different salinities for two weeks, fish were exposed to high environmental ammonia (HEA, 20 mg/L representing 50% of 96h LC50 value for ammonia) for 12 h, 48 h, 84 h and 180 h, and were either fed (2% body weight) or fasted (unfed for 7 days prior to HEA exposure). Results show that in response to decreasing salinities, oxidative stress indices such as xanthine oxidase activity, levels of hydrogen peroxide (H2O2) and lipid peroxidation (malondialdehyde, MDA) increased in the hepatic tissue of fasted fish but remained unaffected in fed fish. HEA exposure at normal salinity (32 ppt) and at reduced salinities (20 ppt and 10 ppt) increased ammonia accumulation significantly (84 h-180 h) in both feeding regimes which was associated with an increment of H2O2 and MDA contents. Unlike in fasted fish, H2O2 and MDA levels in fed fish were restored to control levels (84 h-180 h); with a concomitant increase in superoxide dismutase (SOD), catalase (CAT), components of the glutathione redox cycle (reduced glutathione, glutathione peroxidase and glutathione reductase), ascorbate peroxidase (APX) activity and reduced ascorbate (ASC) content. On the contrary, fasted fish could not activate many of these protective systems and rely mainly on CAT and ASC dependent pathways as antioxidative sentinels. The present findings exemplify that in fed fish single factors and a combination of HEA exposure and reduced seawater salinities (upto 10 ppt) were insufficient to cause oxidative damage due to the highly competent antioxidant system compared to fasted fish. However, the impact of HEA exposure at a hypo-saline environment (2.5 ppt) also defied antioxidant defence system in fed fish, suggesting this combined factor is beyond the tolerance range for both feeding groups. Overall, our results indicate that the oxidative stress mediated by the experimental conditions were exacerbated during starvation, and also suggest that feed deprivation particularly at reduced seawater salinities can instigate fish more susceptible to ammonia toxicity. PMID:26241315

  20. Spatio-temporal covariability in coho salmon ( Oncorhynchus kisutch) survival, from California to southeast Alaska

    NASA Astrophysics Data System (ADS)

    Teo, Steven L. H.; Botsford, Louis W.; Hastings, Alan

    2009-12-01

    One of the motivations of the GLOBEC Northeast Pacific program is to understand the apparent inverse relationship between the increase in salmon catches in the Gulf of Alaska and concurrent declines in the California Current System (CCS). We therefore used coded wire tag (CWT) data to examine the spatial and temporal patterns of covariability in the survival of hatchery coho salmon along the coast from California to southeast Alaska between release years 1980 and 2004. There is substantial covariability in coho salmon survival between neighboring regions along the coast, and there is clear evidence for increased covariability within two main groups - a northern and southern group. The dividing line between the groups lies approximately at the north end of Vancouver Island. However, CWT survivals do not support inverse covariability in hatchery coho salmon survival between southeast Alaska and the CCS over this 25 year time span. Instead, the hatchery coho survival in southeast Alaska is relatively uncorrelated with coho survival in the California Current System on inter-annual time scales. The 50% correlation and e-folding scales (distances at which magnitude of correlations decreases to 50% and e -1 (32.8%), respectively) of pairwise correlations between individual hatcheries were 150 and 217 km, which are smaller than that reported for sockeye, pink, and chum salmon. The 50% correlation scale of coho salmon is also substantially smaller than those reported for upwelling indices and sea surface temperature. There are also periods of 5-10 years with high covariability between adjacent regions on the scale of hundreds of km, which may be of biological and physical significance.

  1. Footprints of Directional Selection in Wild Atlantic Salmon Populations: Evidence for Parasite-Driven Evolution?

    PubMed Central

    Zueva, Ksenia J.; Lumme, Jaakko; Veselov, Alexey E.; Kent, Matthew P.; Lien, Sigbjørn; Primmer, Craig R.

    2014-01-01

    Mechanisms of host-parasite co-adaptation have long been of interest in evolutionary biology; however, determining the genetic basis of parasite resistance has been challenging. Current advances in genome technologies provide new opportunities for obtaining a genome-scale view of the action of parasite-driven natural selection in wild populations and thus facilitate the search for specific genomic regions underlying inter-population differences in pathogen response. European populations of Atlantic salmon (Salmo salar L.) exhibit natural variance in susceptibility levels to the ectoparasite Gyrodactylus salaris Malmberg 1957, ranging from resistance to extreme susceptibility, and are therefore a good model for studying the evolution of virulence and resistance. However, distinguishing the molecular signatures of genetic drift and environment-associated selection in small populations such as land-locked Atlantic salmon populations presents a challenge, specifically in the search for pathogen-driven selection. We used a novel genome-scan analysis approach that enabled us to i) identify signals of selection in salmon populations affected by varying levels of genetic drift and ii) separate potentially selected loci into the categories of pathogen (G. salaris)-driven selection and selection acting upon other environmental characteristics. A total of 4631 single nucleotide polymorphisms (SNPs) were screened in Atlantic salmon from 12 different northern European populations. We identified three genomic regions potentially affected by parasite-driven selection, as well as three regions presumably affected by salinity-driven directional selection. Functional annotation of candidate SNPs is consistent with the role of the detected genomic regions in immune defence and, implicitly, in osmoregulation. These results provide new insights into the genetic basis of pathogen susceptibility in Atlantic salmon and will enable future searches for the specific genes involved. PMID:24670947

  2. Ecology. Can science rescue salmon?

    PubMed

    Mann, C C; Plummer, M L

    2000-08-01

    At a press conference on 27 July, the National Marine Fisheries Service (NMFS) released a long-awaited plan to save the Columbia River's endangered salmon by restoring fish habitat, overhauling hatcheries, limiting harvest, and improving river flow. What the plan did not do, however, was call for immediate breaching of four dams on the Snake River, the Columbia's major tributary--an option that has been the subject of a nationwide environmental crusade. The NMFS will hold that option in abeyance while it sees whether the less drastic measures will do the trick. Responses from both sides were immediate and outraged. PMID:10950712

  3. European Mistletoe

    MedlinePlus

    ... T U V W X Y Z European Mistletoe Share: On This Page Introduction What the Science ... and Cautions For More Information Key References european_mistletoe.jpg © Steven Foster Common Names: European mistletoe, mistletoe ...

  4. Multivariate Models of Adult Pacific Salmon Returns

    PubMed Central

    Burke, Brian J.; Peterson, William T.; Beckman, Brian R.; Morgan, Cheryl; Daly, Elizabeth A.; Litz, Marisa

    2013-01-01

    Most modeling and statistical approaches encourage simplicity, yet ecological processes are often complex, as they are influenced by numerous dynamic environmental and biological factors. Pacific salmon abundance has been highly variable over the last few decades and most forecasting models have proven inadequate, primarily because of a lack of understanding of the processes affecting variability in survival. Better methods and data for predicting the abundance of returning adults are therefore required to effectively manage the species. We combined 31 distinct indicators of the marine environment collected over an 11-year period into a multivariate analysis to summarize and predict adult spring Chinook salmon returns to the Columbia River in 2012. In addition to forecasts, this tool quantifies the strength of the relationship between various ecological indicators and salmon returns, allowing interpretation of ecosystem processes. The relative importance of indicators varied, but a few trends emerged. Adult returns of spring Chinook salmon were best described using indicators of bottom-up ecological processes such as composition and abundance of zooplankton and fish prey as well as measures of individual fish, such as growth and condition. Local indicators of temperature or coastal upwelling did not contribute as much as large-scale indicators of temperature variability, matching the spatial scale over which salmon spend the majority of their ocean residence. Results suggest that effective management of Pacific salmon requires multiple types of data and that no single indicator can represent the complex early-ocean ecology of salmon. PMID:23326586

  5. Multivariate models of adult Pacific salmon returns.

    PubMed

    Burke, Brian J; Peterson, William T; Beckman, Brian R; Morgan, Cheryl; Daly, Elizabeth A; Litz, Marisa

    2013-01-01

    Most modeling and statistical approaches encourage simplicity, yet ecological processes are often complex, as they are influenced by numerous dynamic environmental and biological factors. Pacific salmon abundance has been highly variable over the last few decades and most forecasting models have proven inadequate, primarily because of a lack of understanding of the processes affecting variability in survival. Better methods and data for predicting the abundance of returning adults are therefore required to effectively manage the species. We combined 31 distinct indicators of the marine environment collected over an 11-year period into a multivariate analysis to summarize and predict adult spring Chinook salmon returns to the Columbia River in 2012. In addition to forecasts, this tool quantifies the strength of the relationship between various ecological indicators and salmon returns, allowing interpretation of ecosystem processes. The relative importance of indicators varied, but a few trends emerged. Adult returns of spring Chinook salmon were best described using indicators of bottom-up ecological processes such as composition and abundance of zooplankton and fish prey as well as measures of individual fish, such as growth and condition. Local indicators of temperature or coastal upwelling did not contribute as much as large-scale indicators of temperature variability, matching the spatial scale over which salmon spend the majority of their ocean residence. Results suggest that effective management of Pacific salmon requires multiple types of data and that no single indicator can represent the complex early-ocean ecology of salmon. PMID:23326586

  6. Retention of mercury by salmon

    USGS Publications Warehouse

    Amend, Donald F.

    1970-01-01

    Consuming fish that have been exposed repeatedly to mercury derivatives is a potential public health hazard because fish can accumulate and retain mercury in their tissues (Rucker, 1968). Concern has been expressed in the United States because mercurials have been used extensively in industry and as prophylactic and therapeutic agents in fish hatcheries. Rucker and Amend (1969) showed that yearling rainbow trout (Salmo gairdneri) and chinook salmon (Oncorhynchus tshawytscha) exposed to mercurials accumulated excessive amounts of mercury in many tissues. Further, Rucker and Amend (1969) concluded that wild fish that ate mercury-contaminated fish also could contain high mercury levels. Although mercury was eliminated from most tissues within several months, substantial levels remained in the kidney for more than 33 weeks after the last exposure. Since high levels of mercury can be retained in the kidney for an undetermined time, it is possible that returning adult salmon exposed to mercurials as juveniles could constitute a potential hazard to public health. The purpose of this study was to determine whether such fish contained high residual levels of mercury.

  7. Effects of the total replacement of fish-based diet with plant-based diet on the hepatic transcriptome of two European sea bass (Dicentrarchus labrax) half-sibfamilies showing different growth rates with the plant-based diet

    PubMed Central

    2011-01-01

    Background Efforts towards utilisation of diets without fish meal (FM) or fish oil (FO) in finfish aquaculture have been being made for more than two decades. Metabolic responses to substitution of fishery products have been shown to impact growth performance and immune system of fish as well as their subsequent nutritional value, particularly in marine fish species, which exhibit low capacity for biosynthesis of long-chain poly-unsaturated fatty acids (LC-PUFA). The main objective of the present study was to analyse the effects of a plant-based diet on the hepatic transcriptome of European sea bass (Dicentrarchus labrax). Results We report the first results obtained using a transcriptomic approach on the liver of two half-sibfamilies of the European sea bass that exhibit similar growth rates when fed a fish-based diet (FD), but significantly different growth rates when fed an all-plant diet (VD). Overall gene expression was analysed using oligo DNA microarrays (GPL9663). Statistical analysis identified 582 unique annotated genes differentially expressed between groups of fish fed the two diets, 199 genes regulated by genetic factors, and 72 genes that exhibited diet-family interactions. The expression of several genes involved in the LC-PUFA and cholesterol biosynthetic pathways was found to be up-regulated in fish fed VD, suggesting a stimulation of the lipogenic pathways. No significant diet-family interaction for the regulation of LC-PUFA biosynthesis pathways could be detected by microarray analysis. This result was in agreement with LC-PUFA profiles, which were found to be similar in the flesh of the two half-sibfamilies. In addition, the combination of our transcriptomic data with an analysis of plasmatic immune parameters revealed a stimulation of complement activity associated with an immunodeficiency in the fish fed VD, and different inflammatory status between the two half-sibfamilies. Biological processes related to protein catabolism, amino acid transaminations, RNA splicing and blood coagulation were also found to be regulated by diet, while the expression of genes involved in protein and ATP synthesis differed between the half-sibfamilies. Conclusions Overall, the combined gene expression, compositional and biochemical studies demonstrated a large panel of metabolic and physiological effects induced by total substitution of both FM and FO in the diets of European sea bass and revealed physiological characteristics associated with the two half-sibfamilies. PMID:22017880

  8. Atlantic salmon brood stock management and breeding handbook

    USGS Publications Warehouse

    Kincaid, Harold L.; Stanley, Jon G.

    1989-01-01

    Anadromus runs of Atlantic salmon have been restored to the Connecticut, Merrimack, Pawcatuck, Penobscot, and St. Croix rivers in New England by the stocking of more than 8 million smolts since 1948. Fish-breeding methods have been developed that minimize inbreeding and domestication and enhance natural selection. Methods are available to advance the maturation of brood stock, control the sex of production lots and store gametes. Current hatchery practices emphasize the use of sea-run brood stock trapped upon return to the rivers and a limited number of captive brood stock and rejuvenated kelts. Fish are allowed to mature naturally, after which they are spawned and incubated artificially. Generally, 1-year smolts are produced, and excess fish are stocked as fry in headwater streams. Smolts are stocked during periods of rising water in spring. Self-release pools are planned that enable smolts to choose the emigration time. Culturists keep good records that permit evaluation of the performance of strains and the effects of breeding practices. As Atlantic salmon populations expand, culturists must use sound breeding methods that enhance biotic potential while maintaining genetic diversity and protecting unique gene pools.

  9. River temperature drives salmon survivorship: is it determined prior to ocean entry?

    PubMed Central

    Morita, Kentaro; Ayumi, Nakashima; Kikuchi, Motohiro

    2015-01-01

    Early life is believed to be a critical stage for determining survivorship in all fish. Many studies have suggested that environmental conditions in the ocean determine the fry-to-adult survival rate of Pacific salmon but few investigations have been conducted on the importance of the brief freshwater period during the seaward migration on overall survivorship. Here, we found that most of the variation in survivorship of hatchery-reared chum salmon (Oncorhynchus keta) was explained by river temperature during the fry stage, despite spending most of their life (approx. 99%) at sea. After the annual release of a constant number of fry, the number of fry moving through the river at a downstream location varied greatly. The number of returning adults was positively correlated with the number of fry moving downstream. This result suggests that most salmon mortality occurred prior to ocean entry, and that short-term mortality in the river is a key factor determining major fluctuations in total mortality. Although marine mortality is often invoked in the literature as a key factor determining total mortality of chum salmon, attention should also be paid to freshwater mortality to understand the population dynamics of this species. PMID:26064583

  10. Chemical physiological and morphological studies of feral baltic salmon (Salmo salar) suffering from abnormal fry mortality

    SciTech Connect

    Norrgren, L. . Dept. of Pathology Swedish Environmental Research Inst., Stockholm ); Andersson, T. . Dept. of Zoophysiology); Bergqvist, P.A. . Inst. of Environmental Chemistry); Bjoerklund, I. )

    1993-11-01

    In 1974, abnormally high mortality was recorded among yolk-sac fry of Baltic salmon (Salmo salar) originating from feral females manually stripped and fertilized with milt from feral males. The cause of this mortality, designated M74, is unknown. The hypothesis is that xenobiotic compounds responsible for reproduction failure in higher vertebrates in the Baltic Sea also interfere with reproduction in Baltic salmon. The significance of M74 should not be underestimated, because the syndrome has caused up to 75% yearly mortality of developing Baltic salmon yolk-sac larvae in a fish hatchery dedicated to production of smolt during the last two decades. The author cannot exclude the possibility that only a relatively low number of naturally spawned eggs develop normally because of M74. No individual pollutant has been shown to be responsible for the development of M74 syndrome. However, a higher total body burden of organochlorine substances may be responsible for the M74 syndrome. The presence of induced hepatic cytochrome P450 enzymes in both yolk-sac fry suffering from M74 and adult feral females producing offspring affected by M74 supports this hypothesis. In addition, the P450 enzyme activity in offspring from feral fish is higher than the activity in yolk-sac fry from hatchery-raised fish, suggesting that feral Baltic salmon are influenced by organic xenobiotics.

  11. Geomagnetic imprinting predicts spatio-temporal variation in homing migration of pink and sockeye salmon.

    PubMed

    Putman, Nathan F; Jenkins, Erica S; Michielsens, Catherine G J; Noakes, David L G

    2014-10-01

    Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye (Oncorhynchus nerka) and pink (Oncorhynchus gorbuscha) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species. PMID:25056214

  12. Nutrient fluxes and the recent collapse of coastal California salmon populations

    USGS Publications Warehouse

    Moore, Jonathan W.; Hayes, Sean A.; Duffy, Walter; Gallagher, Sean; Michel, Cyril J.; Wright, David

    2011-01-01

    Migratory salmon move nutrients both in and out of fresh waters during the different parts of their life cycle. We used a mass-balance approach to quantify recent changes in phosphorus (P) fluxes in six coastal California, USA, watersheds that have recently experienced dramatic decreases in salmon populations. As adults, semelparous Chinook (Oncorhynchus tshawytscha) and coho (Oncorhynchus kisutch) salmon imported 8.3 and 10.4 times more P from the ocean, respectively, than they exported as smolts, while iteroparous steelhead (i.e., sea-run rainbow trout, Oncorhynchus mykiss) imported only 1.6 times more than they exported as kelts and smolts. Semelparous species whose life histories led them to import more nutrients were also the species whose populations decreased the most dramatically in California in recent years. In addition, the relationship between import and export was nonlinear, with export being proportionally more important at lower levels of import. This pattern was driven by two density-dependent processes — smolts were larger and disproportionately more abundant at lower spawner abundances. In fact, in four of our six streams we found evidence that salmon can drive net export of P at low abundance, evidence for the reversal of the "conveyor belt" of nutrients.

  13. Geomagnetic imprinting predicts spatio-temporal variation in homing migration of pink and sockeye salmon

    PubMed Central

    Putman, Nathan F.; Jenkins, Erica S.; Michielsens, Catherine G. J.; Noakes, David L. G.

    2014-01-01

    Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye (Oncorhynchus nerka) and pink (Oncorhynchus gorbuscha) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species. PMID:25056214

  14. Modelling the migration opportunities of diadromous fish species along a gradient of dissolved oxygen concentration in a European tidal watershed

    NASA Astrophysics Data System (ADS)

    Maes, J.; Stevens, M.; Breine, J.

    2007-10-01

    The relationship between poor water quality and migration opportunities for fish remains poorly documented, although it is an essential research step in implementing EU water legislation. In this paper, we model the environmental constraints that control the movements of anadromous and catadromous fish populations that migrate through the tidal watershed of River Scheldt, a heavily impacted river basin in Western Europe. Local populations of sturgeon, sea lamprey, sea trout, Atlantic salmon, houting and allis shad were essentially extirpated around 1900. For remaining populations (flounder, three-spined stickleback, twaite shad, thinlip mullet, European eel and European smelt), a data driven logistic model was parameterized. The presence or absence of fish species in samples taken between 1995 and 2004 was modelled as a function of temperature, dissolved oxygen concentration, river flow and season. Probabilities to catch individuals from all diadromous species but three-spined stickleback increased as a function of the interaction between temperature and dissolved oxygen. The hypoxic zone situated in the freshwater tidal part of the estuary was an effective barrier for upstream migrating anadromous spawners since it blocked the entrance to historical spawning sites upstream. Similarly, habitat availability for catadromous fish was greatly reduced and restricted to lower brackish water parts of the estuary. The model was applied to infer preliminary dissolved oxygen criteria for diadromous fish, to make qualitative predictions about future changes in fish distribution given anticipated changes in water quality and to suggest necessary measures with respect to watershed management.

  15. Exploring relationships between recruitment of European hake ( Merluccius merluccius L. 1758) and environmental factors in the Ligurian Sea and the Strait of Sicily (Central Mediterranean)

    NASA Astrophysics Data System (ADS)

    Abella, A.; Fiorentino, F.; Mannini, A.; Orsi Relini, L.

    This paper explores the relationships between the spatial patterns of the distribution of the young hakes of the year (YOY) and the oceanographical features in two areas of the Central Mediterranean (the Ligurian Sea and the Strait of Sicily), characterised by the occurrence of straits and channels. Comparative and correlative approaches were used to investigate coupling between biological and physical patterns. Density indices of the YOY were derived from annual trawl surveys from 1994 to 2004 in spring and autumn. Mean patterns of the YOY distributions were compared with the mesoscale oceanographical features reported in literature. No evident trends in recruitment strength were found in either areas. Inter-annual variability in YOY abundance in the Ligurian Sea was higher than in the Strait of Sicily. The location of nursery grounds in the study areas coincides with zones of relatively higher production, where upwelling and other enrichment processes regularly occur. The presence of predictable eddies and the frontal systems play a major role in the localization of nursery areas in the Strait of Sicily, maintaining their stable position throughout the years. The strongest transport of southern waters from the Tyrrhenian to the Ligurian Sea, due to the East Corsica Current, which is negatively correlated to winter North Atlantic Oscillation, is associated with the highest abundance of hake recruits in the nurseries of the Northern Ligurian Sea.

  16. The Efficacy of Emamectin Benzoate against Infestations of Lepeophtheirus salmonis on Farmed Atlantic Salmon (Salmo salar L) in Scotland, 2002–2006

    PubMed Central

    Lees, Fiona; Baillie, Mark; Gettinby, George; Revie, Crawford W.

    2008-01-01

    Background Infestations of the parasitic copepod Lepeophtheirus salmonis, commonly referred to as sea lice, represent a major challenge to commercial salmon aquaculture. Dependence on a limited number of theraputants to control such infestations has led to concerns of reduced sensitivity in some sea lice populations. This study investigates trends in the efficacy of the in-feed treatment emamectin benzoate in Scotland, the active ingredient most widely used across all salmon producing regions. Methodology/Principal Findings Study data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. An epi-informatics approach was adopted whereby available farm records, descriptive epidemiological summaries and statistical linear modelling methods were used to identify factors that significantly affect sea lice abundance following treatment with emamectin benzoate (SLICE®, Schering Plough Animal Health). The results show that although sea lice infestations are reduced following the application of emamectin benzoate, not all treatments are effective. Specifically there is evidence of variation across geographical regions and a reduction in efficacy over time. Conclusions/Significance Reduced sensitivity and potential resistance to currently available medicines are constant threats to maintaining control of sea lice populations on Atlantic salmon farms. There is a need for on-going monitoring of emamectin benzoate treatment efficacy together with reasons for any apparent reduction in performance. In addition, strategic rotation of medicines should be encouraged and empirical evidence for the benefit of such strategies more fully evaluated. PMID:18253496

  17. Using the H-index to assess disease priorities for salmon aquaculture.

    PubMed

    Murray, Alexander G; Wardeh, Maya; McIntyre, K Marie

    2016-04-01

    Atlantic salmon's (Salmo salar) annual aquaculture production exceeds 2M tonnes globally, and for the UK forms the largest single food export. However, aquaculture production is negatively affected by a range of different diseases and parasites. Effort to control pathogens should be focused on those which are most "important" to aquaculture. It is difficult to specify what makes a pathogen important; this is particularly true in the aquatic sector where data capture systems are less developed than for human or terrestrial animal diseases. Mortality levels might be one indicator, but these can cause a range of different problems such as persistent endemic losses, occasional large epidemics or control/treatment costs. Economic and multi-criteria decision methods can incorporate this range of impacts, however these have not been consistently applied to aquaculture and the quantity and quality of data required is large, so their potential for comparing aquatic pathogens is currently limited. A method that has been developed and applied to both human and terrestrial animal diseases is the analysis of published scientific literature using the H-index method. We applied this method to salmon pathogens using Web of Science searches for 23 pathogens. The top 3 H-indices were obtained for: sea lice, furunculosis, and infectious salmon anaemia; post 2000, Amoebic Gill Disease (AGD) replaced furunculosis. The number of publications per year describing bacterial disease declined significantly, while those for viruses and sea lice increased significantly. This reflects effective bacterial control by vaccination, while problems related to viruses and sea lice have increased. H-indices by country reflected different national concerns (e.g. AGD ranked top for Australia). Averaged national H-indices for salmon diseases tend to increase with log of salmon production; countries with H-Indices significantly below the trend line have suffered particularly large disease losses. The H-index method, supported by other literature analyses, is consistent with the nature and history of salmon diseases and so provides a useful quantitative measure for comparing different diseases in the absence of other measures. PMID:26952883

  18. THE CHALLENGE OF RESTORING WILD SALMON

    EPA Science Inventory

    Many experts have concluded that wild salmon recovery efforts in western North America (especially California, Oregon, Washington, Idaho, and southern British Columbia), as earnest, expensive, and socially disruptive as they currently are, do not appear likely to sustain biologic...

  19. Classroom-Community Salmon Enhancement Project.

    ERIC Educational Resources Information Center

    Hubbard-Gray, Sarah

    1988-01-01

    Describes a program in the Bellevue (Washington) public schools in which elementary and middle school teachers and students raise coho and Chinook salmon in the classroom and later release them into a nearby stream. (TW)

  20. A "virus" disease of chinook salmon

    USGS Publications Warehouse

    Ross, A.J.; Rucker, R.R.

    1960-01-01

    Epizootics among chinook salmon fingerlings at the Coleman National Fish Hatchery have occurred periodically since 1941. A virus or virus-like filterable agent has been demonstrated to be the causative agent of this disease.

  1. Quantifying Temperature Effects on Fall Chinook Salmon

    SciTech Connect

    Jager, Yetta

    2011-11-01

    The motivation for this study was to recommend relationships for use in a model of San Joaquin fall Chinook salmon. This report reviews literature pertaining to relationships between water temperature and fall Chinook salmon. The report is organized into three sections that deal with temperature effects on development and timing of freshwater life stages, temperature effects on incubation survival for eggs and alevin, and temperature effects on juvenile survival. Recommendations are made for modeling temperature influences for all three life stages.

  2. Etiology of sockeye salmon "virus" disease

    USGS Publications Warehouse

    1959-01-01

    Violent epizootics among hatchery reared sockeye salmon fingerLings ( Oncorhynchus nerka) caused by a filterable agent have occurred. In 1954, one source of this infectious, filterable agent was found to be adult sockeye viscera used in the diet for the fingerlings. The results of observations on an epizootic in 1958 indicate that the infection may be transmitted to fingerlings from a water supply to which adult sockeye salmon have access.

  3. Salmon River Habitat Enhancement. 1990 Annual Report

    SciTech Connect

    Rowe, Mike

    1991-12-01

    The annual report contains three individual subproject sections detailing tribal fisheries work completed during the summer and fall of 1990. Subproject I contains summaries of evaluation/monitoring efforts associated with the Bear Valley Creek, Idaho enhancement project. Subproject II contains an evaluation of the Yankee Fork of the Salmon River habitat enhancement project. Subproject III concerns the East Fork of the Salmon River, Idaho.

  4. Cloning and sequence analysis of a vasa homolog in the European sea bass (Dicentrarchus labrax): tissue distribution and mRNA expression levels during early development and sex differentiation.

    PubMed

    Blzquez, Mercedes; Gonzlez, Alicia; Mylonas, Constantinos C; Piferrer, Francesc

    2011-01-15

    Vasa is a protein expressed mainly in germ cells and conserved across taxa. However, sex-related differences and environmental influences on vasa expression have not been documented. This study characterized the cDNA of a vasa homolog in the European sea bass, Dicentrarchuslabrax (sb-vasa), a gonochoristic fish with temperature influences on gonadogenesis. The 1911 bp open reading frame predicted a 637-amino acid protein with the eight conserved domains typical of Vasa proteins. Comparisons of the deduced amino acid sequence with those of other vertebrates and invertebrates revealed the highest homology (68-85%) with those of other teleosts. An updated tree with the full-length sequences for Vasa proteins in 66 species belonging to six different phyla was constructed, establishing the evolutionary relationships of Vasa amino acid sequences. European sea bass vasa was highly expressed in gonads with little or no expression in other tissues. Real time RT-PCR quantification of the temporal expression of sb-vasa from early development throughout sex differentiation showed that mRNA levels were high in unfertilized eggs, decreased during larval development and increased again during the period of germ cell proliferation. Rearing of fish at high temperature resulted in further increased sb-vasa levels, most likely reflecting temperature effects on both somatic and gonadal growth. Differences in expression were also found well before sex differentiation and persisted until the end of the first year, with higher levels present in females. These differences in expression demonstrate the implication of vasa during the initial stages of fish sex differentiation and gametogenesis and suggest that, through its helicase activity, it might be implicated in the translational regulation of mRNAs involved in the specification and differentiation of gonadal-specific cell types. PMID:20955711

  5. Geomorphology and the Restoration Ecology of Salmon

    NASA Astrophysics Data System (ADS)

    Montgomery, D. R.

    2005-05-01

    Natural and anthropogenic influences on watershed processes affect the distribution and abundance of salmon across a wide range of spatial and temporal scales, from differences in species use and density between individual pools and riffles to regional patterns of threatened, endangered, and extinct runs. The specific impacts of human activities (e.g., mining, logging, and urbanization) vary among regions and watersheds, as well as between different channel reaches in the same watershed. Understanding of both disturbance history and key biophysical processes are important for diagnosing the nature and causes of differences between historical and contemporary fluvial and watershed conditions based on evaluation of both historical and spatial contexts. In order to be most effective, the contribution of geomorphologic insight to salmon recovery efforts requires both assessment protocols commensurate with providing adequate knowledge of historical and spatial context, and experienced practitioners well versed in adapting general theory to local settings. The historical record of salmon management in Europe, New England and the Pacific Northwest indicates that there is substantial need to incorporate geomorphic insights on the effects of changes in watershed processes on salmon habitat and salmon abundance into salmon recovery efforts.

  6. Salmon River Habitat Enhancement, 1989 Annual Report.

    SciTech Connect

    Rowe, Mike

    1989-04-01

    This project was funded by the Bonneville Power Administration (BPA). The annual report contains three individual subproject papers detailing tribal fisheries work completed during the summer and fall of 1989. Subproject 1 contains summaries of evaluation/monitoring efforts associated with the Bear Valley Creek, Idaho enhancement project. Subproject 2 contains an evaluation of the Yankee Fork of the Salmon River habitat enhancement project. This report has been sub-divided into two parts: Part 1; stream evaluation and Part 2; pond series evaluation. Subproject 3 concerns the East Fork of the Salmon River, Idaho. This report summarizes the evaluation of the project to date including the 1989 pre-construction evaluation conducted within the East Fork drainage. Dredge mining has degraded spawning and rearing habitat for chinook salmon and steelhead trout in the Yankee Fork drainage of the Salmon River and in Bear Valley Creek. Mining, agricultural, and grazing practices degraded habitat in the East Fork of the Salmon River. Biological monitoring of the success of habitat enhancement for Bear Valley Creek and Yankee Fork are presented in this report. Physical and biological inventories prior to habitat enhancement in East Fork were also conducted. Four series of off-channel ponds of the Yankee Fork are shown to provide effective rearing habitat for chinook salmon. 45 refs., 49 figs., 24 tabs.

  7. Salmon Farming and Salmon People: Identity and Environment in the Leggatt Inquiry

    ERIC Educational Resources Information Center

    Schreiber, Dorothee

    2003-01-01

    In October of 2001, the Leggatt Inquiry into salmon farming traveled to four small communities (Port Hardy, Tofino, Alert Bay, and Campbell River) close to the centers of operation for the finfish aquaculture industry in British Columbia. In doing so, it gave local people, particularly First Nations people, an opportunity to speak about salmon

  8. Salmon-Eating Grizzly Bears Exposed to Elevated Levels of Marine Derived Persistent Organic Pollutants

    NASA Astrophysics Data System (ADS)

    Christensen, J. R.; Ross, P. S.; Whiticar, M. J.

    2004-12-01

    The coastal grizzly bears of British Columbia (BC, Canada) rely heavily on salmon returning from the Pacific Ocean, whereas interior bears do not have access to or readily utilize this marine-derived food source. Since salmon have been shown to accumulate persistent organic pollutants (POPs) from the North Pacific Ocean, we hypothesized that salmon consumption by grizzly bears would be reflected by an increase in the POP burden. To test this hypothesis we collected hair and fat tissue from grizzlies at various locations around BC to compare salmon-eating (coastal) grizzlies to non-salmon-eating (interior) grizzlies. We characterized the feeding habits for each bear sampled by measuring the stable carbon and nitrogen isotope signature of their hair. The positive relationship between 13C/12C and 15N/14N isotopic ratios suggests that the majority of the meat portion of the diet of coastal grizzlies is coming from salmon, rather than from terrestrial or freshwater sources. By contrast, stable isotope ratios revealed that interior bears have an almost exclusive vegetarian diet with no marine influence. As hypothesized, the coastal grizzly bears have significantly greater OC pesticide and lower-brominated PBDE congener body burden than the interior grizzlies. We also found a positive relationship between C and N isotope ratios and these same POP contaminants in bear tissue. Overall, these results demonstrate that Pacific salmon represents a significant vector delivering both OC pesticides and PBDEs to BC coastal grizzly bears.

  9. Identification and characterisation of a novel immune-type receptor (NITR) gene cluster in the European sea bass, Dicentrarchus labrax, reveals recurrent gene expansion and diversification by positive selection

    PubMed Central

    Kuhl, Heiner; Milan, Massimo; Ritchie, David W.; Secombes, Christopher J.; Reinhardt, Richard; Bargelloni, Luca

    2009-01-01

    In the last decade, a new gene family encoding non-rearranging receptors, called novel immune-type receptors (NITRs), has been discovered in teleost fish. NITRs belong to the immunoglobulin superfamily and represent an extraordinarily divergent and rapidly evolving gene complex. Genomic analysis of a region spanning 270 kb led to the discovery of a NITR gene cluster in the European sea bass (Dicentrarchus labrax). In total, 27 NITR genes and three putative pseudogenes, organised in a tandemly arrayed cluster, were identified. Sea bass NITR genes maintain the three major genomic organisations that appear to be essentially conserved among fish species along with new features presumably involving processes of intron loss, exon deletion and acquisition of new exons. Comparative and evolutionary analyses suggest that these receptors have evolved following a “birth-and-death” model of gene evolution in which duplication events together with lineage-specific gain and loss of individual members contributed to the rapid diversification of individual gene families. In this study, we demonstrate that species-specific gene expansions provide the raw material for diversifying, positive Darwinian selection favouring the evolution of a highly diverse array of molecules. Electronic supplementary material The online version of this article (doi:10.1007/s00251-009-0398-3) contains supplementary material, which is available to authorized users. PMID:19851764

  10. Identification and characterisation of a novel immune-type receptor (NITR) gene cluster in the European sea bass, Dicentrarchus labrax, reveals recurrent gene expansion and diversification by positive selection.

    PubMed

    Ferraresso, Serena; Kuhl, Heiner; Milan, Massimo; Ritchie, David W; Secombes, Christopher J; Reinhardt, Richard; Bargelloni, Luca

    2009-12-01

    In the last decade, a new gene family encoding non-rearranging receptors, called novel immune-type receptors (NITRs), has been discovered in teleost fish. NITRs belong to the immunoglobulin superfamily and represent an extraordinarily divergent and rapidly evolving gene complex. Genomic analysis of a region spanning 270 kb led to the discovery of a NITR gene cluster in the European sea bass (Dicentrarchus labrax). In total, 27 NITR genes and three putative pseudogenes, organised in a tandemly arrayed cluster, were identified. Sea bass NITR genes maintain the three major genomic organisations that appear to be essentially conserved among fish species along with new features presumably involving processes of intron loss, exon deletion and acquisition of new exons. Comparative and evolutionary analyses suggest that these receptors have evolved following a "birth-and-death" model of gene evolution in which duplication events together with lineage-specific gain and loss of individual members contributed to the rapid diversification of individual gene families. In this study, we demonstrate that species-specific gene expansions provide the raw material for diversifying, positive Darwinian selection favouring the evolution of a highly diverse array of molecules. PMID:19851764

  11. Genetic differentiation of Alaska Chinook salmon: the missing link for migratory studies.

    PubMed

    Templin, William D; Seeb, James E; Jasper, James R; Barclay, Andrew W; Seeb, Lisa W

    2011-03-01

    Most information about Chinook salmon genetic diversity and life history originates from studies from the West Coast USA, western Canada and southeast Alaska; less is known about Chinook salmon from western and southcentral Alaska drainages. Populations in this large area are genetically distinct from populations to the south and represent an evolutionary legacy of unique genetic, phenotypic and life history diversity. More genetic information is necessary to advance mixed stock analysis applications for studies involving these populations. We assembled a comprehensive, open-access baseline of 45 single nucleotide polymorphisms (SNPs) from 172 populations ranging from Russia to California. We compare SNP data from representative populations throughout the range with particular emphasis on western and southcentral Alaska. We grouped populations into major lineages based upon genetic and geographic characteristics, evaluated the resolution for identifying the composition of admixtures and performed mixed stock analysis on Chinook salmon caught incidentally in the walleye pollock fishery in the Bering Sea. SNP data reveal complex genetic structure within Alaska and can be used in applications to address not only regional issues, but also migration pathways, bycatch studies on the high seas, and potential changes in the range of the species in response to climate change. PMID:21429177

  12. Directional selection by fisheries and the timing of sockeye salmon (Oncorhynchus nerka) migrations.

    PubMed

    Quinn, Thomas P; Hodgson, Sayre; Flynn, Lucy; Hilborn, Ray; Rogers, Donald E

    2007-04-01

    The timing of migration from feeding to breeding areas is a critical link between the growth and survival of adult animals, their reproduction, and the fitness of their progeny. Commercial fisheries often catch a large fraction of the migrants (e.g., salmon), and exploitation rates can vary systematically over the fishing season. We examined daily records of sockeye salmon (Oncorhynchus nerka) in the Egegik and Ugashik management districts in Bristol Bay, Alaska (USA), for evidence of such temporally selective fishing. In recent years, the early migrants have experienced lower fishing rates than later migrants, especially in the Egegik district, and the median migration date of the fish escaping the fisheries has been getting progressively earlier in both districts. Moreover, the overall runs (catch and escapement) in the Egegik district and, to a lesser extent the Ugashik district, have been getting earlier, as predicted in response to the selection on timing. The trends in timing were not correlated with sea surface temperature in the region of the North Pacific Ocean where the salmon tend to concentrate, but the trends in the two districts were correlated with each other, indicating that there may be some common environmental influence in addition to the effect of selection. Despite the selection, both groups of salmon have remained productive. We hypothesize that this resilience may result from representation of all component populations among the early and late migrants, so that the fisheries have not eliminated entire populations, and from density-dependent processes that may have helped maintain the productivity of these salmon populations. PMID:17494392

  13. Biogeomorphic impacts of migration and disturbance: Implications of salmon spawning and decay

    NASA Astrophysics Data System (ADS)

    Albers, S. J.; Petticrew, E. L.

    2013-11-01

    Geomorphologic processes often involve a biotic element that acts to regulate landform development. This biotic element can be plant or animal-based with a feedback that ultimately benefits the ecology of the organism. Pacific salmon (Oncorhynchus sp.) are an example of an animal biogeomorphic agent exhibiting such feedbacks and, because of long migrations from the sea to freshwater spawning grounds, are a species of interest that act on both local and regional scales. Upon returning to their natal streams, salmon generate a dual disturbance, resuspending large amounts of sediment as they construct nests while at the same time generating a substantial nutrient pulse through post-spawn die-off and decay. The retention and export of these nutrients are of importance to any hypothesized productivity boost driven by the marine derived nutrients (MDNs). Using experimental enclosures in the Horsefly River spawning channel in north-central British Columbia, our objectives for this study were to i) quantify the magnitude of organic and inorganic sediment export and retention from an active-spawning area and ii) determine the contribution of fine sediment MDN storage. Using a suspended sediment mass balance model, marine isotope enrichment and a time series of gravel bed sediment infiltration, we found strongly linear relationships between sediment infiltration and marine-derived nutrient enrichment. Elevated suspended sediment produced by salmon redd (nest) construction acted as an effective vector for MDN infiltration into the gravel bed. This study demonstrated that localized patterns of sediment deposition are regulated by salmon activity which in turn act to control MDN storage within, and release from, the gravel bed. Furthermore, this study demonstrates the ability of a biogeomorphic agent like salmon to establish a feedback mechanism that creates favorable conditions which ultimately benefit the organism.

  14. Genetic identification and distribution of the parasitic larvae of Anisakis pegreffii and Anisakis simplex (s. s.) in European hake Merluccius merluccius from the Tyrrhenian Sea and Spanish Atlantic coast: implications for food safety.

    PubMed

    Cipriani, Paolo; Smaldone, Giorgio; Acerra, Virginia; D'Angelo, Luisa; Anastasio, Aniello; Bellisario, Bruno; Palma, Giuseppe; Nascetti, Giuseppe; Mattiucci, Simonetta

    2015-04-01

    The consumption of the hake Merluccius merluccius is widespread in European countries, where this fish has a high commercial value. To date, different larval species of Anisakis have been identified as parasites in M. merluccius from European waters, Anisakis pegreffii and Anisakis simplex (s. s.) being the two most common. The aim of the study is to present data on the occurrence of Anisakis spp. larvae in the viscera and flesh of M. merluccius. Consequently, the distribution and infection rates of different species of Anisakis in different sites (viscera, and dorsal and ventral fillets) were investigated in hake caught in the central Tyrrhenian Sea (FAO 37.1.3) and the NE Atlantic Ocean (FAO 27 IXa). A sample of N=65 fish individuals (length>26 cm) was examined parasitologically from each fishing ground. The fillets were examined using the pepsin digestion method. A large number (1310) of Anisakis specimens were identified by multilocus allozyme electrophoresis (MAE) and mtDNA cox2 sequence analysis; among these, 814 larvae corresponded to A. simplex (s. s.) and 476 to A. pegreffii. They were found to infect both the flesh and the viscera. The two species co-infected the same individual fish (both in the viscera and in the flesh) from the FAO 27 area, whereas only A. pegreffii was found in hake from the Tyrrhenian Sea. The average parasite burden of A. pegreffii in hake from the Tyrrhenian Sea was significantly lower to that observed from hake off the Atlantic coast of Spain, both in prevalence and in abundance. In addition, whereas no significant difference in overall prevalence values was recorded between the two Anisakis species in the viscera of the FAO 27 sample, significant differences were found in the abundance levels observed between these species in the flesh, with A. simplex (s. s.) exhibiting significantly higher levels than that observed for A. pegreffii (p<0.001). Given that the pathogenic role in relation to man is known for these two species of Anisakis, both the flesh inspection and the infection rates of the different anisakid species assume particular importance in terms of assessing the risk they pose to humans. PMID:25584776

  15. POLICY CONUNDRUM: RESTORING WILD SALMON TO THE PACIFIC NORTHWEST

    EPA Science Inventory

    Restoring wild salmon runs to the Pacific Northwest is technically challenging, politically nasty, and socially divisive. Past restoration efforts have been largely unsuccessful. Society's failure to reverse the continuing decline of wild salmon has the characteristics of a pol...

  16. Sequencing the genome of the Atlantic salmon (Salmo salar)

    PubMed Central

    2010-01-01

    The International Collaboration to Sequence the Atlantic Salmon Genome (ICSASG) will produce a genome sequence that identifies and physically maps all genes in the Atlantic salmon genome and acts as a reference sequence for other salmonids. PMID:20887641

  17. Salmon 2100: Some recovery strategies that just might work

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project does not ...

  18. RHEOLOGICAL AND THERMAL PROPERTIES OF SALMON PROCESSING BYPRODUCTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rheological and thermal properties of salmon oil and biodiesel derived from salmon oil are important for designing processing equipment. For example, the viscosity of biodiesel at different temperatures is required for designing a heat exchanger for winterization purposes. Understanding rheological ...

  19. Long-term Records of Pacific Salmon Abundance From Sediment Core Analysis: Relationships to Past Climatic Change, and Implications for the Future

    NASA Astrophysics Data System (ADS)

    Finney, B.

    2002-12-01

    The response of Pacific salmon to future climatic change is uncertain, but will have large impacts on the economy, culture and ecology of the North Pacific Rim. Relationships between sockeye salmon populations and climatic change can be determined by analyzing sediment cores from lakes where sockeye return to spawn. Sockeye salmon return to their natal lake system to spawn and subsequently die following 2 - 3 years of feeding in the North Pacific Ocean. Sockeye salmon abundance can be reconstructed from stable nitrogen isotope analysis of lake sediment cores as returning sockeye transport significant quantities of N, relatively enriched in N-15, from the ocean to freshwater systems. Temporal changes in the input of salmon-derived N, and hence salmon abundance, can be quantified through downcore analysis of N isotopes. Reconstructions of sockeye salmon abundance from lakes in several regions of Alaska show similar temporal patterns, with variability occurring on decadal to millennial timescales. Over the past 2000 years, shifts in sockeye salmon abundance far exceed the historical decadal-scale variability. A decline occurred from about 100 BC - 800 AD, but salmon were consistently more abundant 1200 - 1900 AD. Declines since 1900 AD coincide with the period of extensive commercial fishing. Correspondence between these records and paleoclimatic data suggest that changes in salmon abundance are related to large scale climatic changes over the North Pacific. For example, the increase in salmon abundance c.a. 1200 AD corresponds to a period of glacial advance in southern Alaska, and a shift to drier conditions in western North America. Although the regionally coherent patterns in reconstructed salmon abundance are consistent with the hypothesis that climate is an important driver, the relationships do not always follow patterns observed in the 20th century. A main feature of recorded climate variability in this region is the alternation between multi-decade periods of above and below average strength of the Aleutian Low pressure system. During periods of stronger low pressure, sea surface temperature anomalies are warm in the northeast Pacific and cool in the central and northwest Pacific, a condition referred to as the positive phase of the Pacific Interdecadal Oscillation (PDO). Historically, during positive phases of the PDO Alaska salmon abundance is generally high. Consistent with this pattern, records of reconstructed sockeye salmon generally show higher abundance during warm periods over the past 300 years. However, the long-term trend suggests generally higher abundance during the cooler Little Ice Age, which southern Alaska glacial records suggest occurred between about 1200 - 1900 AD. The apparent complexity of salmon-climate relationships may be due to several factors. Long-term paleoclimate records from this region suggest additional modes of North Pacific climate variability, relative to the PDO. In addition, data on primary and secondary production in the Northeast Pacific Ocean indicates that climatic forcing has a direct impact on lower trophic levels, which subsequently affects salmon production. Thus records of ocean productivity, which are currently unavailable, may provide a mechanistic linkage between climate change and salmon abundance. The long-term perspective provided by the paleodata suggest that historical observations provide a limited understanding of how Pacific salmon respond to climatic change, and point to important areas of research necessary to better predict future responses.

  20. Long-term environmental exposure to metals (Cu, Cd, Pb, Zn) activates the immune cell stress response in the common European sea star (Asterias rubens).

    PubMed

    Matranga, V; Pinsino, A; Randazzo, D; Giallongo, A; Dubois, P

    2012-05-01

    The common sea star Asterias rubens represents a key-species of the North-Eastern Atlantic macro benthic community. The cells of their immune system, known as coelomocytes, are the first line of defence against environmental hazards. Here, we report the results of investigations on the immune cells response of sea stars exposed to marine environmental pollution for long periods. We show that levels of the heat shock cognate protein 70 (HSC70) in coelomocytes from A. rubens, which were collected during a field study in the Sǿrfjord (North Sea, SW coast of Norway) along a contamination gradient, are directly associated with the long-term accumulation of Cd, Cu heavy metals exclusively in the tegument. Conversely, Pb and Zn accumulation in the tegument did not relate to HSC70 levels and none of the metals were found accumulated in the pyloric coeca. In addition the coelomocytes from A. rubens, collected in high and low metal impacted stations were examined by a proteomic approach using two-dimensional electrophoresis (2DE). By comparison of the proteomic maps, we observed that 31 protein spots differed in their relative abundance, indicating a gene expression response to the metal mixture exposure. All together, our results confirm that the echinoderm immune cells are a suitable model for the assessment of long-term exposure to environmental pollution, moreover that the increased level of HSC70 can be considered a signal of an acquired tolerance within a large spectrum of protein profile changes occurring in response to metal contamination. PMID:22000270

  1. The legacy of a vanished sea: a high level of diversification within a European freshwater amphipod species complex driven by 15 My of Paratethys regression.

    PubMed

    Mamos, Tomasz; Wattier, Remi; Burzyński, Artur; Grabowski, Michał

    2016-02-01

    The formation of continental Europe in the Neogene was due to the regression of the Tethys Ocean and of the Paratethys Sea. The dynamic geology of the area and repetitious transitions between marine and freshwater conditions presented opportunities for the colonization of newly emerging hydrological networks and diversification of aquatic biota. Implementing mitochondrial and nuclear markers in conjunction with a large-scale sampling strategy, we investigated the impact of this spatiotemporal framework on the evolutionary history of a freshwater crustacean morphospecies. The Gammarus balcanicus species complex is widely distributed in the area previously occupied by the Paratethys Sea. Our results revealed its high diversification and polyphyly in relation to a number of other morphospecies. The distribution of the studied amphipod is generally characterized by very high local endemism and divergence. The Bayesian time-calibrated reconstruction of phylogeny and geographical distribution of ancestral nodes indicates that this species complex started to diversify in the Early Miocene in the central Balkans, partially in the shallow epicontinental sea. It is possible that there were several episodes of inland water colonization by local brackish water lineages. Subsequent diversification within clades and spread to new areas could have been induced by Alpine orogeny in the Miocene/Pliocene and, finally, by Pleistocene glaciations. The present distribution of clades, in many cases, still reflects Miocene palaeogeography of the area. Our results point out that investigations of the historical aspect of cryptic diversity in other taxa may help in a general understanding of the origins of freshwater invertebrate fauna of Europe. PMID:26615060

  2. 75 FR 78929 - Fraser River Sockeye Salmon Fisheries; Inseason Orders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ...NMFS publishes Fraser River salmon inseason orders to regulate salmon fisheries in U.S. waters. The orders were issued by the Fraser River Panel (Panel) of the Pacific Salmon Commission (Commission) and subsequently approved and issued by NMFS during the 2010 salmon fisheries within the U.S. Fraser River Panel Area. These orders established fishing dates, times, and areas for the gear types of......

  3. Updraft gasification of salmon processing waste.

    PubMed

    Rowland, Sarah; Bower, Cynthia K; Patil, Krushna N; DeWitt, Christina A Mireles

    2009-10-01

    The purpose of this study was to judge the feasibility of gasification for the disposal of waste streams generated through salmon harvesting. Gasification is the process of converting carbonaceous materials into combustible "syngas" in a high temperature (above 700 degrees C), oxygen deficient environment. Syngas can be combusted to generate power, which recycles energy from waste products. At 66% to 79% moisture, raw salmon waste streams are too wet to undergo pyrolysis and combustion. Ground raw or de-oiled salmon whole fish, heads, viscera, or frames were therefore "dried" by mixing with wood pellets to a final moisture content of 20%. Ground whole salmon with moisture reduced to 12% moisture was gasified without a drying agent. Gasification tests were performed in a small-scale, fixed-bed, updraft gasifer. After an initial start-up period, the gasifier was loaded with 1.5 kg of biomass. Temperature was recorded at 6 points in the gasifier. Syngas was collected during the short steady-state period during each gasifier run and analyzed. Percentages of each type of gas in the syngas were used to calculate syngas heating value. High heating value (HHV) ranged from 1.45 to 1.98 MJ/kg. Bomb calorimetry determined maximum heating value for the salmon by-products. Comparing heating values shows the efficiency of gasification. Cold gas efficiencies of 13.6% to 26% were obtained from the various samples gasified. Though research of gasification as a means of salmon waste disposal and energy production is ongoing, it can be concluded that pre-dried salmon or relatively low moisture content mixtures of waste with wood are gasifiable. PMID:19799663

  4. POLICY OPTIONS TO REVERSE THE DECLINE OF WILD PACIFIC SALMON

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project was to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in the Pacific Northwest and California. Wild salmon recovery efforts in western North Americ...

  5. Scientists Strategize at the Salmon River Fish Hatchery

    USGS scientists (L to R) Emily Waldt, Ross Abbett, and Jim Johnson chat with Dan Bishop (far left)of the New York State Department of Environmental Conservation while watching hundreds of salmon swim into troughs at the state's Salmon River Fish Hatchery. Thousands of young Atlantic salmon&nbs...

  6. USGS Scientists Prepare to Release Salmon into Beaverdam Brook

    USGS scientist Ross Abbett transfers young Atlantic salmon from their transportation tank on the back of a truck to small buckets for release into Beaverdam Brook in Altmar, N.Y. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this diminishe...

  7. 7,000 Atlantic Salmon Transported in Tank

    About 7,000 young Atlantic salmon are transported in a large tank from the USGS Tunison Laboratory in Cortland, N.Y., to Beaverdam Brook in Altmar for release. Thousands of young Atlantic salmon are being released into Salmon River in an effort to restore this diminished Lake Ontario fish...

  8. Anisakis simplex (s.s.) larvae in wild Alaska salmon: no indication of post-mortem migration from viscera into flesh.

    PubMed

    Karl, Horst; Baumann, Florian; Ostermeyer, Ute; Kuhn, Thomas; Klimpel, Sven

    2011-05-01

    The prevalence, mean intensity and distribution of Anisakis nematode third-stage larvae (L3) in the muscle and viscera of wild-caught chum salmon Oncorhynchus keta, pink salmon O. gorbuscha and sockeye salmon O. nerka were compared immediately after catch. Salmon were collected during the fishing season in July 2007 in Bristol Bay and Prince William Sound close to Cordova, Alaska (USA). All fish were infected, and more than 90% of the nematode larvae were found in the edible muscle meat. The isolated anisakid L3 were genetically identified as A. simplex (s.s.). The distribution of nematodes in the muscle meat of fresh-caught salmon was examined in 49 O. keta, 50 O. nerka and 12 O. gorbuscha from Cordova. Most of the larvae were detected in the muscle parts around the body cavity, but nematodes were also found in the tail meat and epaxial muscle (loins). The mean intensity of Anisakis larvae in the edible part was 21 individuals for O. gorbuscha, 62 individuals for O. keta and 63 individuals for O. nerka. No difference in the intensity of Anisakis larvae in the hypaxial muscle was found between fresh-caught and immediately gutted salmon and individuals stored ungutted for 24 h either on ice or in refrigerated sea water. PMID:21790067

  9. Kiss2 as a Regulator of Lh and Fsh Secretion via Paracrine/Autocrine Signaling in the Teleost Fish European Sea Bass (Dicentrarchus labrax).

    PubMed

    Espigares, Felipe; Zanuy, Silvia; Gómez, Ana

    2015-11-01

    Kisspeptins are key players in the neuroendocrine control of puberty and other reproductive processes in mammals. Several studies have demonstrated that the KISS/GPR54 system is expressed by gonadotrophs, but in vitro studies assessing the direct stimulatory effects of kisspeptin on gonadotropin secretion in the pituitary have provided conflicting results. In this study, we investigated whether kisspeptin directly influences the reproductive function of sea bass pituitary. First, the highly active peptides Kiss1-15 and Kiss2-12 were used to stimulate dispersed sea bass pituitary cells obtained from mature males. Our results show that, first, Kiss2-12 induced luteinizing hormone (Lh) and follicle-stimulating hormone (Fsh) release, whereas Kiss1-15 had no effect on gonadotropin secretion at full spermiation stage. Second, the distribution and nature of Kiss2 and its potential interactions with the gonadotropin-releasing hormone 1 (Gnrh1) system in the pituitary were analyzed using dual fluorescence immunohistochemistry. Kiss2 cells were found in the proximal pars distalis and colocalized with gonadotropin-immunoreactive cells. In summary, our results provide, for the first time in a teleost species, functional and neuroanatomical evidence that Kiss2 may act through different routes to directly modulate the activity of gonadotrophs, either as a hypophysiotropic neuropeptide or as an autocrine/paracrine factor. PMID:26400402

  10. On the effect of the sampling frequency of sea level measurements on return period estimate of extremes—Southern European examples

    NASA Astrophysics Data System (ADS)

    Tsimplis, M. N.; Marcos, M.; Pérez, B.; Challenor, P.; Garcia-Fernandez, M. J.; Raicich, F.

    2009-10-01

    Estimates of extreme sea levels and return periods have been based mainly on hourly sampling rates. Technological development has enabled the sampling rates to increase and sampling rates of 5-10 min are becoming increasingly common. In this paper we explore the relationship between extreme sea levels and estimated return periods based on hourly and shorter sampling periods in three tide-gauges one at the Atlantic coasts of Spain (Coruña), one in the western Mediterranean (Malaga) and one in the N. Adriatic (Trieste). Significant differences of several centimetres are found in the hourly and 5 min extremes. These reflect in significant underestimation of the 50-year return levels which in Trieste reach 38 cm. A theoretical relationship between the high and the low sampling rate of extremes is also tested. Thus updated 50-year return levels for the Mediterranean and the coasts of the Iberian peninsula are produced assuming that the differences identified in the various stations generalise to other tide-gauge (hourly) records for which hourly values have been analysed earlier.

  11. Mixture toxicity effects of sea louse control agents in Daphnia magna.

    PubMed

    Rose, Stephanie; Altenburger, Rolf; Sturm, Armin

    2016-02-01

    Caligid sea lice are ectoparasites causing major disease problems in industrial salmon farming. Sea louse control currently relies widely on parasiticides. Among non-target species, crustaceans are particularly susceptible to salmon delousing agents. Drug combinations have recently been suggested for sea louse control; however, no information is available on the non-target effects of such mixtures. To obtain first insights into combination effects of salmon parasiticides, acute toxicity tests with the crustacean model species Daphnia magna were conducted. Four compounds, including two organophosphates and two pyrethroids, were tested individually and in all pair-wise combinations at one fixed concentration ratio. For most combinations, observed toxicities were close to predictions assuming concentration additivity. However, deltamethrin and cypermethrin showed greater than predicted combination effects, while the inverse was observed for deltamethrin and malathion. The results demonstrate combination effects of anti-sea louse agents and suggest that predictions based on concentration additivity are in most cases protective. PMID:26401637

  12. Salmon blood plasma: effective inhibitor of protease-laden Pacific whiting surimi and salmon mince.

    PubMed

    Fowler, Matthew R; Park, Jae W

    2015-06-01

    The effect of salmon plasma (SP) from Chinook salmon on proteolytic inhibition was investigated. SP was found to inhibit both cysteine and serine proteases as well as protease extracted from Pacific whiting muscle. SP was found to contain a 55kDa cysteine protease inhibitor through SDS-PAGE inhibitor staining. Freeze dried salmon plasma (FSP) and salmon plasma concentrated by ultrafiltration (CSP) were tested for their ability to inhibit autolysis in Pacific whiting surimi and salmon mince at concentrations of 0.25%, 0.5%, 1%, and 2%. Pacific whiting surimi autolysis was inhibited by an average of 89% regardless of concentration while inhibition of salmon mince autolysis increased with concentration (p<0.05). CSP performed slightly better than FSP at inhibiting salmon mince autolysis (p<0.05). Serine protease inhibition decreased when SP heated above 40°C but was stable across a broad NaCl and pH range. Cysteine protease inhibitors exhibited good temperature, NaCl, and pH stability. PMID:25624255

  13. Effect of Intestinal Tapeworm Clestobothrium crassiceps on Concentrations of Toxic Elements and Selenium in European Hake Merluccius merluccius from the Gulf of Lion (Northwestern Mediterranean Sea).

    PubMed

    Torres, Jordi; Eira, Catarina; Miquel, Jordi; Ferrer-Maza, Dolors; Delgado, Eulàlia; Casadevall, Margarida

    2015-10-28

    The capacity for heavy metal bioaccumulation by some fish parasites has been demonstrated, and their contribution to decreasing metal concentrations in tissues of parasitized fish has been hypothesized. The present study evaluated the effect of the cestode Clestobothrium crassiceps on the accumulation of trace elements in 30 European hake, Merluccius merluccius, in Spain (half of them infested by C. crassiceps). Tissue samples from all M. merluccius and specimens of C. crassiceps from the infected hakes were collected and stored until element analysis by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic, mercury, and selenium were generally present in lower levels in the cestode than in all hake tissues. The mean value of the muscular Se:Hg molar ratio in the infested subsample was higher than that in hakes without cestodes. Values indicate that the edible part of infested hakes presents a lower amount of Cd and Pb in relation to noninfested hakes. PMID:26434500

  14. Spatial variability of the structure of the Harpacticoida (Copepoda) crustacean assemblages in intertidal and shallow-water zones of European seas

    NASA Astrophysics Data System (ADS)

    Chertoprud, E. S.; Chertoprud, M. V.; Garlitskaya, L. A.; Azovsky, A. I.; Kondar', D. V.

    2007-02-01

    On the basis of original and published data for 26 sites off Europe (the Barents, White, Black, Caspian, North, Baltic, Mediterranean, and Adriatic seas and the Atlantic Ocean) we assessed the variability of the near-shore benthic harpacticoid assemblages. A set of six life forms is recognized that retains its composition regardless of the geographical location and species composition of the assemblage. It is shown that the geographical variability of harpacticoid assemblages is low and intraregional and biotopical variations in the structure of these assemblages are often greater than their interregional (geographical) variability. It seems that the main factors that control the composition of species and life forms of harpacticoids are the characteristics of the sediments and the hydrodynamical processes that determine the structure of the sediments and the salinity.

  15. Isolation and characterization of Ff1 and Gsdf family genes in European sea bass and identification of early gonadal markers of precocious puberty in males.

    PubMed

    Crespo, Berta; Gómez, Ana; Mazón, María José; Carrillo, Manuel; Zanuy, Silvia

    2013-09-15

    Puberty represents the transition from an immature to a mature reproductive stage. The mechanisms underlying the onset of normal or precocious puberty have not yet been elucidated. With the goal of gaining an understanding of early events that occur in the testes of precocious animals during this process, a hemigonadectomy was performed on male juvenile sea bass and expression levels of candidate mRNAs were determined through quantitative real-time RT-PCR. For this purpose, the gonadal soma-derived factors gsdf1 and gsdf2, the nuclear receptor 5 subfamily members nr5a1a (ff1b), nr5a1b (ff1d), nr5a2 (ff1a) and nr5a5 (ff1c) and the proliferating cell nuclear antigen or pcna, genes with a putative role in the beginning of spermatogenesis, were isolated and cloned. Hemigonadectomy proved to be a suitable strategy for the study of gonadal stages prior to the appearance of histological differences between precocious and non-precocious fish, as it allowed the subsequent classification of these gonads. The upregulation of the gene encoding the steroidogenic acute regulatory protein (Star) in precocious testes indicates that sex steroids could play a role in the onset of spermatogenesis in sea bass. In contrast, the downregulation observed in ff1b expression indicates that this initial surge in star expression is not the result of Ff1b transactivation, suggesting an alternative pathway for this transcriptional activation. Finally, a decrease in gsdf1 expression in precocious animals suggests that this gene may play a role in the onset of puberty, while its correlation with ff1b expression points to gsdf1 as a putative target for Ff1b-mediated transactivation. PMID:23791759

  16. Teratological hermaphroditism in the chum salmon Oncorhynchus keta (Walbaum)

    USGS Publications Warehouse

    Uzmann, J.R.; Hesselholt, M.N.

    1957-01-01

    The anomalous condition of hermaphroditism appears to be no less rare in fish than in other normally dioecious animals. Previous records of bisexuality' in the Pacific salmons, Oncorhynchus spp., are few in number despite the intensive study accorded this group. Rutter (1902) reported the condition in two king salmon (O. tshawytscha); Crawford (1927) reported the condition in a silver salmon (O. kisutch); and Gibbs (1956) described a bisexual steelhead trout (Salmo gairdneri) and briefly noted another instance of hermaphroditism in the king salmon. We wish to record an example of this anomaly in the chum salmon (O. keta).

  17. Sea Grant Extension Crucial Link to Coastal Resources.

    ERIC Educational Resources Information Center

    Stumbos, John

    1997-01-01

    University of California Sea Grant Extension Program provides training and technical assistance to fishers, farmers, planners, and conservationists on projects such as coastal ecosystem health, marine environmental protection, fisheries management, aquaculture, salmon habitat restoration, and controlling nonpoint-source pollution; supports

  18. Sea Grant Extension Crucial Link to Coastal Resources.

    ERIC Educational Resources Information Center

    Stumbos, John

    1997-01-01

    University of California Sea Grant Extension Program provides training and technical assistance to fishers, farmers, planners, and conservationists on projects such as coastal ecosystem health, marine environmental protection, fisheries management, aquaculture, salmon habitat restoration, and controlling nonpoint-source pollution; supports…

  19. An injectable acoustic transmitter for juvenile salmon

    SciTech Connect

    Deng, Zhiqun; Carlson, Thomas J.; Li, Huidong; Xiao, Jie; Myjak, Mitchell J.; Lu, Jun; Martinez, Jayson J.; Woodley, Christa M.; Weiland, Mark A.; Eppard, Matthew B.

    2015-01-29

    Salmon recovery, and the potential detrimental effects of dams on fish, has been attracting national attention in due to great environmental and economic implications. Acoustic Telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter offers improved performance and 30% weight reduction. Because the new transmitter costs significantly less to use, substantially reduces adverse effects of implantation, and provides additional biological benefits for tagged fish, it will become the enabling technology for studying migration behavior and survival of species and sizes of fish that have never been studied before. This will lead to critical information for salmon recovery and the development of fish-friendly hydroelectric systems.

  20. An injectable acoustic transmitter for juvenile salmon

    PubMed Central

    Deng, Z. D.; Carlson, T. J.; Li, H.; Xiao, J.; Myjak, M. J.; Lu, J.; Martinez, J. J.; Woodley, C. M.; Weiland, M. A.; Eppard, M. B.

    2015-01-01

    Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems. PMID:25630763

  1. An injectable acoustic transmitter for juvenile salmon.

    PubMed

    Deng, Z D; Carlson, T J; Li, H; Xiao, J; Myjak, M J; Lu, J; Martinez, J J; Woodley, C M; Weiland, M A; Eppard, M B

    2015-01-01

    Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems. PMID:25630763

  2. An injectable acoustic transmitter for juvenile salmon

    NASA Astrophysics Data System (ADS)

    Deng, Z. D.; Carlson, T. J.; Li, H.; Xiao, J.; Myjak, M. J.; Lu, J.; Martinez, J. J.; Woodley, C. M.; Weiland, M. A.; Eppard, M. B.

    2015-01-01

    Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems.

  3. An injectable acoustic transmitter for juvenile salmon

    DOE PAGESBeta

    Deng, Zhiqun; Carlson, Thomas J.; Li, Huidong; Xiao, Jie; Myjak, Mitchell J.; Lu, Jun; Martinez, Jayson J.; Woodley, Christa M.; Weiland, Mark A.; Eppard, Matthew B.

    2015-01-29

    Salmon recovery, and the potential detrimental effects of dams on fish, has been attracting national attention in due to great environmental and economic implications. Acoustic Telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter offers improved performance and 30% weight reduction. Because the new transmitter costs significantly less to use, substantially reduces adverse effects of implantation,more » and provides additional biological benefits for tagged fish, it will become the enabling technology for studying migration behavior and survival of species and sizes of fish that have never been studied before. This will lead to critical information for salmon recovery and the development of fish-friendly hydroelectric systems.« less

  4. Molecular faunistics of accidental infections of Gyrodactylus Nordmann, 1832 (Monogenea) parasitic on salmon Salmo salar L. and brown trout Salmo trutta L. in NW Russia.

    PubMed

    Zietara, Marek S; Kuusela, Jussi; Veselov, Alexei; Lumme, Jaakko

    2008-02-01

    Salmon Salmo salar L. and brown trout S. trutta L. juveniles were examined for the presence of accidental monogenean ectoparasitic species of Gyrodactylus Nordmann, 1832 in the Baltic and White Sea basins of Russian Karelia in order to estimate the frequency of host-switching attempts on an ecological timescale. To collect phylogeographical information and for exact species identification, the parasites were characterised by nuclear internal transcribed spacer sequences of rDNA (ITS) and, for some species, also by their mitochondrial DNA (CO1 gene) sequences. Four accidental Gyrodactylus species were observed on salmon and brown trout. A few specimens of G. aphyae Malmberg, 1957, the normal host of which is the Eurasian minnow Phoxinus phoxinus (L.), were observed on lake salmon from the Rivers Kurzhma (Lake Kuito, White Sea basin) and Vidlitsa (Lake Ladoga, Baltic basin). G. lucii Kulakovskaya, 1952, a parasite of the northern pike Esox lucius L., was observed on salmon in the Kurzhma. In the River Vidlitsa, two specimens of G. papernai Ergens & Bychowsky, 1967, normally on stone loach Barbatula barbatula (L.), were found on salmon. On anadromous White Sea salmon in the River Pulonga in Chupa Bay, a few salmon parr carried small colonies of G. arcuatus Bychowsky, 1933, which were shown to have originated from the local three-spined stickleback Gasterosteus aculeatus L. consumed as prey. No specimens of Gyrodactylus salaris Malmberg, 1957 were observed, although the Pulonga is the nearest salmon spawning river to the River Keret', which is heavily infected with introduced G. salaris. In the River Satulinoja, Lake Ladoga, three specimens of G. lotae Gusev, 1953, from burbot Lota lota (L.), were collected from a single brown trout S. trutta. All nonspecific gyrodactylid infections on salmonids were judged to be temporary, because only a few specimens were observed on each of the small number of infected fishes. The prevalence of endemic G. salaris was also low, only 1% (Nfish = 296) in Lake Onega and 0.7% (Nfish = 255) in Lake Ladoga, while brown trout specific Gyrodactylus species were not observed on any of the 429 trout examined from the Ladoga basin. The host-specific and unspecific burden of Gyrodactylus spp. on these 'glacial relict' populations of salmon and brown trout was very low, suggesting a generalised resistance against the co-evolved freshwater parasite community, or some kind of 'vaccination' effect. These hypotheses deserve further testing. PMID:18038199

  5. Abundance, stock origin, and length of marked and unmarked juvenile Chinook salmon in the surface waters of greater Puget Sound

    USGS Publications Warehouse

    Rice, C.A.; Greene, C.M.; Moran, P.; Teel, D.J.; Kuligowski, D.R.; Reisenbichler, R.R.; Beamer, E.M.; Karr, J.R.; Fresh, K.L.

    2011-01-01

    This study focuses on the use by juvenile Chinook salmon Oncorhynchus tshawytscha of the rarely studied neritic environment (surface waters overlaying the sublittoral zone) in greater Puget Sound. Juvenile Chinook salmon inhabit the sound from their late estuarine residence and early marine transition to their first year at sea. We measured the density, origin, and size of marked (known hatchery) and unmarked (majority naturally spawned) juveniles by means of monthly surface trawls at six river mouth estuaries in Puget Sound and the areas in between. Juvenile Chinook salmon were present in all months sampled (April-November). Unmarked fish in the northern portion of the study area showed broader seasonal distributions of density than did either marked fish in all areas or unmarked fish in the central and southern portions of the sound. Despite these temporal differences, the densities of marked fish appeared to drive most of the total density estimates across space and time. Genetic analysis and coded wire tag data provided us with documented individuals from at least 16 source populations and indicated that movement patterns and apparent residence time were, in part, a function of natal location and time passed since the release of these fish from hatcheries. Unmarked fish tended to be smaller than marked fish and had broader length frequency distributions. The lengths of unmarked fish were negatively related to the density of both marked and unmarked Chinook salmon, but those of marked fish were not. These results indicate more extensive use of estuarine environments by wild than by hatchery juvenile Chinook salmon as well as differential use (e.g., rearing and migration) of various geographic regions of greater Puget Sound by juvenile Chinook salmon in general. In addition, the results for hatchery-generated timing, density, and length differences have implications for the biological interactions between hatchery and wild fish throughout Puget Sound. ?? American Fisheries Society 2011.

  6. Neutrino sea scope takes shape

    NASA Astrophysics Data System (ADS)

    Cartlidge, Edwin

    2016-03-01

    A consortium of European physicists building a vast neutrino detector on the floor of the Mediterranean Sea has unveiled the science it will carry out. The Cubic Kilometre Neutrino Telescope (KM3NeT) will use strings of radiation detectors arranged in a 3D network to measure the light emitted when neutrinos very occasionally interact with the surrounding sea water.

  7. Time-Delayed Subsidies: Interspecies Population Effects in Salmon

    PubMed Central

    Nelson, Michelle C.; Reynolds, John D.

    2014-01-01

    Cross-boundary nutrient inputs can enhance and sustain populations of organisms in nutrient-poor recipient ecosystems. For example, Pacific salmon (Oncorhynchus spp.) can deliver large amounts of marine-derived nutrients to freshwater ecosystems through their eggs, excretion, or carcasses. This has led to the question of whether nutrients from one generation of salmon can benefit juvenile salmon from subsequent generations. In a study of 12 streams on the central coast of British Columbia, we found that the abundance of juvenile coho salmon was most closely correlated with the abundance of adult pink salmon from previous years. There was a secondary role for adult chum salmon and watershed size, followed by other physical characteristics of streams. Most of the coho sampled emerged in the spring, and had little to no direct contact with spawning salmon nutrients at the time of sampling in the summer and fall. A combination of techniques suggest that subsidies from spawning salmon can have a strong, positive, time-delayed influence on the productivity of salmon-bearing streams through indirect effects from previous spawning events. This is the first study on the impacts of nutrients from naturally-occurring spawning salmon on juvenile population abundance of other salmon species. PMID:24911974

  8. Evaluation of a chinook salmon (Oncorhynchus tshawytscha) bioenergetics model

    USGS Publications Warehouse

    Madenjian, Charles P.; O'Connor, Daniel V.; Chernyak, Sergei M.; Rediske, Richard R.; O'Keefe, James P.

    2004-01-01

    We evaluated the Wisconsin bioenergetics model for chinook salmon (Oncorhynchus tshawytscha) in both the laboratory and the field. Chinook salmon in laboratory tanks were fed alewife (Alosa pseudoharengus), the predominant food of chinook salmon in Lake Michigan. Food consumption and growth by chinook salmon during the experiment were measured. To estimate the efficiency with which chinook salmon retain polychlorinated biphenyls (PCBs) from their food in the laboratory, PCB concentrations of the alewife and of the chinook salmon at both the beginning and end of the experiment were determined. Based on our laboratory evaluation, the bioenergetics model was furnishing unbiased estimates of food consumption by chinook salmon. Additionally, from the laboratory experiment, we calculated that chinook salmon retained 75% of the PCBs contained within their food. In an earlier study, assimilation rate of PCBs to chinook salmon from their food in Lake Michigan was estimated at 53%, thereby suggesting that the model was substantially overestimating food consumption by chinook salmon in Lake Michigan. However, we concluded that field performance of the model could not be accurately assessed because PCB assimilation efficiency is dependent on feeding rate, and feeding rate of chinook salmon was likely much lower in our laboratory tanks than in Lake Michigan.

  9. CAN WE SUSTAIN WILD SALMON THROUGH 2100? THE SALMON 2100 PROJECT

    EPA Science Inventory

    abstract for presentation Many experts have concluded that wild salmon recovery efforts in western North America (especially California, Oregon, Washington, Idaho, and southern British Columbia), as earnest, expensive, and socially disruptive as they currently are, do not appe...

  10. Life history reconstruction of modern and fossil sockeye salmon ( Oncorhynchus nerka) by oxygen isotopic analysis of otoliths, vertebrae, and teeth: Implication for paleoenvironmental reconstructions

    NASA Astrophysics Data System (ADS)

    Zazzo, A.; Smith, G. R.; Patterson, W. P.; Dufour, E.

    2006-09-01

    We evaluate the use of oxygen isotope values of biogenic apatite for tracking freshwater to marine migration in modern and fossil Pacific sockeye salmon. Oxygen isotope analyses of otoliths, vertebrae, and teeth of three anadromous modern sockeye salmon from Alaska establish a basis for the interpretation of fossil vertebrae and tooth apatite from Pleistocene sockeye salmon of the Skokomish River Valley, Washington. High resolution δ18O profiles in salmon otoliths provide, at a monthly resolution, a detailed record of individual history including continental rearing, migration to sea, seasonal variation in sea surface temperatures during marine life, and spawning migration before capture. Pacific salmon teeth are constantly renewed with the last set of teeth forming under the influence of freshwater. Therefore, they do not allow inference concerning sea-run versus landlocked life history in fossil salmon. Salmon vertebrae are also ambiguous indicators of life history regarding fresh versus marine water because centra are minimally ossified in the freshwater stages of life and the outermost layer of vertebral bone might be resorbed to provide nutrients during the non-feeding phase of the spawning migration. Therefore, δ18O values of accretionary growth rings in sea-run salmon vertebrae are dominated by the marine signal only if they are not diagenetically altered in freshwater deposits. In Pleistocene sockeye reported here, neither the teeth nor vertebral apatite present clear marine δ18O values due to the combined effects of tooth replacement and diagenetic alteration of bone and dentine. δ18O(PO 4) values of fossil vertebrae are intermediate between δ18O(PO 4) values of enamel and basal tooth dentin. Assuming a similar rate of isotope exchange of vertebrae and dentine with freshwater during diagenesis, these results are interpreted to reflect formation of the teeth under the influence of freshwater, and formation of the vertebrae under the influence of oceanic water. Our approach demonstrates that when appropriate knowledge of tissue formation is available, isotopic differences between altered and unaltered tissue holds promise of distinguishing between marine and freshwater origin of the tissues.

  11. The hydrological context determines the beta-diversity of aerobic anoxygenic phototrophic bacteria in European Arctic seas but does not favor endemism

    PubMed Central

    Lehours, Anne-Catherine; Jeanthon, Christian

    2015-01-01

    Despite an increasing number of studies over the last 15 years, aerobic anoxygenic photoheterotrophic (AAP) bacteria remain a puzzling functional group in terms of physiology, metabolism, and ecology. To contribute to a better knowledge of their environmental distribution, the present study aims at analyzing their diversity and structure at the boundary between the Norwegian, Greenland, and Barents Seas. The polymorphism of a marker gene encoding a sub-unit of the photosynthetic apparatus (pufM gene) was analyzed and attempted to be related to environmental parameters. The Atlantic or Arctic origin of water masses had a strong impact on the AAP bacterial community structure whose populations mostly belonged to the Alpha- and Gammaproteobacteria. A majority (>60%) of pufM sequences were affiliated to the Gammaproteobacteria reasserting that this class often represents the major component of the AAP bacterial community in oceanic regions. Two alphaproteobacterial groups dominate locally suggesting that they can constitute key players in this marine system transiently. We found that temperature is a major determinant of alpha diversity of AAP bacteria in this marine biome with specific clades emerging locally according to the partitioning of water masses. Whereas we expected specific AAP bacterial populations in this peculiar and newly explored ecosystem, most pufM sequences were highly related to sequences retrieved elsewhere. This observation highlights that the studied area does not favor AAP bacteria endemism but also opens new questions about the truthfulness of biogeographical patterns and on the extent of AAP bacterial diversity. PMID:26191046

  12. Captive Rearing Initiative for Salmon River Chinook Salmon, 1998-1999 Progress Report.

    SciTech Connect

    Hassemer, Peter F.

    2001-04-01

    During 1999, the Idaho Department of Fish and Game (IDFG) continued developing techniques for the captive rearing of chinook salmon Oncorhynchus tshawytscha. Techniques under development included protocols for rearing juveniles in freshwater and saltwater hatchery environments, and fieldwork to collect brood year 1998 and 1999 juveniles and eggs and to investigate the ability of these fish to spawn naturally. Fish collected as juveniles were held for a short time at the Sawtooth Fish Hatchery and later transferred to the Eagle Fish Hatchery for rearing. Eyed-eggs were transferred immediately to the Eagle Fish Hatchery where they were disinfected and reared by family groups. When fish from either collection method reached approximately 60 mm, they were PIT tagged and reared separately by brood year and source stream. Sixteen different groups were in culture at IDFG facilities in 1999. Hatchery spawning activities of captive-reared chinook salmon produced eyed-eggs for outplanting in streamside incubation chambers in the West Fork Yankee Fork Salmon River (N=2,297) and the East Fork Salmon River (N=1,038). Additionally, a number of these eggs were maintained at the Eagle Fish Hatchery to ensure adequate brood year 1999 representation from these systems, and produced 279 and 87 juveniles from the West Fork Yankee Fork and East Fork Salmon River, respectively. Eyed-eggs were not collected from the West Fork Yankee Fork due to low adult escapement. Brood year 1998 juveniles were collected from the Lemhi River (N=191), West Fork Yankee Fork Salmon River (N=229), and East Fork Salmon River (N=185). Additionally, brood year 1999 eyed-eggs were collected from the Lemhi River (N=264) and East Fork Salmon River (N=143). Sixty-two and seven maturing adults were released into Bear Valley Creek (Lemhi River system) and the East Fork Salmon River, respectively, for spawning evaluation in 1999. Nine female carcasses from Bear Valley Creek were examined for egg retention, and of these five were spawned out, one was partially spawned, and three died before depositing eggs. However, much of the spawning related behavior observed involved female chinook salmon paired with male bull trout Salvelinus confluentus. Two female carcasses from the East Fork Salmon River were recovered and examined for egg retention. One of these had spawned and one had not.

  13. Captive Rearing Initiative for Salmon River Chinook Salmon, 1999 Progress Report.

    SciTech Connect

    Hassemer, Peter F.

    2001-04-01

    During 1999, the Idaho Department of Fish and Game (IDFG) continued developing techniques for the captive rearing of chinook salmon Oncorhynchus tshawytscha. Techniques under development included protocols for rearing juveniles in freshwater and saltwater hatchery environments, and fieldwork to collect brood year 1998 and 1999 juveniles and eggs and to investigate the ability of these fish to spawn naturally. Fish collected as juveniles were held for a short time at the Sawtooth Fish Hatchery and later transferred to the Eagle Fish Hatchery for rearing. Eyed-eggs were transferred immediately to the Eagle Fish Hatchery where they were disinfected and reared by family groups. When fish from either collection method reached approximately 60 mm, they were PIT tagged and reared separately by brood year and source stream. Sixteen different groups were in culture at IDFG facilities in 1999. Hatchery spawning activities of captive-reared chinook salmon produced eyed-eggs for outplanting in streamside incubation chambers in the West Fork Yankee Fork Salmon River (N=2,297) and the East Fork Salmon River (N=1,038). Additionally, a number of these eggs were maintained at the Eagle Fish Hatchery to ensure adequate brood year 1999 representation from these systems, and produced 279 and 87 juveniles from the West Fork Yankee Fork and East Fork Salmon River, respectively. Eyed-eggs were not collected from the West Fork Yankee Fork due to low adult escapement. Brood year 1998 juveniles were collected from the Lemhi River (N=191), West Fork Yankee Fork Salmon River (N=229), and East Fork Salmon River (N=185). Additionally, brood year 1999 eyed-eggs were collected from the Lemhi River (N=264) and East Fork Salmon River (N=143). Sixty-two and seven maturing adults were released into Bear Valley Creek (Lemhi River system) and the East Fork Salmon River, respectively, for spawning evaluation in 1999. Nine female carcasses from Bear Valley Creek were examined for egg retention, and of these five were spawned out, one was partially spawned, and three died before depositing eggs. However, much of the spawning related behavior observed involved female chinook salmon paired with male bull trout Salvelinus confluentus. Two female carcasses from the East Fork Salmon River were recovered and examined for egg retention. One of these had spawned and one had not.

  14. Dietary calcein marking of brook trout, Atlantic salmon, yellow perch, and coho salmon scales

    USGS Publications Warehouse

    Honeyfield, D.C.; Ostrowski, C.S.; Fletcher, J.W.; Mohler, J.W.

    2006-01-01

    Brook trout Salvelinus fontinalis, Atlantic salmon Salmo salar, coho salmon Oncorhynchus kisutch, and yellow perch Perca flavescens fed calcein for 5 d showed characteristic calcein scale marks 7-10 d postmarking. In fish fed 0.75 or 1.25 g of calcein per kilogram of feed, the percentage of fish that exhibited a calcein mark was 100% in brook trout, 93-98% in Atlantic salmon, 60% in yellow perch, and 0% in coho salmon. However, when coho salmon were fed 5.25 g calcein/kg feed, 100% marking was observed 7-10 d postmarking. Brook trout were successfully marked twice with distinct bands when fed calcein 5 months apart. Brook trout scale pixel luminosity increased as dietary calcein increased in experiment 2. For the second calcein mark, scale pixel luminosity from brook trout fed 1.25 g calcein/kg feed was numerically higher (P < 0.08) than scales from fish fed 0.75 g calcein/kg feed. Mean pixel luminosity of calcein-marked Atlantic salmon scales was 57.7 for fish fed 0.75 g calcein/kg feed and 55.2 for fish fed 1.25 g calcein/kg feed. Although feed acceptance presented a problem in yellow perch, these experiments provide evidence that dietary calcein is a viable tool for marking fish for stock identification. ?? Copyright by the American Fisheries Society 2006.

  15. Phylogenetic analysis and serotyping of Vibrio splendidus-related bacteria isolated from salmon farm cleaner fish.

    PubMed

    Gulla, Snorre; Sørum, Henning; Vågnes, Øyvind; Colquhoun, Duncan J

    2015-12-01

    Cleaner fish, i.e. various wrasse (Labridae) species and lumpsucker Cyclopterus lumpus, are to an increasing extent used for biocontrol of the salmon louse Lepeophtheirus salmonis in European salmon farming. Although efficient de-licers, cleaner fish mortality levels in salmon farms are often high. Bacterial infections are common, and Vibrio splendidus-related strains are frequently identified during diagnostic investigations. The population structure of 112 V. splendidus-related isolates, derived primarily from wrasse species, was investigated by means of multilocus sequence analysis using 5 housekeeping genes (rpoD, ftsZ, pyrH, rpoA and atpA). Most isolates were found to be closely related to the V. splendidus type strain, yet displayed extensive genetic microdiversity. Slide agglutination testing using polyclonal rabbit antisera further indicated O-antigen variability. Intra-outbreak genetic and antigenic diversity suggests direct infection from seawater, rather than fish-to-fish transmission, as the main route of infection. The variable nature of isolates involved complicates qualified selection of representative candidate strains, e.g. for infection and vaccine trials. PMID:26648104

  16. Gut morphology and hepatic oxidative status of European sea bass (Dicentrarchus labrax) juveniles fed plant feedstuffs or fishmeal-based diets supplemented with short-chain fructo-oligosaccharides and xylo-oligosaccharides.

    PubMed

    Guerreiro, Inês; Couto, Ana; Pérez-Jiménez, Amalia; Oliva-Teles, Aires; Enes, Paula

    2015-12-28

    The effects of short-chain fructo-oligosaccharides (scFOS) and xylo-oligosaccharides (XOS) on gut morphology and hepatic oxidative status were studied in European sea bass juveniles weighing 60 g. Fish were fed diets including fishmeal (FM diets) or plant feedstuffs (PF diets; 30 FM:70 PF) as main protein sources (control diets). Four other diets were formulated similar to the control diets but including 1 % scFOS or 1 % XOS. At the end of the trial, fish fed PF-based diets presented histomorphological alterations in the distal intestine, whereas only transient alterations were observed in the pyloric caeca. Comparatively to fish fed FM-based diets, fish fed PF diets had higher liver lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activities, and lower glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase activities. In fish fed the PF diets, prebiotic supplementation decreased SOD activity and XOS supplementation further decreased CAT activity. In fish fed the FM diets, XOS supplementation promoted a reduction of all antioxidant enzyme activities. Overall, dietary XOS and scFOS supplementation had only minor effects on gut morphology or LPO levels. However, dietary XOS reduced antioxidant enzymatic activity in both PF and FM diets, which indicate a positive effect on reduction of hepatic reactive oxygen species production. PMID:26435350

  17. n-TiO2 and CdCl2 co-exposure to titanium dioxide nanoparticles and cadmium: Genomic, DNA and chromosomal damage evaluation in the marine fish European sea bass (Dicentrarchus labrax).

    PubMed

    Nigro, M; Bernardeschi, M; Costagliola, D; Della Torre, C; Frenzilli, G; Guidi, P; Lucchesi, P; Mottola, F; Santonastaso, M; Scarcelli, V; Monaci, F; Corsi, I; Stingo, V; Rocco, L

    2015-11-01

    Due to the large production and growing use of titanium dioxide nanoparticles (n-TiO2), their release in the marine environment and their potential interaction with existing toxic contaminants represent a growing concern for biota. Different end-points of genotoxicity were investigated in the European sea bass Dicentrarchus labrax exposed to n-TiO2 (1mgL(-1)) either alone and combined with CdCl2 (0.1mgL(-1)) for 7 days. DNA primary damage (comet assay), apoptotic cells (diffusion assay), occurrence of micronuclei and nuclear abnormalities (cytome assay) were assessed in peripheral erythrocytes and genomic stability (random amplified polymorphism DNA-PCR, RAPD assay) in muscle tissue. Results showed that genome template stability was reduced after CdCl2 and n-TiO2 exposure. Exposure to n-TiO2 alone was responsible for chromosomal alteration but ineffective in terms of DNA damage; while the opposite was observed in CdCl2 exposed specimens. Co-exposure apparently prevents the chromosomal damage and leads to a partial recovery of the genome template stability. PMID:26448269

  18. Snake River Fall Chinook Salmon Brood-Stock Program, 1984 Annual Report of Research.

    SciTech Connect

    Harrell, Lee W.

    1985-02-01

    The objective is the enhancement of upriver stocks through research and development of an eggbank source. Viable gametes, produced from fish held to maturity in sea pens, will be made available for restoration purposes on the Snake River. Seawater entry trials with 0+-age and 1+-age fish have shown that 0+-age Snake River fall chinook salmon are not amenable to seawater entry and will either die or require up to 6 months to fully adapt to seawater. However, 1+-age smolts experience little problem at seawater entry; it is therefore suggested that Snake River fall chinook salmon be released as 1+ smolting fish in hatchery situations. Important marine mortalities occurring from osmoregulatory dysfunction, Bacterial Kidney Disease, and precocity at various life stages have been documented. Also, a previously unreported marine fungal pathogen has been identified. Mortality from this pathogen occurs from 3-years of age to maturity and can exceed 0.5% per day (resulting in losses to 90+%). At the end of December 1984, Snake River fall chinook salmon from 1980 (n = 67), 1981 (n = 876), 1982 (n = 4809), and 1983 (n = 7100) broods were under production. Because of the extensive mortality due to the marine fungal pathogen, only seven spawners were obtained from the 1980 stock in fall 1984. The 1980-brood spawners produced only minimal eggs and these will be used to investigate possible vertical transmission of the fungal pathogen. 4 figs.

  19. A Novel Betaproteobacterial Agent of Gill Epitheliocystis in Seawater Farmed Atlantic Salmon (Salmo salar)

    PubMed Central

    Toenshoff, Elena R.; Kvellestad, Agnar; Mitchell, Susan O.; Steinum, Terje; Falk, Knut; Colquhoun, Duncan J.; Horn, Matthias

    2012-01-01

    Epitheliocystis, a disease characterised by cytoplasmic bacterial inclusions (cysts) in the gill and less commonly skin epithelial cells, has been reported in many marine and freshwater fish species and may be associated with mortality. Previously, molecular and ultrastructural analyses have exclusively associated members of the Chlamydiae with such inclusions. Here we investigated a population of farmed Atlantic salmon from the west coast of Norway displaying gill epitheliocystis. Although ‘Candidatus Piscichlamydia salmonis’, previously reported to be present in such cysts, was detected by PCR in most of the gill samples analysed, this bacterium was found to be a rare member of the gill microbiota, and not associated with the observed cysts as demonstrated by fluorescence in situ hybridization assays. The application of a broad range 16 S rRNA targeted PCR assay instead identified a novel betaproteobacterium as an abundant member of the gill microbiota. Fluorescence in situ hybridization demonstrated that this bacterium, tentatively classified as ‘Candidatus Branchiomonas cysticola’, was the cyst-forming agent in these samples. While histology and ultrastructure of ‘Ca. B. cysticola’ cysts revealed forms similar to the reticulate and intermediate bodies described in earlier reports from salmon in seawater, no elementary bodies typical of the chlamydial developmental cycle were observed. In conclusion, this study identified a novel agent of epitheliocystis in sea-farmed Atlantic salmon and demonstrated that these cysts can be caused by bacteria phylogenetically distinct from the Chlamydiae. PMID:22427865

  20. Development of Rations for the Enhanced Survival of Salmon, 1983-1984 Progress (Annual) Report.

    SciTech Connect

    Crawford, David L.

    1985-04-01

    Hydroelectric development coupled with numerous other encroachments on the supply and quality of water has reduced the natural habitat for the spawning and rearing of salmon in the Columbia river system. Artificial production in hatcheries has become a critical link in the restoration of natural stocks of salmon. Released hatchery salmon must survive predation, be able to acquire sustainable nutrients under natural conditions, possess the vitality to surmount man-made impediments to seaward migration and adapt to a sea water environment. Survival of hatchery salmonids is dependent upon a number of factors. Time of release, natural food abundance, fish size and the health and/or quality of smolts all play synergistic roles. The nutritional and physical characteristics of ration regimes for hatchery fish plays a major role in determining the effectiveness of hatchery production and the health and/or quality of smolts.Ration regimes containing high quality components in uniform and fine-free pellet forms produce efficient growth response and minimize loss of nutrients maintaining the quality of hatchery water supply. Under such feed regimes, fish are less susceptible to disease and more uniform and desirable fish sizes can be achieved at release time. High quality smolts would help to optimize out-migration survival and successful adaptation to salt water.

  1. A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations.

    PubMed

    Baldwin, David H; Spromberg, Julann A; Collier, Tracy K; Scholz, Nathaniel L

    2009-12-01

    For more than a decade, numerous pesticides have been detected in river systems of the western United States that support anadromous species of Pacific salmon and steelhead. Over the same interval, several declining wild salmon populations have been listed as either threatened or endangered under the U.S. Endangered Species Act (ESA). Because pesticides occur in surface waters that provide critical habitat for ESA-listed stocks, they are an ongoing concern for salmon conservation and recovery throughout California and the Pacific Northwest. Because pesticide exposures are typically sublethal, a key question is whether toxicological effects at (or below) the scale of the individual animal ultimately reduce the productivity and recovery potential of wild populations. In this study we evaluate how the sublethal impacts of pesticides on physiology and behavior can reduce the somatic growth of juvenile chinook salmon (Oncorhynchus tshawytscha) and, by extension, subsequent size-dependent survival when animals migrate to the ocean and overwinter in their first year. Our analyses focused on the organophosphate and carbamate classes of insecticides. These neurotoxic chemicals have been widely detected in aquatic environments. They inhibit acetylcholinesterase, an enzyme in the salmon nervous system that regulates neurotransmitter-mediated signaling at synapses. Based on empirical data, we developed a model that explicitly links sublethal reductions in acetylcholinesterase activity to reductions in feeding behavior, food ration, growth, and size at migration. Individual size was then used to estimate size-dependent survival during migration and transition to the sea. Individual survival estimates were then integrated into a life-history population projection matrix and used to calculate population productivity and growth rate. Our results indicate that short-term (i.e., four-day) exposures that are representative of seasonal pesticide use may be sufficient to reduce the growth and size at ocean entry of juvenile chinook. The consequent reduction in individual survival over successive years reduces the intrinsic productivity (lambda) of a modeled ocean-type chinook population. Overall, we show that exposures to common pesticides may place important constraints on the recovery of ESA-listed salmon species, and that simple models can be used to extrapolate toxicological impacts across several scales of biological complexity. PMID:20014574

  2. Estuarine Ecology of Juvenile Salmon in Western Alaska: a Review

    USGS Publications Warehouse

    Zimmerman, Christian E.; Hillgruber, Nicola

    2009-01-01

    In the late 1990s and early 2000s, large declines in numbers of chum salmon Oncorhynchus keta and Chinook salmon O. tshawytscha returning to the Arctic-YukonKuskokwim (AYK) region (Alaska, USA) illuminated the need for an improved understanding of the variables controlling salmon abundance at all life stages. In addressing questions about salmon abundance, large gaps in our knowledge of basic salmon life history and the critical early marine life stage were revealed. In this paper, results from studies conducted on the estuarine ecology of juvenile salmon in western Alaska are summarized and compared, emphasizing timing and distribution during outmigration, environmental conditions, age and growth, feeding, and energy content of salmon smolts. In western Alaska, water temperature dramatically changes with season, ranging from 0C after ice melt in late spring/early summer to 19C in July. Juvenile salmon were found in AYK estuaries from early May until August or September, but to date no information is available on their residence duration or survival probability. Chum salmon were the most abundant juvenile salmon reported, ranging in percent catch from <0.1% to 4.7% and most research effort has focused on this species. Abundances of Chinook salmon, sockeye salmon O. nerka, and pink salmon O. gorbuscha varied among estuaries, while coho salmon O. kisutch juveniles were consistently rare, never amounting to more than 0.8% of the catch. Dietary composition of juvenile salmon was highly variable and a shift was commonly reported from epibenthic and neustonic prey in lower salinity water to pelagic prey in higher salinity water. Gaps in the knowledge of AYK salmon estuarine ecology are still evident. For example, data on outmigration patterns and residence timing and duration, rearing conditions and their effect on diet, growth, and survival are often completely lacking or available only for few selected years and sites. Filling gaps in knowledge concerning salmon use and survival in estuarine and near-shore habitats within the AYK region will aid in assessing the relative roles of all habitats (freshwater to marine) in controlling salmon abundance.

  3. Eco-evolutionary dynamics in Pacific salmon

    PubMed Central

    Carlson, S M; Quinn, T P; Hendry, A P

    2011-01-01

    Increasing acceptance of the idea that evolution can proceed rapidly has generated considerable interest in understanding the consequences of ongoing evolutionary change for populations, communities and ecosystems. The nascent field of ‘eco-evolutionary dynamics' considers these interactions, including reciprocal feedbacks between evolution and ecology. Empirical support for eco-evolutionary dynamics has emerged from several model systems, and we here present some possibilities for diverse and strong effects in Pacific salmon (Oncorhynchus spp.). We specifically focus on the consequences that natural selection on body size can have for salmon population dynamics, community (bear-salmon) interactions and ecosystem process (fluxes of salmon biomass between habitats). For example, we find that shifts in body size because of selection can alter fluxes across habitats by up to 11% compared with ecological (that is, numerical) effects. More generally, we show that selection within a generation can have large effects on ecological dynamics and so should be included within a complete eco-evolutionary framework. PMID:21224877

  4. Echo characteristics of two salmon species

    NASA Astrophysics Data System (ADS)

    Nealson, Patrick A.; Horne, John K.; Burwen, Debby L.

    2005-04-01

    The Alaska Department of Fish and Game relies on split-beam hydroacoustic techniques to estimate Chinook salmon (Oncorhynchus tshawytscha) returns to the Kenai River. Chinook counts are periodically confounded by large numbers of smaller sockeye salmon (O. nerka). Echo target-strength has been used to distinguish fish length classes, but was too variable to separate Kenai River chinook and sockeye distributions. To evaluate the efficacy of alternate echo metrics, controlled acoustic measurements of tethered chinook and sockeye salmon were collected at 200 kHz. Echo returns were digitally sampled at 48 kHz. A suite of descriptive metrics were collected from a series of 1,000 echoes per fish. Measurements of echo width were least variable at the -3 dB power point. Initial results show echo elongation and ping-to-ping variability in echo envelope width were significantly greater for chinook than for sockeye salmon. Chinook were also observed to return multiple discrete peaks from a single broadcast echo. These characteristics were attributed to the physical width of chinook exceeding half of the broadcast echo pulse width at certain orientations. Echo phase variability, correlation coefficient and fractal dimension distributions did not demonstrate significant discriminatory power between the two species. [Work supported by ADF&G, ONR.

  5. SCIENCE, POLITICS, AND PACIFIC NORTHWEST SALMON RECOVERY

    EPA Science Inventory

    Throughout the Pacific Northwest, since 1850, all wild salmon runs have declined and some have disappeared. Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline. Each year, hundreds of millions of dollars continue to be spent in variou...

  6. SCIENCE, POLICY, AND PACIFIC NORTHWEST SALMON RECOVERY

    EPA Science Inventory

    Throughout the Pacific Northwest, since 1850, all wild salmon runs have declined and some have disappeared. Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline. Each year, hundreds of millions of dollars continue to be spent in variou...

  7. Animal navigation: salmon track magnetic variation.

    PubMed

    Hays, Graeme C

    2013-02-18

    How animals navigate long distances to specific targets remains enigmatic. For Pacific salmon, new evidence suggests fish imprint on the magnetic coordinates of their home river and use this information to guide their return from distant open-ocean feeding areas. PMID:23428320

  8. SALMON AND NATIVE FISH HABITAT RESEARCH

    EPA Science Inventory

    The research described in this project deals with the influence of human activities on aquatic and aquatic-dependent biota at landscape, watershed, and regional scales. Specifically, it will examine watershed and landscape scale habitat issues affecting salmon and native fishes i...

  9. Dams and Salmon: A Northwest Choice

    ERIC Educational Resources Information Center

    Tucker, Michael; Tromley, Cheryl L.

    2005-01-01

    This article describes an experiential exercise in which participants assume the roles of various stakeholder groups in the controversy surrounding possible dam removal to revive northwestern U. S. salmon populations. The role-play (a) increases environmental awareness in the context of the competing interests various stakeholders have in our…

  10. Dams and Salmon: A Northwest Choice

    ERIC Educational Resources Information Center

    Tucker, Michael; Tromley, Cheryl L.

    2005-01-01

    This article describes an experiential exercise in which participants assume the roles of various stakeholder groups in the controversy surrounding possible dam removal to revive northwestern U. S. salmon populations. The role-play (a) increases environmental awareness in the context of the competing interests various stakeholders have in our

  11. SALMON RECOVERY: CATEGORIZING AGENTS, DRIVERS, AND DELUSIONS

    EPA Science Inventory

    Throughout the southern region of western North America, many wild salmon stocks have declined and some have disappeared. The decline was induced by an extensively studied combination of causal agents. The public appears to support reversing the downward trajectory for wild sal...

  12. Eco-evolutionary dynamics in Pacific salmon.

    PubMed

    Carlson, S M; Quinn, T P; Hendry, A P

    2011-03-01

    Increasing acceptance of the idea that evolution can proceed rapidly has generated considerable interest in understanding the consequences of ongoing evolutionary change for populations, communities and ecosystems. The nascent field of 'eco-evolutionary dynamics' considers these interactions, including reciprocal feedbacks between evolution and ecology. Empirical support for eco-evolutionary dynamics has emerged from several model systems, and we here present some possibilities for diverse and strong effects in Pacific salmon (Oncorhynchus spp.). We specifically focus on the consequences that natural selection on body size can have for salmon population dynamics, community (bear-salmon) interactions and ecosystem process (fluxes of salmon biomass between habitats). For example, we find that shifts in body size because of selection can alter fluxes across habitats by up to 11% compared with ecological (that is, numerical) effects. More generally, we show that selection within a generation can have large effects on ecological dynamics and so should be included within a complete eco-evolutionary framework. PMID:21224877

  13. Yukon River King Salmon - Ichthyophonus Pilot Study

    USGS Publications Warehouse

    Kocan, R.M.; Hershberger, P.K.

    2001-01-01

    A method for non-lethal sampling of adult spawning Chinook salmon for Ichthyophonus was developed using known infected fish and live returning spawners. The method consisted of taking punch biopsies of skin and muscle and culturing the biopsy tissue in vitro. A 100% correlation was made between known infected fish and cultured biopsy tissue. 

  14. Trace metals in tissues of the six most common fish species in the Black Sea, Turkey.

    PubMed

    Aydın, Didem; Tokalıoğlu, Şerife

    2015-01-01

    Concentrations of Mn, Fe, Co, Ni, As, Se, Cd, Ag and Pb in scale, skin, muscle, gills, liver and the gonads of Gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), Black Sea salmon (Salmo trutta labrax), Horse mackerel (Trachurus trachurus), Red mullet (Mullus barbatus) and Whiting (Merlangius merlangius euxinus) from the Black Sea, in Turkey, were investigated. Elemental analyses were performed with inductively coupled plasma-mass spectrometry after sample preparation by microwave digestion. Mean metal concentrations in different tissues were in the following ranges: Mn 0.09-23.1, Fe 0.58-326, Co 0.01-0.22, Ni 0.03-1.34, As 0.13-3.40, Se 0.13-4.42, Ag 0.01-0.18, Cd 0.32-6.25, Pb 0.02-0.38 mg kg⁻¹ wet weight. Metal concentrations in the muscles of the examined species were generally lower than those in scale, skin, gills, liver and the gonads. The described method was validated by analysis of Dogfish Liver-certified reference material, DOLT-4. PMID:25082436

  15. The economic benefits of disease triggered early harvest: A case study of pancreas disease in farmed Atlantic salmon from Norway.

    PubMed

    Pettersen, J M; Rich, K M; Jensen, B Bang; Aunsmo, A

    2015-10-01

    Pancreas disease (PD) is an important viral disease in Norwegian, Scottish and Irish aquaculture causing biological losses in terms of reduced growth, mortality, increased feed conversion ratio, and carcass downgrading. We developed a bio-economic model to investigate the economic benefits of a disease triggered early harvesting strategy to control PD losses. In this strategy, the salmon farm adopts a PCR (Polymerase Chain Reaction) diagnostic screening program to monitor the virus levels in stocks. Virus levels are used to forecast a clinical outbreak of pancreas disease, which then initiates a prescheduled harvest of the stock to avoid disease losses. The model is based on data inputs from national statistics, literature, company data, and an expert panel, and use stochastic simulations to account for the variation and/or uncertainty associated with disease effects and selected production expenditures. With the model, we compared the impacts of a salmon farm undergoing prescheduled harvest versus the salmon farm going through a PD outbreak. We also estimated the direct costs of a PD outbreak as the sum of biological losses, treatment costs, prevention costs, and other additional costs, less the costs of insurance pay-outs. Simulation results suggests that the economic benefit from a prescheduled harvest is positive once the average salmon weight at the farm has reached 3.2kg or more for an average Norwegian salmon farm stocked with 1,000,000smolts and using average salmon sales prices for 2013. The direct costs from a PD outbreak occurring nine months (average salmon weight 1.91kg) after sea transfer and using 2013 sales prices was on average estimated at NOK 55.4 million (5%, 50% and 90% percentile: 38.0, 55.8 and 72.4) (NOK=€0.128 in 2013). Sensitivity analyses revealed that the losses from a PD outbreak are sensitive to feed- and salmon sales prices, and that high 2013 sales prices contributed to substantial losses associated with a PD outbreak. PMID:26297077

  16. Juvenile Salmon Usage of the Skeena River Estuary

    PubMed Central

    Carr-Harris, Charmaine; Gottesfeld, Allen S.; Moore, Jonathan W.

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2–8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that use the estuary, then numerous fisheries would also be negatively affected. PMID:25749488

  17. Juvenile salmon usage of the Skeena River estuary.

    PubMed

    Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that use the estuary, then numerous fisheries would also be negatively affected. PMID:25749488

  18. Differential use of salmon by vertebrate consumers: implications for conservation.

    PubMed

    Levi, Taal; Wheat, Rachel E; Allen, Jennifer M; Wilmers, Christopher C

    2015-01-01

    Salmon and other anadromous fish are consumed by vertebrates with distinct life history strategies to capitalize on this ephemeral pulse of resource availability. Depending on the timing of salmon arrival, this resource may be in surplus to the needs of vertebrate consumers if, for instance, their populations are limited by food availability during other times of year. However, the life history of some consumers enables more efficient exploitation of these ephemeral resources. Bears can deposit fat and then hibernate to avoid winter food scarcity, and highly mobile consumers such as eagles, gulls, and other birds can migrate to access asynchronous pulses of salmon availability. We used camera traps on pink, chum, and sockeye salmon spawning grounds with various run times and stream morphologies, and on individual salmon carcasses, to discern potentially different use patterns among consumers. Wildlife use of salmon was highly heterogeneous. Ravens were the only avian consumer that fed heavily on pink salmon in small streams. Eagles and gulls did not feed on early pink salmon runs in streams, and only moderately at early sockeye runs, but were the dominant consumers at late chum salmon runs, particularly on expansive river flats. Brown bears used all salmon resources far more than other terrestrial vertebrates. Notably, black bears were not observed on salmon spawning grounds despite being the most frequently observed vertebrate on roads and trails. From a conservation and management perspective, all salmon species and stream morphologies are used extensively by bears, but salmon spawning late in the year are disproportionately important to eagles and other highly mobile species that are seasonally limited by winter food availability. PMID:26339539

  19. Differential use of salmon by vertebrate consumers: implications for conservation

    PubMed Central

    Wheat, Rachel E.; Allen, Jennifer M.; Wilmers, Christopher C.

    2015-01-01

    Salmon and other anadromous fish are consumed by vertebrates with distinct life history strategies to capitalize on this ephemeral pulse of resource availability. Depending on the timing of salmon arrival, this resource may be in surplus to the needs of vertebrate consumers if, for instance, their populations are limited by food availability during other times of year. However, the life history of some consumers enables more efficient exploitation of these ephemeral resources. Bears can deposit fat and then hibernate to avoid winter food scarcity, and highly mobile consumers such as eagles, gulls, and other birds can migrate to access asynchronous pulses of salmon availability. We used camera traps on pink, chum, and sockeye salmon spawning grounds with various run times and stream morphologies, and on individual salmon carcasses, to discern potentially different use patterns among consumers. Wildlife use of salmon was highly heterogeneous. Ravens were the only avian consumer that fed heavily on pink salmon in small streams. Eagles and gulls did not feed on early pink salmon runs in streams, and only moderately at early sockeye runs, but were the dominant consumers at late chum salmon runs, particularly on expansive river flats. Brown bears used all salmon resources far more than other terrestrial vertebrates. Notably, black bears were not observed on salmon spawning grounds despite being the most frequently observed vertebrate on roads and trails. From a conservation and management perspective, all salmon species and stream morphologies are used extensively by bears, but salmon spawning late in the year are disproportionately important to eagles and other highly mobile species that are seasonally limited by winter food availability. PMID:26339539

  20. Genome wide response to dietary tetradecylthioacetic acid supplementation in the heart of Atlantic Salmon (Salmo salar L)

    PubMed Central

    2012-01-01

    Background Under-dimensioned hearts causing functional problems are associated with higher mortality rates in intensive Atlantic salmon aquaculture. Previous studies have indicated that tetradecylthioacetic acid (TTA) induces cardiac growth and also stimulates transcription of peroxisome proliferator activated receptors (PPAR) αand βin the Atlantic salmon heart. Since cardiac and transcriptional responses to feed are of high interest in aquaculture, the objective of this study was to characterize the transcriptional mechanisms induced by TTA in the heart of Atlantic salmon. Results Atlantic salmon were kept at sea for 17 weeks. During the first 8 weeks the fish received a TTA supplemented diet. Using microarrays, profound transcriptional effects were observed in the heart at the end of the experiment, 9 weeks after the feeding of TTA stopped. Approximately 90% of the significant genes were expressed higher in the TTA group. Hypergeometric testing revealed the over-representation of 35 gene ontology terms in the TTA fed group. The GO terms were generally categorized into cardiac performance, lipid catabolism, glycolysis and TCA cycle. Conclusions Our results indicate that TTA has profound effects on cardiac performance based on results from microarray and qRT-PCR analysis. The gene expression profile favors a scenario of ”physiological”lright hypertrophy recognized by increased oxidative fatty acid metabolism, glycolysis and TCA cycle activity as well as cardiac growth and contractility in the heart ventricle. Increased cardiac efficiency may offer significant benefits in the demanding Aquaculture situations. PMID:22577878

  1. Wild salmon in California, Oregon, Washington, and Idaho: Some recovery strategies that just might work

    EPA Science Inventory

    The primary goal of the Salmon 2100 Project is to identify salmon recovery options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project doe...

  2. Diel behavior of rearing fall Chinook salmon

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Kock, Tobias J.; Skalicky, Joseph J.

    2010-01-01

    In fisheries science, habitat use is often inferred when fish are sampled or observed in a particular location. Physical habitat is typically measured where fish are found, and thus deemed important to habitat use. Although less common, a more informative approach is to measure or observe fish behavior within given habitats to more thoroughly assess their use of those locations. While this approach better reflects how fish use habitat, fish behavior can be difficult to quantify, particularly at night. For example, Tiffan and others (2002, 2006) were able to quantify habitat availability and characteristics that were important for rearing juvenile fall Chinook Salmon (Oncorhynchus tshawytscha) in the Hanford Reach of the Columbia River. The authors, however, could only speculate as to how juvenile salmon use habitat and respond to changes in water level fluctuations. Conversely, in this study we provide data on the diel activities of rearing juvenile wild fall Chinook Salmon which provides a better understanding of how fish “use” these rearing habitats. Diel behavior patterns are important because fish in the Hanford Reach are often stranded on shorelines when the water level rapidly recedes because of hydroelectric power generation at upriver dams (Nugent and others 2002; Anglin and others 2006). We hypothesize that juvenile salmon are at greater risk of stranding at night because they are less active and occupy habitat differently than during the day. We used underwater videography to collect behavioral information during the day and night to determine if juvenile fall Chinook Salmon are more susceptible to stranding when water level fluctuations occur at night.

  3. Linkages between coastal and open-ocean habitats and dynamics of Japanese stocks of chum salmon and Japanese sardine

    NASA Astrophysics Data System (ADS)

    Yatsu, Akihiko; Kaeriyama, Masahide

    2005-03-01

    Coastal-ocean-open-ocean migrations, prey-predator relations and long-term population dynamics of chum salmon ( Oncorhynchus keta) and Japanese sardine ( Sardinops melanostictus), associated with large-scale climate and oceanographic conditions, are reviewed. After early marine life in coastal waters in northern Japan, chum salmon of Japanese origin spend their first summer in the Okhotsk Sea, then move to the Western Subarctic Gyre for the first winter at sea. Thereafter, they migrate between summer feeding grounds in the Bering Sea and wintering grounds in the Alaskan Gyre for a period of usually up to four years, and finally return to their natal rivers to spawn. Carrying capacity ( K) for chum salmon at an unfished equilibrium level was estimated from a Ricker spawner-recruitment curve, and the residual carrying capacity ( RCC=(K-abundance)K-1). was positively correlated with body size at age 4, and negatively correlated with age at maturity. Marine survival of Hokkaido chum populations was affected by body size at release, but neither by Aleutian low pressure activity nor sea-surface temperature (SST) around coastal Hokkaido in spring, although there is some correlation between survival rate and coastal SST. Juveniles of the Pacific stock of Japanese sardine become broadly distributed in the Kuroshio Extension (KE) as far east as 180 longitude during spring. Adults disperse as far as the central Pacific and the southern areas of the Okhotsk Sea and Western Subarctic Gyre in years of high abundance. Somatic growth and age at maturation of sardine are density-dependent. We used catch, biomass and residuals of observed recruitment numbers from a Ricker curve (LNRR) as a measure of sardine population dynamics. LNRR was highly correlated with SST of KE in winter, which shifted in 1970 and 1988. Recent biomass and catch remain at extremely low levels due to a combination of adverse environmental conditions and intensive fishing. We suggest that Japanese populations of chum salmon and Japanese sardine have a broader geographic range than North American populations, perhaps because of differences between western and eastern boundary current systems, and associated larval drift (sardine) or avoidance of intra-species competition (chum salmon).

  4. Survival of migrating salmon smolts in large rivers with and without dams.

    PubMed

    Welch, David W; Rechisky, Erin L; Melnychuk, Michael C; Porter, Aswea D; Walters, Carl J; Clements, Shaun; Clemens, Benjamin J; McKinley, R Scott; Schreck, Carl

    2008-10-28

    The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST) array. Survival measurements using acoustic tags were comparable to those obtained independently using the Passive Integrated Transponder (PIT) tag system, which is operational at Columbia and Snake River dams. Because the technology underlying the POST array works in both freshwater and the ocean, it is therefore possible to extend the measurement of survival to large rivers lacking dams, such as the Fraser, and to also extend the measurement of survival to the lower Columbia River and estuary, where there are no dams. Of particular note, survival during the downstream migration of at least some endangered Columbia and Snake River Chinook and steelhead stocks appears to be as high or higher than that of the same species migrating out of the Fraser River in Canada, which lacks dams. Equally surprising, smolt survival during migration through the hydrosystem, when scaled by either the time or distance migrated, is higher than in the lower Columbia River and estuary where dams are absent. Our results raise important questions regarding the factors that are preventing the recovery of salmon stocks in the Columbia and the future health of stocks in the Fraser River. PMID:18959485

  5. Ichthyophoniasis: An emerging disease of Chinook salmon in the Yukon River

    USGS Publications Warehouse

    Kocan, R.; Hershberger, P.; Winton, J.

    2004-01-01

    Before 1985, Ichthyophonus was unreported among Pacific salmon Oncorhynchus spp. from the Yukon River; now it infects more than 40% of returning adult Chinook salmon O. tshawytscha. Overall infection prevalence reached about 45% in the Yukon River and about 30% in the Tanana River between 1999 and 2003. Mean infection prevalence was greater in females than males in the main-stem Yukon River during each of the 5 years of the study, but the infection prevalence in males increased each year until the difference was no longer significant. Clinical signs of ichthyophoniasis (presence of visible punctate white lesions in internal organs) were least at the mouth of the Yukon River (???10%) but increased to 29% when fish reached the middle Yukon River and was 22% at the upper Tanana River. However, clinical signs increased each year from 7% in 1999 to 27% in 2003 at the mouth of the river. As fish approached the upper reaches of the Yukon River (Canada) and the spawning areas of the Chena and Salcha rivers (Alaska), infection prevalence dropped significantly to less than 15% in females on the Yukon River and less than 10% for both sexes in the Chena and Salcha rivers, presumably because of mortality among infected prespawn fish. Age was not a factor in infection prevalence, nor was the position of fish within the run. The source of infection was not determined, but Ichthyophonus was not found in 400 Pacific herring Clupea pallasi from the Bering Sea or in 120 outmigrating juvenile Chinook salmon from two drainages in Alaska and Canada. Freshwater burbot Lota lota from the middle Yukon River were subclinically infected with Ichthyophonus, but the origin and relationship of this agent to the Chinook salmon isolate is unknown.

  6. Neurotoxic behavioral effects of Lake Ontario salmon diets in rats

    SciTech Connect

    Hertzler, D.R. )

    1990-03-01

    Six experiments were conducted to examine possible neurotoxic effects of the exposure to contaminants in Lake Ontario salmon administered through the diets of rats. Rats were fed different concentrations of fish (8%, 15% or 30%) in one of three diet conditions: Lake Ontario salmon, Pacific Ocean salmon, or laboratory rat chow only. Following 20 days on the diets, rats were tested for five minutes per day in a modified open field for one or three days. Lake Ontario salmon diets consistently produced significantly lower activity, rearing, and nosepoke behaviors in comparison with ocean salmon or rat chow diet conditions. A dose-response effect for concentration of lake salmon was obtained, and the attenuation effect occurred in males, females, adult or young animals, and postweaning females, with fish sampled over a five-year period. While only two of several potential contaminants were tested, both fish and brain analyses of mirex and PCBs relate to the behavioral effects.

  7. Concentrations of trace elements in Pacific and Atlantic salmon

    NASA Astrophysics Data System (ADS)

    Khristoforova, N. K.; Tsygankov, V. Yu.; Boyarova, M. D.; Lukyanova, O. N.

    2015-09-01

    Concentrations of Hg, As, Cd, Pb, Zn, and Cu were analyzed in the two most abundant species of Pacific salmon, chum and pink salmon, caught in the Kuril Islands at the end of July, 2013. The concentrations of toxic elements (Hg, As, Pb, Cd) in males and females of these species are below the maximum permissible concentrations for seafood. It was found that farmed filleted Atlantic salmon are dominated by Zn and Cu, while muscles of wild salmon are dominated by Pb. Observed differences are obviously related to peculiar environmental geochemical conditions: anthropogenic impact for Atlantic salmon grown in coastal waters and the influence of the natural factors volcanism and upwelling for wild salmon from the Kuril waters.

  8. Coho Salmon Master Plan, Clearwater River Basin.

    SciTech Connect

    Nez Perce Tribe; FishPro

    2004-10-01

    The Nez Perce Tribe has a desire and a goal to reintroduce and restore coho salmon to the Clearwater River Subbasin at levels of abundance and productivity sufficient to support sustainable runs and annual harvest. Consistent with the Clearwater Subbasin Plan (EcoVista 2003), the Nez Perce Tribe envisions developing an annual escapement of 14,000 coho salmon to the Clearwater River Subbasin. In 1994, the Nez Perce Tribe began coho reintroduction by securing eggs through U.S. v. Oregon; by 1998 this agreement provided an annual transfer of 550,000 coho salmon smolts from lower Columbia River hatchery facilities for release in the Clearwater River Subbasin. In 1998, the Northwest Power and Conservation Council authorized the Bonneville Power Administration to fund the development of a Master Plan to guide this reintroduction effort. This Master Plan describes the results of experimental releases of coho salmon in the Clearwater River Subbasin, which have been ongoing since 1995. These data are combined with results of recent coho reintroduction efforts by the Yakama Nation, general coho life history information, and historical information regarding the distribution and life history of Snake River coho salmon. This information is used to assess a number of alternative strategies aimed at restoring coho salmon to historical habitats in the Clearwater River subbasin. These data suggest that there is a high probability that coho salmon can be restored to the Clearwater River subbasin. In addition, the data also suggest that the re-establishment of coho salmon could be substantially aided by: (1) the construction of low-tech acclimation facilities; (2) the establishment of a 'localized' stock of coho salmon; and (3) the construction of hatchery facilities to provide a source of juvenile coho salmon for future supplementation activities. The Nez Perce Tribe recognizes that there are factors which may limit the success of coho reintroduction. As a result of these uncertainties, the Nez Perce Tribe proposes to utilize a phased approach for coho reintroductions. This Master Plan seeks authorization and funding to move forward to Step 2 in the Northwest Power and Conservation Council 3-Step review process to further evaluate Phase I of the coho reintroduction program, which would focus on the establishment of a localized coho salmon stock capable of enduring the migration to the Clearwater River subbasin. To achieve this goal, the Nez Perce Tribe proposes to utilize space at existing Clearwater River subbasin hatchery facilities in concert with the construction of two low-tech acclimation facilities, to capitalize on the higher survival observed for acclimated versus direct stream released coho. In addition, Phase I would document the natural productivity of localized coho salmon released in two targeted tributaries within the Clearwater River subbasin. If Phase I is successful at establishing a localized coho salmon stock in an abundance capable of filling existing hatchery space, the rates of natural productivity are promising, and the interspecific interactions between coho and sympatric resident and anadromous salmonids are deemed acceptable, then Phase II would be triggered. Phase II of the coho reintroduction plan would focus on establishing natural production in a number of Clearwater River subbasin tributaries. To accomplish this goal, Phase II would utilize existing Clearwater River subbasin hatchery facilities, and expand facilities at the Nez Perce Tribal Hatchery Site 1705 facility to rear approximately 687,700 smolts annually for use in a rotating supplementation schedule. In short, this document identifies a proposed alternative (Phase I), complete with estimates of capital, operations and maintenance, monitoring and evaluation, and permitting that is anticipated to raise average smolt replacement rates from 0.73 (current) to 1.14 using primarily existing facilities, with a limited capital investment for low-tech acclimation facilities. This increase in survival is expected to provide the opportunity for the establishment of a localized broodstock in the near-term, and provide the opportunity to establish natural production over the long-term. Phase II information is presented in this document to clearly articulate the long-term intent and vision of the coho salmon reintroduction program. Phase II would be proposed only if Phase I meets several indicators of success. If Phase I meets all identified indicators of success, authorization for Phase II funding would be pursued via a supplement to this Master Plan.

  9. Overview of environmental and hydrogeologic conditions at King Salmon, Alaska

    USGS Publications Warehouse

    Waythomas, C.F.

    1994-01-01

    The Federal Aviation Administration is conducting preliminary environmental assessments at most of its present or former facilities in Alaska. Information about environmental conditions at King Salmon, Alaska are presented in this report. This report gives an overview of the geology, hydro- logy, and climate of the King Salmon area and describes general geohydrologic conditions. A thick alluvial aquifer underlies King Salmon and both ground water and surface water are plentiful in the area.

  10. Does increased intake of salmon increase markers of oxidative stress in pregnant women? The salmon in pregnancy study.

    PubMed

    García-Rodríguez, Cruz E; Helmersson-Karlqvist, Johanna; Mesa, María Dolores; Miles, Elizabeth A; Noakes, Paul S; Vlachava, Maria; Kremmyda, Lefkothea-Stella; Diaper, Norma D; Godfrey, Keith M; Calder, Philip C; Gil, Angel; Basu, Samar

    2011-12-01

    The Salmon in Pregnancy Study provided two meals of salmon per week to pregnant women from week 20 of gestation; the control group maintained their habitual diet low in oily fish. Salmon is a rich source of marine n-3 fatty acids. Since marine n-3 fatty acids may increase oxidative stress, we investigated whether increased salmon consumption could affect markers of oxidative stress in mid and late pregnancy. Urinary 8-iso-prostaglandin F(2α), urinary 8-hydroxy-2'-deoxyguanosine, and plasma lipid peroxide concentrations did not change from week 20 to 38 of pregnancy and were not altered by increased consumption of salmon. Thus, increased intake of salmon during pregnancy does not increase oxidative stress, as judged by the markers of oxidative damage to lipids and DNA measured herein. PMID:21689025

  11. Downstream Migration of Masu Salmon Smolt at a Diversion Facility of Dam

    NASA Astrophysics Data System (ADS)

    Hayashida, K.; Nii, H.; Kasuga, K.; Watanabe, K.

    2014-12-01

    A diversion facility was installed on the upstream of Pirika Dam in Northern Japan that produced a downstream flow into the fishway, thus allowing the fish to migrate to the sea. On the other hand, if the flow rate in the river was more than 7.00 m 3/s (design flow rate of diversion facility), masu salmon smolt were concerned about accessing the dam reservoir, because the smolt can't migrate to the sea through the diversion facility unfortunately. Therefore, the downstream migration of smolt was investigated around the diversion facility. The PIT tag system and radio transmitters as the biotelemetry were used to determine 1) whether masu salmon smolt were able to migrate downstream through the diversion facility and fishway at Pirika Dam, 2) when the smolt started to migrate downstream, 3) whether the downstream migration of smolt were affected by the flow increase in the river. It was clarified that 88% of the smolt were able to enter the diversion facility, and then 81% of the smolt were able to access the fishway. It was also clarified that smolt downstream migration had two peaks in a day (5:00 and 18:00). During the study period, although the flow rate was in the 2.21 m3/s to 30.44 m3/s range (average 6.70 m3/s), it was revealed that the diversion facility has a satisfactory function for the downstream migration of smolt as presented above. The survey clarified the downstream migration behavior of masu salmon by using two types of biotelemetry equipment. PIT tag and radio transmitter were found to be very effective in tracking the behavior of small fish such as smolt. PIT tags, in particular, require very little operating cost, because once they are inserted in the fish, they do not need human labor for tracking. It is desirable to actively introduce the biotelemetry as tracking equipment when surveying the fish migration in the river.

  12. Spatial and temporal genetic structure of a river-resident Atlantic salmon (Salmo salar) after millennia of isolation

    PubMed Central

    Sandlund, Odd Terje; Karlsson, Sten; Thorstad, Eva B; Berg, Ole Kristian; Kent, Matthew P; Norum, Ine C J; Hindar, Kjetil

    2014-01-01

    The river-resident Salmo salar (“småblank”) has been isolated from other Atlantic salmon populations for 9,500 years in upper River Namsen, Norway. This is the only European Atlantic salmon population accomplishing its entire life cycle in a river. Hydropower development during the last six decades has introduced movement barriers and changed more than 50% of the river habitat to lentic conditions. Based on microsatellites and SNPs, genetic variation within småblank was only about 50% of that in the anadromous Atlantic salmon within the same river. The genetic differentiation (FST) between småblank and the anadromous population was 0.24. This is similar to the differentiation between anadromous Atlantic salmon in Europe and North America. Microsatellite analyses identified three genetic subpopulations within småblank, each with an effective population size Ne of a few hundred individuals. There was no evidence of reduced heterozygosity and allelic richness in contemporary samples (2005–2008) compared with historical samples (1955–56 and 1978–79). However, there was a reduction in genetic differentiation between sampling localities over time. SNP data supported the differentiation of småblank into subpopulations and revealed downstream asymmetric gene flow between subpopulations. In spite of this, genetic variation was not higher in the lower than in the upper areas. The meta-population structure of småblank probably maintains genetic variation better than one panmictic population would do, as long as gene flow among subpopulations is maintained. Småblank is a unique endemic island population of Atlantic salmon. It is in a precarious situation due to a variety of anthropogenic impacts on its restricted habitat area. Thus, maintaining population size and avoiding further habitat fragmentation are important. PMID:24967074

  13. Spatial and temporal genetic structure of a river-resident Atlantic salmon (Salmo salar) after millennia of isolation.

    PubMed

    Sandlund, Odd Terje; Karlsson, Sten; Thorstad, Eva B; Berg, Ole Kristian; Kent, Matthew P; Norum, Ine C J; Hindar, Kjetil

    2014-05-01

    The river-resident Salmo salar ("småblank") has been isolated from other Atlantic salmon populations for 9,500 years in upper River Namsen, Norway. This is the only European Atlantic salmon population accomplishing its entire life cycle in a river. Hydropower development during the last six decades has introduced movement barriers and changed more than 50% of the river habitat to lentic conditions. Based on microsatellites and SNPs, genetic variation within småblank was only about 50% of that in the anadromous Atlantic salmon within the same river. The genetic differentiation (F ST) between småblank and the anadromous population was 0.24. This is similar to the differentiation between anadromous Atlantic salmon in Europe and North America. Microsatellite analyses identified three genetic subpopulations within småblank, each with an effective population size Ne of a few hundred individuals. There was no evidence of reduced heterozygosity and allelic richness in contemporary samples (2005-2008) compared with historical samples (1955-56 and 1978-79). However, there was a reduction in genetic differentiation between sampling localities over time. SNP data supported the differentiation of småblank into subpopulations and revealed downstream asymmetric gene flow between subpopulations. In spite of this, genetic variation was not higher in the lower than in the upper areas. The meta-population structure of småblank probably maintains genetic variation better than one panmictic population would do, as long as gene flow among subpopulations is maintained. Småblank is a unique endemic island population of Atlantic salmon. It is in a precarious situation due to a variety of anthropogenic impacts on its restricted habitat area. Thus, maintaining population size and avoiding further habitat fragmentation are important. PMID:24967074

  14. European Community.

    PubMed

    1987-05-01

    The European Community was established in 1951 to reconcile France and Germany after World War II and to make possible the eventual federation of Europe. By 1986, there were 12 member countries: France, Italy, Belgium, the Federal Republic of Germany, Luxembourg, the Netherlands, Denmark, Ireland, the United Kingdom, Greece, Spain, and Portugal. Principal areas of concern are internal and external trade, agriculture, monetary coordination, fisheries, common industrial and commercial policies, assistance, science and research, and common social and regional policies. The European Community has a budget of US$34.035 billion/year, funded by customs duties and 1.4% of each member's value-added tax. The treaties establishing the European Community call for members to form a common market, a common customs tariff, and common agricultural, transport, economic, and nuclear policies. Major European Community institutions include the Commission, Council of