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Sample records for marine biological community

  1. Marine biology

    SciTech Connect

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  2. Marine Biology

    ERIC Educational Resources Information Center

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  3. Marine Biology

    ERIC Educational Resources Information Center

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  4. Marine protected communities against biological invasions: A case study from an offshore island.

    PubMed

    Gestoso, I; Ramalhosa, P; Oliveira, P; Canning-Clode, J

    2017-03-21

    Biological invasions are a major threat to the world's biota and are considered a major cause of biodiversity loss. Therefore, world marine policy has recognized the need for more marine protected areas (MPAs) as a major tool for biodiversity conservation. The present work experimentally evaluated how protected communities from an offshore island can face the settlement and/or expansion of nonindigenous species (NIS). First, NIS colonization success in marine protected and marina communities was compared by deploying PVC settling plates at the Garajau MPA and Funchal marina (SW Madeira Island). Then, the settling plates from the MPA were transferred to Funchal marina to test their resistance to NIS invasion under high levels of NIS pressure. Results indicated that the structure and composition of fouling communities from the MPA differed from those collected in the marina. Interestingly, communities from the protected area showed lower NIS colonization success, suggesting some degree of biotic resistance against NIS invasion.

  5. Effects of a spill of bunker oil on the marine biological communities in Hong Kong

    SciTech Connect

    Shin, P.K. )

    1988-01-01

    The effects of a recent bunker oil spill on the marine environment were assessed through investigation of the rocky shore fauna, phytoplankton population and macrobenthic communities over a study period of 150 days. In addition, toxicity experiments were carried out in the laboratory to ascertain the toxic effects of the oil-plus-dispersant on selected test organisms. The impacts of the spill on the marine fauna were minimal with no visible reduction in species and individual numbers. Possible reasons were the small amount of oil spilled, the rapid containment and dispersion in the clean-up operations, and the less toxic effects of the heavy bunker oil. On Hong Kong shores, the limpets can be identified as indicator species to oil pollution. A quick survey of the limpet fauna on the rocky shores immediately after a spill provides an initial assessment of the impacts on the shoreline. However, faunal recovery over a long-term period may be difficult to assess in view of the lack of baseline data on most of the marine biological communities in Hong Kong waters.

  6. Response of the bacterial community in oil-contaminated marine water to the addition of chemical and biological dispersants.

    PubMed

    Couto, Camila Rattes de Almeida; Jurelevicius, Diogo de Azevedo; Alvarez, Vanessa Marques; van Elsas, Jan Dirk; Seldin, Lucy

    2016-12-15

    The use of dispersants in different stages of the oil production chain and for the remediation of water and soil is a well established practice. However, the choice for a chemical or biological dispersant is still a controversial subject. Chemical surfactants that persist long in the environment may pose problems of toxicity themselves; therefore, biosurfactants are considered to constitute an environmentally friendly and effective alternative. Nevertheless, the putative effects of such agents on the microbiomes of oil-contaminated and uncontaminated marine environments have not been sufficiently evaluated. Here, we studied the effects of the surfactant Ultrasperse II(®) and the surfactin (biosurfactant) produced by Bacillus sp. H2O-1 on the bacterial communities of marine water. Specifically, we used quantitative PCR and genetic fingerprint analyses to study the abundance and structure of the bacterial communities in marine water collected from two regions with contrasting climatic conditions. The addition of either chemical surfactant or biosurfactant influenced the structure and abundance of total and oil-degrading bacterial communities of oil-contaminated and uncontaminated marine waters. Remarkably, the bacterial communities responded similarly to the addition of oil and/or either the surfactant or the biosurfactant in both set of microcosms. After 30 days of incubation, the addition of surfactin enhanced the oil-degrading bacteria more than the chemical surfactant. However, no increase of hydrocarbon biodegradation values was observed, irrespective of the dispersant used. These data contribute to an increased understanding of the impact of novel dispersants on marine bacteriomes before commercial release into the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Effects of organic pollution on biological communities of marine biofilm on hard substrata.

    PubMed

    Sanz-Lázaro, C; Fodelianakis, S; Guerrero-Meseguer, L; Marín, A; Karakassis, I

    2015-06-01

    We examined the effect of organic enrichment on diatom and bacterial assemblages of marine epilithic biofilms on two locations in the Mediterranean, one situated in Spain and the other in Greece. Total organic carbon, total organic nitrogen, stable isotopes (δ(13)C and δ(15)N) and chlorophyll a indicated significant incorporation of organic wastes, increased primary production and trophic niche modifications on the biofilms close to the organic enrichment source. In Spain, where the organic load was higher than in Greece, diatom and, to some extent, bacterial assemblages varied following the organic enrichment gradient. The taxonomic richness of diatom and bacterial communities was not influenced by organic enrichment. Classical community parameters showed consistent patterns to organic pollution in both locations, whereas community assemblages were only influenced when organic pollution was greatest. The successional patterns of these communities were similar to other epilithic communities. The modification of community assemblages induced by organic pollution may affect ecological functions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Accessing Novel Conoidean Venoms: Biodiverse Lumun-lumun Marine Communities, An Untapped Biological and Toxinological Resource

    PubMed Central

    Seronay, Romell A.; Fedosov, Alexander E.; Astilla, Mary Anne; Watkins, Maren; Saguil, Noel; Heralde, Francisco M.; Tagaro, Sheila; Poppe, Guido T.; Aliño, Porfirio M.; Oliverio, Marco; Kantor, Yuri I.; Concepcion, Gisela P.; Olivera, Baldomero M.

    2010-01-01

    Cone snail venoms have yielded pharmacologically-active natural products of exceptional scientific interest. However, cone snails are a small minority of venomous molluscan biodiversity, the vast majority being tiny venomous morphospecies in the family Turridae. A novel method called lumun-lumun opens access to these micromolluscs and their venoms. Old fishing nets are anchored to the sea bottom for a period of 1–6 months and marine biotas rich in small molluscs are established. In a single lumun-lumun community, we found a remarkable gastropod biodiversity (155 morphospecies). Venomous predators belonging to the superfamily Conoidea (36 morphospecies) were the largest group, the majority being micromolluscs in the family Turridae. We carried out an initial analysis of the most abundant of the turrid morphospecies recovered, Clathurella (Lienardia) cincta (Dunker, 1871). In contrast to all cDNA clones characterized from cone snail venom ducts, one of the C. cincta clones identified encoded two different peptide precursors presumably translated from a single mRNA. The prospect of easily accessing so many different morphospecies of venomous marine snails raises intriguing toxinological possibilities: the 36 conoidean morphospecies in this one net alone have the potential to yield thousands of novel pharmacologically-active compounds. PMID:20005243

  9. Accessing novel conoidean venoms: Biodiverse lumun-lumun marine communities, an untapped biological and toxinological resource.

    PubMed

    Seronay, Romell A; Fedosov, Alexander E; Astilla, Mary Anne Q; Watkins, Maren; Saguil, Noel; Heralde, Francisco M; Tagaro, Sheila; Poppe, Guido T; Aliño, Porfirio M; Oliverio, Marco; Kantor, Yuri I; Concepcion, Gisela P; Olivera, Baldomero M

    2010-12-15

    Cone snail venoms have yielded pharmacologically active natural products of exceptional scientific interest. However, cone snails are a small minority of venomous molluscan biodiversity, the vast majority being tiny venomous morphospecies in the family Turridae. A novel method called lumun-lumun opens access to these micromolluscs and their venoms. Old fishing nets are anchored to the sea bottom for a period of 1-6months and marine biotas rich in small molluscs are established. In a single lumun-lumun community, we found a remarkable gastropod biodiversity (155 morphospecies). Venomous predators belonging to the superfamily Conoidea (36 morphospecies) were the largest group, the majority being micromolluscs in the family Turridae. We carried out an initial analysis of the most abundant of the turrid morphospecies recovered, Clathurella (Lienardia) cincta (Dunker, 1871). In contrast to all cDNA clones characterized from cone snail venom ducts, one of the C. cincta clones identified encoded two different peptide precursors presumably translated from a single mRNA. The prospect of easily accessing so many different morphospecies of venomous marine snails raises intriguing toxinological possibilities: the 36 conoidean morphospecies in this one net alone have the potential to yield thousands of novel pharmacologically active compounds.

  10. New marine community

    NASA Astrophysics Data System (ADS)

    While exploring the West Florida Escarpment, a steep slope in the Gulf of Mexico several hundred kilometers off the Florida coast, the deep submergence research vessel Alvin chanced upon a well-developed community of marine life akin to that found 7 years ago in the eastern Pacific Ocean.According to the Woods Hole Oceanographic Institution, which operates the submersible and its new tender, the Atlantis II (Eos, November 1, 1983, p. 619), the marine community contains large clams, mussels, crabs, fish, and tube worms like those found at hydrothermal vents in the eastern Pacific. While the east Pacific communities exist at spreading centers, the newly discovered group, which may stretch for almost 2 km at a depth of roughly 3200 km, lies in a passive continental margin. Also, whereas the water around the Pacific hydrothermal vents is much warmer than the surrounding seawater, the water around the new found community is apparently the same temperature as the ambient waters.

  11. Marine Fisheries: A Biological Insight.

    ERIC Educational Resources Information Center

    Haefner, Paul A., Jr.

    1980-01-01

    Described is a marine science course offered to high school biology teachers. The course objectives were designed to introduce teachers to a marine science subject that could be used in the secondary science classroom and laboratory and to create an awareness of the issues surrounding the marine sciences. (DS)

  12. Marine Biology and Human Affairs

    ERIC Educational Resources Information Center

    Russell, F. S.

    1976-01-01

    Marine biology has become an important area for study throughout the world. The author of this article discusses some of the important discoveries and fields of research in marine biology that are useful for mankind. Topics include food from the sea, fish farming, pesticides, pollution, and conservation. (MA)

  13. Marine Biology and Human Affairs

    ERIC Educational Resources Information Center

    Russell, F. S.

    1976-01-01

    Marine biology has become an important area for study throughout the world. The author of this article discusses some of the important discoveries and fields of research in marine biology that are useful for mankind. Topics include food from the sea, fish farming, pesticides, pollution, and conservation. (MA)

  14. Central Equipment Facility for Molecular Marine Biology

    DTIC Science & Technology

    1990-03-07

    used. Projects supported include marine symbiosis (Haygood, Felback), cell biology (Vacquier), pressure adaptation in marine bacteria (Bartlett), population genetics and evolution of marine organisms (Perrin, Newman).

  15. Supermarket Marine Biology.

    ERIC Educational Resources Information Center

    Colby, Jennifer A.; And Others

    1995-01-01

    Describes a survey used to determine the availability of intact marine vertebrates and live invertebrates in supermarkets. Results shows that local supermarkets frequently provide a variety of intact marine organisms suitable for demonstrations, experiments, or dissections. (ZWH)

  16. Supermarket Marine Biology.

    ERIC Educational Resources Information Center

    Colby, Jennifer A.; And Others

    1995-01-01

    Describes a survey used to determine the availability of intact marine vertebrates and live invertebrates in supermarkets. Results shows that local supermarkets frequently provide a variety of intact marine organisms suitable for demonstrations, experiments, or dissections. (ZWH)

  17. Biological methods for marine toxin detection.

    PubMed

    Vilariño, Natalia; Louzao, M Carmen; Vieytes, Mercedes R; Botana, Luis M

    2010-07-01

    The presence of marine toxins in seafood poses a health risk to human consumers which has prompted the regulation of the maximum content of marine toxins in seafood in the legislations of many countries. Most marine toxin groups are detected by animal bioassays worldwide. Although this method has well known ethical and technical drawbacks, it is the official detection method for all regulated phycotoxins except domoic acid. Much effort by the scientific and regulatory communities has been focused on the development of alternative techniques that enable the substitution or reduction of bioassays; some of these have recently been included in the official detection method list. During the last two decades several biological methods including use of biosensors have been adapted for detection of marine toxins. The main advances in marine toxin detection using this kind of technique are reviewed. Biological methods offer interesting possibilities for reduction of the number of biosassays and a very promising future of new developments.

  18. Linking marine biology and biotechnology.

    PubMed

    de Nys, Rocky; Steinberg, Peter D

    2002-06-01

    Studies of biological systems in which there is a direct link between the challenges faced by marine organisms and biotechnologies enable us to rationally search for active natural compounds and other novel biotechnologies. This approach is proving successful in developing new methods for the prevention of marine biofouling and for the identification of new lead compounds for the development of ultraviolet sunscreens.

  19. Gloucester Marine Biology Unit.

    ERIC Educational Resources Information Center

    Shearer, Sonja; And Others

    Objectives and activities for a field trip study of the seacoast environment of Gloucester, Massachusetts, are outlined in this guide. One phase of a six-week tenth grade biology unit, the field trip features study of tidal pool and salt marsh ecosystems. Specific objectives of the trip relate to observation and identification of various forms of…

  20. Gloucester Marine Biology Unit.

    ERIC Educational Resources Information Center

    Shearer, Sonja; And Others

    Objectives and activities for a field trip study of the seacoast environment of Gloucester, Massachusetts, are outlined in this guide. One phase of a six-week tenth grade biology unit, the field trip features study of tidal pool and salt marsh ecosystems. Specific objectives of the trip relate to observation and identification of various forms of…

  1. The Physics of Marine Biology.

    ERIC Educational Resources Information Center

    Conn, Kathleen

    1992-01-01

    Discusses ways in which marine biology can be integrated into the physics classroom. Topics suggested for incorporation include the harmonic motion of ocean waves, ocean currents, the interaction of visible light with ocean water, pressure, light absorption, and sound transfer in water. (MDH)

  2. The Physics of Marine Biology.

    ERIC Educational Resources Information Center

    Conn, Kathleen

    1992-01-01

    Discusses ways in which marine biology can be integrated into the physics classroom. Topics suggested for incorporation include the harmonic motion of ocean waves, ocean currents, the interaction of visible light with ocean water, pressure, light absorption, and sound transfer in water. (MDH)

  3. Environmental biology of the marine Roseobacter lineage.

    PubMed

    Wagner-Döbler, Irene; Biebl, Hanno

    2006-01-01

    The Roseobacter lineage is a phylogenetically coherent, physiologically heterogeneous group of alpha-Proteobacteria comprising up to 25% of marine microbial communities, especially in coastal and polar oceans, and it is the only lineage in which cultivated bacteria are closely related to environmental clones. Currently 41 subclusters are described, covering all major marine ecological niches (seawater, algal blooms, microbial mats, sediments, sea ice, marine invertebrates). Members of the Roseobacter lineage play an important role for the global carbon and sulfur cycle and the climate, since they have the trait of aerobic anoxygenic photosynthesis, oxidize the greenhouse gas carbon monoxide, and produce the climate-relevant gas dimethylsulfide through the degradation of algal osmolytes. Production of bioactive metabolites and quorum-sensing-regulated control of gene expression mediate their success in complex communities. Studies of representative isolates in culture, whole-genome sequencing, e.g., of Silicibacter pomeroyi, and the analysis of marine metagenome libraries have started to reveal the environmental biology of this important marine group.

  4. Diversity and biological activities of the bacterial community associated with the marine sponge Phorbas tenacior (Porifera, Demospongiae).

    PubMed

    Dupont, S; Carré-Mlouka, A; Descarrega, F; Ereskovsky, A; Longeon, A; Mouray, E; Florent, I; Bourguet-Kondracki, M L

    2014-01-01

    The diversity of the cultivable microbiota of the marine sponge Phorbas tenacior frequently found in the Mediterranean Sea was investigated, and its potential as a source of antimicrobial, antioxidant and antiplasmodial compounds was evaluated. The cultivable bacterial community was studied by isolation, cultivation and 16S rRNA gene sequencing. Twenty-three bacterial strains were isolated and identified in the Proteobacteria (α or γ classes) and Actinobacteria phyla. Furthermore, three different bacterial morphotypes localized extracellularly within the sponge tissues were revealed by microscopic observations. Bacterial strains were assigned to seven different genera, namely Vibrio, Photobacterium, Shewanella, Pseudomonas, Ruegeria, Pseudovibrio and Citricoccus. The strains affiliated to the same genus were differentiated according to their genetic dissimilarities using random amplified polymorphic DNA (RAPD) analyses. Eleven bacterial strains were selected for evaluation of their bioactivities. Three isolates Pseudovibrio P1Ma4, Vibrio P1MaNal1 and Citricoccus P1S7 revealed antimicrobial activity; Citricoccus P1S7 and Vibrio P1MaNal1 isolates also exhibited antiplasmodial activity, while two Vibrio isolates P1Ma8 and P1Ma5 displayed antioxidant activity. These data confirmed the importance of Proteobacteria and Actinobacteria associated with marine sponges as a reservoir of bioactive compounds. This study presents the first report on the diversity of the cultivable bacteria associated with the marine sponge Phorbas tenacior, frequently found in the Mediterranean Sea. Evaluation of the antiplasmodial, antimicrobial and antioxidant activities of the isolates has been investigated and allowed to select bacterial strains, confirming the importance of Proteobacteria and Actinobacteria as sources of bioactive compounds. © 2013 The Society for Applied Microbiology.

  5. Marine molecular biology: an emerging field of biological sciences.

    PubMed

    Thakur, Narsinh L; Jain, Roopesh; Natalio, Filipe; Hamer, Bojan; Thakur, Archana N; Müller, Werner E G

    2008-01-01

    An appreciation of the potential applications of molecular biology is of growing importance in many areas of life sciences, including marine biology. During the past two decades, the development of sophisticated molecular technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. However, the value of molecular techniques for addressing problems in marine biology has only recently begun to be cherished. It has been proven that the exploitation of molecular biological techniques will allow difficult research questions about marine organisms and ocean processes to be addressed. Marine molecular biology is a discipline, which strives to define and solve the problems regarding the sustainable exploration of marine life for human health and welfare, through the cooperation between scientists working in marine biology, molecular biology, microbiology and chemistry disciplines. Several success stories of the applications of molecular techniques in the field of marine biology are guiding further research in this area. In this review different molecular techniques are discussed, which have application in marine microbiology, marine invertebrate biology, marine ecology, marine natural products, material sciences, fisheries, conservation and bio-invasion etc. In summary, if marine biologists and molecular biologists continue to work towards strong partnership during the next decade and recognize intellectual and technological advantages and benefits of such partnership, an exciting new frontier of marine molecular biology will emerge in the future.

  6. Biological importance of marine algae.

    PubMed

    El Gamal, Ali A

    2010-01-01

    Marine organisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. Algae can be classified into two main groups; first one is the microalgae, which includes blue green algae, dinoflagellates, bacillariophyta (diatoms)… etc., and second one is macroalgae (seaweeds) which includes green, brown and red algae. The microalgae phyla have been recognized to provide chemical and pharmacological novelty and diversity. Moreover, microalgae are considered as the actual producers of some highly bioactive compounds found in marine resources. Red algae are considered as the most important source of many biologically active metabolites in comparison to other algal classes. Seaweeds are used for great number of application by man. The principal use of seaweeds as a source of human food and as a source of gums (phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are primarily constituents of brown and red algal cell walls and are widely used in industry.

  7. Biological importance of marine algae

    PubMed Central

    El Gamal, Ali A.

    2009-01-01

    Marine organisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. Algae can be classified into two main groups; first one is the microalgae, which includes blue green algae, dinoflagellates, bacillariophyta (diatoms)… etc., and second one is macroalgae (seaweeds) which includes green, brown and red algae. The microalgae phyla have been recognized to provide chemical and pharmacological novelty and diversity. Moreover, microalgae are considered as the actual producers of some highly bioactive compounds found in marine resources. Red algae are considered as the most important source of many biologically active metabolites in comparison to other algal classes. Seaweeds are used for great number of application by man. The principal use of seaweeds as a source of human food and as a source of gums (phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are primarily constituents of brown and red algal cell walls and are widely used in industry. PMID:23960716

  8. From marine ecology to biological oceanography

    NASA Astrophysics Data System (ADS)

    Mills, Eric L.

    1995-03-01

    Looking back from the 1990s it seems natural to view the work done in the Biologische Anstalt Helgoland by Friedrich Heincke and his colleagues, beginning in 1892, as marine ecology or marine biology, and that done in Kiel, under Victor Hensen and Karl Brandt, as biological oceanography. But historical analysis shows this view to be untenable. Biological oceanography, as a research category and a profession, does not appear until at least the 1950's. In the German tradition of marine research, “Ozeanographie”, originating in 19th century physical geography, did not include the biological sciences. The categories “Meereskunde” and “Meeresforschung” covered all aspects of marine research in Germany from the 1890's to the present day. “Meeresbiologie” like that of Brandt, Heincke, and other German marine scientists, fitted comfortably into these. But in North America no such satisfactory professional or definitional structure existed before the late 1950's. G. A. Riley, one of the first biological oceanographers, fought against descriptive, nonquantitative American ecology. In 1951 he described biological oceanography as the “ecology of marine populations”, linking it with quantitative population ecology in the U.S.A. By the end of the 1960's the U.S. National Science Foundation had recognized biological oceanography as a research area supported separately from marine biology. There was no need for the category “biological oceanography” in German marine science because its subject matter lay under the umbrella of “Meereskunde” or “Meeresforschung”. But in North America, biological oceanography — a fundamental fusion of physics and chemistry with marine biology — was created to give this marine science a status higher than that of the conceptually overloaded ecological sciences. The sociologists Durkheim and Mauss claimed in 1903 that, “the classification of things reproduces the classification of men”; similarly, in science, the

  9. [Biologically active metabolites of the marine actinobacteria].

    PubMed

    Sobolevskaia, M P; Kuznetsova, T A

    2010-01-01

    This review systematically data on the chemical structure and biological activity of metabolites of obligate and facultative marine actinobacteria, published from 2000 to 2007. We discuss some structural features of the five groups of metabolites related to macrolides and compounds containing lactone, quinone and diketopiperazine residues, cyclic peptides, alkaloids, and compounds of mixed biosynthesis. Survey shows a large chemical diversity of metabolites actinobacteria isolated from marine environment. It is shown that, along with metabolites, identical to previously isolated from terrestrial actinobacteria, marine actinobacteria synthesize unknown compounds not found in other natural sources, including micro organisms. Perhaps the biosynthesis of new chemotypes bioactive compounds in marine actinobacteria is one manifestation of chemical adaptation of microorganisms to environmental conditions at sea. Review stresses the importance of the chemical study of metabolites of marine actinobacteria. These studies are aimed at obtaining new data on marine microorganisms producers of biologically active compounds and chemical structure and biological activity of new low-molecular bioregulators of natural origin.

  10. Marine Pyridoacridine Alkaloids: Biosynthesis and Biological Activities.

    PubMed

    Ibrahim, Sabrin R M; Mohamed, Gamal A

    2016-01-01

    Pyridoacridines are a class of strictly marine-derived alkaloids that constitute one of the largest chemical families of marine alkaloids. During the last few years, both natural pyridoacridines and their analogues have constituted excellent targets for synthetic works. They have been the subject of intense study due to their significant biological activities; cytotoxic, antibacterial, antifungal, antiviral, insecticidal, anti-HIV, and anti-parasitic activities. In the present review, 95 pyridoacridine alkaloids isolated from marine organisms are discussed in term of their occurrence, biosynthesis, biological activities, and structural assignment.

  11. Field Techniques in Marine Biology

    ERIC Educational Resources Information Center

    Crenshaw, Neil

    1977-01-01

    Discussed is one teacher's method of teaching students to use various marine and scientific apparati while studying important relationships within the ecosystem. A data retrieval chart is included with questions and problems to ask about the data, along with information on how to interpret the data chart. (MA)

  12. Field Techniques in Marine Biology

    ERIC Educational Resources Information Center

    Crenshaw, Neil

    1977-01-01

    Discussed is one teacher's method of teaching students to use various marine and scientific apparati while studying important relationships within the ecosystem. A data retrieval chart is included with questions and problems to ask about the data, along with information on how to interpret the data chart. (MA)

  13. Genetic perspectives on marine biological invasions.

    PubMed

    Geller, Jonathan B; Darling, John A; Carlton, James T

    2010-01-01

    The extent to which the geographic distributions of marine organisms have been reshaped by human activities remains underappreciated, and so does, consequently, the impact of invasive species on marine ecosystems. The application of molecular genetic data in fields such as population genetics, phylogeography, and evolutionary biology have improved our ability to make inferences regarding invasion histories. Genetic methods have helped to resolve longstanding questions regarding the cryptogenic status of marine species, facilitated recognition of cryptic marine biodiversity, and provided means to determine the sources of introduced marine populations and to begin to recover the patterns of anthropogenic reshuffling of the ocean's biota. These approaches stand to aid materially in the development of effective management strategies and sustainable science-based policies. Continued advancements in the statistical analysis of genetic data promise to overcome some existing limitations of current approaches. Still other limitations will be best addressed by concerted collaborative and multidisciplinary efforts that recognize the important synergy between understanding the extent of biological invasions and coming to a more complete picture of both modern-day and historical marine biogeography.

  14. Marine fish communities in shallow volcanic habitats.

    PubMed

    Pinault, M; Loiseau, N; Chabanet, P; Durville, P; Magalon, H; Quod, J P; Galzin, R

    2013-06-01

    This survey of the marine ichthyofauna of the Piton de La Fournaise volcano at Reunion Island is the first explanatory study of fish community structures in this area. It describes and analyses the main qualitative descriptors of the fish communities (i.e. species richness, diet, life history and geographical distribution) and their spatio-temporal organization. This investigation in 2011 examined lava flows of different ages, including the most recent flows that entered the ocean between 1977 and 2007. In all, 263 species belonging to 45 families were observed. Overall, the fish community was notable for an absence of top predators and a predominance of opportunistic small-bodied species, with dietary flexibility and high reproductive rates, characteristic of the early stages of ecological succession. Between-site analysis indicated that the fish assemblages differed essentially according to the intensity of the last volcanic disturbances. Fish communities in the most disturbed sites showed the highest numbers of Serranidae and the highest proportions of omnivores and small-bodied opportunistic carnivores, including a high proportion of endemic south-western Indian Ocean species. The spatial pattern of this last category of species could be the result of convergent biological traits, and their adaptation to unstable environments at the expense of their competitiveness in more biodiverse, mature communities. Conversely, fish communities in the less disturbed sites showed the highest number of Holocentridae and the highest proportion of browsers of sessile invertebrates. This last characteristic could be a consequence of higher ecological maturity, illustrated by a more specialized trophic network, for assemblages in areas with less intense disturbances. Otherwise, high structural complexity, either in unconsolidated lava boulders, rocks and rubble or high coral-covered sites, could favour the increase of the total number of species independent of disturbance

  15. From molecules to dynamic biological communities.

    PubMed

    McDonald, Daniel; Vázquez-Baeza, Yoshiki; Walters, William A; Caporaso, J Gregory; Knight, Rob

    2013-03-01

    Microbial ecology is flourishing, and in the process, is making contributions to how the ecology and biology of large organisms is understood. Ongoing advances in sequencing technology and computational methods have enabled the collection and analysis of vast amounts of molecular data from diverse biological communities. While early studies focused on cataloguing microbial biodiversity in environments ranging from simple marine ecosystems to complex soil ecologies, more recent research is concerned with community functions and their dynamics over time. Models and concepts from traditional ecology have been used to generate new insight into microbial communities, and novel system-level models developed to explain and predict microbial interactions. The process of moving from molecular inventories to functional understanding is complex and challenging, and never more so than when many thousands of dynamic interactions are the phenomena of interest. We outline the process of how epistemic transitions are made from producing catalogues of molecules to achieving functional and predictive insight, and show how those insights not only revolutionize what is known about biological systems but also about how to do biology itself. Examples will be drawn primarily from analyses of different human microbiota, which are the microbial consortia found in and on areas of the human body, and their associated microbiomes (the genes of those communities). Molecular knowledge of these microbiomes is transforming microbiological knowledge, as well as broader aspects of human biology, health and disease.

  16. Community Involvement in Marine Protected Areas.

    ERIC Educational Resources Information Center

    Kaza, Stephanie

    1988-01-01

    Lists several key concepts in developing successful interpretive programs for marine protected areas with community involvement. Identifies educational tools that help foster community involvement in conservation and management. Cites three model programs. Sets standards and goals for international success including leadership, education,…

  17. Community Involvement in Marine Protected Areas.

    ERIC Educational Resources Information Center

    Kaza, Stephanie

    1988-01-01

    Lists several key concepts in developing successful interpretive programs for marine protected areas with community involvement. Identifies educational tools that help foster community involvement in conservation and management. Cites three model programs. Sets standards and goals for international success including leadership, education,…

  18. Biology of extinction risk in marine fishes

    PubMed Central

    Reynolds, John D; Dulvy, Nicholas K; Goodwin, Nicholas B; Hutchings, Jeffrey A

    2005-01-01

    We review interactions between extrinsic threats to marine fishes and intrinsic aspects of their biology that determine how populations and species respond to those threats. Information is available on the status of less than 5% of the world's approximately 15 500 marine fish species, most of which are of commercial importance. By 2001, based on data from 98 North Atlantic and northeast Pacific populations, marine fishes had declined by a median 65% in breeding biomass from known historic levels; 28 populations had declined by more than 80%. Most of these declines would be sufficient to warrant a status of threatened with extinction under international threat criteria. However, this interpretation is highly controversial, in part because of a perception that marine fishes have a suite of life history characteristics, including high fecundity and large geographical ranges, which might confer greater resilience than that shown by terrestrial vertebrates. We review 15 comparative analyses that have tested for these and other life history correlates of vulnerability in marine fishes. The empirical evidence suggests that large body size and late maturity are the best predictors of vulnerability to fishing, regardless of whether differences among taxa in fishing mortality are controlled; there is no evidence that high fecundity confers increased resilience. The evidence reviewed here is of direct relevance to the diverse criteria used at global and national levels by various bodies to assess threat status of fishes. Simple life history traits can be incorporated directly into quantitative assessment criteria, or used to modify the conclusions of quantitative assessments, or used as preliminary screening criteria for assessment of the ∼95% of marine fish species whose status has yet to be evaluated either by conservationists or fisheries scientists. PMID:16243696

  19. Anthropogenic perturbations in marine microbial communities.

    PubMed

    Nogales, Balbina; Lanfranconi, Mariana P; Piña-Villalonga, Juana M; Bosch, Rafael

    2011-03-01

    Human activities impact marine ecosystems at a global scale and all levels of complexity of life. Despite their importance as key players in ecosystem processes, the stress caused to microorganisms has been greatly neglected. This fact is aggravated by difficulties in the analysis of microbial communities and their high diversity, making the definition of patterns difficult. In this review, we discuss the effects of nutrient increase, pollution by organic chemicals and heavy metals and the introduction of antibiotics and pathogens into the environment. Microbial communities respond positively to nutrients and chemical pollution by increasing cell numbers. There are also significant changes in community composition, increases in diversity and high temporal variability. These changes, which evidence the modification of the environmental conditions due to anthropogenic stress, usually alter community functionality, although this aspect has not been explored in depth. Altered microbial communities in human-impacted marine environments can in turn have detrimental effects on human health (i.e. spread of pathogens and antibiotic resistance). New threats to marine ecosystems, i.e. related to climate change, could also have an impact on microbial communities. Therefore, an effort dedicated to analyse the microbial compartment in detail should be made when studying the impact of anthropogenic activities on marine ecosystems.

  20. Biological and ecological traits of marine species

    PubMed Central

    Claus, Simon; Dekeyzer, Stefanie; Vandepitte, Leen; Tuama, Éamonn Ó; Lear, Dan; Tyler-Walters, Harvey

    2015-01-01

    This paper reviews the utility and availability of biological and ecological traits for marine species so as to prioritise the development of a world database on marine species traits. In addition, the ‘status’ of species for conservation, that is, whether they are introduced or invasive, of fishery or aquaculture interest, harmful, or used as an ecological indicator, were reviewed because these attributes are of particular interest to society. Whereas traits are an enduring characteristic of a species and/or population, a species status may vary geographically and over time. Criteria for selecting traits were that they could be applied to most taxa, were easily available, and their inclusion would result in new research and/or management applications. Numerical traits were favoured over categorical. Habitat was excluded as it can be derived from a selection of these traits. Ten traits were prioritized for inclusion in the most comprehensive open access database on marine species (World Register of Marine Species), namely taxonomic classification, environment, geography, depth, substratum, mobility, skeleton, diet, body size and reproduction. These traits and statuses are being added to the database and new use cases may further subdivide and expand upon them. PMID:26312188

  1. Biological and ecological traits of marine species.

    PubMed

    Costello, Mark John; Claus, Simon; Dekeyzer, Stefanie; Vandepitte, Leen; Tuama, Éamonn Ó; Lear, Dan; Tyler-Walters, Harvey

    2015-01-01

    This paper reviews the utility and availability of biological and ecological traits for marine species so as to prioritise the development of a world database on marine species traits. In addition, the 'status' of species for conservation, that is, whether they are introduced or invasive, of fishery or aquaculture interest, harmful, or used as an ecological indicator, were reviewed because these attributes are of particular interest to society. Whereas traits are an enduring characteristic of a species and/or population, a species status may vary geographically and over time. Criteria for selecting traits were that they could be applied to most taxa, were easily available, and their inclusion would result in new research and/or management applications. Numerical traits were favoured over categorical. Habitat was excluded as it can be derived from a selection of these traits. Ten traits were prioritized for inclusion in the most comprehensive open access database on marine species (World Register of Marine Species), namely taxonomic classification, environment, geography, depth, substratum, mobility, skeleton, diet, body size and reproduction. These traits and statuses are being added to the database and new use cases may further subdivide and expand upon them.

  2. [Book Review] Biology of marine birds

    USGS Publications Warehouse

    Jodice, Patrick G.; Roby, Daniel D.; Antolos, Michelle; Lyons, Donald E.; Rizzolo, Daniel; Wright, Sadie K.; Anderson, Cynthia D.; Anderson, Scott K.; Nelson, S. Kim; Gall, Adrian E.; Wennerberg, Liv

    2003-01-01

    A text devoted to the biology and ecology of marine birds has not been published in the last 15 years. Although a number of more taxa-specific texts have been produced during that period, there has not been a single publication that attempted to review our knowledge of all the major seabird orders since the works of Nelson (1979), Croxall (1987), and Furness and Monaghan (1987). Following the publication of those works, a large and impressive body of literature has been produced. Given the rapid expansion of the field in the last two decades, the time was ripe for production of an extensive compendium on the biology, ecology, and conservation of the world's seabirds.E. A. Schreiber and J. Burger are editors of this CRC publication, Biology of Marine Birds. The book consists of 19 chapters that vary in length from 15 to 51 pages. There are also two extensive appendices: (1) a list of seabird species (restricted to the orders Sphenisciformes, Procellariiformes, Pelecaniformes, and Charadriiformes, the latter limited to Stercorariidae, Laridae, Rhynchopidae, and Alcidae) and their IUCN status, and (2) a very useful table of species-specific life-history traits. The 19 chapters were prepared by 26 authors, among them some of the most respected and published seabird scientists in the world. A brief preface introduces the book, its objective (to provide an examination and summary of the research on seabirds), its audience (researchers, conservationists, managers, and policy-makers), and the taxa covered. The editors coauthored the introductory chapter, Seabirds in the Marine Environment. The authors describe distinctive characteristics of seabird life-histories in comparison to other taxa, hypotheses for why those lifestyles evolved and the potential role of energy limitation in the evolution of seabird life-histories. Along with a discussion of other common seabird traits, such as a propensity for colonial breeding, the authors also suggest directions for future

  3. Chytrids dominate arctic marine fungal communities.

    PubMed

    Hassett, B T; Gradinger, R

    2016-06-01

    Climate change is altering Arctic ecosystem structure by changing weather patterns and reducing sea ice coverage. These changes are increasing light penetration into the Arctic Ocean that are forecasted to increase primary production; however, increased light can also induce photoinhibition and cause physiological stress in algae and phytoplankton that can favour disease development. Fungi are voracious parasites in many ecosystems that can modulate the flow of carbon through food webs, yet are poorly characterized in the marine environment. We provide the first data from any marine ecosystem in which fungi in the Chytridiomycota dominate fungal communities and are linked in their occurrence to light intensities and algal stress. Increased light penetration stresses ice algae and elevates disease incidence under reduced snow cover. Our results show that chytrids dominate Arctic marine fungal communities and have the potential to rapidly change primary production patterns with increased light penetration. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. The colonial ascidian Didemnum sp. A: current distribution, basic biology and potential threat to marine communities of the northeast and west coasts of North America

    USGS Publications Warehouse

    Bullard, S.G.; Lambert, G.; Carman, M.R.; Byrnes, J.; Whitlatch, R.B.; Ruiz, G.; Miller, R.J.; Harris, L.; Valentine, P.C.; Collie, J.S.; Pederson, J.; McNaught, D.C.; Cohen, A.N.; Asch, R.G.; Dijkstra, J.; Heinonen, K.

    2007-01-01

    Didemnum sp. A is a colonial ascidian with rapidly expanding populations on the east and west coasts of North America. The origin of Didemum sp. A is unknown. Populations were first observed on the northeast coast of the U.S. in the late 1980s and on the west coast during the 1990s. It is currently undergoing a massive population explosion and is now a dominant member of many subtidal communities on both coasts. To determine Didemnum sp. A's current distribution, we conducted surveys from Maine to Virginia on the east coast and from British Columbia to southern California on the west coast of the U.S. between 1998 and 2005. In nearshore locations Didemnum sp. A currently ranges from Eastport, Maine to Shinnecock Bay, New York on the east coast. On the west coast it has been recorded from Humboldt Bay to Port San Luis in California, several sites in Puget Sound, Washington, including a heavily fouled mussel culture facility, and several sites in southwestern British Columbia on and adjacent to oyster and mussel farms. The species also occurs at deeper subtidal sites (up to 81 m) off New England, including Georges, Stellwagen and Tillies Banks. On Georges Bank numerous sites within a 230 km2 area are 50–90% covered by Didemnum sp. A; large colonies cement the pebble gravel into nearly solid mats that may smother infaunal organisms. These observations suggest that Didemnum sp. A has the potential to alter marine communities and affect economically important activities such as fishing and aquaculture.

  5. Systems biology of Microbial Communities

    SciTech Connect

    Navid, A; Ghim, C; Fenley, A; Yoon, S; Lee, S; Almaas, E

    2008-04-11

    Microbes exist naturally in a wide range of environments, spanning the extremes of high acidity and high temperature to soil and the ocean, in communities where their interactions are significant. We present a practical discussion of three different approaches for modeling microbial communities: rate equations, individual-based modeling, and population dynamics. We illustrate the approaches with detailed examples. Each approach is best fit to different levels of system representation, and they have different needs for detailed biological input. Thus, this set of approaches is able to address the operation and function of microbial communities on a wide range of organizational levels.

  6. Marine Invertebrates: Communities at Risk

    PubMed Central

    Mather, Jennifer

    2013-01-01

    Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them. PMID:24832811

  7. Marine invertebrates: communities at risk.

    PubMed

    Mather, Jennifer

    2013-06-10

    Our definition of the word 'animal' centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them.

  8. Marine Riparian Vegetation Communities of Puget Sound

    DTIC Science & Technology

    2007-02-01

    dry, sunny sites with relatively nutrient-poor soils. Other, more specialized riparian communities include prairies, dune-grass associations, salt ...will be a slow task because of the time required to establish and grow mature forests, although early successional trees, shrubs, backshore, and salt ...and Dyrness (1973). A list of the more common native trees, understory, and salt -tolerant vegetation found in marine riparian areas was compiled

  9. Debaryomyces hansenii: A Model System for Marine Molecular Biology

    DTIC Science & Technology

    1991-05-30

    System for Marine Molecular Biology PERIOD OF PERFORMANCE: June 1, 1990 to May 30, 1991 RESEARCH OBJECTIVE: To establish Debaryomyces hansenii as a model...Analysis of 17s rRNA gene from the marine yeast Debaryomyces hansenii . In preparation for Current Genetics. TRAINING ACTIVITIES Two graduate students, one...Institution: University of California, Santa Barbara. Grant Title: Debaryomyces hansenii : A Model System for Marine Molecular Biology. Period of

  10. Life history strategies in zooplankton communities: The significance of female gonad morphology and maturation types for the reproductive biology of marine calanoid copepods

    NASA Astrophysics Data System (ADS)

    Niehoff, Barbara

    2007-07-01

    The present review addresses the reproductive strategies of marine calanoid copepods, as affected by their physiological preconditioning, and aims to enhance understanding of their adaptations to specific environmental conditions. Knowledge about oocyte development and internal gonad structure, especially in relation to feeding conditions, is essential for a complete understanding of the reproductive strategies of the copepods. Therefore, the foci of the review are to identify general patterns in oocyte and gonad development in calanoid copepod species from marine ecosystems worldwide and to elucidate the significance of gonad structures for reproductive strategies. Oogenesis is similar in all copepod species. During maturation, the morphology of the oocytes changes distinctly and, according to oocyte size and appearance of ooplasm and nucleus, five oocyte developmental stages are distinguished. In contrast, the gonad structure and its changes during the spawning cycle differ considerably among species, and these differences are related to specific reproductive traits. Four gonad morphology types can be distinguished: the Calanus-type, found in species from all over the world with distinctly different life history traits, is apparently most common in calanoid copepods. In this gonad type, most oocyte developmental stages are present simultaneously, and usually many oocytes mature synchronously, all of which are released in one clutch. The gonad structure allows frequent spawning and large clutches, hence, high egg production rates. This may be a preconditioning for exploiting seasonally high food supply. However, the Calanus-type was also found in species producing eggs at lower rates. In the diverticula of Pseudocalanus-type gonads, only two oocyte developmental stages are present and usually fewer oocytes mature synchronously. Accordingly, the egg production rate is generally lower as compared to the Calanus-type, and apparently only this gonad-type is

  11. Spatial distribution of marine airborne bacterial communities

    PubMed Central

    Seifried, Jasmin S; Wichels, Antje; Gerdts, Gunnar

    2015-01-01

    The spatial distribution of bacterial populations in marine bioaerosol samples was investigated during a cruise from the North Sea to the Baltic Sea via Skagerrak and Kattegat. The analysis of the sampled bacterial communities with a pyrosequencing approach revealed that the most abundant phyla were represented by the Proteobacteria (49.3%), Bacteroidetes (22.9%), Actinobacteria (16.3%), and Firmicutes (8.3%). Cyanobacteria were assigned to 1.5% of all bacterial reads. A core of 37 bacterial OTUs made up more than 75% of all bacterial sequences. The most abundant OTU was Sphingomonas sp. which comprised 17% of all bacterial sequences. The most abundant bacterial genera were attributed to distinctly different areas of origin, suggesting highly heterogeneous sources for bioaerosols of marine and coastal environments. Furthermore, the bacterial community was clearly affected by two environmental parameters – temperature as a function of wind direction and the sampling location itself. However, a comparison of the wind directions during the sampling and calculated backward trajectories underlined the need for more detailed information on environmental parameters for bioaerosol investigations. The current findings support the assumption of a bacterial core community in the atmosphere. They may be emitted from strong aerosolizing sources, probably being mixed and dispersed over long distances. PMID:25800495

  12. Marine biology: Polar merry-go-round

    NASA Astrophysics Data System (ADS)

    Babin, Marcel

    2016-12-01

    The dynamics of polar marine ecosystems are poorly understood. A laser-based space-borne sensor captures annual cycles of phytoplankton biomass in seasonally ice-free polar waters, and provides clues on how growth drives these cycles.

  13. Variable interaction strengths stabilize marine community pattern.

    PubMed

    Navarrete, Sergio A; Berlow, Eric L

    2006-05-01

    High variability in the strength of species interactions is usually considered a source of unstable or unpredictable community patterns. However, recent theoretical work suggests that some types of variance in interaction strength may actually promote stability. Here we provide the first empirical evidence that highly variable, context-dependent species interaction strengths and resilient community patterns can be two sides of the same coin. Field experiments show that a persistent rocky intertidal seascape is remarkably resilient to multiple sources of environmental stochasticity largely because of scale dependent and variable species interaction strengths. Biological interactions exert a stabilizing effect because their intensity varies systematically with changes in both physical sources of mortality of established species, as well as recruitment of new individuals. Strong variation in species interaction strengths with disturbance size and environmental conditions is ubiquitous in nature. Elucidating when this context dependency will be stabilizing is critical to predict community-level responses to anthropogenic disturbances.

  14. From Darwin to the Census of Marine Life: Marine Biology as Big Science

    PubMed Central

    Vermeulen, Niki

    2013-01-01

    With the development of the Human Genome Project, a heated debate emerged on biology becoming ‘big science’. However, biology already has a long tradition of collaboration, as natural historians were part of the first collective scientific efforts: exploring the variety of life on earth. Such mappings of life still continue today, and if field biology is gradually becoming an important subject of studies into big science, research into life in the world's oceans is not taken into account yet. This paper therefore explores marine biology as big science, presenting the historical development of marine research towards the international ‘Census of Marine Life’ (CoML) making an inventory of life in the world's oceans. Discussing various aspects of collaboration – including size, internationalisation, research practice, technological developments, application, and public communication – I will ask if CoML still resembles traditional collaborations to collect life. While showing both continuity and change, I will argue that marine biology is a form of natural history: a specific way of working together in biology that has transformed substantially in interaction with recent developments in the life sciences and society. As a result, the paper does not only give an overview of transformations towards large scale research in marine biology, but also shines a new light on big biology, suggesting new ways to deepen the understanding of collaboration in the life sciences by distinguishing between different ‘collective ways of knowing’. PMID:23342119

  15. From darwin to the census of marine life: marine biology as big science.

    PubMed

    Vermeulen, Niki

    2013-01-01

    With the development of the Human Genome Project, a heated debate emerged on biology becoming 'big science'. However, biology already has a long tradition of collaboration, as natural historians were part of the first collective scientific efforts: exploring the variety of life on earth. Such mappings of life still continue today, and if field biology is gradually becoming an important subject of studies into big science, research into life in the world's oceans is not taken into account yet. This paper therefore explores marine biology as big science, presenting the historical development of marine research towards the international 'Census of Marine Life' (CoML) making an inventory of life in the world's oceans. Discussing various aspects of collaboration--including size, internationalisation, research practice, technological developments, application, and public communication--I will ask if CoML still resembles traditional collaborations to collect life. While showing both continuity and change, I will argue that marine biology is a form of natural history: a specific way of working together in biology that has transformed substantially in interaction with recent developments in the life sciences and society. As a result, the paper does not only give an overview of transformations towards large scale research in marine biology, but also shines a new light on big biology, suggesting new ways to deepen the understanding of collaboration in the life sciences by distinguishing between different 'collective ways of knowing'.

  16. Biological Activity of Recently Discovered Halogenated Marine Natural Products

    PubMed Central

    Gribble, Gordon W.

    2015-01-01

    This review presents the biological activity—antibacterial, antifungal, anti-parasitic, antiviral, antitumor, antiinflammatory, antioxidant, and enzymatic activity—of halogenated marine natural products discovered in the past five years. Newly discovered examples that do not report biological activity are not included. PMID:26133553

  17. The role of infectious disease in marine communities: chapter 5

    USGS Publications Warehouse

    Lafferty, Kevin D.; Harvell, C. Drew

    2014-01-01

    Marine ecologists recognize that infectious diseases play and important role in ocean ecosystems. This role may have increased in some host taxa over time (Ward and Lafferty 2004). We begin this chapter by introducing infectious agents and their relationships with their hosts in marine systems. We then put infectious disease agents with their hosts in marine systems. We then put infectious disease agents in the perspective of marine biodiversity and discuss the various factors that affect parasites. Specifically, we introduce some basin epidemiological concepts, including the effects of stress and free-living diversity on parasites. Following this, we give brief consideration to communities of parasites within their hosts, particularly as these can lead to general insights into community ecology. We also give examples of how infectious diseases affect host populations, scaling up to marine communities. Finally, we present examples of marine infectious disease that impair conservation and fisheries.

  18. Laboratory Experiences in Marine Biology, Student Edition.

    ERIC Educational Resources Information Center

    Raimist, Roger J.

    This manual contains instructions for laboratory exercises using marine organisms. For each exercise a problem is defined, materials are listed, possible ways to solve the problem are suggested, questions are asked to guide the student in interpreting data, and further reading is suggested. The exercises deal with the measurement of oxygen…

  19. Two If by Sea: Marine Biological Invasions.

    ERIC Educational Resources Information Center

    Heimowitz, Paul

    2000-01-01

    Discusses alien species on the west coast, efforts to combat invasions, methods of transport, and educational projects developed to aid prevention efforts. Includes a list of marine invaders in the Pacific Northwest, plus threats from California and the Great Lakes. (PVD)

  20. Two If by Sea: Marine Biological Invasions.

    ERIC Educational Resources Information Center

    Heimowitz, Paul

    2000-01-01

    Discusses alien species on the west coast, efforts to combat invasions, methods of transport, and educational projects developed to aid prevention efforts. Includes a list of marine invaders in the Pacific Northwest, plus threats from California and the Great Lakes. (PVD)

  1. Marine sponge lectins: actual status on properties and biological activities.

    PubMed

    Gomes Filho, Sandro Mascena; Cardoso, Juscélio Donizete; Anaya, Katya; Silva do Nascimento, Edilza; de Lacerda, José Thalles Jucelino Gomes; Mioso, Roberto; Santi Gadelha, Tatiane; de Almeida Gadelha, Carlos Alberto

    2014-12-26

    Marine sponges are primitive metazoans that produce a wide variety of molecules that protect them against predators. In studies that search for bioactive molecules, these marine invertebrates stand out as promising sources of new biologically-active molecules, many of which are still unknown or little studied; thus being an unexplored biotechnological resource of high added value. Among these molecules, lectins are proteins that reversibly bind to carbohydrates without modifying them. In this review, various structural features and biological activities of lectins derived from marine sponges so far described in the scientific literature are discussed. From the results found in the literature, it could be concluded that lectins derived from marine sponges are structurally diverse proteins with great potential for application in the production of biopharmaceuticals, especially as antibacterial and antitumor agents.

  2. Commentary: Radioactive Wastes and Damage to Marine Communities

    ERIC Educational Resources Information Center

    Wallace, Bruce

    1974-01-01

    Discusses the effects of radioactive wastes on marine communities, with particular reference to the fitness of populations and the need for field and laboratory studies to provide evidence of ecological change. (JR)

  3. Commentary: Radioactive Wastes and Damage to Marine Communities

    ERIC Educational Resources Information Center

    Wallace, Bruce

    1974-01-01

    Discusses the effects of radioactive wastes on marine communities, with particular reference to the fitness of populations and the need for field and laboratory studies to provide evidence of ecological change. (JR)

  4. Zooplankton fecal pellets, marine snow, phytodetritus and the ocean's biological pump

    NASA Astrophysics Data System (ADS)

    Turner, Jefferson T.

    2015-01-01

    phytodetritus, phytodetritus from Phaeocystis spp., picoplankton in phytodetritus, the summer export pulse (SEP) of phytodetritus in the subtropical North Pacific, benthic community responses to phytodetritus; (5) other components of the biological pump, including fish fecal pellets and fish-mediated export, sinking carcasses of animals and macrophytes, feces from marine mammals, transparent exopolymer particles (TEP); (6) the biological pump and climate, including origins of the biological pump, the biological pump and glacial/interglacial cycles, the biological pump and contemporary climate variations, and the biological pump and anthropogenic climate change. The review concludes with potential future modifications in the biological pump due to climate change.

  5. Biological Potential of Chitinolytic Marine Bacteria

    PubMed Central

    Paulsen, Sara Skøtt; Andersen, Birgitte; Gram, Lone; Machado, Henrique

    2016-01-01

    Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria (Pseudoalteromonadaceae, Vibrionaceae) for chitin degradation using in silico and phenotypic assays. Of 10 chitinolytic strains, three strains, Photobacterium galatheae S2753, Pseudoalteromonas piscicida S2040 and S2724, produced large clearing zones on chitin plates. All strains were antifungal, but against different fungal targets. One strain, Pseudoalteromonas piscicida S2040, had a pronounced antifungal activity against all seven fungal strains. There was no correlation between the number of chitin modifying enzymes as found by genome mining and the chitin degrading activity as measured by size of clearing zones on chitin agar. Based on in silico and in vitro analyses, we cloned and expressed two ChiA-like chitinases from the two most potent candidates to exemplify the industrial potential. PMID:27999269

  6. Natural products with health benefits from marine biological resources

    USDA-ARS?s Scientific Manuscript database

    The ocean is the cradle of lives, which provides a diverse array of intriguing natural products that has captured scientists’ attention in the past few decades due to their significant and extremely potent biological activities. In addition to being rich sources for pharmaceutical drugs, marine nat...

  7. Biology, genome organization and evolution of parvoviruses in marine shrimp

    USDA-ARS?s Scientific Manuscript database

    A number of parvoviruses are now know to infect marine shrimp, and these viruses alone or in combination with other viruses have the potential to cause major losses in shrimp aquaculture globally. This review provides a comprehensive overview of the biology, genome organization, gene expression, and...

  8. Marine Carotenoids: Biological Functions and Commercial Applications

    PubMed Central

    Vílchez, Carlos; Forján, Eduardo; Cuaresma, María; Bédmar, Francisco; Garbayo, Inés; Vega, José M.

    2011-01-01

    Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon. PMID:21556162

  9. Marine carotenoids: biological functions and commercial applications.

    PubMed

    Vílchez, Carlos; Forján, Eduardo; Cuaresma, María; Bédmar, Francisco; Garbayo, Inés; Vega, José M

    2011-03-03

    Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon.

  10. Marine protected areas increase resilience among coral reef communities.

    PubMed

    Mellin, Camille; Aaron MacNeil, M; Cheal, Alistair J; Emslie, Michael J; Julian Caley, M

    2016-06-01

    With marine biodiversity declining globally at accelerating rates, maximising the effectiveness of conservation has become a key goal for local, national and international regulators. Marine protected areas (MPAs) have been widely advocated for conserving and managing marine biodiversity yet, despite extensive research, their benefits for conserving non-target species and wider ecosystem functions remain unclear. Here, we demonstrate that MPAs can increase the resilience of coral reef communities to natural disturbances, including coral bleaching, coral diseases, Acanthaster planci outbreaks and storms. Using a 20-year time series from Australia's Great Barrier Reef, we show that within MPAs, (1) reef community composition was 21-38% more stable; (2) the magnitude of disturbance impacts was 30% lower and (3) subsequent recovery was 20% faster that in adjacent unprotected habitats. Our results demonstrate that MPAs can increase the resilience of marine communities to natural disturbance possibly through herbivory, trophic cascades and portfolio effects.

  11. Marine biology, intertidal ecology, and a new place for biology.

    PubMed

    Benson, Keith R

    2015-01-01

    At the present time, there is considerable interest for the physical setting of science, that is, its actual 'place' of practice. Among historians of biology, place has been considered to be a crucial component for the study of ecology. Other historians have noted the 'built' environments (laboratories) for the study of biology along the seashore, even referring to these places in terms more applicable to vacation sites. In this paper, I examine the place of intertidal ecology investigations, both in terms of the physical space and the built space. Part of the examination will investigate the aesthetic aspect of the Pacific Coast, part will evaluate the unique character of the intertidal zone, and part will consider the construction of natural laboratories and built laboratories as characteristic places for biology.

  12. Enhanced role of eddies in the Arctic marine biological pump.

    PubMed

    Watanabe, Eiji; Onodera, Jonaotaro; Harada, Naomi; Honda, Makio C; Kimoto, Katsunori; Kikuchi, Takashi; Nishino, Shigeto; Matsuno, Kohei; Yamaguchi, Atsushi; Ishida, Akio; Kishi, Michio J

    2014-05-27

    The future conditions of Arctic sea ice and marine ecosystems are of interest not only to climate scientists, but also to economic and governmental bodies. However, the lack of widespread, year-long biogeochemical observations remains an obstacle to understanding the complicated variability of the Arctic marine biological pump. Here we show an early winter maximum of sinking biogenic flux in the western Arctic Ocean and illustrate the importance of shelf-break eddies to biological pumping from wide shelves to adjacent deep basins using a combination of year-long mooring observations and three-dimensional numerical modelling. The sinking flux trapped in the present study included considerable fresh organic material with soft tissues and was an order of magnitude larger than previous estimates. We predict that further reductions in sea ice will promote the entry of Pacific-origin biological species into the Arctic basin and accelerate biogeochemical cycles connecting the Arctic and subarctic oceans.

  13. Enhanced role of eddies in the Arctic marine biological pump

    PubMed Central

    Watanabe, Eiji; Onodera, Jonaotaro; Harada, Naomi; Honda, Makio C.; Kimoto, Katsunori; Kikuchi, Takashi; Nishino, Shigeto; Matsuno, Kohei; Yamaguchi, Atsushi; Ishida, Akio; Kishi, Michio J.

    2014-01-01

    The future conditions of Arctic sea ice and marine ecosystems are of interest not only to climate scientists, but also to economic and governmental bodies. However, the lack of widespread, year-long biogeochemical observations remains an obstacle to understanding the complicated variability of the Arctic marine biological pump. Here we show an early winter maximum of sinking biogenic flux in the western Arctic Ocean and illustrate the importance of shelf-break eddies to biological pumping from wide shelves to adjacent deep basins using a combination of year-long mooring observations and three-dimensional numerical modelling. The sinking flux trapped in the present study included considerable fresh organic material with soft tissues and was an order of magnitude larger than previous estimates. We predict that further reductions in sea ice will promote the entry of Pacific-origin biological species into the Arctic basin and accelerate biogeochemical cycles connecting the Arctic and subarctic oceans. PMID:24862402

  14. Community College Biology Lesson Index.

    ERIC Educational Resources Information Center

    Manteuffel, Mary S., Comp.; Herrick, Kathie, Comp.

    This catalog contains lesson descriptions of the available biology lessons on PLATO IV, compiled to assist instructors in planning their curricula. Information is provided for 87 lessons in the following areas: introductory material on experimental tools and techniques; chemical basis of life; cellular structure and function; reproduction and…

  15. Community College Biology Lesson Catalogue.

    ERIC Educational Resources Information Center

    Herrick, Kathie G.

    This catalog contains descriptions of the available biology lessons on PLATO IV, compiled to assist instructors in planning their curricula. Information is provided for 87 lessons in the following areas: experimental tools and techniques; chemical basis of life; cellular structure and function; bioenergetics - enzymes and cellular metabolism;…

  16. Guidelines for Marine Biological Reference Collections. Unesco Reports in Marine Sciences, No. 22.

    ERIC Educational Resources Information Center

    Hureau, J. C.; Rice, A. L.

    This manual provides practical advice on the appropriation, conservation, and documentation of a marine biological reference collection, in response to needs expressed by Mediterranean Arab countries. A reference collection is defined as a working museum containing a series of specimens with which biologists are able to compare their own material.…

  17. Guidelines for Marine Biological Reference Collections. Unesco Reports in Marine Sciences, No. 22.

    ERIC Educational Resources Information Center

    Hureau, J. C.; Rice, A. L.

    This manual provides practical advice on the appropriation, conservation, and documentation of a marine biological reference collection, in response to needs expressed by Mediterranean Arab countries. A reference collection is defined as a working museum containing a series of specimens with which biologists are able to compare their own material.…

  18. Characterization of marine isoprene-degrading communities.

    PubMed

    Alvarez, Laura Acuña; Exton, Daniel A; Timmis, Kenneth N; Suggett, David J; McGenity, Terry J

    2009-12-01

    Isoprene is a volatile and climate-altering hydrocarbon with an atmospheric concentration similar to that of methane. It is well established that marine algae produce isoprene; however, until now there was no specific information about marine isoprene sinks. Here we demonstrate isoprene consumption in samples from temperate and tropical marine and coastal environments, and furthermore show that the most rapid degradation of isoprene coincides with the highest rates of isoprene production in estuarine sediments. Isoprene-degrading enrichment cultures, analysed by denaturing gradient gel electrophoresis and 454 pyrosequencing of the 16S rRNA gene and by culturing, were generally dominated by Actinobacteria, but included other groups such as Alphaproteobacteria and Bacteroidetes, previously not known to degrade isoprene. In contrast to specialist methane-oxidizing bacteria, cultivated isoprene degraders were nutritionally versatile, and nearly all of them were able to use n-alkanes as a source of carbon and energy. We therefore tested and showed that the ubiquitous marine hydrocarbon-degrader, Alcanivorax borkumensis, could also degrade isoprene. A mixture of the isolates consumed isoprene emitted from algal cultures, confirming that isoprene can be metabolized at low, environmentally relevant concentrations, and suggesting that, in the absence of spilled petroleum hydrocarbons, algal production of isoprene could maintain viable populations of hydrocarbon-degrading microbes. This discovery of a missing marine sink for isoprene is the first step in obtaining more robust predictions of its flux, and suggests that algal-derived isoprene provides an additional source of carbon for diverse microbes in the oceans.

  19. How Can the Deactivation of the Marine Prowler Community Best Serve the Marine Corps?

    DTIC Science & Technology

    2010-03-01

    other assignments will be needed in their community prior to the community sundown in order to augment the process outlined above. Unfortunately theN...individual squadron due to the Navy’s sundown ofEA-6Bs there can be dedicated squadron aircraft solely for refresh· accomplishment. Therefore these...Plus Up Marines the Prowler community could easily filllO% ofthese required billets until sundown begins and after deactivations begin they could fill

  20. Global patterns of diversity and community structure in marine bacterioplankton.

    PubMed

    Pommier, T; Canbäck, B; Riemann, L; Boström, K H; Simu, K; Lundberg, P; Tunlid, A; Hagström, A

    2007-02-01

    Because of their small size, great abundance and easy dispersal, it is often assumed that marine planktonic microorganisms have a ubiquitous distribution that prevents any structured assembly into local communities. To challenge this view, marine bacterioplankton communities from coastal waters at nine locations distributed world-wide were examined through the use of comprehensive clone libraries of 16S ribosomal RNA genes, used as operational taxonomic units (OTU). Our survey and analyses show that there were marked differences in the composition and richness of OTUs between locations. Remarkably, the global marine bacterioplankton community showed a high degree of endemism, and conversely included few cosmopolitan OTUs. Our data were consistent with a latitudinal gradient of OTU richness. We observed a positive relationship between the relative OTU abundances and their range of occupation, i.e. cosmopolitans had the largest population sizes. Although OTU richness differed among locations, the distributions of the major taxonomic groups represented in the communities were analogous, and all local communities were similarly structured and dominated by a few OTUs showing variable taxonomic affiliations. The observed patterns of OTU richness indicate that similar evolutionary and ecological processes structured the communities. We conclude that marine bacterioplankton share many of the biogeographical and macroecological features of macroscopic organisms. The general processes behind those patterns are likely to be comparable across taxa and major global biomes.

  1. Sustainable production of biologically active molecules of marine based origin.

    PubMed

    Murray, Patrick M; Moane, Siobhan; Collins, Catherine; Beletskaya, Tanya; Thomas, Olivier P; Duarte, Alysson W F; Nobre, Fernando S; Owoyemi, Ifeloju O; Pagnocca, Fernando C; Sette, L D; McHugh, Edward; Causse, Eric; Pérez-López, Paula; Feijoo, Gumersindo; Moreira, Ma T; Rubiolo, Juan; Leirós, Marta; Botana, Luis M; Pinteus, Susete; Alves, Celso; Horta, André; Pedrosa, Rui; Jeffryes, Clayton; Agathos, Spiros N; Allewaert, Celine; Verween, Annick; Vyverman, Wim; Laptev, Ivan; Sineoky, Sergei; Bisio, Angela; Manconi, Renata; Ledda, Fabio; Marchi, Mario; Pronzato, Roberto; Walsh, Daniel J

    2013-09-25

    The marine environment offers both economic and scientific potential which are relatively untapped from a biotechnological point of view. These environments whilst harsh are ironically fragile and dependent on a harmonious life form balance. Exploitation of natural resources by exhaustive wild harvesting has obvious negative environmental consequences. From a European industry perspective marine organisms are a largely underutilised resource. This is not due to lack of interest but due to a lack of choice the industry faces for cost competitive, sustainable and environmentally conscientious product alternatives. Knowledge of the biotechnological potential of marine organisms together with the development of sustainable systems for their cultivation, processing and utilisation are essential. In 2010, the European Commission recognised this need and funded a collaborative RTD/SME project under the Framework 7-Knowledge Based Bio-Economy (KBBE) Theme 2 Programme 'Sustainable culture of marine microorganisms, algae and/or invertebrates for high value added products'. The scope of that project entitled 'Sustainable Production of Biologically Active Molecules of Marine Based Origin' (BAMMBO) is outlined. Although the Union is a global leader in many technologies, it faces increasing competition from traditional rivals and emerging economies alike and must therefore improve its innovation performance. For this reason innovation is placed at the heart of a European Horizon 2020 Strategy wherein the challenge is to connect economic performance to eco performance. This article provides a synopsis of the research activities of the BAMMBO project as they fit within the wider scope of sustainable environmentally conscientious marine resource exploitation for high-value biomolecules. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Life in the "plastisphere": microbial communities on plastic marine debris.

    PubMed

    Zettler, Erik R; Mincer, Tracy J; Amaral-Zettler, Linda A

    2013-07-02

    Plastics are the most abundant form of marine debris, with global production rising and documented impacts in some marine environments, but the influence of plastic on open ocean ecosystems is poorly understood, particularly for microbial communities. Plastic marine debris (PMD) collected at multiple locations in the North Atlantic was analyzed with scanning electron microscopy (SEM) and next-generation sequencing to characterize the attached microbial communities. We unveiled a diverse microbial community of heterotrophs, autotrophs, predators, and symbionts, a community we refer to as the "Plastisphere". Pits visualized in the PMD surface conformed to bacterial shapes suggesting active hydrolysis of the hydrocarbon polymer. Small-subunit rRNA gene surveys identified several hydrocarbon-degrading bacteria, supporting the possibility that microbes play a role in degrading PMD. Some Plastisphere members may be opportunistic pathogens (the authors, unpublished data) such as specific members of the genus Vibrio that dominated one of our plastic samples. Plastisphere communities are distinct from surrounding surface water, implying that plastic serves as a novel ecological habitat in the open ocean. Plastic has a longer half-life than most natural floating marine substrates, and a hydrophobic surface that promotes microbial colonization and biofilm formation, differing from autochthonous substrates in the upper layers of the ocean.

  3. 50 CFR 216.191 - Designation of Offshore Biologically Important Marine Mammal Areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Detailed information on the biology of marine mammals within the area, including estimated population size... Important Marine Mammal Areas. 216.191 Section 216.191 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE...

  4. 50 CFR 216.191 - Designation of Offshore Biologically Important Marine Mammal Areas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Detailed information on the biology of marine mammals within the area, including estimated population size... Important Marine Mammal Areas. 216.191 Section 216.191 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE...

  5. Bio-logging of physiological parameters in higher marine vertebrates

    NASA Astrophysics Data System (ADS)

    Ponganis, Paul J.

    2007-02-01

    Bio-logging of physiological parameters in higher marine vertebrates had its origins in the field of bio-telemetry in the 1960s and 1970s. The development of microprocessor technology allowed its first application to bio-logging investigations of Weddell seal diving physiology in the early 1980s. Since that time, with the use of increased memory capacity, new sensor technology, and novel data processing techniques, investigators have examined heart rate, temperature, swim speed, stroke frequency, stomach function (gastric pH and motility), heat flux, muscle oxygenation, respiratory rate, diving air volume, and oxygen partial pressure (P) during diving. Swim speed, heart rate, and body temperature have been the most commonly studied parameters. Bio-logging investigation of pressure effects has only been conducted with the use of blood samplers and nitrogen analyses on animals diving at isolated dive holes. The advantages/disadvantages and limitations of recording techniques, probe placement, calibration techniques, and study conditions are reviewed.

  6. High Risk Behaviors in Marine Mammals: Linking Behavioral Responses to Anthropogenic Disturbance to Biological Consequences

    DTIC Science & Technology

    2015-09-30

    Locomotion and the cost of hunting in large, stealthy marine carnivores. Integrative and Comparative Biology : doi:10.1093/icb/icv025. [published...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. High Risk Behaviors in Marine Mammals: Linking...Behavioral Responses to Anthropogenic Disturbance to Biological Consequences Terrie M. Williams Center for Ocean Health- Long Marine Lab Department of

  7. Gap analysis on the biology of Mediterranean marine fishes.

    PubMed

    Dimarchopoulou, Donna; Stergiou, Konstantinos I; Tsikliras, Athanassios C

    2017-01-01

    We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length

  8. Gap analysis on the biology of Mediterranean marine fishes

    PubMed Central

    Dimarchopoulou, Donna; Stergiou, Konstantinos I.

    2017-01-01

    We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length

  9. Marine bacterial communities are resistant to elevated carbon dioxide levels.

    PubMed

    Oliver, Anna E; Newbold, Lindsay K; Whiteley, Andrew S; van der Gast, Christopher J

    2014-12-01

    It is well established that the release of anthropogenic-derived CO2 into the atmosphere will be mainly absorbed by the oceans, with a concomitant drop in pH, a process termed ocean acidification. As such, there is considerable interest in how changes in increased CO2 and lower pH will affect marine biota, such as bacteria, which play central roles in oceanic biogeochemical processes. Set within an ecological framework, we investigated the direct effects of elevated CO2, contrasted with ambient conditions on the resistance and resilience of marine bacterial communities in a replicated temporal seawater mesocosm experiment. The results of the study strongly indicate that marine bacterial communities are highly resistant to the elevated CO2 and lower pH conditions imposed, as demonstrated from measures of turnover using taxa–time relationships and distance–decay relationships. In addition, no significant differences in community abundance, structure or composition were observed. Our results suggest that there are no direct effects on marine bacterial communities and that the bacterial fraction of microbial plankton holds enough flexibility and evolutionary capacity to withstand predicted future changes from elevated CO2 and subsequent ocean acidification.

  10. Marine Chemical Ecology: Chemical Signals and Cues Structure Marine Populations, Communities, and Ecosystems

    PubMed Central

    Hay, Mark E.

    2012-01-01

    Chemical cues constitute much of the language of life in the sea. Our understanding of biotic interactions and their effects on marine ecosystems will advance more rapidly if this language is studied and understood. Here, I review how chemical cues regulate critical aspects of the behavior of marine organisms from bacteria to phytoplankton to benthic invertebrates and water column fishes. These chemically mediated interactions strongly affect population structure, community organization, and ecosystem function. Chemical cues determine foraging strategies, feeding choices, commensal associations, selection of mates and habitats, competitive interactions, and transfer of energy and nutrients within and among ecosystems. In numerous cases, the indirect effects of chemical signals on behavior have as much or more effect on community structure and function as the direct effects of consumers and pathogens. Chemical cues are critical for understanding marine systems, but their omnipresence and impact are inadequately recognized. PMID:21141035

  11. Biological effects and subsequent economic effects and losses from marine pollution and degradations in marine environments: Implications from the literature.

    PubMed

    Ofiara, Douglas D; Seneca, Joseph J

    2006-08-01

    This paper serves as the missing piece in a more fuller understanding about economic losses from marine pollution, and demonstrates what losses have been estimated in the literature. Biological effects from marine pollution are linked with resulting economic effects and losses. The merging of these two areas is usually absent in studies of marine pollution losses. The literature has examined several effects due to marine pollution: damages due to harvest closures-restrictions, damages from consumption of unsafe seafood, damages due to decreased recreational activity, and damages related to waterfront real estate adjacent to contaminated water. Overall, marine pollution can and has resulted in sizable economic effects and losses. On the basis of the literature there is adequate justification for public policy actions to curb marine pollution, require inspection of seafood for toxic substances, and preserve marine water quality and sensitive marine environments.

  12. Environmental influences on living marine stromatolites: insights from benthic microalgal communities.

    PubMed

    Rishworth, Gavin M; van Elden, Sean; Perissinotto, Renzo; Miranda, Nelson A F; Steyn, Paul-Pierre; Bornman, Thomas G

    2016-02-01

    Extant marine stromatolites act as partial analogues of their Achaean counterparts, but are rare due to depleted ocean calcium carbonate levels and suppression by eukaryotic organisms. Unique, peritidal tufa stromatolites at the interface between marine and freshwater inputs were discovered in South Africa in the past decade. Our aim was to investigate the benthic microalgal community (green algae, diatoms and cyanobacteria) of these stromatolites to assess succession and dominance patterns using real-time, in situ measurements of algal concentrations and composition. These biological measurements were modelled using generalized linear modelling (GLM) multivariate statistics against water physical and chemical parameters measured at regular monthly intervals, from January to December 2014. Salinity peaked and temperature dipped in winter, with both correlated to microalgal community change (GLM: P < 0.01). Diatoms and cyanobacteria, which construct the stromatolites, were consistently the dominant groups within the algal community, with minimal green algae present throughout the year. Importantly, this demonstrates a unique, relatively stable microalgal stromatolite community as opposed to those of other marine stromatolites, which likely require seasonal and stochastic disturbance to persist. This has implications in terms of interpreting community succession and differential layering in modern and fossilized stromatolites respectively. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Marine parasites as biological tags in South American Atlantic waters, current status and perspectives.

    PubMed

    Cantatore, D M P; Timi, J T

    2015-01-01

    Many marine fisheries in South American Atlantic coasts (SAAC) are threatened by overfishing and under serious risk of collapsing. The SAAC comprises a diversity of environments, possesses a complex oceanography and harbours a vast biodiversity that provide an enormous potential for using parasites as biological tags for fish stock delineation, a prerequisite for the implementation of control and management plans. Here, their use in the SAAC is reviewed. Main evidence is derived from northern Argentine waters, where fish parasite assemblages are dominated by larval helminth species that share a low specificity, long persistence and trophic transmission, parasitizing almost indiscriminately all available fish species. The advantages and constraints of such a combination of characteristics are analysed and recommendations are given for future research. Shifting the focus from fish/parasite populations to communities allows expanding the concept of biological tags from local to regional scales, providing essential information to delineate ecosystem boundaries for host communities. This new concept arose as a powerful tool to help the implementation of ecosystem-based approaches to fisheries management, the new paradigm for fisheries science. Holistic approaches, including parasites as biological tags for stock delineation will render valuable information to help insure fisheries and marine ecosystems against further depletion and collapse.

  14. Skill assessment for coupled biological/physical models of marine systems

    NASA Astrophysics Data System (ADS)

    Stow, Craig A.; Jolliff, Jason; McGillicuddy, Dennis J., Jr.; Doney, Scott C.; Allen, J. Icarus; Friedrichs, Marjorie A. M.; Rose, Kenneth A.; Wallhead, Philip

    2009-02-01

    Coupled biological/physical models of marine systems serve many purposes including the synthesis of information, hypothesis generation, and as a tool for numerical experimentation. However, marine system models are increasingly used for prediction to support high-stakes decision-making. In such applications it is imperative that a rigorous model skill assessment is conducted so that the model's capabilities are tested and understood. Herein, we review several metrics and approaches useful to evaluate model skill. The definition of skill and the determination of the skill level necessary for a given application is context specific and no single metric is likely to reveal all aspects of model skill. Thus, we recommend the use of several metrics, in concert, to provide a more thorough appraisal. The routine application and presentation of rigorous skill assessment metrics will also serve the broader interests of the modeling community, ultimately resulting in improved forecasting abilities as well as helping us recognize our limitations.

  15. Skill Assessment for Coupled Biological/Physical Models of Marine Systems

    PubMed Central

    Jolliff, Jason; McGillicuddy, Dennis J.; Doney, Scott C.; Allen, J. Icarus; Friedrichs, Marjorie A. M.; Rose, Kenneth A.; Wallhead, Philip

    2017-01-01

    Coupled biological/physical models of marine systems serve many purposes including the synthesis of information, hypothesis generation, and as a tool for numerical experimentation. However, marine system models are increasingly used for prediction to support high-stakes decision-making. In such applications it is imperative that a rigorous model skill assessment is conducted so that the model’s capabilities are tested and understood. Herein, we review several metrics and approaches useful to evaluate model skill. The definition of skill and the determination of the skill level necessary for a given application is context specific and no single metric is likely to reveal all aspects of model skill. Thus, we recommend the use of several metrics, in concert, to provide a more thorough appraisal. The routine application and presentation of rigorous skill assessment metrics will also serve the broader interests of the modeling community, ultimately resulting in improved forecasting abilities as well as helping us recognize our limitations. PMID:28366997

  16. Spatial pattern of distribution of marine invertebrates within a subtidal community: do communities vary more among patches or plots?

    PubMed

    Chang, Chun-Yi; Marshall, Dustin J

    2016-11-01

    Making links between ecological processes and the scales at which they operate is an enduring challenge of community ecology. Our understanding of ecological communities cannot advance if we do not distinguish larger scale processes from smaller ones. Variability at small spatial scales can be important because it carries information about biological interactions, which cannot be explained by environmental heterogeneity alone. Marine fouling communities are shaped by both the supply of larvae and competition for resources among colonizers-these two processes operate on distinctly different scales. Here, we demonstrate how fouling community structure varies with spatial scale in a temperate Australian environment, and we identify the spatial scale that captures the most variability. Community structure was quantified with both univariate (species richness and diversity) and multivariate (similarity in species composition) indices. Variation in community structure was unevenly distributed between the spatial scales that we examined. While variation in community structure within patch was usually greater than among patch, variation among patch was always significant. Opportunistic taxa that rely heavily on rapid colonization of free space spread more evenly among patches during early succession. In contrast, taxa that are strong adult competitors but slow colonizers spread more evenly among patches only during late succession. Our findings show significant patchiness can develop in a habitat showing no systematic environmental spatial variation, and this patchiness can be mediated through different biological factors at different spatial scales.

  17. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    NASA Astrophysics Data System (ADS)

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-06-01

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  18. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    PubMed Central

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-01-01

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns. PMID:27344967

  19. Dispersal similarly shapes both population genetics and community patterns in the marine realm.

    PubMed

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-06-27

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  20. The marine biological week as an approach to science

    NASA Astrophysics Data System (ADS)

    Ransdorf, Angela; Satzinger, Viktoria

    2017-04-01

    The "Wiedner Gymnasium" is an academic high school with two branches: one focusses on languages and the other one on science. In the language branch the students learn at least three languages; one of which is Latin, whereas the students of the scientific branch can learn geometrical drawing and have to attend a scientific laboratory throughout the last four upper classes. As incentive highlights the language classes have a one week's school trip to France, Italy or Spain at the beginning of their 7th form in order to attend a language school and to practice their language skills. As a counterbalance, there was introduced the "marine biological week" several years ago, in which the students of the scientific branch take part whilst their colleagues have their language trips. The marine biological week takes place in Rovinj, Croatia. A team of biologists and divers leads through a programme, by which the students get an overview of different habitats, their conditions and the different ways of adaptation organisms find. Thus, they also become acquainted with several species of animals and plants which are characteristic for this area. They become familiar with some methods of scientific work and also get to know some of the problems marine ecosystems are confronted with. They also learn a little bit if the Mediterranean history and culture. Back in school all the findings are reviewed and brought into an ecological context. The insights can be used for many other topics, too, such as e.g. evolution. This week has proved to be a good start as well for the topic of ecology as for learning to think scientifically in general. So, you can call it a pivot for the scientific branch of our school.

  1. Differential response of marine flagellate communities to prokaryotic food quality

    NASA Astrophysics Data System (ADS)

    De Corte, D.; Paredes, G.; Sintes, E.; Herndl, G. J.

    2016-02-01

    Marine prokaryotes play a major role in the biogeochemical cycles. The main predators of prokaryotes are heterotrophic nanoflagellates (HNF). HNF are thus a major link connecting dissolved organic material through prokaryotic grazing to the higher trophic levels. However, little is known about the grazing specificity of HNF on specific prokaryotic taxa. Bacterial and archaeal microbes may have different nutritive values for the HNF communities, thus affecting growth rates and community composition of HNFs. In this study we investigated the influence of prey food quality on Cafeteria roenbergensis and on a natural HNF community isolated in the northern Adriatic Sea. Two Nitrosopumilus maritimus-related strains isolated from the northern Adriatic Sea (Nitrosopumilus adriaticus, Nitrosopumilus piranensis), two Nitrosococcus strains and two fast growing marine Bacteria (Pseudomonas marina and Marinobacter algicola) were fed to the HNFs. The two fast growing bacterial strains resulted in high growth rates of Cafeteria roenbergensis and the mixed HNF community, while the two Nitrosococcus strains did not. Cafeteria roenbergensis fed on N. adriaticus but it did not graze N. piranensis, suggesting that the subtle metabolic and physiological differences between these two closely related thaumarchaeal strains affect the grazing pressure to which they are exposed. Our study also indicates that prokaryotic community composition influences the composition of the HNF community.

  2. Results of efforts by the Convention on Biological Diversity to describe ecologically or biologically significant marine areas.

    PubMed

    Bax, Nicholas J; Cleary, Jesse; Donnelly, Ben; Dunn, Daniel C; Dunstan, Piers K; Fuller, Mike; Halpin, Patrick N

    2016-06-01

    In 2004, Parties to the Convention on Biological Diversity (CBD) addressed a United Nations (UN) call for area-based planning, including for marine-protected areas that resulted in a global effort to describe ecologically or biologically significant marine areas (EBSAs). We summarized the results, assessed their consistency, and evaluated the process developed by the Secretariat of the CBD to engage countries and experts in 9 regional workshops held from 2011 to 2014. Experts from 92 countries and 79 regional or international bodies participated. They considered 250 million km(2) of the world's ocean area (two-thirds of the total). The 204 areas they examined in detail differed widely in area (from 5.5 km(2) to 11.1 million km(2) ). Despite the initial focus of the CBD process on areas outside national jurisdiction, only 31 of the areas examined were solely outside national jurisdiction. Thirty-five extended into national jurisdictions, 137 were solely within national jurisdictions, and 28 included the jurisdictions of more than 1 country (1 area lacked precise boundaries). Data were sufficient to rank 88-99% of the areas relative to each of the 7 criteria for EBSAs agreed to previously by Parties to the CBD. The naturalness criterion ranked high for a smaller percentage of the EBSAs (31%) than other criteria (51-70%), indicating the difficulty in finding relatively undisturbed areas in the ocean. The highly participatory nature of the workshops, including easy and consistent access to the relevant information facilitated by 2 technical teams, contributed to the workshop participants success in identifying areas that could be ranked relative to most criteria and areas that extend across jurisdictional boundaries. The formal recognition of workshop results by the Conference of Parties to the CBD resulted in these 204 areas being identified as EBSAs by the 196 Parties. They represent the only suite of marine areas recognized by the international community for their

  3. Endophytic bacterial community of a Mediterranean marine angiosperm (Posidonia oceanica)

    PubMed Central

    Garcias-Bonet, Neus; Arrieta, Jesus M.; de Santana, Charles N.; Duarte, Carlos M.; Marbà, Núria

    2012-01-01

    Bacterial endophytes are crucial for the survival of many terrestrial plants, but little is known about the presence and importance of bacterial endophytes of marine plants. We conducted a survey of the endophytic bacterial community of the long-living Mediterranean marine angiosperm Posidonia oceanica in surface-sterilized tissues (roots, rhizomes, and leaves) by Denaturing Gradient Gel Electrophoresis (DGGE). A total of 26 Posidonia oceanica meadows around the Balearic Islands were sampled, and the band patterns obtained for each meadow were compared for the three sampled tissues. Endophytic bacterial sequences were detected in most of the samples analyzed. A total of 34 OTUs (Operational Taxonomic Units) were detected. The main OTUs of endophytic bacteria present in P. oceanica tissues belonged primarily to Proteobacteria (α, γ, and δ subclasses) and Bacteroidetes. The OTUs found in roots significantly differed from those of rhizomes and leaves. Moreover, some OTUs were found to be associated to each type of tissue. Bipartite network analysis revealed differences in the bacterial endophyte communities present on different islands. The results of this study provide a pioneering step toward the characterization of the endophytic bacterial community associated with tissues of a marine angiosperm and reveal the presence of bacterial endophytes that differed among locations and tissue types. PMID:23049528

  4. Marine fish community structure and habitat associations on the Canadian Beaufort shelf and slope

    NASA Astrophysics Data System (ADS)

    Majewski, Andrew R.; Atchison, Sheila; MacPhee, Shannon; Eert, Jane; Niemi, Andrea; Michel, Christine; Reist, James D.

    2017-03-01

    Marine fishes in the Canadian Beaufort Sea have complex interactions with habitats and prey, and occupy a pivotal position in the food web by transferring energy between lower- and upper-trophic levels, and also within and among habitats (e.g., benthic-pelagic coupling). The distributions, habitat associations, and community structure of most Beaufort Sea marine fishes, however, are unknown thus precluding effective regulatory management of emerging offshore industries in the region (e.g., hydrocarbon development, shipping, and fisheries). Between 2012 and 2014, Fisheries and Oceans Canada conducted the first baseline survey of offshore marine fishes, their habitats, and ecological relationships in the Canadian Beaufort Sea. Benthic trawling was conducted at 45 stations spanning 18-1001 m depths across shelf and slope habitats. Physical oceanographic variables (depth, salinity, temperature, oxygen), biological variables (benthic chlorophyll and integrated water-column chlorophyll) and sediment composition (grain size) were assessed as potential explanatory variables for fish community structure using a non-parametric statistical approach. Selected stations were re-sampled in 2013 and 2014 for a preliminary assessment of inter-annual variability in the fish community. Four distinct fish assemblages were delineated on the Canadian Beaufort Shelf and slope: 1) Nearshore-shelf: <50 m depth, 2) Offshore-shelf: >50 and ≤200 m depths, 3) Upper-slope: ≥200 and ≤500 m depths, and 4) Lower-slope: ≥500 m depths. Depth was the environmental variable that best explained fish community structure, and each species assemblage was spatially associated with distinct aspects of the vertical water mass profile. Significant differences in the fish community from east to west were not detected, and the species composition of the assemblages on the Canadian Beaufort Shelf have not changed substantially over the past decade. This community analysis provides a framework for testing

  5. Short-term community transition and selection in shallow marine embayment fauna from Pennsylvanian of north-central Texas

    SciTech Connect

    Cate, A.S.

    1988-02-01

    Community and size-frequency analyses were obtained for macrofauna from a thin fossiliferous interval within an otherwise barren shallow marine embayment facies in the East Mountain Shale (Strawn Group). Vertically contiguous sampling of this discrete unit allowed reconstruction of short-term community transition and detection of shifts in the population structure of two gastropod species (Glabrocingulum G. grayvillensis, Straparollus A. catilloides). These biological phenomena could be related to environmental shifts brought about by deltaic progradation.

  6. Laboratory Experiences in Marine Biology for Upper Elementary and Secondary School Grades, Teachers Edition.

    ERIC Educational Resources Information Center

    Raimist, Roger J.

    Designed to assist the teacher who wishes to use marine organisms for biological laboratory investigations, this manual includes general information on maintaining marine aquaria and collecting marine organisms as well as five tested laboratory exercises. The exercises deal with the measurement of oxygen consumption (giving techniques for…

  7. Spillover Effects of a Community-Managed Marine Reserve

    PubMed Central

    da Silva, Isabel Marques; Hill, Nick; Shimadzu, Hideyasu; Soares, Amadeu M. V. M.; Dornelas, Maria

    2015-01-01

    The value of no-take marine reserves as fisheries-management tools is controversial, particularly in high-poverty areas where human populations depend heavily on fish as a source of protein. Spillover, the net export of adult fish, is one mechanism by which no-take marine reserves may have a positive influence on adjacent fisheries. Spillover can contribute to poverty alleviation, although its effect is modulated by the number of fishermen and fishing intensity. In this study, we quantify the effects of a community-managed marine reserve in a high poverty area of Northern Mozambique. For this purpose, underwater visual censuses of reef fish were undertaken at three different times: 3 years before (2003), at the time of establishment (2006) and 6 years after the marine reserve establishment (2012). The survey locations were chosen inside, outside and on the border of the marine reserve. Benthic cover composition was quantified at the same sites in 2006 and 2012. After the reserve establishment, fish sizes were also estimated. Regression tree models show that the distance from the border and the time after reserve establishment were the variables with the strongest effect on fish abundance. The extent and direction of the spillover depends on trophic group and fish size. Poisson Generalized Linear Models show that, prior to the reserve establishment, the survey sites did not differ but, after 6 years, the abundance of all fish inside the reserve has increased and caused spillover of herbivorous fish. Spillover was detected 1km beyond the limit of the reserve for small herbivorous fishes. Six years after the establishment of a community-managed reserve, the fish assemblages have changed dramatically inside the reserve, and spillover is benefitting fish assemblages outside the reserve. PMID:25927235

  8. Detecting regime shifts in marine systems with limited biological data: An example from southeast Australia

    NASA Astrophysics Data System (ADS)

    Litzow, Michael A.; Hobday, Alistair J.; Frusher, Stewart D.; Dann, Peter; Tuck, Geoffrey N.

    2016-02-01

    The ability to detect ecological regime shifts in a data-limited setting was investigated, using southeast Australian ecosystems as a model. Community variability was summarized for 1968-2008 with the first two principal components (PCs) of recruitment estimates for six fish stocks and reproductive parameters for four seabird species; regional climate was summarized for 1953-2008 with the first two PCs for three parameters (sea surface temperature [SST], sea surface salinity, surface nitrate) measured at two stations; and basin-scale climate variability was summarized for 1950-2012 with mean South Pacific SST and the first two PCs of detrended South Pacific SST. The first two biology PCs explained 45% of total community variability. The first two PCs of basin-scale SST showed abrupt shifts similar to "regime" behavior observed in other ocean basins, and the first PC of basin-scale SST showed significant covariation with the first PC of regional climate. Together, these results are consistent with the strong community variability and decadal-scale red noise climatic variability associated with Northern Hemisphere regime shifts. However, statistical model selection showed that the first two PCs of regional climate and the first PC of biology time series all exhibited linear change, rather than abrupt shifts. This result is consistent with previous studies documenting rapid linear change in the climate and biology of southeast Australian shelf ecosystems, and we conclude that there is no evidence for regime shift behavior in the region's ecology. However, analysis of a large set of previously-published biological time series from the North Pacific (n = 64) suggests that studies using fewer than ∼30 biological time series, such as this one, may be unable to detect regime shifts. Thus we conclude that the nature of ecological variability in the region cannot be determined with available data. The development of additional long-term biological observations is needed

  9. Marine and giant viruses as indicators of a marine microbial community in a riverine system.

    PubMed

    Dann, Lisa M; Rosales, Stephanie; McKerral, Jody; Paterson, James S; Smith, Renee J; Jeffries, Thomas C; Oliver, Rod L; Mitchell, James G

    2016-12-01

    Viral communities are important for ecosystem function as they are involved in critical biogeochemical cycles and controlling host abundance. This study investigates riverine viral communities around a small rural town that influences local water inputs. Myoviridae, Siphoviridae, Phycodnaviridae, Mimiviridae, Herpesviridae, and Podoviridae were the most abundant families. Viral species upstream and downstream of the town were similar, with Synechoccocus phage, salinus, Prochlorococcus phage, Mimivirus A, and Human herpes 6A virus most abundant, contributing to 4.9-38.2% of average abundance within the metagenomic profiles, with Synechococcus and Prochlorococcus present in metagenomes as the expected hosts for the phage. Overall, the majority of abundant viral species were or were most similar to those of marine origin. At over 60 km to the river mouth, the presence of marine communities provides some support for the Baas-Becking hypothesis "everything is everywhere, but, the environment selects." We conclude marine microbial species may occur more frequently in freshwater systems than previously assumed, and hence may play important roles in some freshwater ecosystems within tens to a hundred kilometers from the sea. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  10. Marine Biology and Oceanography, Grades Nine to Twelve. Part II.

    ERIC Educational Resources Information Center

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 9-12. The unit, focusing on sea plants/animals and their interactions with each other and the non-living environment, has sections dealing with: marine ecology; marine bacteriology;…

  11. Marine Biology and Oceanography, Grades Nine to Twelve. Part II.

    ERIC Educational Resources Information Center

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 9-12. The unit, focusing on sea plants/animals and their interactions with each other and the non-living environment, has sections dealing with: marine ecology; marine bacteriology;…

  12. Authorized Course of Instruction for the Quinmester Program. Science: Introduction to Marine Science; Recreation and the Sea; Oceanography; Marine Ecology of South Florida, and Invertebrate Marine Biology.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    All five units, developed for the Dade County Florida Quinmester Program, included in this collection concern some aspect of marine studies. Except for "Recreation and the Sea," intended to give students basic seamanship skills and experience of other marine recreation, all units are designed for students with a background in biology or…

  13. Parasites as biological tags for stock discrimination in marine fish from South American Atlantic waters.

    PubMed

    Timi, Juan T

    2007-06-01

    The use of parasites as biological tags in population studies of marine fish in the south-western Atlantic has proved to be a successful tool for discriminating stocks for all species to which it has been applied, namely: Scomber japonicus, Engraulis anchoita, Merluccius hubbsi and Cynoscion guatucupa, the latter studied on a broader geographic scale, including samples from Uruguayan and Brazilian waters. The distribution patterns of marine parasites are determined mainly by temperature-salinity profiles and by their association with specific masses of water. Analyses of distribution patterns of some parasite species in relation to gradients in environmental (oceanographic) conditions showed that latitudinal gradients in parasite distribution are common in the study area, and are probably directly related to water temperature. Indeed, temperature, which is a good predictor of latitudinal gradients of richness and diversity of species, shows a latitudinal pattern in south-western Atlantic coasts, decreasing southwards, due to the influence of subtropical and subantarctic marine currents flowing along the edge of the continental slope. This pattern also determines the distribution of zooplankton, with a characteristic specific composition in different water masses. The gradient in the distribution of parasites determines differential compositions of their communities at different latitudes, which makes possible the identification of different stocks of their fish hosts. Other features of the host-parasite systems contributing to the success of the parasitological method are: (1) parasites identified as good biological tags (i.e. anisakids) are widely distributed in the local fauna; (2) many of these species show low specificity and use paratenic hosts; and (3) the structure of parasite communities are, to a certain degree, predictable in time and space.

  14. Bacterial communities in sediment of a Mediterranean marine protected area.

    PubMed

    Catania, Valentina; Sarà, Gianluca; Settanni, Luca; Quatrini, Paola

    2017-04-01

    Biodiversity is crucial in preservation of ecosystems, and bacterial communities play an indispensable role for the functioning of marine ecosystems. The Mediterranean marine protected area (MPA) "Capo Gallo-Isola delle Femmine" was instituted to preserve marine biodiversity. The bacterial diversity associated with MPA sediment was compared with that from sediment of an adjacent harbour exposed to intense nautical traffic. The MPA sediment showed higher diversity with respect to the impacted site. A 16S rDNA clone library of the MPA sediment allowed the identification of 7 phyla: Proteobacteria (78%), Firmicutes (11%), Acidobacteria (3%), Actinobacteria (3%), Bacteroidetes (2%), Planctomycetes (2%), and Cyanobacteria (1%). Analysis of the hydrocarbon (HC)-degrading bacteria was performed using enrichment cultures. Most of the MPA sediment isolates were affiliated with Gram-positive G+C rich bacteria, whereas the majority of taxa in the harbour sediment clustered with Alpha- and Gammaproteobacteria; no Gram-positive HC degraders were isolated from the harbour sediment. Our results show that protection probably has an influence on bacterial diversity, and suggest the importance of monitoring the effects of protection at microbial level as well. This study creates a baseline of data that can be used to assess changes over time in bacterial communities associated with a Mediterranean MPA.

  15. A model for Bioinformatics training: the marine biological laboratory.

    PubMed

    Yamashita, Grant; Miller, Holly; Goddard, Anthony; Norton, Cathy

    2010-11-01

    Many areas of science such as biology, medicine and oceanography are becoming increasingly data-rich and most programs that train scientists do not address informatics techniques or technologies that are necessary for managing and analysing large amounts of data. Educational resources for scientists in informatics are scarce, yet scientists need the skills and knowledge to work with informaticians and manage graduate students and post-docs in informatics projects. The Marine Biological Laboratory houses a world-renowned library and is involved in a number of informatics projects in the sciences. The MBL has been home to the National Library of Medicine's BioMedical Informatics Course for nearly two decades and is committed to educating scientists and other scholars in informatics. In an innovative, immersive learning experience, G.Y., a biologist and post-doc at Arizona State University, visited the Science Informatics Group at the MBL to learn first hand how informatics is done and how informatics teams work. Hands-on work with developers, systems administrators, librarians and other scientists provided an invaluable education in informatics and is a model for future science informatics training.

  16. Spatial and body-size dependent response of marine pelagic communities to projected global climate change.

    PubMed

    Lefort, Stelly; Aumont, Olivier; Bopp, Laurent; Arsouze, Thomas; Gehlen, Marion; Maury, Olivier

    2015-01-01

    Temperature, oxygen, and food availability directly affect marine life. Climate models project a global warming of the ocean's surface (~+3 °C), a de-oxygenation of the ocean's interior (~-3%) and a decrease in total marine net primary production (~-8%) under the 'business as usual' climate change scenario (RCP8.5). We estimated the effects of these changes on biological communities using a coupled biogeochemical (PISCES)--ecosystems (APECOSM) model forced by the physical outputs of the last generation of the IPSL-CM Earth System Model. The APECOSM model is a size-structured bio-energetic model that simulates the 3D dynamical distributions of three interactive pelagic communities (epipelagic, mesopelagic, and migratory) under the effects of multiple environmental factors. The PISCES-APECOSM model ran from 1850 to 2100 under historical forcing followed by RCP8.5. Our RCP8.5 simulation highlights significant changes in the spatial distribution, biomass, and maximum body-size of the simulated pelagic communities. Biomass and maximum body-size increase at high latitude over the course of the century, reflecting the capacity of marine organisms to respond to new suitable environment. At low- and midlatitude, biomass and maximum body-size strongly decrease. In those regions, large organisms cannot maintain their high metabolic needs because of limited and declining food availability. This resource reduction enhances the competition and modifies the biomass distribution among and within the three communities: the proportion of small organisms increases in the three communities and the migrant community that initially comprised a higher proportion of small organisms is favored. The greater resilience of small body-size organisms resides in their capacity to fulfill their metabolic needs under reduced energy supply and is further favored by the release of predation pressure due to the decline of large organisms. These results suggest that small body-size organisms might be

  17. Use of marine fouling communities to evaluate the ecological effects of pollution. Final report

    SciTech Connect

    Johnston, R.K.

    1990-06-01

    The ecological consequences of pollution were evaluated by measuring the biological responses of marine fouling communities to increasing levels of pollution in San Diego Bay, California. Measurements of a gradient of increasing levels of copper and organotin compounds were made using anodic stripping voltammetry and inductively coupled plasma spectroscopy for copper and hydride derivation with atomic spectroscopy detection for the organotin compounds tributyltin (TBT), dibutyltin, and monobutyltin. The copper gradient increased by a factor of 4.2 and the TBT gradient increased by a factor of 8.75. Differences in community structures were correlated with distinctly higher concentrations of toxic chemicals present at locations along the gradient. A portable microcosm system was used to study the community responses to different concentrations of TBT in controlled environments. The microcosm study was inconclusive because there was very low settlement of fouling organisms in the microcosm tanks relative to their settlement and colonization in the bay.

  18. Strong Seasonality and Interannual Recurrence in Marine Myovirus Communities

    PubMed Central

    Chow, C.-E. T.; Johannessen, T.; Fuhrman, J. A.; Thingstad, T. F.; Sandaa, R. A.

    2013-01-01

    The temporal community dynamics and persistence of different viral types in the marine environment are still mostly obscure. Polymorphism of the major capsid protein gene, g23, was used to investigate the community composition dynamics of T4-like myoviruses in a North Atlantic fjord for a period of 2 years. A total of 160 unique operational taxonomic units (OTUs) were identified by terminal restriction fragment length polymorphism (TRFLP) of the gene g23. Three major community profiles were identified (winter-spring, summer, and autumn), which resulted in a clear seasonal succession pattern. These seasonal transitions were recurrent over the 2 years and significantly correlated with progression of seawater temperature, Synechococcus abundance, and turbidity. The appearance of the autumn viral communities was concomitant with the occurrence of prominent Synechococcus blooms. As a whole, we found a highly dynamic T4-like viral community with strong seasonality and recurrence patterns. These communities were unexpectedly dominated by a group of persistently abundant viruses. PMID:23913432

  19. Palaeoecology and evolution of marine hard substrate communities

    NASA Astrophysics Data System (ADS)

    Taylor, P. D.; Wilson, M. A.

    2003-07-01

    Marine organisms have occupied hard substrates since the Archaean. Shells, rocks, wood and sedimentary hardgrounds offer relatively stable habitats compared to unconsolidated sediments, but the plants and animals which inhabit them must develop means to gain and defend this premium attachment space. Hard substrate communities are formed by organisms with a variety of strategies for adhering to and/or excavating the substrates they inhabit. While mobile grazers, organically attached and even soft-bodied organisms may leave evidence of their former presence in ancient hard substrate communities, a superior fossil record is left by sessile encrusters with mineralised skeletons and by borers which leave trace fossils. Furthermore, encrusters and borers are preserved in situ, retaining their spatial relationships to one another and to the substrate. Spatial competition, ecological succession, oriented growth, and differential utilisation of exposed vs. hidden substrate surfaces can all be observed or inferred. Hard substrate communities are thus excellent systems with which to study community evolution over hundreds of millions of years. Here we review the research on modern and ancient hard substrate communities, and point to some changes that have affected them over geological time scales. Such changes include a general increase in bioerosion of hard substrates, particularly carbonate surfaces, through the Phanerozoic. This is, at least in part, analogous to the infaunalisation trends seen in soft substrate communities. Encrusting forms show an increase in skeletalisation from the Palaeozoic into the Mesozoic and Cenozoic, which may be a response to increasing levels of predation. Hard substrate communities, considering borers and encrusters together, show a rough increase in tiering through the Phanerozoic which again parallels trends seen in soft substrate communities. This extensive review of the literature on living and fossil hard substrate organisms shows that

  20. Islands in a Sea of Mud: Insights From Terrestrial Island Theory for Community Assembly on Insular Marine Substrata.

    PubMed

    Meyer, K S

    Most marine hard-bottom habitats are isolated, separated from other similar habitats by sand or mud flats, and can be considered analogous to terrestrial islands. The extensive scientific literature on terrestrial islands provides a theoretical framework for the analysis of isolated marine habitats. More individuals and higher species richness occur on larger marine substrata, a pattern that resembles terrestrial islands. However, while larger terrestrial islands have greater habitat diversity and productivity, the higher species richness on larger marine hard substrata can be explained by simple surface area and hydrodynamic phenomena: larger substrata extend further into the benthic boundary, exposing fauna to faster current and higher food supply. Marine island-like communities are also influenced by their distance to similar habitats, but investigations into the reproductive biology and dispersal ability of individual species are required for a more complete understanding of population connectivity. On terrestrial islands, nonrandom co-occurrence patterns have been attributed to interspecific competition, but while nonrandom co-occurrence patterns have been found for marine fauna, different mechanisms are responsible, including epibiontism. Major knowledge gaps for community assembly in isolated marine habitats include the degree of connectivity between isolated habitats, mechanisms of succession, and the extent of competition on hard substrata, particularly in the deep sea. Anthropogenic hard substrata of known age can be used opportunistically as "natural" laboratories to begin answering these questions. © 2017 Elsevier Ltd. All rights reserved.

  1. Engaging a community towards marine cyberinfrastructure: Lessons Learned from The Marine Metadata Interoperability initiative

    NASA Astrophysics Data System (ADS)

    Galbraith, N. R.; Graybeal, J.; Bermudez, L. E.; Wright, D.

    2005-12-01

    The Marine Metadata Interoperability (MMI) initiative promotes the exchange, integration and use of marine data through enhanced data publishing, discovery, documentation and accessibility. The project, operating since late 2004, presents several cultural organizational challenges because of the diversity of participants: scientists, technical experts, and data managers from around the world, all working in organizations with different corporate cultures, funding structures, and systems of decision-making. MMI provides educational resources at several levels. For instance, short introductions to metadata concepts are available, as well as guides and "cookbooks" for the quick and efficient preparation of marine metadata. For those who are building major marine data systems, including ocean-observing capabilities, there are training materials, marine metadata content examples, and resources for mapping elements between different metadata standards. The MMI also provides examples of good metadata practices in existing data systems, including the EU's Marine XML project, and functioning ocean/coastal clearinghouses and atlases developed by MMI team members. Communication tools that help build community: 1) Website, used to introduce the initiative to new visitors, and to provide in-depth guidance and resources to members and visitors. The site is built using Plone, an open source web content management system. Plone allows the site to serve as a wiki, to which every user can contribute material. This keeps the membership engaged and spreads the responsibility for the tasks of updating and expanding the site. 2) Email-lists, to engage the broad ocean sciences community. The discussion forums "news," "ask," and "site-help" are available for receiving regular updates on MMI activities, seeking advice or support on projects and standards, or for assistance with using the MMI site. Internal email lists are provided for the Technical Team, the Steering Committee and

  2. Anthropogenic and natural disturbances to marine benthic communities in Antarctica

    SciTech Connect

    Lenihan, H.; Oliver, J.S.

    1995-05-01

    Sampling and field experiments were conducted from 1975 to 1990 to test how the structure of marine benthic communities around McMurdo Station, Antarctica varied with levels of anthropogenic contaminants in marine sediments. The structure of communities (e.g., infauna density, species composition, and life history characteristics) in contaminated and uncontaminated areas were compared with the structure of communities influenced by two large-scale natural disturbances, anchor ice formation and uplift or iceberg scour. Benthic communities changed radically along a steep spatial gradient of anthropogenic hydrocarbon, metal, and PCB contamination around McMurdo Station. The heavily contaminated end of the gradient, Winter Quarters Bay, was low in infaunal and epifaunal abundance and was dominated by a few opportunistic species of polychaete worms. The edge of the heavily contaminated bay, the transition area, contained several motile polychaete species with less opportunistic life histories. Uncontaminated sedimentary habitats harbored dense tube mats of infaunal animals numerically dominated by populations of polychaete worms, crustaceans, and a large suspension feeding bivalve. These species are generally large and relatively sessile, except for several crustacean species living among the tubes. Although the community patterns around anthropogenic and natural disturbances were similar, particularly motile and opportunistic species at heavily disturbed and marginal areas, the natural disturbances cover much greater areas of the sea floor about the entire Antarctic continent. On the other hand, recovery from chemical contamination is likely to take many more decades than recovery from natural disturbances as contaminant degradation is a slow process. 77 refs., 6 figs., 5 tabs.

  3. Disturbance Increases Microbial Community Diversity and Production in Marine Sediments

    PubMed Central

    Galand, Pierre E.; Lucas, Sabrina; Fagervold, Sonja K.; Peru, Erwan; Pruski, Audrey M.; Vétion, Gilles; Dupuy, Christine; Guizien, Katell

    2016-01-01

    Disturbance strongly impacts patterns of community diversity, yet the shape of the diversity-disturbance relationship remains a matter of debate. The topic has been of interest in theoretical ecology for decades as it has practical implications for the understanding of ecosystem services in nature. One of these processes is the remineralization of organic matter by microorganisms in coastal marine sediments, which are periodically impacted by disturbances across the sediment-water interface. Here we set up an experiment to test the hypothesis that disturbance impacts microbial diversity and function during the anaerobic degradation of organic matter in coastal sediments. We show that during the first 3 weeks of the experiment, disturbance increased both microbial production, derived from the increase in microbial abundance, and diversity of the active fraction of the community. Both community diversity and phylogenetic diversity increased, which suggests that disturbance promoted the cohabitation of ecologically different microorganisms. Metagenome analysis also showed that disturbance increased the relative abundance of genes diagnostic of metabolism associated with the sequential anaerobic degradation of organic matter. However, community composition was not impacted in a systematic way and changed over time. In nature, we can hypothesize that moderate storm disturbances, which impact coastal sediments, promote diverse, and productive communities. These events, rather than altering the decomposition of organic matter, may increase the substrate turnover and, ultimately, remineralization rates. PMID:27994581

  4. Phenotypic plasticity in heterotrophic marine microbial communities in continuous cultures

    PubMed Central

    Beier, Sara; Rivers, Adam R; Moran, Mary Ann; Obernosterer, Ingrid

    2015-01-01

    Phenotypic plasticity (PP) is the development of alternate phenotypes of a given taxon as an adaptation to environmental conditions. Methodological limitations have restricted the quantification of PP to the measurement of a few traits in single organisms. We used metatranscriptomic libraries to overcome these challenges and estimate PP using the expressed genes of multiple heterotrophic organisms as a proxy for traits in a microbial community. The metatranscriptomes captured the expression response of natural marine bacterial communities grown on differing carbon resource regimes in continuous cultures. We found that taxa with different magnitudes of PP coexisted in the same cultures, and that members of the order Rhodobacterales had the highest levels of PP. In agreement with previous studies, our results suggest that continuous culturing may have specifically selected for taxa featuring a rather high range of PP. On average, PP and abundance changes within a taxon contributed equally to the organism's change in functional gene abundance, implying that both PP and abundance mediated observed differences in community function. However, not all functional changes due to PP were directly reflected in the bulk community functional response: gene expression changes in individual taxa due to PP were partly masked by counterbalanced expression of the same gene in other taxa. This observation demonstrates that PP had a stabilizing effect on a community's functional response to environmental change. PMID:25397947

  5. Diversity of Secondary Metabolites from Marine Bacillus Species: Chemistry and Biological Activity

    PubMed Central

    Mondol, Muhammad Abdul Mojid; Shin, Hee Jae; Islam, Mohammad Tofazzal

    2013-01-01

    Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activities of secondary metabolites from marine isolates. Side by side, the potential for application of these novel natural products from marine Bacillus strains as drugs, pesticides, carotenoids, and tools for the bioremediation of heavy metal toxicity are also discussed. PMID:23941823

  6. Structure of marine predator and prey communities along environmental gradients in a glaciated fjord

    USGS Publications Warehouse

    Renner, Martin; Arimitsu, Mayumi L.; Piatt, John F.

    2012-01-01

    Spatial patterns of marine predator communities are influenced to varying degrees by prey distribution and environmental gradients. We examined physical and biological attributes of an estuarine fjord with strong glacier influence to determine the factors that most influence the structure of predator and prey communities. Our results suggest that some species, such as walleye pollock (Theragra chalcogramma), black-legged kittiwake (Rissa tridactyla), and glaucous-winged gull (Larus glaucescens), were widely distributed across environmental gradients, indicating less specialization, whereas species such as capelin (Mallotus villosus), harbor seal (Phoca vitulina), and Kittlitz's murrelet (Brachyramphus brevirostris) appeared to have more specialized habitat requirements related to glacial influence. We found that upper trophic level communities were well correlated with their mid trophic level prey community, but strong physical gradients in photic depth, temperature, and nutrients played an important role in community structure as well. Mid-trophic level forage fish communities were correlated with the physical gradients more closely than upper trophic levels were, and they showed strong affinity to tidewater glaciers. Silica was closely correlated with the distribution of fish communities, the mechanisms of which deserve further study.

  7. Chiral alkynylcarbinols from marine sponges: asymmetric synthesis and biological relevance.

    PubMed

    Listunov, Dymytrii; Maraval, Valérie; Chauvin, Remi; Génisson, Yves

    2015-01-01

    Covering: up to March 2014. Previous review on the topic: B. W. Gung, C. R. Chim., 2009, 12, 489-505. Chiral α-functional lipidic propargylic alcohols extracted from marine sponges, in particular of the pacific genus Petrosia, constitute a class of acetylenic natural products exhibiting remarkable in vitro biological activities, especially anti-tumoral cytotoxicity. These properties, associated to functionalities that are uncommon among natural products, have prompted recent projects on asymmetric total synthesis. On the basis of a three-sector structural typology, three main sub-types of secondary alkynylcarbinols (with either alkyl, alkenyl, or alkynyl as the second substituent) can be identified as the minimal pharmacophoric units. Selected natural products containing these functionalities have been targeted using previously known or on purpose-designed procedures, where the stereo-determining step can be: (i) a C-C bond forming reaction (e.g. the Zn-mediated addition of alkynyl nucleophiles to aldehydes in the presence of chiral aminoalcohols), (ii) a functional layout (e.g. the asymmetric organo- or metallo-catalytic reduction of ynones), or (iii) an enantiomeric resolution (e.g. a lipase-mediated kinetic resolution via acetylation). The promising medicinal importance of these targets is finally surveyed, and future investigation prospects are proposed, such as: (i) further total synthesis of known or future extraction products; (ii) the synthesis of non-natural analogues, with simpler lipophilic environments of the alkynylcarbinol-based pharmacophoric units; (iii) the variation and optimization of both the pharmacophoric units and their lipophilic environment; and (iv) investigations into the biological mode of action of these unique structures.

  8. Predicting the effects of climate change on marine communities and the consequences for fisheries

    NASA Astrophysics Data System (ADS)

    Jennings, Simon; Brander, Keith

    2010-02-01

    Climate effects on the structure and function of marine communities have received scant attention. The few existing approaches for predicting climate effects suggest that community responses might be predicted from the responses of component populations. These approaches require a very complex understanding of ecological interactions among populations. An alternate and informative parallel process is to ask whether it is possible to make predictions about community level responses to climate that are independent of knowledge about the identity and dynamics of component populations. We propose that it is possible to make such predictions, based on knowledge of the processes that determine the size-structure of communities. We suggest that theory that relates metabolic scaling, predator-prey interactions and energy transfer in size-based food webs, allows the size-structure and productivity of communities across a range of trophic levels to be predicted, provided that predictions of the effects of climate on primary production are available. One simple application of the community-focused predictions is to ask whether predictions of the size composition and abundance of populations for alternate climate scenarios are compatible with predictions for the size composition and relative abundance of communities. More sophisticated treatments could predict the effects of climate scenarios on multiple interacting populations and compare their combined size-abundance structure and production with that predicted for the community under the same climate scenario. The main weakness of the community approach is that the methods predict abundance and production by size-class rather than taxonomic group, and society would be particularly concerned if climate driven changes had a strong effect on the relative production of fishable and non-fishable species in the community. The main strength of the community approach is that it provides widely applicable 'null' models for assessing

  9. Phylogenetically and Spatially Close Marine Sponges Harbour Divergent Bacterial Communities

    PubMed Central

    Hardoim, Cristiane C. P.; Esteves, Ana I. S.; Pires, Francisco R.; Gonçalves, Jorge M. S.; Cox, Cymon J.; Xavier, Joana R.; Costa, Rodrigo

    2012-01-01

    Recent studies have unravelled the diversity of sponge-associated bacteria that may play essential roles in sponge health and metabolism. Nevertheless, our understanding of this microbiota remains limited to a few host species found in restricted geographical localities, and the extent to which the sponge host determines the composition of its own microbiome remains a matter of debate. We address bacterial abundance and diversity of two temperate marine sponges belonging to the Irciniidae family - Sarcotragus spinosulus and Ircinia variabilis – in the Northeast Atlantic. Epifluorescence microscopy revealed that S. spinosulus hosted significantly more prokaryotic cells than I. variabilis and that prokaryotic abundance in both species was about 4 orders of magnitude higher than in seawater. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles of S. spinosulus and I. variabilis differed markedly from each other – with higher number of ribotypes observed in S. spinosulus – and from those of seawater. Four PCR-DGGE bands, two specific to S. spinosulus, one specific to I. variabilis, and one present in both sponge species, affiliated with an uncultured sponge-specific phylogenetic cluster in the order Acidimicrobiales (Actinobacteria). Two PCR-DGGE bands present exclusively in S. spinosulus fingerprints affiliated with one sponge-specific phylogenetic cluster in the phylum Chloroflexi and with sponge-derived sequences in the order Chromatiales (Gammaproteobacteria), respectively. One Alphaproteobacteria band specific to S. spinosulus was placed in an uncultured sponge-specific phylogenetic cluster with a close relationship to the genus Rhodovulum. Our results confirm the hypothesized host-specific composition of bacterial communities between phylogenetically and spatially close sponge species in the Irciniidae family, with S. spinosulus displaying higher bacterial community diversity and distinctiveness than I. variabilis. These

  10. Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use

    DTIC Science & Technology

    2011-09-30

    Biological, and Acoustic Signals on Marine Mammal Habitat Use Jennifer L. Miksis-Olds Applied Research Laboratory The Pennsylvania State University PO...signals impact marine mammal prey and resulting marine mammal habitat use. This is especially critical in areas like the Bering Sea where global climate...animal presence and habitat use. Objective 1: What effect do changing sea ice dynamics have on zooplankton populations? a) How does zooplankton

  11. Climate scaling behaviour in the dynamics of the marine interstitial ciliate community

    NASA Astrophysics Data System (ADS)

    Varotsos, Costas A.; Mazei, Yuri A.; Burkovsky, Igor; Efstathiou, Maria N.; Tzanis, Chris G.

    2016-08-01

    The present paper uses characteristics of the marine interstitial ciliate community in the White Sea intertidal sandflat during the period of 1991-2011, in order to study its long-term dynamics, investigating in particular whether it exhibits scaling behaviour into its fluctuations, which is a characteristic feature of the climate system. To this aim, a recently proposed version of the detrended fluctuation analysis is herewith employed which has been successfully applied to a wide range of simulated and physiologic time series in recent years. In case that the fluctuations of the ciliate community present self-similarity processes, an ideal field test for the currently proposed biological models will be established, allowing to evaluate their reliability. Indeed, we show for the first time that different ciliate species exhibit long-range power-law persistent correlations. This means that ciliate fluctuations in different intervals are positively correlated, obeying a power-law behaviour. Although the origin of power-law temporal evolution of ciliates should be further investigated, this finding is probably associated with the self-organized criticality of ciliates. It should be noted that the long-range correlations obtained do not imply the presence of specific cycles but rather the existence of dynamic links between long-term and short-term temporal evolution. The scaling behaviour found in marine interstitial ciliate community should be taken into account in the investigation of their response to the present or future climate change.

  12. Marine Biology and Oceanography, Grades Nine to Twelve. Part I.

    ERIC Educational Resources Information Center

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 9-12. The unit, focusing on physical factors influencing life in the sea, is divided into sections dealing with: (1) the ocean floor; (2) tides; (3) ocean waves; (4) ocean currents; (5)…

  13. Marine Biology and Oceanography, Grades Seven and Eight.

    ERIC Educational Resources Information Center

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 7 and 8. The unit, focusing on life in the sea and the physical factors which influence that life, is divided into sections dealing with: (1) the theory of plate tectonics; (2) ocean floor…

  14. Marine Biology and Oceanography, Grades Nine to Twelve. Part I.

    ERIC Educational Resources Information Center

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 9-12. The unit, focusing on physical factors influencing life in the sea, is divided into sections dealing with: (1) the ocean floor; (2) tides; (3) ocean waves; (4) ocean currents; (5)…

  15. Marine Biology and Oceanography, Grades Seven and Eight.

    ERIC Educational Resources Information Center

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 7 and 8. The unit, focusing on life in the sea and the physical factors which influence that life, is divided into sections dealing with: (1) the theory of plate tectonics; (2) ocean floor…

  16. Differential responses of marine communities to natural and anthropogenic changes.

    PubMed

    Kowalewski, Michał; Wittmer, Jacalyn M; Dexter, Troy A; Amorosi, Alessandro; Scarponi, Daniele

    2015-03-22

    Responses of ecosystems to environmental changes vary greatly across habitats, organisms and observational scales. The Quaternary fossil record of the Po Basin demonstrates that marine communities of the northern Adriatic re-emerged unchanged following the most recent glaciation, which lasted approximately 100,000 years. The Late Pleistocene and Holocene interglacial ecosystems were both dominated by the same species, species turnover rates approximated predictions of resampling models of a homogeneous system, and comparable bathymetric gradients in species composition, sample-level diversity, dominance and specimen abundance were observed in both time intervals. The interglacial Adriatic ecosystems appear to have been impervious to natural climate change either owing to their persistence during those long-term perturbations or their resilient recovery during interglacial phases of climate oscillations. By contrast, present-day communities of the northern Adriatic differ notably from their Holocene counterparts. The recent ecosystem shift stands in contrast to the long-term endurance of interglacial communities in face of climate-driven environmental changes.

  17. Differential responses of marine communities to natural and anthropogenic changes

    PubMed Central

    Kowalewski, Michał; Wittmer, Jacalyn M.; Dexter, Troy A.; Amorosi, Alessandro; Scarponi, Daniele

    2015-01-01

    Responses of ecosystems to environmental changes vary greatly across habitats, organisms and observational scales. The Quaternary fossil record of the Po Basin demonstrates that marine communities of the northern Adriatic re-emerged unchanged following the most recent glaciation, which lasted approximately 100 000 years. The Late Pleistocene and Holocene interglacial ecosystems were both dominated by the same species, species turnover rates approximated predictions of resampling models of a homogeneous system, and comparable bathymetric gradients in species composition, sample-level diversity, dominance and specimen abundance were observed in both time intervals. The interglacial Adriatic ecosystems appear to have been impervious to natural climate change either owing to their persistence during those long-term perturbations or their resilient recovery during interglacial phases of climate oscillations. By contrast, present-day communities of the northern Adriatic differ notably from their Holocene counterparts. The recent ecosystem shift stands in contrast to the long-term endurance of interglacial communities in face of climate-driven environmental changes. PMID:25673689

  18. The Gut Bacterial Community of Mammals from Marine and Terrestrial Habitats

    PubMed Central

    Nelson, Tiffanie M.; Rogers, Tracey L.; Brown, Mark V.

    2013-01-01

    After birth, mammals acquire a community of bacteria in their gastro-intestinal tract, which harvests energy and provides nutrients for the host. Comparative studies of numerous terrestrial mammal hosts have identified host phylogeny, diet and gut morphology as primary drivers of the gut bacterial community composition. To date, marine mammals have been excluded from these comparative studies, yet they represent distinct examples of evolutionary history, diet and lifestyle traits. To provide an updated understanding of the gut bacterial community of mammals, we compared bacterial 16S rRNA gene sequence data generated from faecal material of 151 marine and terrestrial mammal hosts. This included 42 hosts from a marine habitat. When compared to terrestrial mammals, marine mammals clustered separately and displayed a significantly greater average relative abundance of the phylum Fusobacteria. The marine carnivores (Antarctic and Arctic seals) and the marine herbivore (dugong) possessed significantly richer gut bacterial community than terrestrial carnivores and terrestrial herbivores, respectively. This suggests that evolutionary history and dietary items specific to the marine environment may have resulted in a gut bacterial community distinct to that identified in terrestrial mammals. Finally we hypothesize that reduced marine trophic webs, whereby marine carnivores (and herbivores) feed directly on lower trophic levels, may expose this group to high levels of secondary metabolites and influence gut microbial community richness. PMID:24386245

  19. The gut bacterial community of mammals from marine and terrestrial habitats.

    PubMed

    Nelson, Tiffanie M; Rogers, Tracey L; Brown, Mark V

    2013-01-01

    After birth, mammals acquire a community of bacteria in their gastro-intestinal tract, which harvests energy and provides nutrients for the host. Comparative studies of numerous terrestrial mammal hosts have identified host phylogeny, diet and gut morphology as primary drivers of the gut bacterial community composition. To date, marine mammals have been excluded from these comparative studies, yet they represent distinct examples of evolutionary history, diet and lifestyle traits. To provide an updated understanding of the gut bacterial community of mammals, we compared bacterial 16S rRNA gene sequence data generated from faecal material of 151 marine and terrestrial mammal hosts. This included 42 hosts from a marine habitat. When compared to terrestrial mammals, marine mammals clustered separately and displayed a significantly greater average relative abundance of the phylum Fusobacteria. The marine carnivores (Antarctic and Arctic seals) and the marine herbivore (dugong) possessed significantly richer gut bacterial community than terrestrial carnivores and terrestrial herbivores, respectively. This suggests that evolutionary history and dietary items specific to the marine environment may have resulted in a gut bacterial community distinct to that identified in terrestrial mammals. Finally we hypothesize that reduced marine trophic webs, whereby marine carnivores (and herbivores) feed directly on lower trophic levels, may expose this group to high levels of secondary metabolites and influence gut microbial community richness.

  20. Genome Annotation in a Community College Cell Biology Lab

    ERIC Educational Resources Information Center

    Beagley, C. Timothy

    2013-01-01

    The Biology Department at Salt Lake Community College has used the IMG-ACT toolbox to introduce a genome mapping and annotation exercise into the laboratory portion of its Cell Biology course. This project provides students with an authentic inquiry-based learning experience while introducing them to computational biology and contemporary learning…

  1. Genome Annotation in a Community College Cell Biology Lab

    ERIC Educational Resources Information Center

    Beagley, C. Timothy

    2013-01-01

    The Biology Department at Salt Lake Community College has used the IMG-ACT toolbox to introduce a genome mapping and annotation exercise into the laboratory portion of its Cell Biology course. This project provides students with an authentic inquiry-based learning experience while introducing them to computational biology and contemporary learning…

  2. Community composition has greater impact on the functioning of marine phytoplankton communities than ocean acidification.

    PubMed

    Eggers, Sarah L; Lewandowska, Aleksandra M; Barcelos E Ramos, Joana; Blanco-Ameijeiras, Sonia; Gallo, Francesca; Matthiessen, Birte

    2014-03-01

    Ecosystem functioning is simultaneously affected by changes in community composition and environmental change such as increasing atmospheric carbon dioxide (CO2 ) and subsequent ocean acidification. However, it largely remains uncertain how the effects of these factors compare to each other. Addressing this question, we experimentally tested the hypothesis that initial community composition and elevated CO2 are equally important to the regulation of phytoplankton biomass. We full-factorially exposed three compositionally different marine phytoplankton communities to two different CO2 levels and examined the effects and relative importance (ω(2) ) of the two factors and their interaction on phytoplankton biomass at bloom peak. The results showed that initial community composition had a significantly greater impact than elevated CO2 on phytoplankton biomass, which varied largely among communities. We suggest that the different initial ratios between cyanobacteria, diatoms, and dinoflagellates might be the key for the varying competitive and thus functional outcome among communities. Furthermore, the results showed that depending on initial community composition elevated CO2 selected for larger sized diatoms, which led to increased total phytoplankton biomass. This study highlights the relevance of initial community composition, which strongly drives the functional outcome, when assessing impacts of climate change on ecosystem functioning. In particular, the increase in phytoplankton biomass driven by the gain of larger sized diatoms in response to elevated CO2 potentially has strong implications for nutrient cycling and carbon export in future oceans. © 2013 John Wiley & Sons Ltd.

  3. Biological activities and potential health benefits of bioactive peptides derived from marine organisms.

    PubMed

    Ngo, Dai-Hung; Vo, Thanh-Sang; Ngo, Dai-Nghiep; Wijesekara, Isuru; Kim, Se-Kwon

    2012-11-01

    Marine organisms have been recognized as rich sources of bioactive compounds with valuable nutraceutical and pharmaceutical potentials. Recently, marine bioactive peptides have gained much attention because of their numerous health beneficial effects. Notably, these peptides exhibit various biological activities such as antioxidant, anti-hypertensive, anti-human immunodeficiency virus, anti-proliferative, anticoagulant, calcium-binding, anti-obesity and anti-diabetic activities. This review mainly presents biological activities of peptides from marine organisms and emphasizing their potential applications in foods as well as pharmaceutical areas.

  4. Synthetic Biology and Metabolic Engineering for Marine Carotenoids: New Opportunities and Future Prospects

    PubMed Central

    Wang, Chonglong; Kim, Jung-Hun; Kim, Seon-Won

    2014-01-01

    Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations. PMID:25233369

  5. Synthetic biology and metabolic engineering for marine carotenoids: new opportunities and future prospects.

    PubMed

    Wang, Chonglong; Kim, Jung-Hun; Kim, Seon-Won

    2014-09-17

    Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations.

  6. Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

    SciTech Connect

    1994-12-31

    The ocean plays an important role in regulating the earth`s climate, sustains a large portion of the earth`s biodiversity, is a tremendous reservoir of commercially important substances, and is used for a variety of often conflicting purposes. In recent decades marine scientists have discovered much about the ocean and its organisms, yet many important fundamental questions remain unanswered. Human populations have increased, particularly in coastal regions. As a result, the marine environment in these areas is increasingly disrupted by human activities, including pollution and the depletion of some ecologically and commercially important species. There is a sense of urgency about reducing human impacts on the ocean and a need to understand how altered ecosystems and the loss of marine species and biodiversity could affect society. During the past two decades, the development of sophisticated technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. While some of these technologies have been readily incorporated into the study of marine organisms as models for understanding basic biology, the value of molecular techniques for addressing problems in marine biology and biological oceanography has only recently begun to be appreciated. This report defines critical scientific questions in marine biology and biological oceanography, describes the molecular technologies that could be used to answer these questions, and discusses some of the implications and economic opportunities that might result from this research which could potentially improve the international competitive position of the United States in the rapidly growing area of marine biotechnology. The committee recommends that the federal government provide the infrastructure necessary to use the techniques of molecular biology in the marine sciences.

  7. The Fate of Marine Bacterial Exopolysaccharide in Natural Marine Microbial Communities

    SciTech Connect

    Zhang, Zilian; Chen, Yi; Wang, Rui; Cai, Ruanhong; Fu, Yingnan; Jiao, Nianzhi; Quigg, Antonietta

    2015-11-16

    Most marine bacteria produce exopolysaccharides (EPS), and bacterial EPS represent an important source of dissolved organic carbon in marine ecosystems. It was proposed that bacterial EPS rich in uronic acid is resistant to mineralization by microbes and thus has a long residence time in global oceans. To confirm this hypothesis, bacterial EPS rich in galacturonic acid was isolated from Alteromonas sp. JL2810. The EPS was used to amend natural seawater to investigate the bioavailability of this EPS by native populations, in the presence and absence of ammonium and phosphate amendment. The data indicated that the bacterial EPS could not be completely consumed during the cultivation period and that the bioavailability of EPS was not only determined by its intrinsic properties, but was also determined by other factors such as the availability of inorganic nutrients. During the experiment, the humic-like component of fluorescent dissolved organic matter (FDOM) was freshly produced. Bacterial community structure analysis indicated that the class Flavobacteria of the phylum Bacteroidetes was the major contributor for the utilization of EPS. This report is the first to indicate that Flavobacteria are a major contributor to bacterial EPS degradation. Finally, the fraction of EPS that could not be completely utilized and the FDOM (e.g., humic acid-like substances) produced de novo may be refractory and may contribute to the carbon storage in the oceans.

  8. The Fate of Marine Bacterial Exopolysaccharide in Natural Marine Microbial Communities

    DOE PAGES

    Zhang, Zilian; Chen, Yi; Wang, Rui; ...

    2015-11-16

    Most marine bacteria produce exopolysaccharides (EPS), and bacterial EPS represent an important source of dissolved organic carbon in marine ecosystems. It was proposed that bacterial EPS rich in uronic acid is resistant to mineralization by microbes and thus has a long residence time in global oceans. To confirm this hypothesis, bacterial EPS rich in galacturonic acid was isolated from Alteromonas sp. JL2810. The EPS was used to amend natural seawater to investigate the bioavailability of this EPS by native populations, in the presence and absence of ammonium and phosphate amendment. The data indicated that the bacterial EPS could not bemore » completely consumed during the cultivation period and that the bioavailability of EPS was not only determined by its intrinsic properties, but was also determined by other factors such as the availability of inorganic nutrients. During the experiment, the humic-like component of fluorescent dissolved organic matter (FDOM) was freshly produced. Bacterial community structure analysis indicated that the class Flavobacteria of the phylum Bacteroidetes was the major contributor for the utilization of EPS. This report is the first to indicate that Flavobacteria are a major contributor to bacterial EPS degradation. Finally, the fraction of EPS that could not be completely utilized and the FDOM (e.g., humic acid-like substances) produced de novo may be refractory and may contribute to the carbon storage in the oceans.« less

  9. The Fate of Marine Bacterial Exopolysaccharide in Natural Marine Microbial Communities

    PubMed Central

    Zhang, Zilian; Chen, Yi; Wang, Rui; Cai, Ruanhong; Fu, Yingnan; Jiao, Nianzhi

    2015-01-01

    Most marine bacteria produce exopolysaccharides (EPS), and bacterial EPS represent an important source of dissolved organic carbon in marine ecosystems. It was proposed that bacterial EPS rich in uronic acid is resistant to mineralization by microbes and thus has a long residence time in global oceans. To confirm this hypothesis, bacterial EPS rich in galacturonic acid was isolated from Alteromonas sp. JL2810. The EPS was used to amend natural seawater to investigate the bioavailability of this EPS by native populations, in the presence and absence of ammonium and phosphate amendment. The data indicated that the bacterial EPS could not be completely consumed during the cultivation period and that the bioavailability of EPS was not only determined by its intrinsic properties, but was also determined by other factors such as the availability of inorganic nutrients. During the experiment, the humic-like component of fluorescent dissolved organic matter (FDOM) was freshly produced. Bacterial community structure analysis indicated that the class Flavobacteria of the phylum Bacteroidetes was the major contributor for the utilization of EPS. This report is the first to indicate that Flavobacteria are a major contributor to bacterial EPS degradation. The fraction of EPS that could not be completely utilized and the FDOM (e.g., humic acid-like substances) produced de novo may be refractory and may contribute to the carbon storage in the oceans. PMID:26571122

  10. Microbial Communities from Methane Hydrate-Bearing Deep Marine Sediments

    SciTech Connect

    Reed, David William; Fujita, Yoshiko; Delwiche, Mark Edmond; Blackwelder, David Bradley; Colwell, Frederick Scott; Uchida, T.

    2002-08-01

    Microbial communities in cores obtained from methane hydrate-bearing deep marine sediments (down to more than 300 m below the seafloor) in the forearc basin of the Nankai Trough near Japan were characterized with cultivation-dependent and -independent techniques. Acridine orange direct count data indicated that cell numbers generally decreased with sediment depth. Lipid biomarker analyses indicated the presence of viable biomass at concentrations greater than previously reported for terrestrial subsurface environments at similar depths. Archaeal lipids were more abundant than bacterial lipids. Methane was produced from both acetate and hydrogen in enrichments inoculated with sediment from all depths evaluated, at both 10 and 35°C. Characterization of 16S rRNA genes amplified from the sediments indicated that archaeal clones could be discretely grouped within the Euryarchaeota and Crenarchaeota domains. The bacterial clones exhibited greater overall diversity than the archaeal clones, with sequences related to the Bacteroidetes, Planctomycetes, Actinobacteria, Proteobacteria, and green nonsulfur groups. The majority of the bacterial clones were either members of a novel lineage or most closely related to uncultured clones. The results of these analyses suggest that the microbial community in this environment is distinct from those in previously characterized methane hydrate-bearing sediments.

  11. Exploring community structure in biological networks with random graphs

    PubMed Central

    2014-01-01

    Background Community structure is ubiquitous in biological networks. There has been an increased interest in unraveling the community structure of biological systems as it may provide important insights into a system’s functional components and the impact of local structures on dynamics at a global scale. Choosing an appropriate community detection algorithm to identify the community structure in an empirical network can be difficult, however, as the many algorithms available are based on a variety of cost functions and are difficult to validate. Even when community structure is identified in an empirical system, disentangling the effect of community structure from other network properties such as clustering coefficient and assortativity can be a challenge. Results Here, we develop a generative model to produce undirected, simple, connected graphs with a specified degrees and pattern of communities, while maintaining a graph structure that is as random as possible. Additionally, we demonstrate two important applications of our model: (a) to generate networks that can be used to benchmark existing and new algorithms for detecting communities in biological networks; and (b) to generate null models to serve as random controls when investigating the impact of complex network features beyond the byproduct of degree and modularity in empirical biological networks. Conclusion Our model allows for the systematic study of the presence of community structure and its impact on network function and dynamics. This process is a crucial step in unraveling the functional consequences of the structural properties of biological systems and uncovering the mechanisms that drive these systems. PMID:24965130

  12. Biology of the Marine Heterotrophic Dinoflagellate Oxyrrhis marina: Current Status and Future Directions

    PubMed Central

    Guo, Zhiling; Zhang, Huan; Liu, Sheng; Lin, Senjie

    2013-01-01

    Heterotrophic dinoflagellates are prevalent protists in marine environments, which play an important role in the carbon cycling and energy flow in the marine planktonic community. Oxyrrhis marina (Dinophyceae), a widespread heterotrophic dinoflagellate, is a model species used for a broad range of ecological, biogeographic, and evolutionary studies. Despite the increasing research effort on this species, there lacks a synthesis of the existing data and a coherent picture of this organism. Here we reviewed the literature to provide an overview of what is known regarding the biology of O. marina, and identify areas where further studies are needed. As an early branch of the dinoflagellate lineage, O. marina shares similarity with typical dinoflagellates in permanent condensed chromosomes, less abundant nucleosome proteins compared to other eukaryotes, multiple gene copies, the occurrence of trans-splicing in nucleus-encoded mRNAs, highly fragmented mitochondrial genome, and disuse of ATG as a start codon for mitochondrial genes. On the other hand, O. marina also exhibits some distinct cytological features (e.g., different flagellar structure, absence of girdle and sulcus or pustules, use of intranuclear spindle in mitosis, presence of nuclear plaque, and absence of birefringent periodic banded chromosomal structure) and genetic features (e.g., a single histone-like DNA-associated protein, cob-cox3 gene fusion, 5′ oligo-U cap in the mitochondrial transcripts of protein-coding genes, the absence of mRNA editing, the presence of stop codon in the fused cob-cox3 mRNA produced by post-transcriptional oligoadenylation, and vestigial plastid genes). The best-studied biology of this dinoflagellate is probably the prey and predators types, which include a wide range of organisms. On the other hand, the abundance of this species in the natural waters and its controlling factors, genome organization and gene expression regulation that underlie the unusual cytological and

  13. Biology of the Marine Heterotrophic Dinoflagellate Oxyrrhis marina: Current Status and Future Directions.

    PubMed

    Guo, Zhiling; Zhang, Huan; Liu, Sheng; Lin, Senjie

    2013-10-21

    Heterotrophic dinoflagellates are prevalent protists in marine environments, which play an important role in the carbon cycling and energy flow in the marine planktonic community. Oxyrrhismarina (Dinophyceae), a widespread heterotrophic dinoflagellate, is a model species used for a broad range of ecological, biogeographic, and evolutionary studies. Despite the increasing research effort on this species, there lacks a synthesis of the existing data and a coherent picture of this organism. Here we reviewed the literature to provide an overview of what is known regarding the biology of O. marina, and identify areas where further studies are needed. As an early branch of the dinoflagellate lineage, O. marina shares similarity with typical dinoflagellates in permanent condensed chromosomes, less abundant nucleosome proteins compared to other eukaryotes, multiple gene copies, the occurrence of trans-splicing in nucleus-encoded mRNAs, highly fragmented mitochondrial genome, and disuse of ATG as a start codon for mitochondrial genes. On the other hand, O. marina also exhibits some distinct cytological features (e.g., different flagellar structure, absence of girdle and sulcus or pustules, use of intranuclear spindle in mitosis, presence of nuclear plaque, and absence of birefringent periodic banded chromosomal structure) and genetic features (e.g., a single histone-like DNA-associated protein, cob-cox3 gene fusion, 5' oligo-U cap in the mitochondrial transcripts of protein-coding genes, the absence of mRNA editing, the presence of stop codon in the fused cob-cox3 mRNA produced by post-transcriptional oligoadenylation, and vestigial plastid genes). The best-studied biology of this dinoflagellate is probably the prey and predators types, which include a wide range of organisms. On the other hand, the abundance of this species in the natural waters and its controlling factors, genome organization and gene expression regulation that underlie the unusual cytological and

  14. Ecology of selected marine communities in Glacier Bay: Zooplankton, forage fish, seabirds and marine mammals

    USGS Publications Warehouse

    Robards, Martin D.; Drew, Gary S.; Piatt, John F.; Anson, Jennifer Marie; Abookire, Alisa A.; Bodkin, James L.; Hooge, Philip N.; Speckman, Suzann G.

    2003-01-01

    We studied oceanography (including primary production), secondary production, small schooling fish (SSF), and marine bird and mammal predators in Glacier Bay during 1999 and 2000. Results from these field efforts were combined with a review of current literature relating to the Glacier Bay environment. Since the conceptual model developed by Hale and Wright (1979) ‘changes and cycles’ continue to be the underlying theme of the Glacier Bay ecosystem. We found marked seasonality in many of the parameters that we investigated over the two years of research, and here we provide a comprehensive description of the distribution and relative abundance of a wide array of marine biota. Glacier Bay is a tidally mixed estuary that leads into basins, which stratify in summer, with the upper arms behaving as traditional estuaries. The Bay is characterized by renewal and mixing events throughout the year, and markedly higher primary production than in many neighboring southeast Alaska fjords (Hooge and Hooge, 2002). Zooplankton diversity and abundance within the upper 50 meters of the water column in Glacier Bay is similar to communities seen throughout the Gulf of Alaska. Zooplankton in the lower regions of Glacier Bay peak in abundance in late May or early June, as observed at Auke Bay and in the Gulf of Alaska. The key distinction between the lower Bay and other estuaries in the Gulf of Alaska is that a second smaller peak in densities occurs in August. The upper Bay behaved uniformly in temporal trends, peaking in July. Densities had begun to decline in August, but were still more than twice those observed in that region in May. The highest density of zooplankton observed was 17,870 organisms/m3 in Tarr Inlet during July. Trends in zooplankton community abundance and diversity within the lower Bay were distinct from upper-Glacier Bay trends. Whereas the lower Bay is strongly influenced by Gulf of Alaska processes, local processes are the strongest influence in the upper

  15. Deciphering associations between dissolved organic molecules and bacterial communities in a pelagic marine system

    PubMed Central

    Osterholz, Helena; Singer, Gabriel; Wemheuer, Bernd; Daniel, Rolf; Simon, Meinhard; Niggemann, Jutta; Dittmar, Thorsten

    2016-01-01

    Dissolved organic matter (DOM) is the main substrate and energy source for heterotrophic bacterioplankton. To understand the interactions between DOM and the bacterial community (BC), it is important to identify the key factors on both sides in detail, chemically distinct moieties in DOM and the various bacterial taxa. Next-generation sequencing facilitates the classification of millions of reads of environmental DNA and RNA amplicons and ultrahigh-resolution mass spectrometry yields up to 10 000 DOM molecular formulae in a marine water sample. Linking this detailed biological and chemical information is a crucial first step toward a mechanistic understanding of the role of microorganisms in the marine carbon cycle. In this study, we interpreted the complex microbiological and molecular information via a novel combination of multivariate statistics. We were able to reveal distinct relationships between the key factors of organic matter cycling along a latitudinal transect across the North Sea. Total BC and DOM composition were mainly driven by mixing of distinct water masses and presumably retain their respective terrigenous imprint on similar timescales on their way through the North Sea. The active microbial community, however, was rather influenced by local events and correlated with specific DOM molecular formulae indicative of compounds that are easily degradable. These trends were most pronounced on the highest resolved level, that is, operationally defined ‘species', reflecting the functional diversity of microorganisms at high taxonomic resolution. PMID:26800236

  16. Fungal community dynamics during a marine dinoflagellate (Noctiluca scintillans) bloom.

    PubMed

    Sun, Jing-Yun; Song, Yu; Ma, Zhi-Ping; Zhang, Huai-Jing; Yang, Zhong-Duo; Cai, Zhong-Hua; Zhou, Jin

    2017-10-04

    Contamination and eutrophication have caused serious ecological events (such as algal bloom) in coastal area. During this ecological process, microbial community structure is critical for algal bloom succession. The diversity and composition of bacteria and archaea communities in algal blooms have been widely investigated; however, those of fungi are poorly understood. To fill this gap, we used pyrosequencing and correlation approaches to assess fungal patterns and associations during a dinoflagellate (Noctiluca scintillans) bloom. Phylum level fungal types were predominated by Ascomycota, Chytridiomycota, Mucoromycotina, and Basidiomycota. At the genus level drastic changes were observed with Hysteropatella, Malassezia and Saitoella dominating during the initial bloom stage, while Malassezia was most abundant (>50%) during onset and peak-bloom stages. Saitoella and Lipomyces gradually became more abundant and, in the decline stage, contributed almost 70% of sequences. In the terminal stage of the bloom, Rozella increased rapidly to a maximum of 50-60%. Fungal population structure was significantly influenced by temperature and substrate (N and P) availability (P < 0.05). Inter-specific network analyses demonstrated that Rozella and Saitoella fungi strongly impacted the ecological trajectory of N. scintillans. The functional prediction show that symbiotrophic fungi was dominated in the onset stage; saprotroph type was the primary member present during the exponential growth period; whereas pathogentroph type fungi enriched in decline phase. Overall, fungal communities and functions correlated significantly with N. scintillans processes, suggesting that they may regulate dinoflagellate bloom fates. Our results will facilitate deeper understanding of the ecological importance of marine fungi and their roles in algal bloom formation and collapse. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. [Hyperbolic growth of marine and continental biodiversity through the phanerozoic and community evolution].

    PubMed

    Markov, A V; Korotaev, A V

    2008-01-01

    Among diverse models that are used to describe and interpret the changes in global biodiversity through the Phanerozoic, the exponential and logistic models (traditionally used in population biology) are the most popular. As we have recently demonstrated (Markov, Korotayev, 2007), the growth of the Phanerozoic marine biodiversity at genus level correlates better with the hyperbolic model (widely used in demography and macrosociology). Here we show that the hyperbolic model is also applicable to the Phanerozoic continental biota at genus and family levels, and to the marine biota at species, genus, and family levels. There are many common features in the evolutionary dynamics of the marine and continental biotas that imply similarity and common nature of the factors and mechanisms underlying the hyperbolic growth. Both marine and continental biotas are characterized by continuous growth of the mean longevity of taxa, by decreasing extinction and origination rates, by similar pattern of replacement of dominant groups, by stepwise accumulation of evolutionary stable, adaptable and "physiologically buffered" taxa with effective mechanisms of parental care, protection of early developmental stages, etc. At the beginning of the development of continental biota, the observed taxonomic diversity was substantially lower than that predicted by the hyperbolic model. We suggest that this is due, firstly, to the fact that, during the earliest stages of the continental biota evolution, the groups that are not preserved in the fossil record (such as soil bacteria, unicellular algae, lichens, etc.) played a fundamental role, and secondly, to the fact that the continental biota initially formed as a marginal portion of the marine biota, rather than a separate system. The hyperbolic dynamics is most prominent when both marine and continental biotas are considered together. This fact can be interpreted as a proof of the integrated nature of the biosphere. In the macrosociological

  18. Biological activities and health effects of terpenoids from marine fungi.

    PubMed

    Kim, Se-Kwon; Li, Yong-Xin

    2012-01-01

    Recently, a great deal of interest has been developed by the consumers toward natural bioactive compounds as functional ingredients in the nutraceutical, cosmeceutical, and pharmaceutical products due to their various health beneficial effects. Hence, it can be suggested that bioactive functional ingredients from marine bioresources and their by-products are alternative sources for synthetic ingredients that can contribute to consumer's well-being, as a part of nutraceuticals and functional foods. Marine-derived fungi produce a vast array of secondary metabolites including terpenes, steroids, polyketides, peptides, alkaloids, and polysaccharides. These secondary metabolites serve many biopharmaceutical purposes. This chapter discusses about marine fungi-derived terpenoids and presents an overview of their beneficial health effects.

  19. Marine organic aerosol and oceanic biological activity: what we know and what we need (Invited)

    NASA Astrophysics Data System (ADS)

    Facchini, M.

    2009-12-01

    Observations carried out in the North Atlantic as well as in other marine locations evidenced a seasonal dependence of sub micron particle chemical composition on biological oceanic activity and a potentially important marine aerosol organic component from primary and/or secondary formation processes associated to marine vegetation and its seasonal cycle. Primary organics generated by bubble bursting in high biological activity periods are almost entirely water insoluble (WIOM up to 96 ± 2 % )and are constituted by aggregation of lipopolysaccharides exuded by phytoplankton with dominant surface tension character. In many marine environments the secondary organic fraction is dominated by MSA and by several oxygenated species (mainly carboxylic acids). New measurements also show the potential importance of secondary organic N species (biogenic amine salts ). However a large fraction of the secondary organic fraction (SOA) is still not characterized and the precursors are not identified. For modeling marine organics, besides reducing the uncertainty in the knowledge of the chemical composition and new precursors, it is of crucial importance to link marine aerosol organic composition to satellite products that could be better proxy for marine biological activity and of its decomposition products than chlorophyll-a.

  20. Synthesis and biology of cyclic imine toxins, an emerging class of potent, globally distributed marine toxins.

    PubMed

    Stivala, Craig E; Benoit, Evelyne; Aráoz, Rómulo; Servent, Denis; Novikov, Alexei; Molgó, Jordi; Zakarian, Armen

    2015-03-01

    From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulation in shellfish, and chemical stability are important considerations in assessing risk factors for human health. This review article aims to provide an account of chemistry, biology, and toxicology of CI toxins from their discovery to the present day.

  1. The Coastal Marine Biology Program at the University of Puerto Rico at Humacao

    NASA Astrophysics Data System (ADS)

    Sastre, M.; Vélez, S.; Parrilla, D.; Ortiz, E.; Rosa, B.

    2016-02-01

    Our Marine Biology Program at the University of Puerto Rico at Humacao is one of the four BS programs available in the Department of Biology at this institution. This program started approximately thirty years ago and was the first program of this kind in Puerto Rico. The program admits every year approximatley 55 students. The retention rate of this program is approximately 35 percent. Approximately 16 students graduate every year from the program. Graduated student usually work in marine biology-related fields such as environmental law, etc.

  2. Global change and marine communities: alien species and climate change.

    PubMed

    Occhipinti-Ambrogi, Anna

    2007-01-01

    Anthropogenic influences on the biosphere since the advent of the industrial age are increasingly causing global changes. Climatic change and the rising concentration of greenhouse gases in the atmosphere are ranking high in scientific and public agendas, and other components of global change are also frequently addressed, among which are the introductions of non indigenous species (NIS) in biogeographic regions well separated from the donor region, often followed by spectacular invasions. In the marine environment, both climatic change and spread of alien species have been studied extensively; this review is aimed at examining the main responses of ecosystems to climatic change, taking into account the increasing importance of biological invasions. Some general principles on NIS introductions in the marine environment are recalled, such as the importance of propagule pressure and of development stages during the time course of an invasion. Climatic change is known to affect many ecological properties; it interacts also with NIS in many possible ways. Direct (proximate) effects on individuals and populations of altered physical-chemical conditions are distinguished from indirect effects on emergent properties (species distribution, diversity, and production). Climatically driven changes may affect both local dispersal mechanisms, due to the alteration of current patterns, and competitive interactions between NIS and native species, due to the onset of new thermal optima and/or different carbonate chemistry. As well as latitudinal range expansions of species correlated with changing temperature conditions, and effects on species richness and the correlated extinction of native species, some invasions may provoke multiple effects which involve overall ecosystem functioning (material flow between trophic groups, primary production, relative extent of organic material decomposition, extent of benthic-pelagic coupling). Some examples are given, including a special

  3. COMPARISON OF BIOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

    EPA Science Inventory

    Obtaining an adequate, representative sample of biological communities or assemblages to make richness or compositional comparisons among sites is a continuing challenge. Traditionally, sample size is based on numbers of replicates or area collected or numbers of individuals enum...

  4. Quantifying the response of structural complexity and community composition to environmental change in marine communities.

    PubMed

    Ferrari, Renata; Bryson, Mitch; Bridge, Tom; Hustache, Julie; Williams, Stefan B; Byrne, Maria; Figueira, Will

    2016-05-01

    Habitat structural complexity is a key factor shaping marine communities. However, accurate methods for quantifying structural complexity underwater are currently lacking. Loss of structural complexity is linked to ecosystem declines in biodiversity and resilience. We developed new methods using underwater stereo-imagery spanning 4 years (2010-2013) to reconstruct 3D models of coral reef areas and quantified both structural complexity at two spatial resolutions (2.5 and 25 cm) and benthic community composition to characterize changes after an unprecedented thermal anomaly on the west coast of Australia in 2011. Structural complexity increased at both resolutions in quadrats (4 m(2)) that bleached, but not those that did not bleach. Changes in complexity were driven by species-specific responses to warming, highlighting the importance of identifying small-scale dynamics to disentangle ecological responses to disturbance. We demonstrate an effective, repeatable method for quantifying the relationship among community composition, structural complexity and ocean warming, improving predictions of the response of marine ecosystems to environmental change. © 2015 John Wiley & Sons Ltd.

  5. Bioaccumulation and biological effects of cigarette litter in marine worms

    PubMed Central

    Wright, Stephanie L.; Rowe, Darren; Reid, Malcolm J.; Thomas, Kevin V.; Galloway, Tamara S.

    2015-01-01

    Marine debris is a global environmental issue. Smoked cigarette filters are the predominant coastal litter item; 4.5 trillion are littered annually, presenting a source of bioplastic microfibres (cellulose acetate) and harmful toxicants to marine environments. Despite the human health risks associated with smoking, little is known of the hazards cigarette filters present to marine life. Here we studied the impacts of smoked cigarette filter toxicants and microfibres on the polychaete worm Hediste diversicolor (ragworm), a widespread inhabitant of coastal sediments. Ragworms exposed to smoked cigarette filter toxicants in seawater at concentrations 60 fold lower than those reported for urban run-off exhibited significantly longer burrowing times, >30% weight loss, and >2-fold increase in DNA damage compared to ragworms maintained in control conditions. In contrast, ragworms exposed to smoked cigarette filter microfibres in marine sediment showed no significant effects. Bioconcentration factors for nicotine were 500 fold higher from seawater than from sediment. Our results illustrate the vulnerability of organisms in the water column to smoking debris and associated toxicants, and highlight the risks posed by smoked cigarette filter debris to aquatic life. PMID:26369692

  6. An overview of recent research in marine biological invasions.

    PubMed

    Chan, Farrah T; Briski, Elizabeta

    2017-01-01

    The Topical Collection on Invasive Species includes 50 articles addressing many tenets of marine invasion ecology. The collection covers important topics relating to propagule pressure associated with transport vectors, species characteristics, attributes of recipient ecosystems, invasion genetics, biotic interactions, testing of invasion hypotheses, invasion dynamics and spread, and impacts of nonindigenous species. This article summarizes some of the collection's highlights.

  7. How-to-Do-It. Community Biology.

    ERIC Educational Resources Information Center

    Stencel, John E.

    1990-01-01

    Described is a project in which students find a living population in their community and either study it in the field or bring it into the laboratory for study. Seven example projects are suggested. (CW)

  8. How-to-Do-It. Community Biology.

    ERIC Educational Resources Information Center

    Stencel, John E.

    1990-01-01

    Described is a project in which students find a living population in their community and either study it in the field or bring it into the laboratory for study. Seven example projects are suggested. (CW)

  9. Integrated metagenomic and metaproteomic analyses of marine biofilm communities.

    PubMed

    Leary, Dagmar H; Li, Robert W; Hamdan, Leila J; Hervey, W Judson; Lebedev, Nikolai; Wang, Zheng; Deschamps, Jeffrey R; Kusterbeck, Anne W; Vora, Gary J

    2014-01-01

    Metagenomic and metaproteomic analyses were utilized to determine the composition and function of complex air-water interface biofilms sampled from the hulls of two US Navy destroyers. Prokaryotic community analyses using PhyloChip-based 16S rDNA profiling revealed two significantly different and taxonomically rich biofilm communities (6,942 taxa) in which the majority of unique taxa were ascribed to members of the Gammaproteobacteria, Alphaproteobacteria and Clostridia. Although metagenomic sequencing indicated that both biofilms were dominated by prokaryotic sequence reads (> 91%) with the majority of the bacterial reads belonging to the Alphaproteobacteria, the Ship-1 metagenome harbored greater organismal and functional diversity and was comparatively enriched for sequences from Cyanobacteria, Bacteroidetes and macroscopic eukaryotes, whereas the Ship-2 metagenome was enriched for sequences from Proteobacteria and microscopic photosynthetic eukaryotes. Qualitative liquid chromatography-tandem mass spectrometry metaproteome analyses identified 678 unique proteins, revealed little overlap in species and protein composition between the ships and contrasted with the metagenomic data in that ~80% of classified and annotated proteins were of eukaryotic origin and dominated by members of the Bacillariophyta, Cnidaria, Chordata and Arthropoda (data deposited to the ProteomeXchange, identifier PXD000961). Within the shared metaproteome, quantitative (18)O and iTRAQ analyses demonstrated a significantly greater abundance of structural proteins from macroscopic eukaryotes on Ship-1 and diatom photosynthesis proteins on Ship-2. Photosynthetic pigment composition and elemental analyses confirmed that both biofilms were dominated by phototrophic processes. These data begin to provide a better understanding of the complex organismal and biomolecular composition of marine biofilms while highlighting caveats in the interpretation of stand-alone environmental '-omics' datasets.

  10. Connecting alveolate cell biology with trophic ecology in the marine plankton using the ciliate Favella as a model.

    PubMed

    Echevarria, Michael L; Wolfe, Gordon V; Strom, Suzanne L; Taylor, Alison R

    2014-10-01

    Planktonic alveolates (ciliates and dinoflagellates), key trophic links in marine planktonic communities, exhibit complex behaviors that are underappreciated by microbiologists and ecologists. Furthermore, the physiological mechanisms underlying these behaviors are still poorly understood except in a few freshwater model ciliates, which are significantly different in cell structure and behavior than marine planktonic species. Here, we argue for an interdisciplinary research approach to connect physiological mechanisms with population-level outcomes of behaviors. Presenting the tintinnid ciliate Favella as a model alveolate, we review its population ecology, behavior, and cellular/molecular biology in the context of sensory biology and synthesize past research and current findings to construct a conceptual model describing the sensory biology of Favella. We discuss how emerging genomic information and new technical methods for integrating research across different levels of biological organization are paving the way for rapid advance. These research approaches will yield a deeper understanding of the role that planktonic alveolates may play in biogeochemical cycles, and how they may respond to future ocean conditions.

  11. Expanding biological data standards development processes for US IOOS: visual line transect observing community for mammal, bird, and turtle data

    USGS Publications Warehouse

    Fornwall, M.; Gisiner, R.; Simmons, S. E.; Moustahfid, Hassan; Canonico, G.; Halpin, P.; Goldstein, P.; Fitch, R.; Weise, M.; Cyr, N.; Palka, D.; Price, J.; Collins, D.

    2012-01-01

    The US Integrated Ocean Observing System (IOOS) has recently adopted standards for biological core variables in collaboration with the US Geological Survey/Ocean Biogeographic Information System (USGS/OBIS-USA) and other federal and non-federal partners. In this Community White Paper (CWP) we provide a process to bring into IOOS a rich new source of biological observing data, visual line transect surveys, and to establish quality data standards for visual line transect observations, an important source of at-sea bird, turtle and marine mammal observation data. The processes developed through this exercise will be useful for other similar biogeographic observing efforts, such as passive acoustic point and line transect observations, tagged animal data, and mark-recapture (photo-identification) methods. Furthermore, we suggest that the processes developed through this exercise will serve as a catalyst for broadening involvement by the larger marine biological data community within the goals and processes of IOOS.

  12. The Synthetic Biology Open Language (SBOL) provides a community standard for communicating designs in synthetic biology.

    PubMed

    Galdzicki, Michal; Clancy, Kevin P; Oberortner, Ernst; Pocock, Matthew; Quinn, Jacqueline Y; Rodriguez, Cesar A; Roehner, Nicholas; Wilson, Mandy L; Adam, Laura; Anderson, J Christopher; Bartley, Bryan A; Beal, Jacob; Chandran, Deepak; Chen, Joanna; Densmore, Douglas; Endy, Drew; Grünberg, Raik; Hallinan, Jennifer; Hillson, Nathan J; Johnson, Jeffrey D; Kuchinsky, Allan; Lux, Matthew; Misirli, Goksel; Peccoud, Jean; Plahar, Hector A; Sirin, Evren; Stan, Guy-Bart; Villalobos, Alan; Wipat, Anil; Gennari, John H; Myers, Chris J; Sauro, Herbert M

    2014-06-01

    The re-use of previously validated designs is critical to the evolution of synthetic biology from a research discipline to an engineering practice. Here we describe the Synthetic Biology Open Language (SBOL), a proposed data standard for exchanging designs within the synthetic biology community. SBOL represents synthetic biology designs in a community-driven, formalized format for exchange between software tools, research groups and commercial service providers. The SBOL Developers Group has implemented SBOL as an XML/RDF serialization and provides software libraries and specification documentation to help developers implement SBOL in their own software. We describe early successes, including a demonstration of the utility of SBOL for information exchange between several different software tools and repositories from both academic and industrial partners. As a community-driven standard, SBOL will be updated as synthetic biology evolves to provide specific capabilities for different aspects of the synthetic biology workflow.

  13. Sedimentation: Potential Biological Effects of Dredging Operations in Estuarine and Marine Environments

    DTIC Science & Technology

    2005-05-01

    1999). “Impacts of sediment burial on mangroves.” Marine Pollution Bulletin 37, 420-426. Fonseca, M. S., Kenworthy, W. J., and Thayer, G W. (1998... Marine Pollution Bulletin 4, 166-169. Tomasko, D.A., Dawes, C. J., and Hall, M. O. (1996). “The effects of anthropogenic nutrient enrichment in...adjacent coral reefs,” Marine Pollution Bulletin 42, 864-872. Wilber, D. H., and Clarke, D. G. (2001). “Biological effects of suspended sediments: a

  14. Mariner Model: Charting the Course for Health-Promoting School Communities

    ERIC Educational Resources Information Center

    Hoyle, Tena Bostrom

    2007-01-01

    The Mariner Model provides a step-by-step systems-building process and tool by which schools, school districts, and communities can develop capacity and create an infrastructure that supports continuous improvement in health-promoting environments for children. The Mariner Model follows a public health program planning development model that is…

  15. A Comprehensive Web-Based Library of Marine Biological Sounds

    DTIC Science & Technology

    2008-07-07

    sound recordings were digitized, documented in an extensive metadata base, and made available for free online playback. Users can search the collection...staff, educators, K-12 and college students, conservation and wildlife programs, the arts, museums , zoos, and aquaria, publishers, nature outreach...6 year period. 5700 audio clips (1200 hours) of marine mammal and fish sound recordings were digitized, documented in an extensive metadata base

  16. How are climate and marine biological outbreaks functionally linked?

    USGS Publications Warehouse

    Hayes, M.L.; Bonaventura, J.; Mitchell, T.P.; Prospero, J.M.; Shinn, E.A.; Van Dolah, F.; Barber, R.T.

    2001-01-01

    Since the mid-1970s, large-scale episodic events such as disease epidemics, mass mortalities, harmful algal blooms and other population explosions have been occurring in marine environments at an historically unprecedented rate. The variety of organisms involved (host, pathogens and other opportunists) and the absolute number of episodes have also increased during this period. Are these changes coincidental? Between 1972 and 1976, a global climate regime shift took place, and it is manifest most clearly by a change in strength of the North Pacific and North Atlantic pressure systems. Consequences of this regime shift are: (1) prolonged drought conditions in the Sahel region of Africa; (2) increased dust supply to the global atmosphere, by a factor of approximately four; (3) increased easterly trade winds across the Atlantic; (4) increased eolian transport of dust to the Atlantic and Caribbean basins; and (5) increased deposition of iron-rich eolian dust to typically iron-poor marine regions. On the basis of well-documented climate and dust observations and the widely accepted increase in marine outbreak rates, this paper proposes that the increased iron supply has altered the micronutrient factors limiting growth of opportunistic organisms and virulence of pathogenic microbes, particularly in macronutrient-rich coastal systems.

  17. THE NEED TO ESTABLISH A MARINE SCIENCES TECHNOLOGY PROGRAM AT SHORELINE COMMUNITY COLLEGE.

    ERIC Educational Resources Information Center

    TEEL, WARD; AND OTHERS

    DURING THE SUMMER OF 1966, FACULTY MEMBERS OF THE COLLEGE CONDUCTED AN INTERVIEW SURVEY TO DETERMINE THE FEASIBILITY OF ESTABLISHING A MARINE SCIENCE TECHNOLOGY PROGRAM. MANPOWER NEEDS OF 70 INDUSTRIES, INSTITUTIONS, AND GOVERNMENTAL AGENCIES CONCERNED WITH THE FIELDS OF OCEANOGRAPHY AND MARINE BIOLOGY WERE STUDIED IN TERMS OF JOBS PERFORMED BY…

  18. Oil, biological communities and contingency planning

    USGS Publications Warehouse

    Albers, P.H.; Frink, Lynne; Ball-Weir, Katherine; Smith, Charlotte

    1995-01-01

    The Oil Pollution Act of 1990 mandates the inclusion of a fish and wildlife response plan in the National Contingency Plan (NCP) and the creation of Area Committees that must develop an Area Contingency Plan (ACP). Area Contingency Plans must include a detailed annex containing a Fish and Wildlife and Sensitive Environments Plan. Tank vessels, offshore facilities, and certain onshore facilities must have response plans consistent with the requirements of the NCP and the ACP. New regulations to supersede the Type A and B procedures of the Natural Resources Damage Assessment Regulations are being developed for oil spills. Currently, four assessment methods have been proposed: (1) Type A, (2) comprehensive (Type B), (3) intermediate (between types A and B), and (4) compensation tables. The Oil Spill Liability Trust Fund is approaching its ceiling of $1 billion, but only $50 million has been appropriated. Effective biological contingency planning requires extensive knowledge of (1) the environmental fate of petroleum, (2) the effects of petroleum on organisms, (3) the existing biological resources, and (4) the establishment of a system of biological priorities. The characteristics and fate of petroleum and the biological effects of petroleum are reviewed. Assessment of biological resources includes plant and animal distributions, important habitat, endangered or threatened species, and economic considerations. The establishment by Area Committees of priorities for environmental protection, injury assessment, and restoration will promote efficient spill response. Three special issues are discussed: (1) improving our ability to restore natural resources, (2) the potential role of biological diversity in spill response planning, and (3) planning for animal rehabilitation.

  19. Five scientists on excursion — a picture of marine biology on Helgoland before 1892

    NASA Astrophysics Data System (ADS)

    Zissler, D.

    1995-03-01

    Five scientists on excursion — a picture of marine biology on Helgoland before 1892. The picture, of which several variant poses with minor differences exist, is a photograph taken on Helgoland in September, 1865. The original is to be found in the collections of the Ernst-Haeckel-Haus in Jena. The photograph shows only a few objects and fewer persons, but they are arranged like a bouquet: in front, collecting vessels; behind, grouped around a table, five scientists, Dohrn, Greeff, Haeckel, Salverda, Marchi. They hold up their catching nets like insignia, identifying their basic activity. This photograph is a unique document for the marine biological research on Helgoland before 1892. Furthermore, it illustrates a time and place for the birth of the idea of establishing the world's most famous marine biological station, the Stazione Zoologica di Napoli.

  20. Characterization of an anaerobic marine microbial community exposed to combined fluxes of perchlorate and salinity.

    PubMed

    Carlström, Charlotte I; Lucas, Lauren N; Rohde, Robert A; Haratian, Aryan; Engelbrektson, Anna L; Coates, John D

    2016-11-01

    The recent recognition of the environmental prevalence of perchlorate and its discovery on Mars, Earth's moon, and in meteorites, in addition to its novel application to controlling oil reservoir sulfidogenesis, has resulted in a renewed interest in this exotic ion and its associated microbiology. However, while plentiful data exists on freshwater perchlorate respiring organisms, information on their halophilic counterparts and microbial communities is scarce. Here, we investigated the temporal evolving structure of perchlorate respiring communities under a range of NaCl concentrations (1, 3, 5, 7, and 10 % wt/vol) using marine sediment amended with acetate and perchlorate. In general, perchlorate consumption rates were inversely proportional to NaCl concentration with the most rapid rate observed at 1 % NaCl. At 10 % NaCl, no perchlorate removal was observed. Transcriptional analysis of the 16S rRNA gene indicated that salinity impacted microbial community structure and the most active members were in families Rhodocyclaceae (1 and 3 % NaCl), Pseudomonadaceae (1 NaCl), Campylobacteraceae (1, 5, and 7 % NaCl), Sedimenticolaceae (3 % NaCl), Desulfuromonadaceae (5 and 7 % NaCl), Pelobacteraceae (5 % NaCl), Helicobacteraceae (5 and 7 % NaCl), and V1B07b93 (7 %). Novel isolates of genera Sedimenticola, Marinobacter, Denitromonas, Azoarcus, and Pseudomonas were obtained and their perchlorate respiring capacity confirmed. Although the obligate anaerobic, sulfur-reducing Desulfuromonadaceae species were dominant at 5 and 7 % NaCl, their enrichment may result from biological sulfur cycling, ensuing from the innate ability of DPRB to oxidize sulfide. Additionally, our results demonstrated enrichment of an archaeon of phylum Parvarchaeota at 5 % NaCl. To date, this phylum has only been described in metagenomic experiments of acid mine drainage and is unexpected in a marine community. These studies identify the intrinsic capacity of marine systems to respire

  1. Building functional groups of marine benthic macroinvertebrates on the basis of general community assembly mechanisms

    NASA Astrophysics Data System (ADS)

    Alexandridis, Nikolaos; Bacher, Cédric; Desroy, Nicolas; Jean, Fred

    2017-03-01

    The accurate reproduction of the spatial and temporal dynamics of marine benthic biodiversity requires the development of mechanistic models, based on the processes that shape macroinvertebrate communities. The modelled entities should, accordingly, be able to adequately represent the many functional roles that are performed by benthic organisms. With this goal in mind, we applied the emergent group hypothesis (EGH), which assumes functional equivalence within and functional divergence between groups of species. The first step of the grouping involved the selection of 14 biological traits that describe the role of benthic macroinvertebrates in 7 important community assembly mechanisms. A matrix of trait values for the 240 species that occurred in the Rance estuary (Brittany, France) in 1995 formed the basis for a hierarchical classification that generated 20 functional groups, each with its own trait values. The functional groups were first evaluated based on their ability to represent observed patterns of biodiversity. The two main assumptions of the EGH were then tested, by assessing the preservation of niche attributes among the groups and the neutrality of functional differences within them. The generally positive results give us confidence in the ability of the grouping to recreate functional diversity in the Rance estuary. A first look at the emergent groups provides insights into the potential role of community assembly mechanisms in shaping biodiversity patterns. Our next steps include the derivation of general rules of interaction and their incorporation, along with the functional groups, into mechanistic models of benthic biodiversity.

  2. Genome annotation in a community college cell biology lab.

    PubMed

    Beagley, C Timothy

    2013-01-01

    The Biology Department at Salt Lake Community College has used the IMG-ACT toolbox to introduce a genome mapping and annotation exercise into the laboratory portion of its Cell Biology course. This project provides students with an authentic inquiry-based learning experience while introducing them to computational biology and contemporary learning skills. Additionally, the project strengthens student understanding of the scientific method and contributes to student learning gains in curricular objectives centered around basic molecular biology, specifically, the Central Dogma. Importantly, inclusion of this project in the laboratory course provides students with a positive learning environment and allows for the use of cooperative learning strategies to increase overall student success.

  3. What is marine biology?: Defining a science in the United States in the mid 20th century.

    PubMed

    Ellis, Erik

    2007-01-01

    Marine biology and biological oceanography are two disciplinary subfields that have long struggled with their definitions. Should marine biology simply be considered a part of biology that takes place in the marine environment or is it a distinct entity, with conceptual problems and methodological approaches all its own? Similarly, biological oceanography could be seen as a necessary adjunct to physical and chemical oceanography or it could be defined more as an extension of biology into the marine realm. In the United States, these issues were directly addressed from the mid 1950s through the mid 1960s in a series of events that shed light on how marine biologists came to a working definition of their field that provided a broad methodological tent for practitioners and, at the same time, allied the field to oceanography during a period in which exploration of uncharted areas drew considerable funding from the post-WWII federal agencies charged with keeping American science at the forefront.

  4. Insights from the Sea: Structural Biology of Marine Polyketide Synthases

    PubMed Central

    Akey, David L.; Gehret, Jennifer J.; Khare, Dheeraj; Smith, Janet L.

    2013-01-01

    The world’s oceans are a rich source of natural products with extremely interesting chemistry. Biosynthetic pathways have been worked out for a few, and the story is being enriched with crystal structures of interesting pathway enzymes. By far, the greatest number of structural insights from marine biosynthetic pathways has originated with studies of curacin A, a poster child for interesting marine chemistry with its cyclopropane and thiazoline rings, internal cis double bond, and terminal alkene. Using the curacin A pathway as a model, structural details are now available for a novel loading enzyme with remarkable dual decarboxylase and acetyltransferase activities, an Fe2+/α-ketoglutarate-dependent halogenase that dictates substrate binding order through conformational changes, a decarboxylase that establishes regiochemistry for cyclopropane formation, and a thioesterase with specificity for β-sulfated substrates that lead to terminal alkene offloading. The four curacin A pathway dehydratases reveal an intrinsic flexibility that may accommodate bulky or stiff polyketide intermediates. In the salinosporamide A pathway, active site volume determines the halide specificity of a halogenase that catalyzes for the synthesis of a halogenated building block. Structures of a number of putative polyketide cyclases may help in understanding reaction mechanisms and substrate specificities although their substrates are presently unknown. PMID:22498975

  5. Insights from the sea: structural biology of marine polyketide synthases.

    PubMed

    Akey, David L; Gehret, Jennifer J; Khare, Dheeraj; Smith, Janet L

    2012-10-01

    The world's oceans are a rich source of natural products with extremely interesting chemistry. Biosynthetic pathways have been worked out for a few, and the story is being enriched with crystal structures of interesting pathway enzymes. By far, the greatest number of structural insights from marine biosynthetic pathways has originated with studies of curacin A, a poster child for interesting marine chemistry with its cyclopropane and thiazoline rings, internal cis double bond, and terminal alkene. Using the curacin A pathway as a model, structural details are now available for a novel loading enzyme with remarkable dual decarboxylase and acetyltransferase activities, an Fe(2+)/α-ketoglutarate-dependent halogenase that dictates substrate binding order through conformational changes, a decarboxylase that establishes regiochemistry for cyclopropane formation, and a thioesterase with specificity for β-sulfated substrates that lead to terminal alkene offloading. The four curacin A pathway dehydratases reveal an intrinsic flexibility that may accommodate bulky or stiff polyketide intermediates. In the salinosporamide A pathway, active site volume determines the halide specificity of a halogenase that catalyzes for the synthesis of a halogenated building block. Structures of a number of putative polyketide cyclases may help in understanding reaction mechanisms and substrate specificities although their substrates are presently unknown.

  6. Contaminants reduce the richness and evenness of marine communities: a review and meta-analysis.

    PubMed

    Johnston, Emma L; Roberts, David A

    2009-06-01

    Biodiversity of marine ecosystems is integral to their stability and function and is threatened by anthropogenic processes. We conducted a literature review and meta-analysis of 216 studies to understand the effects of common contaminants upon diversity in various marine communities. The most common diversity measures were species richness, the Shannon-Wiener index (H') and Pielou evenness (J). Largest effect sizes were observed for species richness, which tended to be the most sensitive index. Pollution was associated with marine communities containing fewer species or taxa than their pristine counterparts. Marine habitats did not vary in their susceptibility to contamination, rather a approximately 40% reduction in richness occurred across all habitats. No class of contaminant was associated with significantly greater impacts on diversity than any other. Survey studies identified larger effects than laboratory or field experiments. Anthropogenic contamination is strongly associated with reductions in the species richness and evenness of marine habitats.

  7. Social capital as a key determinant of perceived benefits of community-based marine protected areas.

    PubMed

    Diedrich, Amy; Stoeckl, Natalie; Gurney, Georgina G; Esparon, Michelle; Pollnac, Richard

    2017-04-01

    Globally, marine protected areas (MPAs) have been relatively unsuccessful in meeting biodiversity objectives. To be effective, they require some alteration of people's use and access to marine resources, which they will resist if they do not perceive associated benefits. Stakeholders' support is crucial to ecological success of MPAs, and their support is likely to depend on their capacity to adapt to and benefit from MPAs. We examined the influence of social adaptive capacity (SAC) on perceived benefits of MPAs in Siquijor, Philippines, in the Coral Triangle. This region has substantial biodiversity and a population of over 120 million people, many of them dependent on marine resources for food and income. The region has many MPAs, most of which are managed under decentralized governance systems. We collected survey data from 540 households in 19 villages with associated MPAs. We evaluated the influence of multiple SAC variables (e.g., occupational multiplicity and social capital) on perceived benefits with decision trees (CHAID) and qualitatively analyzed this relationship with respect to types and recipients of benefits. Our models revealed the key role of social capital, particularly trust in leadership, in influencing perceptions of benefits (χ(2) = 14.762, p = 0.000). A path analysis revealed that perceptions of distributional equity were a key mechanism through which social capital affected perceived MPA benefits (root mean-square error of approximation = 0.050). Building social capital and equity within communities could lead to more effective management of MPAs and thus to expenditure of fewer resources relative to, for example, regulation enforcement. © 2016 Society for Conservation Biology.

  8. How do changes in plankton community structure influence the biological pump? A mesocosm study

    NASA Astrophysics Data System (ADS)

    Stange, P.; Taucher, J.; Bach, L. T.; Boxhammer, T.; Riebesell, U.

    2016-02-01

    Strength and efficiency of the biological pump have a profound influence on the marine carbon cycle and depend on the plankton community structure of the ocean. Unraveling this control will significantly increase our understanding of the biological pump and help predicting changes in the future. However, investigating this relationship with traditional methods is challenging in the open ocean. During autumn 2014, we conducted a mesocosm experiment off the coast of the Canary Islands (CE Atlantic). We closely followed the development of a plankton community under different CO2 levels for eight weeks, while simultaneously measuring the mass flux, sinking velocity and remineralization rates of sinking detritus. After two weeks of low productivity we added deep-water (collected from 500 m depth) to each mesocosm to mimic eddy-induced upwelling. The addition induced a diatom bloom, characterized by an increased abundance of large particles and high mass flux. However, sinking velocities decreased by up to 30% and remineralization rates remained rather constant, indicating that higher mass flux is associated with lower export efficiency during the bloom. Our first results highlight the importance of community-related changes on both export strength and efficiency of the biological pump. We show that high mass flux events are potentially less efficient in sequestering carbon from the atmosphere. Ultimately, changes in plankton community structure have the potential to significantly affect oceanic carbon sequestration in a changing environment.

  9. Ecotonal marine regions - ecotonal parasite communities: helminth assemblages in the convergence of masses of water in the southwestern Atlantic Ocean.

    PubMed

    Lanfranchi, Ana L; Braicovich, Paola E; Cantatore, Delfina M P; Alarcos, Ana J; Luque, José L; Timi, Juan T

    2016-11-01

    With the aim of evaluating the utility of marine parasites as indicators of ecotonal regions in the marine environment, we analysed data on assemblages of long-lived larval parasites of Zenopsis conchifer inhabiting the region of convergence of three masses of water in the southwestern Atlantic Oceans. These masses of water with different origins are expected to affect the structure of parasite communities by acting as sources of infective stages of helminth species typical of adjacent zoogeographical regions. Multivariate analyses at both infracommunity and component community levels, including data of four other species recognised as harbouring parasite assemblages representatives of these zoogeographical regions, were carried out to corroborate the existence of repeatable distribution patterns and to provide further evidence of the utility of parasites as zoogeographic indicators in the region. Results showed a tight correspondence with the existing zoogeographical classification in the study region, namely two zoogeographical provinces, one of which is subdivided into two districts demonstrating the ecotonal nature of parasite assemblages from the convergence region, which were characterised by a species rich component community but depauperate and heterogeneous infracommunities. The borders of biological communities have been suggested as priority areas for conservation where a fully functioning ecosystem can be protected and parasite communities can be considered as reliable indicators to define such transitional regions.

  10. Diversity and population structure of a near-shore marine-sediment viral community.

    PubMed Central

    Breitbart, Mya; Felts, Ben; Kelley, Scott; Mahaffy, Joseph M.; Nulton, James; Salamon, Peter; Rohwer, Forest

    2004-01-01

    Viruses, most of which are phage, are extremely abundant in marine sediments, yet almost nothing is known about their identity or diversity. We present the metagenomic analysis of an uncultured near-shore marine-sediment viral community. Three-quarters of the sequences in the sample were not related to anything previously reported. Among the sequences that could be identified, the majority belonged to double-stranded DNA phage. Temperate phage were more common than lytic phage, suggesting that lysogeny may be an important lifestyle for sediment viruses. Comparisons between the sediment sample and previously sequenced seawater viral communities showed that certain phage phylogenetic groups were abundant in all marine viral communities, while other phage groups were under-represented or absent. This 'marineness' suggests that marine phage are derived from a common set of ancestors. Several independent mathematical models, based on the distribution of overlapping shotgun sequence fragments from the library, were used to show that the diversity of the viral community was extremely high, with at least 10(4) viral genotypes per kilogram of sediment and a Shannon index greater than 9 nats. Based on these observations we propose that marine-sediment viral communities are one of the largest unexplored reservoirs of sequence space on the planet. PMID:15156913

  11. Rate of biological invasions is lower in coastal marine protected areas

    PubMed Central

    Ardura, A.; Juanes, F.; Planes, S.; Garcia-Vazquez, E.

    2016-01-01

    Marine biological invasions threaten biodiversity worldwide. Here we explore how Marine Protected areas, by reducing human use of the coast, confer resilience against the introduction of non-indigenous species (NIS), using two very different Pacific islands as case studies for developing and testing mathematical models. We quantified NIS vectors and promoters on Vancouver (Canada) and Moorea (French Polynesia) islands, sampled and barcoded NIS, and tested models at different spatial scales with different types of interaction among vectors and between marine protection and NIS frequency. In our results NIS were negatively correlated with the dimension of the protected areas and the intensity of the protection. Small to medium geographical scale protection seemed to be efficient against NIS introductions. The likely benefit of MPAs was by exclusion of aquaculture, principally in Canada. These results emphasize the importance of marine protected areas for biodiversity conservation, and suggest that small or medium protected zones would confer efficient protection against NIS introduction. PMID:27609423

  12. Rate of biological invasions is lower in coastal marine protected areas.

    PubMed

    Ardura, A; Juanes, F; Planes, S; Garcia-Vazquez, E

    2016-09-09

    Marine biological invasions threaten biodiversity worldwide. Here we explore how Marine Protected areas, by reducing human use of the coast, confer resilience against the introduction of non-indigenous species (NIS), using two very different Pacific islands as case studies for developing and testing mathematical models. We quantified NIS vectors and promoters on Vancouver (Canada) and Moorea (French Polynesia) islands, sampled and barcoded NIS, and tested models at different spatial scales with different types of interaction among vectors and between marine protection and NIS frequency. In our results NIS were negatively correlated with the dimension of the protected areas and the intensity of the protection. Small to medium geographical scale protection seemed to be efficient against NIS introductions. The likely benefit of MPAs was by exclusion of aquaculture, principally in Canada. These results emphasize the importance of marine protected areas for biodiversity conservation, and suggest that small or medium protected zones would confer efficient protection against NIS introduction.

  13. Sequential determination of biological and pollutant elements in marine bivalves

    SciTech Connect

    Zeisler, R.; Stone, S.F.; Sanders, R.W.

    1988-12-15

    A unique sequence of instrumental methods has been employed to obtain concentrations for 44 elements in marine bivalve tissue. The techniques used were (1) X-ray fluorescence, (2) prompt gamma activation analysis, and (3) neutron activation analysis. It is possible to use a single subsample and follow it nondestructively through the three instrumental analysis techniques. A final radiochemical procedure for tin was also applied after completing the instrumental analyses. Comparison of results for elements determined by more than one technique in sequence showed good agreement, as did results from certified reference material samples analyzed along with the samples. The concentrations found in the bivalve samples ranged from carbon at more than 50% dry weight down to gold at several microgram per kilogram.

  14. Marine-derived biological macromolecule-based biomaterials for wound healing and skin tissue regeneration.

    PubMed

    Chandika, Pathum; Ko, Seok-Chun; Jung, Won-Kyo

    2015-01-01

    Wound healing is a complex biological process that depends on the wound condition, the patient's health, and the physicochemical support given through external materials. The development of bioactive molecules and engineered tissue substitutes to provide physiochemical support to enhance the wound healing process plays a key role in advancing wound-care management. Thus, identification of ideal molecules in wound treatment is still in progress. The discovery of natural products that contain ideal molecules for skin tissue regeneration has been greatly advanced by exploration of the marine bioenvironment. Consequently, tremendously diverse marine organisms have become a great source of numerous biological macromolecules that can be used to develop tissue-engineered substitutes with wound healing properties. This review summarizes the wound healing process, the properties of macromolecules from marine organisms, and the involvement of these molecules in skin tissue regeneration applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles

    PubMed Central

    Kalinin, Vladimir I.; Ivanchina, Natalia V.; Krasokhin, Vladimir B.; Makarieva, Tatyana N.; Stonik, Valentin A.

    2012-01-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. PMID:23015769

  16. Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.

    PubMed

    Kalinin, Vladimir I; Ivanchina, Natalia V; Krasokhin, Vladimir B; Makarieva, Tatyana N; Stonik, Valentin A

    2012-08-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.

  17. Marine biology: new light on growth in the cold.

    PubMed

    Barnes, David K A

    2013-07-22

    The recent collapse of the Antarctic Larson ice shelves revealed a slow growing benthic community on the seabed below. But a revisit just four years later revealed rapid growth of glass sponges. Antarctic continental shelves could become sites of significant carbon sequestration.

  18. What are undergraduates doing at biological field stations and marine laboratories?

    Treesearch

    Janet Hodder

    2009-01-01

    Biological field stations and marine laboratories (FSMLs) serve as places to study the natural environment in a variety of ways, from the level of the molecule to the globe. Undergraduate opportunities at FSMLs reflect the diversity of study options -- formal courses, research and service internships, and field-trip experiences -- and students are responding to those...

  19. Marine Biology: Ecology of the Sea. A Zephyr Learning Packet. Revised.

    ERIC Educational Resources Information Center

    Tanner, Joey

    From the smallest plankton to the most massive whales, marine biology is the study of the flora and fauna, the living creatures of the ocean. This Zephyr self-directed study unit was developed to bridge the gap between students as passive learners to students as active participants. Originally developed for gifted students, these units emphasize…

  20. Marine Biology: Ecology of the Sea. A Zephyr Learning Packet. Revised.

    ERIC Educational Resources Information Center

    Tanner, Joey

    From the smallest plankton to the most massive whales, marine biology is the study of the flora and fauna, the living creatures of the ocean. This Zephyr self-directed study unit was developed to bridge the gap between students as passive learners to students as active participants. Originally developed for gifted students, these units emphasize…

  1. Effectiveness of Biological Surrogates for Predicting Patterns of Marine Biodiversity: A Global Meta-Analysis

    PubMed Central

    Mellin, Camille; Delean, Steve; Caley, Julian; Edgar, Graham; Meekan, Mark; Pitcher, Roland; Przeslawski, Rachel; Williams, Alan; Bradshaw, Corey

    2011-01-01

    The use of biological surrogates as proxies for biodiversity patterns is gaining popularity, particularly in marine systems where field surveys can be expensive and species richness high. Yet, uncertainty regarding their applicability remains because of inconsistency of definitions, a lack of standard methods for estimating effectiveness, and variable spatial scales considered. We present a Bayesian meta-analysis of the effectiveness of biological surrogates in marine ecosystems. Surrogate effectiveness was defined both as the proportion of surrogacy tests where predictions based on surrogates were better than random (i.e., low probability of making a Type I error; P) and as the predictability of targets using surrogates (R2). A total of 264 published surrogacy tests combined with prior probabilities elicited from eight international experts demonstrated that the habitat, spatial scale, type of surrogate and statistical method used all influenced surrogate effectiveness, at least according to either P or R2. The type of surrogate used (higher-taxa, cross-taxa or subset taxa) was the best predictor of P, with the higher-taxa surrogates outperforming all others. The marine habitat was the best predictor of R2, with particularly low predictability in tropical reefs. Surrogate effectiveness was greatest for higher-taxa surrogates at a <10-km spatial scale, in low-complexity marine habitats such as soft bottoms, and using multivariate-based methods. Comparisons with terrestrial studies in terms of the methods used to study surrogates revealed that marine applications still ignore some problems with several widely used statistical approaches to surrogacy. Our study provides a benchmark for the reliable use of biological surrogates in marine ecosystems, and highlights directions for future development of biological surrogates in predicting biodiversity. PMID:21695119

  2. Microscale characterization of dissolved organic matter production and uptake in marine microbial mat communities

    NASA Technical Reports Server (NTRS)

    Paerl, H. W.; Bebout, B. M.; Joye, S. B.; Des Marais, D. J.

    1993-01-01

    Intertidal marine microbial mats exhibited biologically mediated uptake of low molecular weight dissolved organic matter (DOM), including D-glucose, acetate, and an L-amino acid mixture at trace concentrations. Uptake of all compounds occurred in darkness, but was frequently enhanced under natural illumination. The photosystem 2 inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) generally failed to inhibit light-stimulated DOM uptake. Occasionally, light plus DCMU-amended treatments led to uptake rates higher than light-incubated samples, possibly due to phototrophic bacteria present in subsurface anoxic layers. Uptake was similar with either 3H- or 14C-labeled substrates, indicating that recycling of labeled CO2 via photosynthetic fixation was not interfering with measurements of light-stimulated DOM uptake. Microautoradiographs showed a variety of pigmented and nonpigmented bacteria and, to a lesser extent, cyanobacteria and eucaryotic microalgae involved in light-mediated DOM uptake. Light-stimulated DOM uptake was often observed in bacteria associated with sheaths and mucilage surrounding filamentous cyanobacteria, revealing a close association of organisms taking up DOM with photoautotrophic members of the mat community. The capacity for dark- and light-mediated heterotrophy, coupled to efficient retention of fixed carbon in the mat community, may help optimize net production and accretion of mats, even in oligotrophic waters.

  3. Microscale characterization of dissolved organic matter production and uptake in marine microbial mat communities

    NASA Technical Reports Server (NTRS)

    Paerl, H. W.; Bebout, B. M.; Joye, S. B.; Des Marais, D. J.

    1993-01-01

    Intertidal marine microbial mats exhibited biologically mediated uptake of low molecular weight dissolved organic matter (DOM), including D-glucose, acetate, and an L-amino acid mixture at trace concentrations. Uptake of all compounds occurred in darkness, but was frequently enhanced under natural illumination. The photosystem 2 inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) generally failed to inhibit light-stimulated DOM uptake. Occasionally, light plus DCMU-amended treatments led to uptake rates higher than light-incubated samples, possibly due to phototrophic bacteria present in subsurface anoxic layers. Uptake was similar with either 3H- or 14C-labeled substrates, indicating that recycling of labeled CO2 via photosynthetic fixation was not interfering with measurements of light-stimulated DOM uptake. Microautoradiographs showed a variety of pigmented and nonpigmented bacteria and, to a lesser extent, cyanobacteria and eucaryotic microalgae involved in light-mediated DOM uptake. Light-stimulated DOM uptake was often observed in bacteria associated with sheaths and mucilage surrounding filamentous cyanobacteria, revealing a close association of organisms taking up DOM with photoautotrophic members of the mat community. The capacity for dark- and light-mediated heterotrophy, coupled to efficient retention of fixed carbon in the mat community, may help optimize net production and accretion of mats, even in oligotrophic waters.

  4. Quorum quenching in cultivable bacteria from dense marine coastal microbial communities.

    PubMed

    Romero, Manuel; Martin-Cuadrado, Ana-Belen; Roca-Rivada, Arturo; Cabello, Ana María; Otero, Ana

    2011-02-01

    Acylhomoserine lactone (AHLs)-mediated quorum-sensing (QS) processes seem to be common in the marine environment and among marine pathogenic bacteria, but no data are available on the prevalence of bacteria capable of interfering with QS in the sea, a process that has been generally termed 'quorum quenching' (QQ). One hundred and sixty-six strains isolated from different marine dense microbial communities were screened for their ability to interfere with AHL activity. Twenty-four strains (14.4%) were able to eliminate or significantly reduce N-hexanoyl-l-homoserine lactone activity as detected by the biosensor strain Chromobacterium violaceum CV026, a much higher percentage than that reported for soil isolates, which reinforces the ecological role of QS and QQ in the marine environment. Among these, 15 strains were also able to inhibit N-decanoyl-l-homoserine lactone activity and all of them were confirmed to enzymatically inactivate the AHL signals by HPLC-MS. Active isolates belonged to nine different genera of prevalently or exclusively marine origin, including members of the Alpha- and Gammaproteobacteria (8), Actinobacteria (2), Firmicutes (4) and Bacteroidetes (1). Whether the high frequency and diversity of cultivable bacteria with QQ activity found in near-shore marine isolates reflects their prevalence among pelagic marine bacterial communities deserves further investigation in order to understand the ecological importance of AHL-mediated QS and QQ processes in the marine environment.

  5. Night-time lighting alters the composition of marine epifaunal communities

    PubMed Central

    Davies, Thomas W.; Coleman, Matthew; Griffith, Katherine M.; Jenkins, Stuart R.

    2015-01-01

    Marine benthic communities face multiple anthropogenic pressures that compromise the future of some of the most biodiverse and functionally important ecosystems in the world. Yet one of the pressures these ecosystems face, night-time lighting, remains unstudied. Light is an important cue in guiding the settlement of invertebrate larvae, and altering natural regimes of nocturnal illumination could modify patterns of recruitment among sessile epifauna. We present the first evidence of night-time lighting changing the composition of temperate epifaunal marine invertebrate communities. Illuminating settlement surfaces with white light-emitting diode lighting at night, to levels experienced by these communities locally, both inhibited and encouraged the colonization of 39% of the taxa analysed, including three sessile and two mobile species. Our results indicate that ecological light pollution from coastal development, shipping and offshore infrastructure could be changing the composition of marine epifaunal communities. PMID:25926694

  6. Night-time lighting alters the composition of marine epifaunal communities.

    PubMed

    Davies, Thomas W; Coleman, Matthew; Griffith, Katherine M; Jenkins, Stuart R

    2015-04-01

    Marine benthic communities face multiple anthropogenic pressures that compromise the future of some of the most biodiverse and functionally important ecosystems in the world. Yet one of the pressures these ecosystems face, night-time lighting, remains unstudied. Light is an important cue in guiding the settlement of invertebrate larvae, and altering natural regimes of nocturnal illumination could modify patterns of recruitment among sessile epifauna. We present the first evidence of night-time lighting changing the composition of temperate epifaunal marine invertebrate communities. Illuminating settlement surfaces with white light-emitting diode lighting at night, to levels experienced by these communities locally, both inhibited and encouraged the colonization of 39% of the taxa analysed, including three sessile and two mobile species. Our results indicate that ecological light pollution from coastal development, shipping and offshore infrastructure could be changing the composition of marine epifaunal communities. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. Biological responses of marine flatfish exposed to municipal wastewater effluent.

    PubMed

    Vidal-Dorsch, Doris E; Bay, Steven M; Greenstein, Darrin J; Baker, Michael E; Hardiman, Gary; Reyes, Jesus A; Kelley, Kevin M; Schlenk, Daniel

    2014-03-01

    There is increasing concern over the presence of pharmaceutical compounds, personal care products, and other chemicals collectively known as contaminants of emerging concern (CECs) in municipal effluents, yet knowledge of potential environmental impacts related to these compounds is still limited. The present study used laboratory exposures to examine estrogenic, androgenic, and thyroid-related endocrine responses in marine hornyhead turbot (Pleuronichthys verticalis) exposed to CECs from municipal effluents with 2 degrees of treatment. Fish were exposed for 14 d to environmentally realistic concentrations of effluent (0.5%) and to a higher concentration (5%) to investigate dose responses. Plasma concentrations of estradiol (E2), vitellogenin (VTG), 11-keto testosterone, and thyroxine were measured to assess endocrine responses. Contaminants of emerging concern were analyzed to characterize the effluents. Diverse types of effluent CECs were detected. Statistically significant responses were not observed in fish exposed to environmentally realistic concentrations of effluent. Elevated plasma E2 concentrations were observed in males exposed to ammonia concentrations similar to those found in effluents. However, exposure to ammonia did not induce VTG production in male fish. The results of the present study highlight the importance of conducting research with sentinel organisms in laboratory studies to understand the environmental significance of the presence of CECs in aquatic systems.

  8. Anaerobic ammonium-oxidising bacteria: A biological source of the bacteriohopanetetrol stereoisomer in marine sediments

    NASA Astrophysics Data System (ADS)

    Rush, Darci; Sinninghe Damsté, Jaap S.; Poulton, Simon W.; Thamdrup, Bo; Garside, A. Leigh; Acuña González, Jenaro; Schouten, Stefan; Jetten, Mike S. M.; Talbot, Helen M.

    2014-09-01

    Bacterially-derived bacteriohopanepolyols (BHPs) are abundant, well preserved lipids in modern and paleo-environments. Bacteriohopanetetrol (BHT) is a ubiquitously produced BHP while its less common stereoisomer (BHT isomer) has previously been associated with anoxic environments; however, its biological source remained unknown. We investigated the occurrence of BHPs in Golfo Dulce, an anoxic marine fjord-like enclosure located in Costa Rica. The distribution of BHT isomer in four sediment cores and a surface sediment transect closely followed the distribution of ladderane fatty acids, unique biomarkers for bacteria performing anaerobic ammonium oxidation (anammox). This suggests that BHT isomer and ladderane lipids likely shared the same biological source in Golfo Dulce. This was supported by examining the BHP lipid compositions of two enrichment cultures of a marine anammox species ('Candidatus Scalindua profunda'), which were found to contain both BHT and BHT isomer. Remarkably, the BHT isomer was present in higher relative abundance than BHT. However, a non-marine anammox enrichment contained only BHT, which explains the infrequence of BHT isomer observations in terrestrial settings, and indicates that marine anammox bacteria are likely responsible for at least part of the environmentally-observed marine BHT isomer occurrences. Given the substantially greater residence time of BHPs in sediments, compared to ladderanes, BHT isomer is a potential biomarker for past anammox activity.

  9. Synthesis and Biology of Cyclic Imine Toxins, An Emerging Class of Potent, Globally Distributed Marine Toxins

    PubMed Central

    Stivala, Craig E.; Benoit, Evelyne; Araoz, Romulo; Servent, Denis; Novikov, Alexei

    2014-01-01

    From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulation in shellfish, and chemical stability are important considerations in assessing risk factors for human health. This review article aims to provide an account of chemistry, biology, and toxicology of CI toxins from their discovery to the present day. PMID:25338021

  10. Biological soil crusts: Diminutive communities of potential global importance

    USGS Publications Warehouse

    Ferrenberg, Scott; Tucker, Colin; Reed, Sasha C.

    2017-01-01

    Biological soil crusts (biocrusts) are widespread, diverse communities of cyanobacteria, fungi, lichens, and mosses living on soil surfaces, primarily in drylands. Biocrusts can locally govern primary production, soil fertility, hydrology, and surface energy balance, with considerable variation in these functions across alternate community states. Further, these communities have been implicated in Earth system functioning via potential influences on global biogeochemistry and climate. Biocrusts are easily destroyed by disturbances and appear to be exceptionally vulnerable to warming temperatures and altered precipitation inputs, signaling possible losses of dryland functions with global change. Despite these concerns, we lack sufficient spatiotemporal data on biocrust function, cover, and community structure to confidently assess their ecological roles across the extensive dryland biome. Here, we present the case for cross-scale research and restoration efforts coupled with remote-sensing and modeling approaches that improve our collective understanding of biocrust responses to global change and the ecological roles of these diminutive communities at global scales.

  11. Microbial community diversity, structure and assembly across oxygen gradients in meromictic marine lakes, Palau.

    PubMed

    Meyerhof, Matthew S; Wilson, Jesse M; Dawson, Michael N; Michael Beman, J

    2016-12-01

    Microbial communities consume oxygen, alter biogeochemistry and compress habitat in aquatic ecosystems, yet our understanding of these microbial-biogeochemical-ecological interactions is limited by a lack of systematic analyses of low-oxygen ecosystems. Marine lakes provide an ideal comparative system, as they range from well-mixed holomictic lakes to stratified, anoxic, meromictic lakes that vary in their vertical extent of anoxia. We examined microbial communities inhabiting six marine lakes and one ocean site using pyrosequencing of 16S rRNA genes. Microbial richness and evenness was typically highest in the anoxic monimolimnion of meromictic lakes, with common marine bacteria present in mixolimnion communities replaced by anoxygenic phototrophs, sulfate-reducing bacteria and SAR406 in the monimolimnion. These sharp changes in community structure were linked to environmental gradients (constrained variation in redundancy analysis = 68%-76%) - particularly oxygen and pH. However, in those lakes with the steepest oxygen gradients, salinity and dissolved nutrients were important secondary constraining variables, indicating that subtle but substantive differences in microbial communities occur within similar low-oxygen habitats. Deterministic processes were a dominant influence on whole community assembly (all nearest taxon index values >4), demonstrating that the strong environmental gradients present in meromictic marine lakes drive microbial community assembly. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Heat shock proteins as key biological targets of the marine natural cyclopeptide perthamide C.

    PubMed

    Margarucci, Luigi; Monti, Maria Chiara; Mencarelli, Andrea; Cassiano, Chiara; Fiorucci, Stefano; Riccio, Raffaele; Zampella, Angela; Casapullo, Agostino

    2012-04-01

    Linking bioactive compounds to their cellular targets is a central challenge in chemical biology. Herein we report the mode of action of perthamide C, a natural cyclopeptide isolated from the marine sponge Theonella swinhoei. Through an emerging mass spectrometry-based chemical proteomics approach, Heat Shock Protein 90 and Glucose Regulated Protein 94 were identified as key targets of perthamide C and this evidence has been validated using surface plasmon resonance. The ability of perthamide C to influence heat shock protein-mediated cell apoptosis revealed that this marine metabolite could be a good candidate for the development of a lead compound with therapeutic applications based on apoptosis modulation.

  13. Biological diversity of fish communities: pattern and process.

    PubMed

    Magurran, A E; Khachonpisitsak, S; Ahmad, A B

    2011-12-01

    For over 150 years, ecologists have been striving to explain fundamental patterns of biological diversity, such as the observation that communities invariably consist of common and rare species, and to unravel the processes that underpin these patterns. This task is increasingly urgent given the accelerating loss of biological diversity. Although fishes are the most diverse vertebrate taxon and fish communities occur in a wide range of habitats, they have been relatively little studied in the quest to elucidate the processes that shape patterns of biological diversity. Here, some of the topics that investigations of fish assemblages can illuminate are highlighted. These include the characteristics of ecological communities and the role that dispersal limitation plays in structuring them, the distinction between core and occasional species, the insights that evaluating abundance in different currencies can bring and the assessment of community capacity. Questions are identified that future investigations of fish communities might tackle and a case study of a biodiverse ecoregion (Thailand and Peninsula Malaysia) is used to illustrate the need for better links between these ecological questions and effective conservation practice.

  14. Marine biological controls on atmospheric CO2 and climate

    NASA Technical Reports Server (NTRS)

    Mcelroy, M. B.

    1983-01-01

    It is argued that the ocean is losing N gas faster than N is being returned to the ocean, and that replenishment of the N supply in the ocean usually occurs during ice ages. Available N from river and estruarine transport and from rainfall after formation by lightning are shown to be at a rate too low to compensate for the 10,000 yr oceanic lifetime of N. Ice sheets advance and transfer moraine N to the ocean, lower the sea levels, erode the ocean beds, promote greater biological productivity, and reduce CO2. Ice core samples have indicated a variability in the atmospheric N content that could be attributed to the ice age scenario.

  15. Robustness of surrogates of biodiversity in marine benthic communities.

    PubMed

    Magierowski, Regina H; Johnson, Craig R

    2006-12-01

    The usefulness of surrogates to estimate complex variables describing community structure, such as the various components of biodiversity, is long established. Most attention has been given to surrogates of species richness and species diversity and has focused on identifying a subset of taxa as a surrogate of total community richness or diversity. In adopting a surrogate measure, it is assumed that the relationship between the surrogate(s) and total richness or diversity is consistent in both space and time. These assumptions are rarely examined explicitly. We examined the robustness of potential surrogates of familial richness and multivariate community structure for macrofauna communities inhabiting artificial kelp holdfasts by comparing among communities of dissimilar ages and among communities established at different times of the year. This is important because most benthic "landscapes" will be a mosaic of patches reflecting different intensities, frequencies, and timing of disturbances. The total abundance of organisms and familial richness of crustaceans or polychaetes were all good predictors of total familial richness (R2 > 0.68). In contrast, while the familial richness of other groups, such as mollusks and echinoderms, were well correlated with total familial richness for communities at an early stage of development, the strength of these relationships declined with community age. For multivariate community structure, carefully selected subsets of approximately 10% of the total taxa yielded similar patterns to the total suite of taxa, irrespective of the age of the community. Thus, useful surrogates of both familial richness and multivariate community structure can be identified for this type of community. However, the choice of technique for selecting surrogate taxa largely depends on the nature of the pilot data available, and careful selection is required to ensure that surrogates perform consistently across different-aged communities. While the

  16. Matching biological traits to environmental conditions in marine benthic ecosystems

    NASA Astrophysics Data System (ADS)

    Bremner, J.; Rogers, S. I.; Frid, C. L. J.

    2006-05-01

    The effects of variability in environmental conditions on species composition in benthic ecosystems are well established, but relatively little is known about how environmental variability relates to ecosystem functioning. Benthic invertebrate assemblages are heavily involved in the maintenance of ecological processes and investigation of the biological characteristics (traits) expressed in these assemblages can provide information about some aspects of functioning. The aim of this study was to establish and explore relationships between environmental variability and biological traits expressed in megafauna assemblages in two UK regions. Patterns of trait composition were matched to environmental conditions and subsets of variables best describing these patterns determined. The nature of the relationships were subsequently examined at two separate scales, both between and within the regions studied. Over the whole area, some traits related to size, longevity, reproduction, mobility, flexibility, feeding method, sociability and living habit were negatively correlated with salinity, sea surface temperature, annual temperature range and the level of fishing effort, and positively associated with fish taxon richness and shell content of the substratum. Between the two regions, reductions in temperature range and shell content were associated with infrequent relative occurrences of short-lived, moderately mobile, flexible, solitary, opportunistic, permanent-burrow dwelling fauna and those exhibiting reproductive strategies based on benthic development. Relationships between some traits and environmental conditions diverged within the two regions, with increases in fishing effort and shell content of the substratum being associated with low frequencies of occurrence of moderately mobile and moderately to highly flexible fauna within one region, but high frequencies in the other. These changes in trait composition have implications for ecosystem processes, with, for

  17. The Influence of the Biological Pump on Marine Redox Conditions During Earth History

    NASA Astrophysics Data System (ADS)

    Meyer, K. M.; Ridgwell, A.; Payne, J.

    2015-12-01

    Evidence for bottom-water anoxia on the continental shelves waned over the course of the Phanerozoic, which may be influenced by secular changes in the biological pump that led to weaker positive feedbacks within the oceans. The biological pump describes the transfer of carbon from the atmosphere to the deep ocean, which creates vertical gradients in nutrients and oxygen, both important influences in the structure of marine ecosystems. We used the cGENIE Earth system model to quantitatively test the hypothesis that reductions in the efficiency of the nutrient recycling loop of the biological pump during the past 550 Ma reduced the extent of anoxia on the shelves and acted as an important control on marine animal ecosystems. When the modeled remineralization depth is shallow relative to the modern ocean, anoxia tends to be more widespread at continental shelf depths. As the modeled remineralization depth increases toward modern conditions, anoxia is less prevalent and occurs at depths below the continental shelves. Reduced marine productivity in the closed system configuration of cGENIE cannot produce the frequent bottom-water anoxia conditions envisioned for the Paleozoic. We hypothesize that evidence for greater animal abundance and metabolic demand during the Phanerozoic was driven by progressive oxygenation of shelf environments related to changes in the biological pump rather than greater food availability. In general, these model simulations suggest changes in the depth distribution of organic carbon remineralization may have controlled observed shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure during the Phanerozoic.

  18. 30 CFR 550.216 - What biological, physical, and socioeconomic information must accompany the EP?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the Marine Mammal Protection Act (MMPA), sensitive underwater features, marine sanctuaries, critical habitat designated under the Endangered Species Act (ESA), or other areas of biological concern...

  19. 30 CFR 550.216 - What biological, physical, and socioeconomic information must accompany the EP?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the Marine Mammal Protection Act (MMPA), sensitive underwater features, marine sanctuaries, critical habitat designated under the Endangered Species Act (ESA), or other areas of biological concern...

  20. 30 CFR 550.216 - What biological, physical, and socioeconomic information must accompany the EP?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the Marine Mammal Protection Act (MMPA), sensitive underwater features, marine sanctuaries, critical habitat designated under the Endangered Species Act (ESA), or other areas of biological concern...

  1. 30 CFR 250.216 - What biological, physical, and socioeconomic information must accompany the EP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the Marine Mammal Protection Act (MMPA), sensitive underwater features, marine sanctuaries, critical habitat designated under the Endangered Species Act (ESA), or other areas of biological...

  2. Glycosaminoglycans analogs from marine invertebrates: structure, biological effects, and potential as new therapeutics.

    PubMed

    Pavão, Mauro S G

    2014-01-01

    In this review, several glycosaminoglycan analogs obtained from different marine invertebrate are reported. The structure, biological activity and mechanism of action of these unique molecules are detailed reviewed and exemplified by experiments in vitro and in vivo. Among the glycans studied are low-sulfated heparin-like polymers from ascidians, containing significant anticoagulant activity and no bleeding effect; dermatan sulfates with significant neurite outgrowth promoting activity and anti-P-selectin from ascidians, and a unique fucosylated chondroitin sulfate from sea cucumbers, possessing anticoagulant activity after oral administration and high anti P- and L-selectin activities. The therapeutic value and safety of these invertebrate glycans have been extensively proved by several experimental animal models of diseases, including thrombosis, inflammation and metastasis. These invertebrate glycans can be obtained in high concentrations from marine organisms that have been used as a food source for decades, and usually obtained from marine farms in sufficient quantities to be used as starting material for new therapeutics.

  3. Dispersal of marine organisms and the grand challenges in biology: an introduction to the symposium.

    PubMed

    Lindsay, Sara M

    2012-10-01

    Understanding dispersal and its complex variables is critical to understanding the ecology and evolution of life histories of species, but research on dispersal tends to reflect or emphasize particular disciplines, such as population genetics, functional morphology, evolutionary and developmental biology, physiology, and biophysics, or to emphasize a particular clade or functional group (e.g., fish, planktotrophs or lecithotrophs, pelagic or benthic organisms) in marine ecosystems. The symposium on "Dispersal of Marine Organisms" assembled an interdisciplinary group of outstanding young and established speakers to address dispersal in marine organisms in order to foster integration and cross-talk among different disciplines and to identify gaps in our knowledge and suggest areas for future research.

  4. Marine biological production from in situ oxygen measurements on a profiling float in the subarctic Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Bushinsky, Seth M.; Emerson, Steven

    2015-12-01

    Evaluating the organic carbon flux from the surface ocean to the interior (the marine biological pump) is essential for predictions of ocean carbon cycle feedback to climate change. One approach for determining these fluxes is to measure the concentration of oxygen in the upper ocean over a seasonal cycle, calculate the net O2 flux using an upper ocean model, and then use a stoichiometric relationship between oxygen evolved and organic carbon produced. Applying this tracer in a variety of ocean areas over seasonal cycles requires accurate O2 measurements on autonomous vehicles. Here we demonstrate this approach using an O2 sensor on a profiling float that is periodically calibrated against atmospheric pO2. Using accurate data and a model that includes all physical and biological processes influencing oxygen, we determine an annual net community production of 0.7 ± 0.5 mol C m-2 yr-1 in the northeast Pacific Ocean (50°N, 145°W) from June 2012 to June 2013. There is a strong seasonal cycle in net biological oxygen production with wintertime fluxes caused by bubble processes critical to determining the annual flux. Approximately 50% of net autotrophic production during summer months is consumed by net respiration during the winter. The result is a biological pump in the subarctic Pacific Ocean that is less than that determined by similar methods in the subtropics to the south. This estimate is significantly lower than that predicted by satellite remote sensing and global circulation models.

  5. Effects of marine reserves and urchin disease on southern Californian rocky reef communities

    USGS Publications Warehouse

    Behrens, Michael D.; Lafferty, Kevin D.

    2004-01-01

    While the species level effects of marine reserves are widely recognized, community level shifts due to marine reserves have only recently been documented. Protection from fishing of top predators may lead to trophic cascades, which have community-wide implications. Disease may act in a similar manner, regulating population levels of dominant species within a community. Two decades of data from the Channel Islands National Park Service's Kelp Forest Monitoring database allowed us to compare the effects of fishing and urchin disease on rocky reef community patterns and dynamics. Different size-frequency distributions of urchins inside and outside of reserves indicated reduced predation on urchins at sites where fishing removes urchin predators. Rocky reefs inside reserves were more likely to support kelp forests than were fished areas. We suggest that this results from cascading effects of the fishery on urchin predators outside the reserves, which releases herbivores (urchins) from predation. After periods of prevalent urchin disease, the reef community shifted more towards kelp forest assemblages. Specific groups of algae and invertebrates were associated with kelp forest and barrens communities. The community dynamics leading to transitions between kelp forests and barrens are driven by both fishing and disease; however the fishery effect was of greater magnitude. This study further confirms the importance of marine reserves not only for fisheries conservation, but also for the conservation of historically dominant community types.

  6. Biology, genome organization, and evolution of parvoviruses in marine shrimp.

    PubMed

    Dhar, Arun K; Robles-Sikisaka, Refugio; Saksmerprome, Vanvimon; Lakshman, Dilip K

    2014-01-01

    As shrimp aquaculture has evolved from a subsistent farming activity to an economically important global industry, viral diseases have also become a serious threat to the sustainable growth and productivity of this industry. Parvoviruses represent an economically important group of viruses that has greatly affected shrimp aquaculture. In the early 1980s, an outbreak of a shrimp parvovirus, infectious hypodermal and hematopoietic necrosis virus (IHHNV), led to the collapse of penaeid shrimp farming in the Americas. Since then, considerable progress has been made in characterizing the parvoviruses of shrimp and developing diagnostic methods aimed to preventing the spread of diseases caused by these viruses. To date, four parvoviruses are known that infect shrimp; these include IHHNV, hepatopancreatic parvovirus (HPV), spawner-isolated mortality virus (SMV), and lymphoid organ parvo-like virus. Due to the economic repercussions that IHHNV and HPV outbreaks have caused to shrimp farming over the years, studies have been focused mostly on these two pathogens, while information on SMV and LPV remains limited. IHHNV was the first shrimp virus to be sequenced and the first for which highly sensitive diagnostic methods were developed. IHHNV-resistant lines of shrimp were also developed to mitigate the losses caused by this virus. While the losses due to IHHNV have been largely contained in recent years, reports of HPV-induced mortalities in larval stages in hatchery and losses due to reduced growth have increased. This review presents a comprehensive account of the history and current knowledge on the biology, diagnostics methods, genomic features, mechanisms of evolution, and management strategies of shrimp parvoviruses. We also highlighted areas where research efforts should be focused in order to gain further insight on the mechanisms of parvoviral pathogenicity in shrimp that will help to prevent future losses caused by these viruses. © 2014 Elsevier Inc. All rights

  7. Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

    SciTech Connect

    Not Available

    1994-12-31

    The ocean plays an important role in regulating the earth`s climate, sustains a large portion of the earth`s biodiversity, is a tremendous reservoir of commercially important substances, and is used for a variety of often conflicting purposes. In recent decades marine scientists have discovered much about the ocean and its organisms, yet many important fundamental questions remain unanswered. Human populations have increased, particularly in coastal regions. As a result, the marine environment in these areas is increasingly disrupted by human activities, including pollution and the depletion of some ecologically and commercially important species. There is a sense of urgency about reducing human impacts on the ocean and a need to understand how altered ecosystems and the loss of marine species and biodiversity could affect society. This report describes molecular techniques that could be invaluable in addressing process-oriented problems in the ocean sciences that have perplexed oceanographers for decades, such as understanding the basis for biogeochemical processes, recruitment processes, upper-ocean dynamics, biological impacts of global warming, and ecological impacts of human activities. The coupling of highly sophisticated methods, such as satellite remote sensing, which permits synoptic monitoring of chemical, physical, and biological parameters over large areas, with the power of modern molecular tools for ground truthing at small scales could allow scientists to address questions about marine organisms and the ocean in which they live that could not be answered previously.

  8. Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

    SciTech Connect

    1994-12-31

    This report describes molecular techniques that could be invaluable in addressing process-oriented problems in the ocean sciences that have perplexed oceanographers for decades, such as understanding the basis for biogeochemical processes, recruitment processes, upper-ocean dynamics, biological impacts of global warming, and ecological impacts of human activities. The coupling of highly sophisticated methods, such as satellite remote sensing, which permits synoptic monitoring of chemical, physical, and biological parameters over large areas, with the power of modern molecular tools for ``ground truthing`` at small scales could allow scientists to address questions about marine organisms and the ocean in which they live that could not be answered previously. Clearly, the marine sciences are on the threshold of an exciting new frontier of scientific discovery and economic opportunity.

  9. Ideas and perspectives: climate-relevant marine biologically driven mechanisms in Earth system models

    NASA Astrophysics Data System (ADS)

    Hense, Inga; Stemmler, Irene; Sonntag, Sebastian

    2017-01-01

    The current generation of marine biogeochemical modules in Earth system models (ESMs) considers mainly the effect of marine biota on the carbon cycle. We propose to also implement other biologically driven mechanisms in ESMs so that more climate-relevant feedbacks are captured. We classify these mechanisms in three categories according to their functional role in the Earth system: (1) biogeochemical pumps, which affect the carbon cycling; (2) biological gas and particle shuttles, which affect the atmospheric composition; and (3) biogeophysical mechanisms, which affect the thermal, optical, and mechanical properties of the ocean. To resolve mechanisms from all three classes, we find it sufficient to include five functional groups: bulk phyto- and zooplankton, calcifiers, and coastal gas and surface mat producers. We strongly suggest to account for a larger mechanism diversity in ESMs in the future to improve the quality of climate projections.

  10. Introduced rats indirectly change marine rocky intertidal communities from algae- to invertebrate-dominated.

    PubMed

    Kurle, Carolyn M; Croll, Donald A; Tershy, Bernie R

    2008-03-11

    It is widely recognized that trophic interactions structure ecological communities, but their effects are usually only demonstrated on a small scale. As a result, landscape-level documentations of trophic cascades that alter entire communities are scarce. Islands invaded by animals provide natural experiment opportunities both to measure general trophic effects across large spatial scales and to determine the trophic roles of invasive species within native ecosystems. Studies addressing the trophic interactions of invasive species most often focus on their direct effects. To investigate both the presence of a landscape-level trophic cascade and the direct and indirect effects of an invasive species, we examined the impacts of Norway rats (Rattus norvegicus) introduced to the Aleutian Islands on marine bird densities and marine rocky intertidal community structures through surveys conducted on invaded and rat-free islands throughout the entire 1,900-km archipelago. Densities of birds that forage in the intertidal were higher on islands without rats. Marine intertidal invertebrates were more abundant on islands with rats, whereas fleshy algal cover was reduced. Our results demonstrate that invasive rats directly reduce bird densities through predation and significantly affect invertebrate and marine algal abundance in the rocky intertidal indirectly via a cross-community trophic cascade, unexpectedly changing the intertidal community structure from an algae- to an invertebrate-dominated system.

  11. Potential of marine reserves to cause community-wide changes beyond their boundaries.

    PubMed

    Guidetti, Paolo

    2007-04-01

    Fishing and other human activities can alter the abundances, size structure, and behavior of species playing key roles in shaping marine communities (e.g., keystone predators), which may in turn cause ecosystem shifts. Despite extensive evidence that cascading trophic interactions can underlie community-wide recovery inside no-take marine reserves by protecting high-level predators, the spatial extent of these effects into adjacent fished areas is unknown. I examined the potential for community-wide changes (i.e., the transition from overgrazed coralline barrens to macroalgal beds) in temperate rocky reefs within and around a no-take marine reserve. For this purpose I assessed distribution patterns of predatory fishes, sea urchins, and barrens across the reserve boundaries. Predatory fishes were significantly more abundant within the reserve than in adjacent locations, with moderate spillover across the reserve edges. In contrast, community-wide changes of benthic assemblages were apparent well beyond the reserve boundaries, which is consistent with temporary movements of predatory fishes (e.g., foraging migration) from the reserve to surrounding areas. My results suggest that no-take marine reserves can promote community-wide changes beyond their boundaries.

  12. Introduced rats indirectly change marine rocky intertidal communities from algae- to invertebrate-dominated

    PubMed Central

    Kurle, Carolyn M.; Croll, Donald A.; Tershy, Bernie R.

    2008-01-01

    It is widely recognized that trophic interactions structure ecological communities, but their effects are usually only demonstrated on a small scale. As a result, landscape-level documentations of trophic cascades that alter entire communities are scarce. Islands invaded by animals provide natural experiment opportunities both to measure general trophic effects across large spatial scales and to determine the trophic roles of invasive species within native ecosystems. Studies addressing the trophic interactions of invasive species most often focus on their direct effects. To investigate both the presence of a landscape-level trophic cascade and the direct and indirect effects of an invasive species, we examined the impacts of Norway rats (Rattus norvegicus) introduced to the Aleutian Islands on marine bird densities and marine rocky intertidal community structures through surveys conducted on invaded and rat-free islands throughout the entire 1,900-km archipelago. Densities of birds that forage in the intertidal were higher on islands without rats. Marine intertidal invertebrates were more abundant on islands with rats, whereas fleshy algal cover was reduced. Our results demonstrate that invasive rats directly reduce bird densities through predation and significantly affect invertebrate and marine algal abundance in the rocky intertidal indirectly via a cross-community trophic cascade, unexpectedly changing the intertidal community structure from an algae- to an invertebrate-dominated system. PMID:18308929

  13. Natural Proline-Rich Cyclopolypeptides from Marine Organisms: Chemistry, Synthetic Methodologies and Biological Status

    PubMed Central

    Fang, Wan-Yin; Dahiya, Rajiv; Qin, Hua-Li; Mourya, Rita; Maharaj, Sandeep

    2016-01-01

    Peptides have gained increased interest as therapeutics during recent years. More than 60 peptide drugs have reached the market for the benefit of patients and several hundreds of novel therapeutic peptides are in preclinical and clinical development. The key contributor to this success is the potent and specific, yet safe, mode of action of peptides. Among the wide range of biologically-active peptides, naturally-occurring marine-derived cyclopolypeptides exhibit a broad range of unusual and potent pharmacological activities. Because of their size and complexity, proline-rich cyclic peptides (PRCPs) occupy a crucial chemical space in drug discovery that may provide useful scaffolds for modulating more challenging biological targets, such as protein-protein interactions and allosteric binding sites. Diverse pharmacological activities of natural cyclic peptides from marine sponges, tunicates and cyanobacteria have encouraged efforts to develop cyclic peptides with well-known synthetic methods, including solid-phase and solution-phase techniques of peptide synthesis. The present review highlights the natural resources, unique structural features and the most relevant biological properties of proline-rich peptides of marine-origin, focusing on the potential therapeutic role that the PRCPs may play as a promising source of new peptide-based novel drugs. PMID:27792168

  14. Natural Proline-Rich Cyclopolypeptides from Marine Organisms: Chemistry, Synthetic Methodologies and Biological Status.

    PubMed

    Fang, Wan-Yin; Dahiya, Rajiv; Qin, Hua-Li; Mourya, Rita; Maharaj, Sandeep

    2016-10-26

    Peptides have gained increased interest as therapeutics during recent years. More than 60 peptide drugs have reached the market for the benefit of patients and several hundreds of novel therapeutic peptides are in preclinical and clinical development. The key contributor to this success is the potent and specific, yet safe, mode of action of peptides. Among the wide range of biologically-active peptides, naturally-occurring marine-derived cyclopolypeptides exhibit a broad range of unusual and potent pharmacological activities. Because of their size and complexity, proline-rich cyclic peptides (PRCPs) occupy a crucial chemical space in drug discovery that may provide useful scaffolds for modulating more challenging biological targets, such as protein-protein interactions and allosteric binding sites. Diverse pharmacological activities of natural cyclic peptides from marine sponges, tunicates and cyanobacteria have encouraged efforts to develop cyclic peptides with well-known synthetic methods, including solid-phase and solution-phase techniques of peptide synthesis. The present review highlights the natural resources, unique structural features and the most relevant biological properties of proline-rich peptides of marine-origin, focusing on the potential therapeutic role that the PRCPs may play as a promising source of new peptide-based novel drugs.

  15. Microbial Communities and Bioactive Compounds in Marine Sponges of the Family Irciniidae—A Review

    PubMed Central

    Hardoim, Cristiane C. P.; Costa, Rodrigo

    2014-01-01

    Marine sponges harbour complex microbial communities of ecological and biotechnological importance. Here, we propose the application of the widespread sponge family Irciniidae as an appropriate model in microbiology and biochemistry research. Half a gram of one Irciniidae specimen hosts hundreds of bacterial species—the vast majority of which are difficult to cultivate—and dozens of fungal and archaeal species. The structure of these symbiont assemblages is shaped by the sponge host and is highly stable over space and time. Two types of quorum-sensing molecules have been detected in these animals, hinting at microbe-microbe and host-microbe signalling being important processes governing the dynamics of the Irciniidae holobiont. Irciniids are vulnerable to disease outbreaks, and concerns have emerged about their conservation in a changing climate. They are nevertheless amenable to mariculture and laboratory maintenance, being attractive targets for metabolite harvesting and experimental biology endeavours. Several bioactive terpenoids and polyketides have been retrieved from Irciniidae sponges, but the actual producer (host or symbiont) of these compounds has rarely been clarified. To tackle this, and further pertinent questions concerning the functioning, resilience and physiology of these organisms, truly multi-layered approaches integrating cutting-edge microbiology, biochemistry, genetics and zoology research are needed. PMID:25272328

  16. Microbial communities and bioactive compounds in marine sponges of the family irciniidae-a review.

    PubMed

    Hardoim, Cristiane C P; Costa, Rodrigo

    2014-09-30

    Marine sponges harbour complex microbial communities of ecological and biotechnological importance. Here, we propose the application of the widespread sponge family Irciniidae as an appropriate model in microbiology and biochemistry research. Half a gram of one Irciniidae specimen hosts hundreds of bacterial species-the vast majority of which are difficult to cultivate-and dozens of fungal and archaeal species. The structure of these symbiont assemblages is shaped by the sponge host and is highly stable over space and time. Two types of quorum-sensing molecules have been detected in these animals, hinting at microbe-microbe and host-microbe signalling being important processes governing the dynamics of the Irciniidae holobiont. Irciniids are vulnerable to disease outbreaks, and concerns have emerged about their conservation in a changing climate. They are nevertheless amenable to mariculture and laboratory maintenance, being attractive targets for metabolite harvesting and experimental biology endeavours. Several bioactive terpenoids and polyketides have been retrieved from Irciniidae sponges, but the actual producer (host or symbiont) of these compounds has rarely been clarified. To tackle this, and further pertinent questions concerning the functioning, resilience and physiology of these organisms, truly multi-layered approaches integrating cutting-edge microbiology, biochemistry, genetics and zoology research are needed.

  17. Marine wildlife entanglement: Assessing knowledge, attitudes, and relevant behaviour in the Australian community.

    PubMed

    Pearson, Elissa; Mellish, Sarah; Sanders, Ben; Litchfield, Carla

    2014-12-15

    Marine debris remains a global challenge, with significant impacts on wildlife. Despite this, there is a paucity of research examining public understanding about marine wildlife entanglement [MWE], particularly within an Australian context. The present study surveyed two hundred and thirteen participants across three coastal sites to assess familiarity with MWE and the effectiveness of a new community education initiative 'Seal the Loop' [STL]. Results revealed attitudes toward marine wildlife were very positive (M 40.5, SD 4.12); however 32% of participants were unable to correctly explain what MWE is and risks to wildlife were under-estimated. STL may be one method to enhance public understanding and engagement-if community familiarity with the program can be increased. For those aware of STL (<13% of the sample at the time of the study), findings revealed this was having a positive impact (e.g. learning something new, changed waste disposal behaviours). Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Effect of ultraviolet radiation on marine phytoplankton community in Akkeshi Bay, Japan

    SciTech Connect

    Taguchi, S.; Saito, H.; Kasai, H. )

    1992-01-01

    Effect of ultraviolet radiation on marine phytoplankton community was determined during a spring and fall bloom in a boreal embayment, Akkeshi Bay, Japan, which was located at 43[degrees]N, 144[degrees]50[prime]E. A time-series of observation was made every 6 h for 24 hours. Exposure to ultraviolet radiation always caused a depression of photosynthetic activity was observed at the end of day light period in both blooms. During a nigh period a degree of depression was decreased by 50% at least. The results of the present study may suggest that the effect of ultraviolet radiation on photosynthesis of marine phytoplankton is significantly large even in the boreal sea region and marine phytoplankton community has a capability to recover more than 40% from a damage by ultraviolet radiation during a night period.

  19. Structure of macroalgal communities on tropical rocky shores inside and outside a marine protected area.

    PubMed

    Portugal, Adriana Brizon; Carvalho, Fabrício Lopes; Soares, Marcelo de Oliveira; Horta, Paulo Antunes; de Castro Nunes, José Marcos

    2017-09-01

    The structure of marine macroalgal communities and morpho-functional groups were investigated in a poorly characterized region on the Tropical Southwestern Atlantic coast, Brazil. The survey was conducted at six rocky shores located on the mainland and on coastal islands distributed inside a marine protected area (MPA) and outside the MPA (near a densely populated area). We hypothesized that tropical rocky shores inside the MPA and islands have higher species richness, diversity, and evenness of marine macroalgae. Results confirmed that species richness, diversity and evenness were significantly higher inside the MPA than in rocky shores outside the MPA. Only species richness was higher on islands than on the mainland. The results suggest that human impacts could lead to a competitive advantage and dominance in the articulated calcareous morphotype, resulting in community differences and lower benthic biodiversity in tropical ecosystems near urbanized sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Integrated metagenomic and metaproteomic analyses of an ANME-1-dominated community in marine cold seep sediments.

    PubMed

    Stokke, Runar; Roalkvam, Irene; Lanzen, Anders; Haflidason, Haflidi; Steen, Ida H

    2012-05-01

    Sulfate-reducing methanotrophy by anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) is a major biological sink of methane in anoxic methane-enriched marine sediments. The physiology of a microbial community dominated by free-living ANME-1 at 14-16 cm below the seafloor in the G11 pockmark at Nyegga was investigated by integrated metagenomic and metaproteomic approaches. Total DNA was subjected to 454-pyrosequencing (829 527 reads), and 16.6 Mbp of sequence information was assembled into 27352 contigs. Taxonomic analysis supported a high abundance of Euryarchaea (70%) with 66% of the assembled metagenome belonging to ANME-1. Extracted sediment proteins were separated in two dimensions and subjected to mass spectrometry (LTQ-Orbitrap XL). Of 356 identified proteins, 245 were expressed by ANME-1. These included proteins for cold-adaptation and production of gas vesicles, reflecting both the adaptation of the ANME-1 community to a permanently cold environment and its potential for positioning in specific sediment depths respectively. In addition, key metabolic enzymes including the enzymes in the reverse methanogenesis pathway (except N(5) ,N(10) -methylene-tetrahydromethanopterin reductase), heterodisulfide reductases and the F(420) H(2) :quinone oxidoreductase (Fqo) complex were identified. A complete dissimilatory sulfate reduction pathway was expressed by sulfate-reducing Deltaproteobacteria. Interestingly, an APS-reductase comprising Gram-positive SRB and related sequences were identified in the proteome. Overall, the results demonstrated that our approach was effective in assessing in situ metabolic processes in cold seep sediments.

  1. Comparisons of the fungal and protistan communities among different marine sponge holobionts by pyrosequencing.

    PubMed

    He, Liming; Liu, Fang; Karuppiah, Valliappan; Ren, Yi; Li, Zhiyong

    2014-05-01

    To date, the knowledge of eukaryotic communities associated with sponges remains limited compared with prokaryotic communities. In a manner similar to prokaryotes, it could be hypothesized that sponge holobionts have phylogenetically diverse eukaryotic symbionts, and the eukaryotic community structures in different sponge holobionts were probably different. In order to test this hypothesis, the communities of eukaryota associated with 11 species of South China Sea sponges were compared with the V4 region of 18S ribosomal ribonucleic acid gene using 454 pyrosequencing. Consequently, 135 and 721 unique operational taxonomic units (OTUs) of fungi and protists were obtained at 97 % sequence similarity, respectively. These sequences were assigned to 2 phyla of fungi (Ascomycota and Basidiomycota) and 9 phyla of protists including 5 algal phyla (Chlorophyta, Haptophyta, Streptophyta, Rhodophyta, and Stramenopiles) and 4 protozoal phyla (Alveolata, Cercozoa, Haplosporidia, and Radiolaria) including 47 orders (12 fungi, 35 protists). Entorrhizales of fungi and 18 orders of protists were detected in marine sponges for the first time. Particularly, Tilletiales of fungi and Chlorocystidales of protists were detected for the first time in marine habitats. Though Ascomycota, Alveolata, and Radiolaria were detected in all the 11 sponge species, sponge holobionts have different fungi and protistan communities according to OTU comparison and principal component analysis at the order level. This study provided the first insights into the fungal and protistan communities associated with different marine sponge holobionts using pyrosequencing, thus further extending the knowledge on sponge-associated eukaryotic diversity.

  2. The Power of Computer-aided Tomography to Investigate Marine Benthic Communities

    EPA Science Inventory

    Utilization of Computer-aided-Tomography (CT) technology is a powerful tool to investigate benthic communities in aquatic systems. In this presentation, we will attempt to summarize our 15 years of experience in developing specific CT methods and applications to marine benthic co...

  3. The Power of Computer-aided Tomography to Investigate Marine Benthic Communities

    EPA Science Inventory

    Utilization of Computer-aided-Tomography (CT) technology is a powerful tool to investigate benthic communities in aquatic systems. In this presentation, we will attempt to summarize our 15 years of experience in developing specific CT methods and applications to marine benthic co...

  4. Mammalian mesopredators on islands directly impact both terrestrial and marine communities.

    PubMed

    Suraci, Justin P; Clinchy, Michael; Zanette, Liana Y; Currie, Christopher M A; Dill, Lawrence M

    2014-12-01

    Medium-sized mammalian predators (i.e. mesopredators) on islands are known to have devastating effects on the abundance and diversity of terrestrial vertebrates. Mesopredators are often highly omnivorous, and on islands, may have access not only to terrestrial prey, but to marine prey as well, though impacts of mammalian mesopredators on marine communities have rarely been considered. Large apex predators are likely to be extirpated or absent on islands, implying a lack of top-down control of mesopredators that, in combination with high food availability from terrestrial and marine sources, likely exacerbates their impacts on island prey. We exploited a natural experiment--the presence or absence of raccoons (Procyon lotor) on islands in the Gulf Islands, British Columbia, Canada--to investigate the impacts that this key mesopredator has on both terrestrial and marine prey in an island system from which all native apex predators have been extirpated. Long-term monitoring of song sparrow (Melospiza melodia) nests showed raccoons to be the predominant nest predator in the Gulf Islands. To identify their community-level impacts, we surveyed the distribution of raccoons across 44 Gulf Islands, and then compared terrestrial and marine prey abundances on six raccoon-present and six raccoon-absent islands. Our results demonstrate significant negative effects of raccoons on terrestrial, intertidal, and shallow subtidal prey abundance, and point to additional community-level effects through indirect interactions. Our findings show that mammalian mesopredators not only affect terrestrial prey, but that, on islands, their direct impacts extend to the surrounding marine community.

  5. Marine protected areas increase temporal stability of community structure, but not density or diversity, of tropical seagrass fish communities.

    PubMed

    Alonso Aller, Elisa; Jiddawi, Narriman S; Eklöf, Johan S

    2017-01-01

    Marine protected areas (MPAs) have been shown to increase long-term temporal stability of fish communities and enhance ecosystem resilience to anthropogenic disturbance. Yet, the potential ability of MPAs to buffer effects of environmental variability at shorter time scales remains widely unknown. In the tropics, the yearly monsoon cycle is a major natural force affecting marine organisms in tropical regions, and its timing and severity are predicted to change over the coming century, with potentially severe effects on marine organisms, ecosystems and ecosystem services. Here, we assessed the ability of MPAs to buffer effects of monsoon seasonality on seagrass-associated fish communities, using a field survey in two MPAs (no-take zones) and two unprotected (open-access) sites around Zanzibar (Tanzania). We assessed the temporal stability of fish density and community structure within and outside MPAs during three monsoon seasons in 2014-2015, and investigated several possible mechanisms that could regulate temporal stability. Our results show that MPAs did not affect fish density and diversity, but that juvenile fish densities were temporally more stable within MPAs. Second, fish community structure was more stable within MPAs for juvenile and adult fish, but not for subadult fish or the total fish community. Third, the observed effects may be due to a combination of direct and indirect (seagrass-mediated) effects of seasonality and, potentially, fluctuating fishing pressure outside MPAs. In summary, these MPAs may not have the ability to enhance fish density and diversity and to buffer effects of monsoon seasonality on the whole fish community. However, they may increase the temporal stability of certain groups, such as juvenile fish. Consequently, our results question whether MPAs play a general role in the maintenance of biodiversity and ecosystem functioning under changing environmental conditions in tropical seagrass fish communities.

  6. Delineating ecological regions in marine systems: Integrating physical structure and community composition to inform spatial management in the eastern Bering Sea

    NASA Astrophysics Data System (ADS)

    Baker, Matthew R.; Hollowed, Anne B.

    2014-11-01

    Characterizing spatial structure and delineating meaningful spatial boundaries have useful applications to understanding regional dynamics in marine systems, and are integral to ecosystem approaches to fisheries management. Physical structure and drivers combine with biological responses and interactions to organize marine systems in unique ways at multiple scales. We apply multivariate statistical methods to define spatially coherent ecological units or ecoregions in the eastern Bering Sea. We also illustrate a practical approach to integrate data on species distribution, habitat structure and physical forcing mechanisms to distinguish areas with distinct biogeography as one means to define management units in large marine ecosystems. We use random forests to quantify the relative importance of habitat and environmental variables to the distribution of individual species, and to quantify shifts in multispecies assemblages or community composition along environmental gradients. Threshold shifts in community composition are used to identify regions with distinct physical and biological attributes, and to evaluate the relative importance of predictor variables to determining regional boundaries. Depth, bottom temperature and frontal boundaries were dominant factors delineating distinct biological communities in this system, with a latitudinal divide at approximately 60°N. Our results indicate that distinct climatic periods will shift habitat gradients and that dynamic physical variables such as temperature and stratification are important to understanding temporal stability of ecoregion boundaries. We note distinct distribution patterns among functional guilds and also evidence for resource partitioning among individual species within each guild. By integrating physical and biological data to determine spatial patterns in community composition, we partition ecosystems along ecologically significant gradients. This may provide a basis for defining spatial management

  7. Influence of Sea Ice on Arctic Marine Sulfur Biogeochemistry in the Community Climate System Model

    SciTech Connect

    Deal, Clara; Jin, Meibing

    2013-06-30

    Global climate models (GCMs) have not effectively considered how responses of arctic marine ecosystems to a warming climate will influence the global climate system. A key response of arctic marine ecosystems that may substantially influence energy exchange in the Arctic is a change in dimethylsulfide (DMS) emissions, because DMS emissions influence cloud albedo. This response is closely tied to sea ice through its impacts on marine ecosystem carbon and sulfur cycling, and the ice-albedo feedback implicated in accelerated arctic warming. To reduce the uncertainty in predictions from coupled climate simulations, important model components of the climate system, such as feedbacks between arctic marine biogeochemistry and climate, need to be reasonably and realistically modeled. This research first involved model development to improve the representation of marine sulfur biogeochemistry simulations to understand/diagnose the control of sea-ice-related processes on the variability of DMS dynamics. This study will help build GCM predictions that quantify the relative current and possible future influences of arctic marine ecosystems on the global climate system. Our overall research objective was to improve arctic marine biogeochemistry in the Community Climate System Model (CCSM, now CESM). Working closely with the Climate Ocean Sea Ice Model (COSIM) team at Los Alamos National Laboratory (LANL), we added 1 sea-ice algae and arctic DMS production and related biogeochemistry to the global Parallel Ocean Program model (POP) coupled to the LANL sea ice model (CICE). Both CICE and POP are core components of CESM. Our specific research objectives were: 1) Develop a state-of-the-art ice-ocean DMS model for application in climate models, using observations to constrain the most crucial parameters; 2) Improve the global marine sulfur model used in CESM by including DMS biogeochemistry in the Arctic; and 3) Assess how sea ice influences DMS dynamics in the arctic marine

  8. Polar marine biology science in Portugal and Spain: Recent advances and future perspectives

    NASA Astrophysics Data System (ADS)

    Xavier, José C.; Barbosa, Andrés; Agustí, Susana; Alonso-Sáez, Laura; Alvito, Pedro; Ameneiro, Julia; Ávila, Conxita; Baeta, Alexandra; Canário, João; Carmona, Raquel; Catry, Paulo; Ceia, Filipe; Clark, Melody S.; Cristobo, Francisco J.; Cruz, Bruno; Duarte, Carlos M.; Figuerola, Blanca; Gili, Josep-Maria; Gonçalves, Ana R.; Gordillo, Francisco J. L.; Granadeiro, José P.; Guerreiro, Miguel; Isla, Enrique; Jiménez, Carlos; López-González, Pablo J.; Lourenço, Sílvia; Marques, João C.; Moreira, Elena; Mota, Ana M.; Nogueira, Marta; Núñez-Pons, Laura; Orejas, Covadonga; Paiva, Vitor H.; Palanques, Albert; Pearson, Gareth A.; Pedrós-Alió, Carlos; Peña Cantero, Álvaro L.; Power, Deborah M.; Ramos, Jaime A.; Rossi, Sergi; Seco, José; Sañé, Elisabet; Serrão, Ester A.; Taboada, Sergi; Tavares, Sílvia; Teixidó, Núria; Vaqué, Dolors; Valente, Tiago; Vázquez, Elsa; Vieira, Rui P.; Viñegla, Benjamin

    2013-10-01

    Polar marine ecosystems have global ecological and economic importance because of their unique biodiversity and their major role in climate processes and commercial fisheries, among others. Portugal and Spain have been highly active in a wide range of disciplines in marine biology of the Antarctic and the Arctic. The main aim of this paper is to provide a synopsis of some of the results and initiatives undertaken by Portuguese and Spanish polar teams within the field of marine sciences, particularly on benthic and pelagic biodiversity (species diversity and abundance, including microbial, molecular, physiological and chemical mechanisms in polar organisms), conservation and ecology of top predators (particularly penguins, albatrosses and seals), and pollutants and evolution of marine organisms associated with major issues such as climate change, ocean acidification and UV radiation effects. Both countries have focused their polar research more in the Antarctic than in the Arctic. Portugal and Spain should encourage research groups to continue increasing their collaborations with other countries and develop multi-disciplinary research projects, as well as to maintain highly active memberships within major organizations, such as the Scientific Committee for Antarctic Research (SCAR), the International Arctic Science Council (IASC) and the Association of Polar Early Career Scientists (APECS), and in international research projects.

  9. Emerging Concepts Promising New Horizons for Marine Biodiscovery and Synthetic Biology

    PubMed Central

    Reen, F. Jerry; Gutiérrez-Barranquero, José A.; Dobson, Alan D. W.; Adams, Claire; O’Gara, Fergal

    2015-01-01

    The vast oceans of the world, which comprise a huge variety of unique ecosystems, are emerging as a rich and relatively untapped source of novel bioactive compounds with invaluable biotechnological and pharmaceutical potential. Evidence accumulated over the last decade has revealed that the diversity of marine microorganisms is enormous with many thousands of bacterial species detected that were previously unknown. Associated with this diversity is the production of diverse repertoires of bioactive compounds ranging from peptides and enzymes to more complex secondary metabolites that have significant bioactivity and thus the potential to be exploited for innovative biotechnology. Here we review the discovery and functional potential of marine bioactive peptides such as lantibiotics, nanoantibiotics and peptidomimetics, which have received particular attention in recent years in light of their broad spectrum of bioactivity. The significance of marine peptides in cell-to-cell communication and how this may be exploited in the discovery of novel bioactivity is also explored. Finally, with the recent advances in bioinformatics and synthetic biology, it is becoming clear that the integration of these disciplines with genetic and biochemical characterization of the novel marine peptides, offers the most potential in the development of the next generation of societal solutions. PMID:25984990

  10. Emerging concepts promising new horizons for marine biodiscovery and synthetic biology.

    PubMed

    Reen, F Jerry; Gutiérrez-Barranquero, José A; Dobson, Alan D W; Adams, Claire; O'Gara, Fergal

    2015-05-13

    The vast oceans of the world, which comprise a huge variety of unique ecosystems, are emerging as a rich and relatively untapped source of novel bioactive compounds with invaluable biotechnological and pharmaceutical potential. Evidence accumulated over the last decade has revealed that the diversity of marine microorganisms is enormous with many thousands of bacterial species detected that were previously unknown. Associated with this diversity is the production of diverse repertoires of bioactive compounds ranging from peptides and enzymes to more complex secondary metabolites that have significant bioactivity and thus the potential to be exploited for innovative biotechnology. Here we review the discovery and functional potential of marine bioactive peptides such as lantibiotics, nanoantibiotics and peptidomimetics, which have received particular attention in recent years in light of their broad spectrum of bioactivity. The significance of marine peptides in cell-to-cell communication and how this may be exploited in the discovery of novel bioactivity is also explored. Finally, with the recent advances in bioinformatics and synthetic biology, it is becoming clear that the integration of these disciplines with genetic and biochemical characterization of the novel marine peptides, offers the most potential in the development of the next generation of societal solutions.

  11. Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

    PubMed Central

    Kuete, Victor; Biavatti, Maique W

    2015-01-01

    Summary This review focuses on pyridoacridine-related metabolites as one biologically interesting group of alkaloids identified from marine sources. They are produced by marine sponges, ascidians and tunicates, and they are structurally comprised of four to eight fused rings including heterocycles. Acridine, acridone, dihydroacridine, and quinolone cores are features regularly found in these alkaloid skeletons. The lack of hydrogen atoms next to quaternary carbon atoms for two or three rings makes the chemical shift assignment a difficult task. In this regard, one of the aims of this review is the compilation of previously reported, pyridoacridine 13C NMR data. Observations have been made on the delocalization of electrons and the presence of some functional groups that lead to changes in the chemical shift of some carbon resonances. The lack of mass spectra information for these alkaloids due to the compactness of their structures is further discussed. Moreover, the biosynthetic pathways of some of these metabolites have been shown since they could inspire biomimetic synthesis. The synthesis routes used to prepare members of these marine alkaloids (as well as their analogues), which are synthesized for biological purposes are also discussed. Pyridoacridines were found to have a large spectrum of bioactivity and this review highlights and compares the pharmacophores that are responsible for the observed bioactivity. PMID:26664587

  12. Phylogenetic analysis suggests that habitat filtering is structuring marine bacterial communities across the globe.

    PubMed

    Pontarp, Mikael; Canbäck, Björn; Tunlid, Anders; Lundberg, Per

    2012-07-01

    The phylogenetic structure and community composition were analysed in an existing data set of marine bacterioplankton communities to elucidate the evolutionary and ecological processes dictating the assembly. The communities were sampled from coastal waters at nine locations distributed worldwide and were examined through the use of comprehensive clone libraries of 16S ribosomal RNA genes. The analyses show that the local communities are phylogenetically different from each other and that a majority of them are phylogenetically clustered, i.e. the species (operational taxonomic units) were more related to each other than expected by chance. Accordingly, the local communities were assembled non-randomly from the global pool of available bacterioplankton. Further, the phylogenetic structures of the communities were related to the water temperature at the locations. In agreement with similar studies, including both macroorganisms and bacteria, these results suggest that marine bacterial communities are structured by “habitat filtering”, i.e. through non-random colonization and invasion determined by environmental characteristics. Different bacterial types seem to have different ecological niches that dictate their survival in different habitats. Other eco-evolutionary processes that may contribute to the observed phylogenetic patterns are discussed. The results also imply a mapping between phenotype and phylogenetic relatedness which facilitates the use of community phylogenetic structure analysis to infer ecological and evolutionary assembly processes.

  13. Chromophoric Dissolved Organic Matter across a Marine Distributed Biological Observatory in the Pacific Arctic Region

    NASA Astrophysics Data System (ADS)

    Berman, S. L.; Frey, K. E.; Shake, K. L.; Cooper, L. W.; Grebmeier, J. M.

    2014-12-01

    Dissolved organic matter (DOM) plays an important role in marine ecosystems as both a carbon source for the microbial food web (and thus a source of CO2 to the atmosphere) and as a light inhibitor in marine environments. The presence of chromophoric dissolved organic matter (CDOM; the optically active portion of total DOM) can have significant controlling effects on transmittance of sunlight through the water column and therefore on primary production as well as the heat balance of the upper ocean. However, CDOM is also susceptible to photochemical degradation, which decreases the flux of solar radiation that is absorbed. Knowledge of the current spatial and temporal distribution of CDOM in marine environments is thus critical for understanding how ongoing and future changes in climate may impact these biological, biogeochemical, and physical processes. We describe the quantity and quality of CDOM along five key productive transects across a developing Distributed Biological Observatory (DBO) in the Pacific Arctic region. The samples were collected onboard the CCGS Sir Wilfred Laurier in July 2013 and 2014. Monitoring of the variability of CDOM along transects of high productivity can provide important insights into biological and biogeochemical cycling across the region. Our analyses include overall concentrations of CDOM, as well as proxy information such as molecular weight, lability, and source (i.e., autochthonous vs. allochthonous) of organic matter. We utilize these field observations to compare with satellite-derived CDOM concentrations determined from the Aqua MODIS satellite platform, which ultimately provides a spatially and temporally continuous synoptic view of CDOM concentrations throughout the region. Examining the current relationships among CDOM, sea ice variability, biological productivity, and biogeochemical cycling in the Pacific Arctic region will likely provide key insights for how ecosystems throughout the region will respond in future

  14. Pole-to-pole biogeography of surface and deep marine bacterial communities.

    PubMed

    Ghiglione, Jean-François; Galand, Pierre E; Pommier, Thomas; Pedrós-Alió, Carlos; Maas, Elizabeth W; Bakker, Kevin; Bertilson, Stefan; Kirchmanj, David L; Lovejoy, Connie; Yager, Patricia L; Murray, Alison E

    2012-10-23

    The Antarctic and Arctic regions offer a unique opportunity to test factors shaping biogeography of marine microbial communities because these regions are geographically far apart, yet share similar selection pressures. Here, we report a comprehensive comparison of bacterioplankton diversity between polar oceans, using standardized methods for pyrosequencing the V6 region of the small subunit ribosomal (SSU) rRNA gene. Bacterial communities from lower latitude oceans were included, providing a global perspective. A clear difference between Southern and Arctic Ocean surface communities was evident, with 78% of operational taxonomic units (OTUs) unique to the Southern Ocean and 70% unique to the Arctic Ocean. Although polar ocean bacterial communities were more similar to each other than to lower latitude pelagic communities, analyses of depths, seasons, and coastal vs. open waters, the Southern and Arctic Ocean bacterioplankton communities consistently clustered separately from each other. Coastal surface Southern and Arctic Ocean communities were more dissimilar from their respective open ocean communities. In contrast, deep ocean communities differed less between poles and lower latitude deep waters and displayed different diversity patterns compared with the surface. In addition, estimated diversity (Chao1) for surface and deep communities did not correlate significantly with latitude or temperature. Our results suggest differences in environmental conditions at the poles and different selection mechanisms controlling surface and deep ocean community structure and diversity. Surface bacterioplankton may be subjected to more short-term, variable conditions, whereas deep communities appear to be structured by longer water-mass residence time and connectivity through ocean circulation.

  15. Comparison of bacterial communities on limnic versus coastal marine particles reveals profound differences in colonization.

    PubMed

    Bižić-Ionescu, Mina; Zeder, Michael; Ionescu, Danny; Orlić, Sandi; Fuchs, Bernhard M; Grossart, Hans-Peter; Amann, Rudolf

    2015-10-01

    Marine and limnic particles are hotspots of organic matter mineralization significantly affecting biogeochemical element cycling. Fluorescence in-situ hybridization and pyrosequencing of 16S rRNA genes were combined to investigate bacterial diversity and community composition on limnic and coastal marine particles > 5 and > 10 μm respectively. Limnic particles were more abundant (average: 1 × 10(7) l(-1)), smaller in size (average areas: 471 versus 2050 μm(2)) and more densely colonized (average densities: 7.3 versus 3.6 cells 100 μm(-2)) than marine ones. Limnic particle-associated (PA) bacteria harboured Alphaproteobacteria and Betaproteobacteria, and unlike previously suggested sizeable populations of Gammaproteobacteria, Actinobacteria and Bacteroidetes. Marine particles were colonized by Planctomycetes and Betaproteobacteria additionally to Alphaproteobacteria, Bacteroidetes and Gammaproteobacteria. Large differences in individual particle colonization could be detected. High-throughput sequencing revealed a significant overlap of PA and free-living (FL) bacteria highlighting an underestimated connectivity between both fractions. PA bacteria were in 14/21 cases more diverse than FL bacteria, reflecting a high heterogeneity in the particle microenvironment. We propose that a ratio of Chao 1 indices of PA/FL < 1 indicates the presence of rather homogeneously colonized particles. The identification of different bacterial families enriched on either limnic or marine particles demonstrates that, despite the seemingly similar ecological niches, PA communities of both environments differ substantially. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Integrated metagenomic and metaproteomic analyses of marine biofilm communities

    USDA-ARS?s Scientific Manuscript database

    Metagenomic and metaproteomic analyses were utilized to begin to understand the role varying environments play on the composition and function of complex air-water interface biofilms sampled from the hulls of two ships that were deployed in different geographic waters. Prokaryotic community analyses...

  17. Elevated nutrients change bacterial community composition and connectivity: high throughput sequencing of young marine biofilms.

    PubMed

    Lawes, Jasmin C; Neilan, Brett A; Brown, Mark V; Clark, Graeme F; Johnston, Emma L

    2016-01-01

    Biofilms are integral to many marine processes but their formation and function may be affected by anthropogenic inputs that alter environmental conditions, including fertilisers that increase nutrients. Density composition and connectivity of biofilms developed in situ (under ambient and elevated nutrients) were compared using 454-pyrosequencing of the 16S gene. Elevated nutrients shifted community composition from bacteria involved in higher processes (eg Pseudoalteromonas spp. invertebrate recruitment) towards more nutrient-tolerant bacterial species (eg Terendinibacter sp.). This may enable the persistence of biofilm communities by increasing resistance to nutrient inputs. A core biofilm microbiome was identified (predominantly Alteromonadales and Oceanospirillales) and revealed shifts in abundances of core microbes that could indicate enrichment by fertilisers. Fertiliser decreased density and connectivity within biofilms indicating that associations were disrupted perhaps via changes to energetic allocations within the core microbiome. Density composition and connectivity changes suggest nutrients can affect the stability and function of these important marine communities.

  18. Recommendations on methods for the detection and control of biological pollution in marine coastal waters.

    PubMed

    Olenin, Sergej; Elliott, Michael; Bysveen, Ingrid; Culverhouse, Phil F; Daunys, Darius; Dubelaar, George B J; Gollasch, Stephan; Goulletquer, Philippe; Jelmert, Anders; Kantor, Yuri; Mézeth, Kjersti Bringsvor; Minchin, Dan; Occhipinti-Ambrogi, Anna; Olenina, Irina; Vandekerkhove, Jochen

    2011-12-01

    Adverse effects of invasive alien species (IAS), or biological pollution, is an increasing problem in marine coastal waters, which remains high on the environmental management agenda. All maritime countries need to assess the size of this problem and consider effective mechanisms to prevent introductions, and if necessary and where possible to monitor, contain, control or eradicate the introduced impacting organisms. Despite this, and in contrast to more enclosed water bodies, the openness of marine systems indicates that once species are in an area then eradication is usually impossible. Most institutions in countries are aware of the problem and have sufficient governance in place for management. However, there is still a general lack of commitment and concerted action plans are needed to address this problem. This paper provides recommendations resulting from an international workshop based upon a large amount of experience relating to the assessment and control of biopollution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Variability and abundance of the epiphytic bacterial community associated with a green marine Ulvacean alga.

    PubMed

    Tujula, Niina A; Crocetti, Gregory R; Burke, Catherine; Thomas, Torsten; Holmström, Carola; Kjelleberg, Staffan

    2010-02-01

    Marine Ulvacean algae are colonized by dense microbial communities predicted to have an important role in the development, defense and metabolic activities of the plant. Here we assess the diversity and seasonal dynamics of the bacterial community of the model alga Ulva australis to identify key groups within this epiphytic community. A total of 48 algal samples of U. australis that were collected as 12 individuals at 3 monthly intervals, were processed by applying denaturing gradient gel electrophoresis (DGGE), and three samples from each season were subjected to catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH). CARD-FISH revealed that the epiphytic microbial community was comprised mainly of bacterial cells (90%) and was dominated by the groups Alphaproteobacteria (70%) and Bacteroidetes (13%). A large portion (47%) of sequences from the Alphaproteobacteria fall within the Roseobacter clade throughout the different seasons, and an average relative proportion of 19% was observed using CARD-FISH. DGGE based spatial (between tidal pools) and temporal (between season) comparisons of bacterial community composition demonstrated that variation occurs. Between individuals from both the same and different tidal pools, the variation was highest during winter (30%) and between seasons a 40% variation was observed. The community also includes a sub-population of bacteria that is consistently present. Sequences from excised DGGE bands indicate that members of the Alphaproteobacteria and the Bacteroidetes are part of this stable sub-population, and are likely to have an important role in the function of this marine epiphytic microbial community.

  20. Colonization in the photic zone and subsequent changes during sinking determine bacterial community composition in marine snow.

    PubMed

    Thiele, Stefan; Fuchs, Bernhard M; Amann, Rudolf; Iversen, Morten H

    2015-02-01

    Due to sampling difficulties, little is known about microbial communities associated with sinking marine snow in the twilight zone. A drifting sediment trap was equipped with a viscous cryogel and deployed to collect intact marine snow from depths of 100 and 400 m off Cape Blanc (Mauritania). Marine snow aggregates were fixed and washed in situ to prevent changes in microbial community composition and to enable subsequent analysis using catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH). The attached microbial communities collected at 100 m were similar to the free-living community at the depth of the fluorescence maximum (20 m) but different from those at other depths (150, 400, 550, and 700 m). Therefore, the attached microbial community seemed to be “inherited” from that at the fluorescence maximum. The attached microbial community structure at 400 m differed from that of the attached community at 100 m and from that of any free-living community at the tested depths, except that collected near the sediment at 700 m. The differences between the particle-associated communities at 400 m and 100 m appeared to be due to internal changes in the attached microbial community rather than de novo colonization, detachment, or grazing during the sinking of marine snow. The new sampling method presented here will facilitate future investigations into the mechanisms that shape the bacterial community within sinking marine snow, leading to better understanding of the mechanisms which regulate biogeochemical cycling of settling organic matter.

  1. Biological Targets and Mechanisms of Action of Natural Products from Marine Cyanobacteria

    PubMed Central

    Salvador-Reyes, Lilibeth A.

    2015-01-01

    Marine cyanobacteria are an ancient group of organisms and prolific producers of bioactive secondary metabolites. These compounds are presumably optimized by evolution over billions of years to exert high affinity for their intended biological target in the ecologically relevant organism but likely also possess activity in different biological contexts such as human cells. Screening of marine cyanobacterial extracts for bioactive natural products has largely focused on cancer cell viability; however, diversification of the screening platform led to the characterization of many new bioactive compounds. Targets of compounds have oftentimes been elusive if the compounds were discovered through phenotypic assays. Over the past few years, technology has advanced to determine mechanism of action (MOA) and targets through reverse chemical genetic and proteomic approaches, which has been applied to certain cyanobacterial compounds and will be discussed in this review. Some cyanobacterial molecules are the most-potent-in-class inhibitors and therefore may become valuable tools for chemical biology to probe protein function but also be templates for novel drugs, assuming in vitro potency translates into cellular and in vivo activity. Our review will focus on compounds for which the direct targets have been deciphered or which were found to target a novel pathway, and link them to disease states where target modulation may be beneficial. PMID:25571978

  2. Evolutionary biology, community ecology and avian influenza research.

    PubMed

    Caron, Alexandre; Gaidet, Nicolas; de Garine-Wichatitsky, Michel; Morand, Serge; Cameron, Elissa Z

    2009-03-01

    The epidemiology of H5N1 HPAI is still unclear despite the efforts of the research community. Studies bringing new insights add more variability in the host-pathogen system and uncertainty in the prediction of local risks. Global analyses of the pathways of wild birds in parallel with virus outbreaks have brought limited conclusions once the raw information was extracted from relevant maps. In this article, we propose an integration of epidemiology, evolutionary biology and community ecology on a local level in a research framework. This multidisciplinary approach aims at understanding the pathogen transmission processes at the interface between different bird groups whether wild or domesticated. We believe that this ecological data brought together with the epidemiological and molecular data is a key element to explore the mechanism of the AIV ecology in their hosts.

  3. Syntheses and biological studies of marine terpenoids derived from inorganic cyanide.

    PubMed

    Schnermann, Martin J; Shenvi, Ryan A

    2015-04-01

    Isocyanoterpenes (ICTs) are marine natural products biosynthesized through an unusual pathway that adorns terpene scaffolds with nitrogenous functionality derived from cyanide. The appendage of nitrogen functional groups - isonitriles in particular - onto stereochemically-rich carbocyclic ring systems provides enigmatic, bioactive molecules that have required innovative chemical syntheses. This review discusses the challenges inherent to the synthesis of this diverse family and details the development of the field. We also present recent progress in isolation and discuss key aspects of the remarkable biological activity of these compounds.

  4. Determination of trace metals in marine biological reference materials by inductively coupled plasma mass spectrometry

    SciTech Connect

    Beauchemin, D.; McLaren, J.W.; Willie, S.N.; Berman, S.S.

    1988-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) was used for the analysis of two marine biological reference materials (dogfish liver tissue (DOLT-1) and dogfish muscle tissue (DORM-1)). The materials were put into solution by digestion in a nitric acid/hydrogen peroxide mixture. Thirteen elements (Na, Mg, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb) were then determined. Accurate results were obtained by standard additions or isotope dilution techniques for all of these elements in DORM-1 and for all but Cr in DOLT-1.

  5. Syntheses and Biological Studies of Marine Terpenoids Derived from Inorganic Cyanide

    PubMed Central

    Schnermann, Martin J.; Shenvi, Ryan A.

    2015-01-01

    Isocyanoterpenes (ICTs) are marine natural products biosynthesized through an unusual pathway that adorns terpene scaffolds with nitrogenous functionality derived from cyanide. The appendage of nitrogen functional groups–isonitriles in particular–onto stereochemically-rich carbocyclic ring systems provides enigmatic, bioactive molecules that have required innovative chemical syntheses. This review discusses the challenges inherent to the synthesis of this diverse family and details the development of the field. We also present recent progress in isolation and discuss key aspects of the remarkable biological activity of these compounds. PMID:25514696

  6. Biological effects: Marine mammals and sea turtles (chapter 14). Book chapter

    SciTech Connect

    Haebler, R.

    1994-01-01

    All spills are different, varying in type and amount of oil spilled, species exposed, and geographic and atmospheric conditions. It is important to understand as much as possible about both the natural history and characteristics of various species and the specific effects oil has on wildlife. Doing so improves the ability to extrapolate from one spill to another and improves prediction of types and severity of effects to wildlife. This chapter presents an overview of the biological effects of oil on marine mammals and sea turtles.

  7. Surrogate taxa and fossils as reliable proxies of spatial biodiversity patterns in marine benthic communities.

    PubMed

    Tyler, Carrie L; Kowalewski, Michał

    2017-03-15

    Rigorous documentation of spatial heterogeneity (β-diversity) in present-day and preindustrial ecosystems is required to assess how marine communities respond to environmental and anthropogenic drivers. However, the overwhelming majority of contemporary and palaeontological assessments have centred on single higher taxa. To evaluate the validity of single taxa as community surrogates and palaeontological proxies, we compared macrobenthic communities and sympatric death assemblages at 52 localities in Onslow Bay (NC, USA). Compositional heterogeneity did not differ significantly across datasets based on live molluscs, live non-molluscs, and all live organisms. Death assemblages were less heterogeneous spatially, likely reflecting homogenization by time-averaging. Nevertheless, live and dead datasets were greater than 80% congruent in pairwise comparisons to the literature estimates of β-diversity in other marine ecosystems, yielded concordant bathymetric gradients, and produced nearly identical ordinations consistently delineating habitats. Congruent estimates from molluscs and non-molluscs suggest that single groups can serve as reliable community proxies. High spatial fidelity of death assemblages supports the emerging paradigm of Conservation Palaeobiology. Integrated analyses of ecological and palaeontological data based on surrogate taxa can quantify anthropogenic changes in marine ecosystems and advance our understanding of spatial and temporal aspects of biodiversity.

  8. Microbial communities in marine sediments modify success of an invasive macrophyte.

    PubMed

    Gribben, Paul E; Nielsen, Shaun; Seymour, Justin R; Bradley, Daniel J; West, Matthew N; Thomas, Torsten

    2017-08-29

    Invasive plants have extensive impacts on ecosystem function and biodiversity globally. Our inability to manage invasive species stems in part from a lack of understanding of the processes that control their successful establishment and spread. To date, studies have largely considered how above-ground processes control native/invasive plant interactions. Emerging research from terrestrial and wetland ecosystems demonstrates that below-ground processes under microbial control can determine the outcome of interactions between native and invasive plants. Whether sediment microbes modify the success of invasive macrophytes in marine ecosystems is untested, despite marine sediment microbes controlling many ecological processes (e.g. nutrient cycling) comparable to those in terrestrial ecosystems. We first show that sediment bacterial communities differ between the native seagrass Zostera capricorni and the invasive alga Caulerpa taxifolia and that those differences relate to functional changes in sulfur cycling between the macrophytes. Second, by experimentally manipulating the microbial communities we show that intact microbial communities in Z. capricorni sediments provide biotic resistance by reducing C. taxifolia fragment growth 119% compared to when they are inactive, and intact microbial communities in C. taxifolia sediments have positive feedbacks by increasing fragment growth 200%. Thus, similar to terrestrial ecosystems, microorganisms appear to indirectly control the success of invasive macrophytes in marine ecosystems.

  9. S.E.A. Lab. Science Experiments and Activities. Marine Science for High School Students in Chemistry, Biology and Physics.

    ERIC Educational Resources Information Center

    Hart, Kathy, Ed.

    A series of science experiments and activities designed for secondary school students taking biology, chemistry, physics, physical science or marine science courses are outlined. Each of the three major sections--chemistry, biology, and physics--addresses concepts that are generally covered in those courses but incorporates aspects of marine…

  10. Sr/Ca and Ba/Ca variations in environmental and biological sources: A survey of marine and terrestrial systems

    NASA Astrophysics Data System (ADS)

    Peek, Stephanie; Clementz, Mark T.

    2012-10-01

    The relative concentrations of strontium to calcium (Sr/Ca) and barium to calcium (Ba/Ca) in mammalian bioapatite are common biogeochemical indicators for trophic level and/or dietary preferences in terrestrial foodwebs; however, similar research in marine foodwebs is lacking. This study combined environmental and biological Sr/Ca and Ba/Ca data from both terrestrial and marine settings from 62 published books, reports, and studies along with original data collected from 149 marine mammals (30 species) and 83 prey items (18 species) and found that variations in Sr/Ca and Ba/Ca ratios of biological and environmental samples are appreciably different in terrestrial and marine systems. In terrestrial systems, environmental sources account for most of the variations in Sr/Ca and Ba/Ca ratios. In contrast, environmental sources in marine systems (i.e., seawater) are comparatively invariant, meaning most of the variations in Sr/Ca and Ba/Ca ratios originate from biological processes. Marine consumers, particularly non-mammalian and mammalian vertebrates, show evidence of biopurification of Ca relative to Sr and Ba, similar to what is observed in terrestrial systems; however, unlike terrestrial systems, variations in Sr/Ca and Ba/Ca ratios of environmental sources are overprinted by bioaccumulation of Sr and Ba at the base of marine foodwebs. This demonstrates that in marine systems, spatial or temporal differences may have little to no effect on Sr/Ca and Ba/Ca ratios of marine vertebrates, making Sr/Ca, and to a lesser extent Ba/Ca, potentially useful global proxies for trophic level and dietary preferences of marine vertebrates.

  11. Investigation of Marine-Derived Fungal Diversity and Their Exploitable Biological Activities.

    PubMed

    Hong, Joo-Hyun; Jang, Seokyoon; Heo, Young Mok; Min, Mihee; Lee, Hwanhwi; Lee, Young Min; Lee, Hanbyul; Kim, Jae-Jin

    2015-06-30

    Marine fungi are potential producers of bioactive compounds that may have pharmacological and medicinal applications. Fungi were cultured from marine brown algae and identified using multiple target genes to confirm phylogenetic placement. These target genes included the internal transcribed spacer (ITS), the nuclear large subunit (LSU), and the β-tubulin region. Various biological activities of marine-derived fungi were evaluated, including their antifungal, antioxidant and cellulolytic enzyme activities. As a result, a total of 50 fungi was isolated from the brown algae Sargassum sp. Among the 50 isolated fungi, Corollospora angusta was the dominant species in this study. The genus Arthrinium showed a relatively strong antifungal activity to all of the target plant pathogenic fungi. In particular, Arthrinium saccharicola KUC21221 showed high radical scavenging activity and the highest activities in terms of filter paper units (0.39 U/mL), endoglucanase activity (0.38 U/mL), and β-glucosidase activity (1.04 U/mL).

  12. High throughput extraction of plant, marine and fungal specimens for preservation of biologically active molecules.

    PubMed

    McCloud, Thomas G

    2010-06-24

    The Developmental Therapeutics Program (DTP) of the U.S. National Cancer Institute (NCI), at its NCI-Frederick facility, has built perhaps the largest and most diverse natural products screening library in the world for drug discovery. Composed of plant, marine organism and microbial extracts, it currently contains in excess of 230,000 unique materials. From the inception of this program to identify new anticancer chemotherapeutics from natural products sources in 1987, two extracts have been sequentially prepared from each specimen: one produced by organic solvent extraction, which yields a complex material that contains non- to moderately polar small molecules, and a water-soluble extract, a milieu largely unexplored for useful drugs in earlier years, which contains polar small to medium-sized molecules. Plant specimens and microbial ferments are extracted by modified traditional methods, while the method developed to produce extracts from marine organisms is unique and very different from that used by marine natural products chemists previously, but again yields both an organic solvent soluble and a water soluble material for inclusion into the screening library. Details of high throughput extract production for preservation of biologically active molecules are presented.

  13. Investigation of Marine-Derived Fungal Diversity and Their Exploitable Biological Activities

    PubMed Central

    Hong, Joo-Hyun; Jang, Seokyoon; Heo, Young Mok; Min, Mihee; Lee, Hwanhwi; Lee, Young Min; Lee, Hanbyul; Kim, Jae-Jin

    2015-01-01

    Marine fungi are potential producers of bioactive compounds that may have pharmacological and medicinal applications. Fungi were cultured from marine brown algae and identified using multiple target genes to confirm phylogenetic placement. These target genes included the internal transcribed spacer (ITS), the nuclear large subunit (LSU), and the β-tubulin region. Various biological activities of marine-derived fungi were evaluated, including their antifungal, antioxidant and cellulolytic enzyme activities. As a result, a total of 50 fungi was isolated from the brown algae Sargassum sp. Among the 50 isolated fungi, Corollospora angusta was the dominant species in this study. The genus Arthrinium showed a relatively strong antifungal activity to all of the target plant pathogenic fungi. In particular, Arthrinium saccharicola KUC21221 showed high radical scavenging activity and the highest activities in terms of filter paper units (0.39 U/mL), endoglucanase activity (0.38 U/mL), and β-glucosidase activity (1.04 U/mL). PMID:26133554

  14. Biological invasions as a component of global change in stressed marine ecosystems.

    PubMed

    Occhipinti-Ambrogi, A; Savini, D

    2003-05-01

    Biological invasions in marine environment are the lesser known aspect of global change. However, recent events which occurred in the Mediterranean Sea demonstrate that they represent a serious ecological and economical menace leading to biodiversity loss, ecosystem unbalancing, fishery and tourism impairment. In this paper we review marine bioinvasions using examples taken from the Mediterranean/Black Sea region. Particular attention is given to the environmental status of the receiving area as a fundamental pre-requisite for the colonisation success of alien species. The spread of the tropical algae belonging to the genus Caulerpa in the northwestern basin of the Mediterranean Sea has been facilitated by pre-existing conditions of instability of the Posidonia oceanica endemic ecosystem in relation to stress of both natural and anthropogenic origin. Human interventions caused long-term modification in the Black Sea environment, preparing a fertile ground for mass bioinvasion of aquatic nuisance species which, in some cases, altered the original equilibrium of the entire basin. Finally, the Venice lagoon is presented as the third example of an environment subjected to high propagule pressure and anthropogenic forcing and bearing the higher "diversity" of non-indigenous species compared to the other Mediterranean lagoons. Stressed environments are easily colonised by alien species; understanding the links between human and natural disturbance and massive development of non-indigenous species will help prevent marine bioinvasions, that are already favoured by global oceanic trade.

  15. BioDEAL: community generation of biological annotations

    PubMed Central

    Breimyer, Paul; Green, Nathan; Kumar, Vinay; Samatova, Nagiza F

    2009-01-01

    Background Publication databases in biomedicine (e.g., PubMed, MEDLINE) are growing rapidly in size every year, as are public databases of experimental biological data and annotations derived from the data. Publications often contain evidence that confirm or disprove annotations, such as putative protein functions, however, it is increasingly difficult for biologists to identify and process published evidence due to the volume of papers and the lack of a systematic approach to associate published evidence with experimental data and annotations. Natural Language Processing (NLP) tools can help address the growing divide by providing automatic high-throughput detection of simple terms in publication text. However, NLP tools are not mature enough to identify complex terms, relationships, or events. Results In this paper we present and extend BioDEAL, a community evidence annotation system that introduces a feedback loop into the database-publication cycle to allow scientists to connect data-driven biological concepts to publications. Conclusion BioDEAL may change the way biologists relate published evidence with experimental data. Instead of biologists or research groups searching and managing evidence independently, the community can collectively build and share this knowledge. PMID:19891799

  16. Determination of Iodine-129 in fish samples as new tracer of marine biology

    NASA Astrophysics Data System (ADS)

    Kusuno, Haruka; Matsuzaki, Hiroyuki; Nagata, Toshi; Miyairi, Yosuke; Yokoyama, Yusuke; Ohkouchi, Naohiko

    2014-05-01

    Most of Iodine-129 in the surface environment is the anthropogenic origin, i.e., the result of the human nuclear activities. In the marine environment, like Pacific ocean, I-129 is transferred from atmosphere and slowly diffuses into deeper layer so that there is steep gradient of I-129 concentration, i.e., the surface layer has high I-129 concentration and it suddenly decreases going deeper. This peculiar depth profile is thus reflected by the isotopic ratio (I-129/I-127) profile because stable iodine (I-127) concentration is almost uniform in the seawater (ca. 60 ppb). Iodine isotopic ratio (I-129/I-127) of marine lives like fish should be determined by their habitats and the ways exchanging iodine with seawater. This means that the iodine isotopic ratio is potential indicator of marine biology. However there have been only few studies using I-129 for marine biology. This is because I-129 is so rare in the marine lives that ordinary analytical techniques cannot detect. Recently, the technique of accelerator mass spectrometry has been developed and demonstrates excellent sensitivity to detect I-129/I-127 ratio as low as 1E-14. However it requires typically 1 mg AgI sample. To obtain such amount of iodine several hundreds gram should be treated in the case of typical fish. In this study "carrier method" was adopted to overcome this difficulty. Our procedure is following: A fish sample was first dried completely then homogenized well. Iodine was extracted into an alkaline solution by the thermal hydrolysis from 0.1 to 0.5g of dried sample. An aliquot of this solution was taken for ICP-MS analysis to determine the stable iodine concentration. The remaining was, added with carrier iodine (about 1 mg), purified by solvent extraction and collected as AgI precipitation. I-129/I-127 ratio of obtained AgI was determined by AMS. From the AMS result and the stable iodine concentration, the isotopic ratio of the fish samples themselves can be calculated. The result of fish

  17. Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Pan, Hongmiao; Yue, Haidong; Song, Tao; Zhao, Yong; Chen, Guanjun; Wu, Longfei; Xiao, Tian

    2006-12-01

    Magnetotactic bacteria have become a hot spot of research in microbiology attracting intensive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fastidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in diameter of 100nm, and consist of Fe and Co shown on energy dispersive X-ray spectrum. The biological and physiological characteristics of this bacterium were also described. The colour of YSC-1 colony is white in small rod. The gram stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

  18. Synthesis of marine guanidine alkaloids and their application as chemical/biological tools.

    PubMed

    Nagasawa, Kazuo; Hashimoto, Yuichi

    2003-01-01

    Ptilomycalin A and crambescidins, novel marine guanidine alkaloids, have a unique pentacyclic guanidine structure, and exhibit a considerable array of biological activities. The first method developed for the synthesis of the pentacyclic guanidine core structure involved successive 1,3-dipolar cycloaddition reactions and resulted in the first total synthesis of crambescidin 359. The synthesis of other pentacyclic guanidine derivatives has been based on this methodology and applied as tools for studying biological activities, and as chemical reaction catalysts. Copyright 2003 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 3: 201-211; 2003: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10064

  19. Integrated chemical and biological assessment of contaminant impacts in selected European coastal and offshore marine areas.

    PubMed

    Hylland, Ketil; Robinson, Craig D; Burgeot, Thierry; Martínez-Gómez, Concepción; Lang, Thomas; Svavarsson, Jörundur; Thain, John E; Vethaak, A Dick; Gubbins, Mattew J

    2017-03-01

    This paper reports a full assessment of results from ICON, an international workshop on marine integrated contaminant monitoring, encompassing different matrices (sediment, fish, mussels, gastropods), areas (Iceland, North Sea, Baltic, Wadden Sea, Seine estuary and the western Mediterranean) and endpoints (chemical analyses, biological effects). ICON has demonstrated the use of a framework for integrated contaminant assessment on European coastal and offshore areas. The assessment showed that chemical contamination did not always correspond with biological effects, indicating that both are required. The framework can be used to develop assessments for EU directives. If a 95% target were to be used as a regional indicator of MSFD GES, Iceland and offshore North Sea would achieve the target using the ICON dataset, but inshore North Sea, Baltic and Spanish Mediterranean regions would fail.

  20. Molecular diversity of fungal and bacterial communities in the marine sponge Dragmacidon reticulatum.

    PubMed

    Passarini, Michel R Z; Miqueletto, Paula B; de Oliveira, Valéria M; Sette, Lara D

    2015-02-01

    The present work aimed to investigate the diversity of bacteria and filamentous fungi of southern Atlantic Ocean marine sponge Dragmacidon reticulatum using cultivation-independent approaches. Fungal ITS rDNA and 18S gene analyses (DGGE and direct sequencing approaches) showed the presence of representatives of three order (Polyporales, Malasseziales, and Agaricales) from the phylum Basidiomycota and seven orders belonging to the phylum Ascomycota (Arthoniales, Capnodiales, Dothideales, Eurotiales, Hypocreales, Pleosporales, and Saccharomycetales). On the other hand, bacterial 16S rDNA gene analyses by direct sequencing approach revealed the presence of representatives of seven bacterial phyla (Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes, Lentisphaerae, Chloroflexi, and Planctomycetes). Results from statistical analyses (rarefaction curves) suggested that the sampled clones covered the fungal diversity in the sponge samples studied, while for the bacterial community additional sampling would be necessary for saturation. This is the first report related to the molecular analyses of fungal and bacterial communities by cultivation-independent approaches in the marine sponges D. reticulatum. Additionally, the present work broadening the knowledge of microbial diversity associated to marine sponges and reports innovative data on the presence of some fungal genera in marine samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Impact of a harbour construction on the benthic community of two shallow marine caves.

    PubMed

    Nepote, Ettore; Bianchi, Carlo Nike; Morri, Carla; Ferrari, Marco; Montefalcone, Monica

    2017-01-15

    Marine caves are unique and vulnerable habitats, threatened by multiple global and local disturbances. Whilst the effects of climate change on marine caves have already been investigated, no information exists about the effects of local human impacts, such as coastal development, on these habitats. This study investigated the impact of the construction of a touristic harbour on two shallow underwater marine caves in the Ligurian Sea (NW Mediterranean). As a standard methodology for monitoring marine caves does not exist yet, changes over time on the benthic community were assessed adopting two different non-taxonomic descriptors: trophic guilds and growth forms. Harbour construction caused an increase of sediment load within the caves, with a consequent decline of filter feeder organisms. Abundance of small organisms, such as encrusting and flattened sponges, was greatly reduced in comparison to organisms with larger and erect growth forms, such as domed mounds and pedunculated sponges. Our study indicated that growth forms and trophic guilds are effective descriptors for evaluating changes over time in marine caves, and could be easily standardised and applied in monitoring plans. In addition, as the harbour construction impacted differently according to the cave topography, the use of a systematic sampling in different zones of an underwater cave is recommended. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Assessing the effect of marine reserves on household food security in Kenyan coral reef fishing communities.

    PubMed

    Darling, Emily S

    2014-01-01

    Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management.

  3. Assessing the Effect of Marine Reserves on Household Food Security in Kenyan Coral Reef Fishing Communities

    PubMed Central

    Darling, Emily S.

    2014-01-01

    Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management. PMID:25422888

  4. Changes in bacterial communities of the marine sponge Mycale laxissima on transfer into aquaculture.

    PubMed

    Mohamed, Naglaa M; Enticknap, Julie J; Lohr, Jayme E; McIntosh, Scott M; Hill, Russell T

    2008-02-01

    The changes in bacterial communities associated with the marine sponge Mycale laxissima on transfer to aquaculture were studied using culture-based and molecular techniques. M. laxissima was maintained alive in flowthrough and closed recirculating aquaculture systems for 2 years and 1 year, respectively. The bacterial communities associated with wild and aquacultured sponges, as well as the surrounding water, were assessed using 16S rRNA gene clone library analysis and denaturing gradient gel electrophoresis (DGGE). Bacterial richness and diversity were measured using DOTUR computer software, and clone libraries were compared using S-LIBSHUFF. DGGE analysis revealed that the diversity of the bacterial community of M. laxissima increased when sponges were maintained in aquaculture and that bacterial communities associated with wild and aquacultured M. laxissima were markedly different than those of the corresponding surrounding water. Clone libraries of bacterial 16S rRNA from sponges confirmed that the bacterial communities changed during aquaculture. These communities were significantly different than those of seawater and aquarium water. The diversity of bacterial communities associated with M. laxissima increased significantly in aquaculture. Our work shows that it is important to monitor changes in bacterial communities when examining the feasibility of growing sponges in aquaculture systems because these communities may change. This could have implications for the health of sponges or for the production of bioactive compounds by sponges in cases where these compounds are produced by symbiotic bacteria rather than by the sponges themselves.

  5. Anthraquinones and Derivatives from Marine-Derived Fungi: Structural Diversity and Selected Biological Activities.

    PubMed

    Fouillaud, Mireille; Venkatachalam, Mekala; Girard-Valenciennes, Emmanuelle; Caro, Yanis; Dufossé, Laurent

    2016-03-25

    Anthraquinones and their derivatives constitute a large group of quinoid compounds with about 700 molecules described. They are widespread in fungi and their chemical diversity and biological activities recently attracted attention of industries in such fields as pharmaceuticals, clothes dyeing, and food colorants. Their positive and/or negative effect(s) due to the 9,10-anthracenedione structure and its substituents are still not clearly understood and their potential roles or effects on human health are today strongly discussed among scientists. As marine microorganisms recently appeared as producers of an astonishing variety of structurally unique secondary metabolites, they may represent a promising resource for identifying new candidates for therapeutic drugs or daily additives. Within this review, we investigate the present knowledge about the anthraquinones and derivatives listed to date from marine-derived filamentous fungi's productions. This overview highlights the molecules which have been identified in microorganisms for the first time. The structures and colors of the anthraquinoid compounds come along with the known roles of some molecules in the life of the organisms. Some specific biological activities are also described. This may help to open doors towards innovative natural substances.

  6. Anthraquinones and Derivatives from Marine-Derived Fungi: Structural Diversity and Selected Biological Activities

    PubMed Central

    Fouillaud, Mireille; Venkatachalam, Mekala; Girard-Valenciennes, Emmanuelle; Caro, Yanis; Dufossé, Laurent

    2016-01-01

    Anthraquinones and their derivatives constitute a large group of quinoid compounds with about 700 molecules described. They are widespread in fungi and their chemical diversity and biological activities recently attracted attention of industries in such fields as pharmaceuticals, clothes dyeing, and food colorants. Their positive and/or negative effect(s) due to the 9,10-anthracenedione structure and its substituents are still not clearly understood and their potential roles or effects on human health are today strongly discussed among scientists. As marine microorganisms recently appeared as producers of an astonishing variety of structurally unique secondary metabolites, they may represent a promising resource for identifying new candidates for therapeutic drugs or daily additives. Within this review, we investigate the present knowledge about the anthraquinones and derivatives listed to date from marine-derived filamentous fungi′s productions. This overview highlights the molecules which have been identified in microorganisms for the first time. The structures and colors of the anthraquinoid compounds come along with the known roles of some molecules in the life of the organisms. Some specific biological activities are also described. This may help to open doors towards innovative natural substances. PMID:27023571

  7. Connecting marine productivity to sea-spray via nanoscale biological processes: Phytoplankton Dance or Death Disco?

    NASA Astrophysics Data System (ADS)

    O'Dowd, Colin; Ceburnis, Darius; Ovadnevaite, Jurgita; Bialek, Jakub; Stengel, Dagmar B.; Zacharias, Merry; Nitschke, Udo; Connan, Solene; Rinaldi, Matteo; Fuzzi, Sandro; Decesari, Stefano; Cristina Facchini, Maria; Marullo, Salvatore; Santoleri, Rosalia; Dell'Anno, Antonio; Corinaldesi, Cinzia; Tangherlini, Michael; Danovaro, Roberto

    2015-10-01

    Bursting bubbles at the ocean-surface produce airborne salt-water spray-droplets, in turn, forming climate-cooling marine haze and cloud layers. The reflectance and ultimate cooling effect of these layers is determined by the spray’s water-uptake properties that are modified through entrainment of ocean-surface organic matter (OM) into the airborne droplets. We present new results illustrating a clear dependence of OM mass-fraction enrichment in sea spray (OMss) on both phytoplankton-biomass, determined from Chlorophyll-a (Chl-a) and Net Primary Productivity (NPP). The correlation coefficient for OMss as a function of Chl-a increased form 0.67 on a daily timescale to 0.85 on a monthly timescale. An even stronger correlation was found as a function of NPP, increasing to 0.93 on a monthly timescale. We suggest the observed dependence is through the demise of the bloom, driven by nanoscale biological processes (such as viral infections), releasing large quantities of transferable OM comprising cell debris, exudates and other colloidal materials. This OM, through aggregation processes, leads to enrichment in sea-spray, thus demonstrating an important coupling between biologically-driven plankton bloom termination, marine productivity and sea-spray modification with potentially significant climate impacts.

  8. Parasites as biological tags in marine fisheries research: European Atlantic waters.

    PubMed

    Mackenzie, K; Hemmingsen, W

    2015-01-01

    Studies of the use of parasites as biological tags for stock identification and to follow migrations of marine fish, mammals and invertebrates in European Atlantic waters are critically reviewed and evaluated. The region covered includes the North, Baltic, Barents and White Seas plus Icelandic waters, but excludes the Mediterranean and Black Seas. Each fish species or ecological group of species is treated separately. More parasite tag studies have been carried out on Atlantic herring Clupea harengus than on any other species, while cod Gadus morhua have also been the subject of many studies. Other species that have been the subjects of more than one study are: blue whiting Micromesistius poutassou, whiting Merlangius merlangus, haddock Melanogrammus aeglefinus, Norway pout Trisopterus esmarkii, horse mackerel Trachurus trachurus and mackerel Scomber scombrus. Other species are dealt with under the general headings redfishes, flatfish, tunas, anadromous fish, elasmobranchs, marine mammals and invertebrates. A final section highlights how parasites can be, and have been, misused as biological tags, and how this can be avoided. It also reviews recent developments in methodology and parasite genetics, considers the potential effects of climate change on the distributions of both hosts and parasites, and suggests host-parasite systems that should reward further research.

  9. Connecting marine productivity to sea-spray via microscale biological processes: phytoplancton demise and viral infection

    NASA Astrophysics Data System (ADS)

    Facchini, C.; O'Dowd, C. D. D.; Danovaro, R.

    2015-12-01

    The processes that link phytoplankton biomass and productivity to the organic matter enrichment in sea spray aerosol are far from being elucidated and modelling predictions remain highly uncertain at the moment. While some studies have asserted that the enrichment of OM in sea spray aerosol is independent on marine productivity, others, have shown significant correlation with phytoplankton biomass and productivity (Chl-a retrieved by satellites). We present here new results illustrating a clear link between OM mass-fraction enrichment in sea spray (OMss) and both phytoplankton-biomass and Net Primary Productivity (NPP). We suggest that the OM enrichment of sea spray through the demise of the bloom, driven by nanoscale biological processes (such as viral infections), which determine the release of celldebris, exudates and other colloidal material. This OM, through processes, leads to enrichment in sea-spray, thus demonstrating an important coupling between biologically-drive plankton bloom termination, marine productivity and sea-spraymodification with potentially significant climate impacts.

  10. Connecting marine productivity to sea-spray via nanoscale biological processes: Phytoplankton Dance or Death Disco?

    PubMed

    O'Dowd, Colin; Ceburnis, Darius; Ovadnevaite, Jurgita; Bialek, Jakub; Stengel, Dagmar B; Zacharias, Merry; Nitschke, Udo; Connan, Solene; Rinaldi, Matteo; Fuzzi, Sandro; Decesari, Stefano; Facchini, Maria Cristina; Marullo, Salvatore; Santoleri, Rosalia; Dell'Anno, Antonio; Corinaldesi, Cinzia; Tangherlini, Michael; Danovaro, Roberto

    2015-10-14

    Bursting bubbles at the ocean-surface produce airborne salt-water spray-droplets, in turn, forming climate-cooling marine haze and cloud layers. The reflectance and ultimate cooling effect of these layers is determined by the spray's water-uptake properties that are modified through entrainment of ocean-surface organic matter (OM) into the airborne droplets. We present new results illustrating a clear dependence of OM mass-fraction enrichment in sea spray (OMss) on both phytoplankton-biomass, determined from Chlorophyll-a (Chl-a) and Net Primary Productivity (NPP). The correlation coefficient for OMss as a function of Chl-a increased form 0.67 on a daily timescale to 0.85 on a monthly timescale. An even stronger correlation was found as a function of NPP, increasing to 0.93 on a monthly timescale. We suggest the observed dependence is through the demise of the bloom, driven by nanoscale biological processes (such as viral infections), releasing large quantities of transferable OM comprising cell debris, exudates and other colloidal materials. This OM, through aggregation processes, leads to enrichment in sea-spray, thus demonstrating an important coupling between biologically-driven plankton bloom termination, marine productivity and sea-spray modification with potentially significant climate impacts.

  11. Connecting marine productivity to sea-spray via nanoscale biological processes: Phytoplankton Dance or Death Disco?

    PubMed Central

    O’Dowd, Colin; Ceburnis, Darius; Ovadnevaite, Jurgita; Bialek, Jakub; Stengel, Dagmar B.; Zacharias, Merry; Nitschke, Udo; Connan, Solene; Rinaldi, Matteo; Fuzzi, Sandro; Decesari, Stefano; Cristina Facchini, Maria; Marullo, Salvatore; Santoleri, Rosalia; Dell’Anno, Antonio; Corinaldesi, Cinzia; Tangherlini, Michael; Danovaro, Roberto

    2015-01-01

    Bursting bubbles at the ocean-surface produce airborne salt-water spray-droplets, in turn, forming climate-cooling marine haze and cloud layers. The reflectance and ultimate cooling effect of these layers is determined by the spray’s water-uptake properties that are modified through entrainment of ocean-surface organic matter (OM) into the airborne droplets. We present new results illustrating a clear dependence of OM mass-fraction enrichment in sea spray (OMss) on both phytoplankton-biomass, determined from Chlorophyll-a (Chl-a) and Net Primary Productivity (NPP). The correlation coefficient for OMss as a function of Chl-a increased form 0.67 on a daily timescale to 0.85 on a monthly timescale. An even stronger correlation was found as a function of NPP, increasing to 0.93 on a monthly timescale. We suggest the observed dependence is through the demise of the bloom, driven by nanoscale biological processes (such as viral infections), releasing large quantities of transferable OM comprising cell debris, exudates and other colloidal materials. This OM, through aggregation processes, leads to enrichment in sea-spray, thus demonstrating an important coupling between biologically-driven plankton bloom termination, marine productivity and sea-spray modification with potentially significant climate impacts. PMID:26464099

  12. Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities

    NASA Astrophysics Data System (ADS)

    Salim, S. S.; Paytan, A.

    2016-12-01

    The project `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' (GULLS) falls within the Belmont Forum and G8 Research Councils Initiative on Multilateral Research Funding. Participants include teams from nine countries: Australia, Brazil, India, Madagascar, Mozambique, New Zealand, South Africa, the United Kingdom and the United States of America. The project focuses on five regional `hotspots' of climate and social change, defined as fast-warming marine areas and areas experiencing social tensions as a result of change: south-east Australia, Brazil, India, South Africa, and the Mozambique Channel and adjacent countries of Mozambique and Madagascar. These areas require most urgent attention and serve as valuable case studies for wider applications. The project aims to assist coastal communities and other stakeholders dependent on marine resources to adapt to climate change and variability through an integrated and trans-disciplinary approach. Combining best available global knowledge with local knowledge and conditions, it is exploring adaptation options and approaches to strengthen resilience at local and community levels, with a focus on options for reconciling the needs for food security with long-term sustainability and conservation. The project will also contribute to capacity development and empowering fishing communities and other fisheries-dependent stakeholders.A standardized vulnerability assessment framework is being developed that will be used to integrate results from natural, social and economic studies in order to identify needs and options for strengthening management and existing policies. Structured comparisons between the hot-spots will assist global efforts for adaptation and strengthening resilience in marine and coastal social-ecological systems.

  13. Effects of exotic fish farms on bird communities in lake and marine ecosystems.

    PubMed

    Jiménez, Jaime E; Arriagada, Aldo M; Fontúrbel, Francisco E; Camus, Patricio A; Avila-Thieme, M Isidora

    2013-08-01

    Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

  14. Effects of exotic fish farms on bird communities in lake and marine ecosystems

    NASA Astrophysics Data System (ADS)

    Jiménez, Jaime E.; Arriagada, Aldo M.; Fontúrbel, Francisco E.; Camus, Patricio A.; Ávila-Thieme, M. Isidora

    2013-08-01

    Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

  15. Experimental confirmation of multiple community states in a marine ecosystem

    PubMed Central

    Petraitis, Peter S.; Methratta, Elizabeth T.; Rhile, Erika C.; Vidargas, Nicholas A.; Dudgeon, Steve R.

    2009-01-01

    Small changes in environmental conditions can unexpectedly tip an ecosystem from one community type to another, and these often irreversible shifts have been observed in semi-arid grasslands, freshwater lakes and ponds, coral reefs, and kelp forests. A commonly accepted explanation is that these ecosystems contain multiple stable points, but experimental tests confirming multiple stable states have proven elusive. Here we present a novel approach and show that mussel beds and rockweed stands are multiple stable states on intertidal shores in the Gulf of Maine, USA. Using broad-scale observational data and long-term data from experimental clearings, we show that the removal of rockweed by winter ice scour can tip persistent rockweed stands to mussel beds. The observational data were analyzed with Anderson's discriminant analysis of principal coordinates, which provided an objective function to separate mussel beds from rockweed stands. The function was then applied to 55 experimental plots, which had been established in rockweed stands in 1996. Based on 2005 data, all uncleared controls and all but one of the small clearings were classified as rockweed stands; 37% of the large clearings were classified as mussel beds. Our results address the establishment of mussels versus rockweeds and complement rather than refute the current paradigm that mussel beds and rockweed stands, once established, are maintained by site-specific differences in strong consumer control. PMID:19399520

  16. Changes in habitat heterogeneity alter marine sessile benthic communities.

    PubMed

    Munguia, Pablo; Osman, Richard W; Hamilton, John; Whitlatch, Robert; Zajac, Roman

    2011-04-01

    Habitat heterogeneity is considered an important mechanism influencing diversity patterns in spatially structured habitats. However, spatial heterogeneity is not static and it can change along temporal scales. These changes, whether gradual or rapid, have the potential of forcing species extinctions or facilitating the introduction of nonnative species. Here, we present modeling results that show how changes in spatial heterogeneity over several generations can produce strong changes in benthic species composition residing in eastern Long Island Sound, USA. For many benthic species, hard substrate is a limiting resource which can vary in availability among different coastal areas. We modeled gradual changes from a heterogeneous landscape (mimicking patches of natural hard and soft substrate) to a homogenous one (analogous to a fully developed coast with hard, manmade substrate) and followed the abundance and distribution patterns of species possessing four different life histories. We also modeled changes from homogeneous to heterogeneous landscapes. We found that as regions become more homogeneous, species extinctions become more frequent and poor dispersers dominate locally. In contrast, as habitats become more heterogeneous, species distributing across localities leads to regional species coexistence and fewer extinctions. These results suggest that focusing on changing habitat heterogeneity can be a useful management strategy to prevent poor dispersing species, such as invasive ascidians, from driving communities to monocultures.

  17. Ecological succession reveals potential signatures of marine-terrestrial transition in salt marsh fungal communities.

    PubMed

    Dini-Andreote, Francisco; Pylro, Victor Satler; Baldrian, Petr; van Elsas, Jan Dirk; Salles, Joana Falcão

    2016-08-01

    Marine-to-terrestrial transition represents one of the most fundamental shifts in microbial life. Understanding the distribution and drivers of soil microbial communities across coastal ecosystems is critical given the roles of microbes in soil biogeochemistry and their multifaceted influence on landscape succession. Here, we studied the fungal community dynamics in a well-established salt marsh chronosequence that spans over a century of ecosystem development. We focussed on providing high-resolution assessments of community composition, diversity and ecophysiological shifts that yielded patterns of ecological succession through soil formation. Notably, despite containing 10- to 100-fold lower fungal internal transcribed spacer abundances, early-successional sites revealed fungal richnesses comparable to those of more mature soils. These newly formed sites also exhibited significant temporal variations in β-diversity that may be attributed to the highly dynamic nature of the system imposed by the tidal regime. The fungal community compositions and ecophysiological assignments changed substantially along the successional gradient, revealing a clear signature of ecological replacement and gradually transforming the environment from a marine into a terrestrial system. Moreover, distance-based linear modelling revealed soil physical structure and organic matter to be the best predictors of the shifts in fungal β-diversity along the chronosequence. Taken together, our study lays the basis for a better understanding of the spatiotemporally determined fungal community dynamics in salt marshes and highlights their ecophysiological traits and adaptation in an evolving ecosystem.

  18. Influence of deglaciation on microbial communities in marine sediments off the coast of Svalbard, Arctic Circle.

    PubMed

    Park, Soo-Je; Park, Byoung-Joon; Jung, Man-Young; Kim, So-Jeong; Chae, Jong-Chan; Roh, Yul; Forwick, Matthias; Yoon, Ho-Il; Rhee, Sung-Keun

    2011-10-01

    Increases in global temperatures have been shown to enhance glacier melting in the Arctic region. Here, we have evaluated the effects of meltwater runoff on the microbial communities of coastal marine sediment located along a transect of Temelfjorden, in Svalbard. As close to the glacier front, the sediment properties were clearly influenced by deglaciation. Denaturing gradient gel electrophoresis profiles showed that the sediment microbial communities of the stations of glacier front (stations 188-178) were distinguishable from that of outer fjord region (station 176). Canonical correspondence analysis indicated that total carbon and calcium carbonate in sediment and chlorophyll a in bottom water were key factors driving the change of microbial communities. Analysis of 16S rRNA gene clone libraries suggested that microbial diversity was higher within the glacier-proximal zone (station 188) directly affected by the runoffs than in the outer fjord region. While the crenarchaeotal group I.1a dominated at station 176 (62%), Marine Benthic Group-B and other Crenarchaeota groups were proportionally abundant. With regard to the bacterial community, alpha-Proteobacteria and Flavobacteria lineages prevailed (60%) at station 188, whereas delta-Proteobacteria (largely sulfate-reducers) predominated (32%) at station 176. Considering no clone sequences related to sulfate-reducers, station 188 may be more oxic compared to station 176. The distance-wise compositional variation in the microbial communities is attributable to their adaptations to the sediment environments which are differentially affected by melting glaciers.

  19. Diversity and distribution of fungal communities in the marine sediments of Kongsfjorden, Svalbard (High Arctic).

    PubMed

    Zhang, Tao; Wang, Neng Fei; Zhang, Yu Qin; Liu, Hong Yu; Yu, Li Yan

    2015-10-23

    This study assessed the diversity and distribution of fungal communities in eight marine sediments of Kongsfjorden (Svalbard, High Arctic) using 454 pyrosequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Sedimentary fungal communities showed high diversity with 42,219 reads belonging to 113 operational taxonomic units (OTUs). Of these OTUs, 62 belonged to the Ascomycota, 26 to Basidiomycota, 2 to Chytridiomycota, 1 to Zygomycota, 1 to Glomeromycota, and 21 to unknown fungi. The major known orders included Hypocreales and Saccharomycetales. The common fungal genera were Pichia, Fusarium, Alternaria, and Malassezia. Interestingly, most fungi occurring in these Arctic sediments may originate from the terrestrial habitats and different basins in Kongsfjorden (i.e., inner basin, central basin, and outer basin) harbor different sedimentary fungal communities. These results suggest the existence of diverse fungal communities in the Arctic marine sediments, which may serve as a useful community model for further ecological and evolutionary study of fungi in the Arctic.

  20. Diversity and distribution of fungal communities in the marine sediments of Kongsfjorden, Svalbard (High Arctic)

    PubMed Central

    Zhang, Tao; Fei Wang, Neng; Qin Zhang, Yu; Yu Liu, Hong; Yan Yu, Li

    2015-01-01

    This study assessed the diversity and distribution of fungal communities in eight marine sediments of Kongsfjorden (Svalbard, High Arctic) using 454 pyrosequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Sedimentary fungal communities showed high diversity with 42,219 reads belonging to 113 operational taxonomic units (OTUs). Of these OTUs, 62 belonged to the Ascomycota, 26 to Basidiomycota, 2 to Chytridiomycota, 1 to Zygomycota, 1 to Glomeromycota, and 21 to unknown fungi. The major known orders included Hypocreales and Saccharomycetales. The common fungal genera were Pichia, Fusarium, Alternaria, and Malassezia. Interestingly, most fungi occurring in these Arctic sediments may originate from the terrestrial habitats and different basins in Kongsfjorden (i.e., inner basin, central basin, and outer basin) harbor different sedimentary fungal communities. These results suggest the existence of diverse fungal communities in the Arctic marine sediments, which may serve as a useful community model for further ecological and evolutionary study of fungi in the Arctic. PMID:26494429

  1. Diversity and distribution of fungal communities in the marine sediments of Kongsfjorden, Svalbard (High Arctic)

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Fei Wang, Neng; Qin Zhang, Yu; Yu Liu, Hong; Yan Yu, Li

    2015-10-01

    This study assessed the diversity and distribution of fungal communities in eight marine sediments of Kongsfjorden (Svalbard, High Arctic) using 454 pyrosequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Sedimentary fungal communities showed high diversity with 42,219 reads belonging to 113 operational taxonomic units (OTUs). Of these OTUs, 62 belonged to the Ascomycota, 26 to Basidiomycota, 2 to Chytridiomycota, 1 to Zygomycota, 1 to Glomeromycota, and 21 to unknown fungi. The major known orders included Hypocreales and Saccharomycetales. The common fungal genera were Pichia, Fusarium, Alternaria, and Malassezia. Interestingly, most fungi occurring in these Arctic sediments may originate from the terrestrial habitats and different basins in Kongsfjorden (i.e., inner basin, central basin, and outer basin) harbor different sedimentary fungal communities. These results suggest the existence of diverse fungal communities in the Arctic marine sediments, which may serve as a useful community model for further ecological and evolutionary study of fungi in the Arctic.

  2. Biogeological signatures of microboring cyanobacterial communities in marine carbonates from Cabo Rojo, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Chacón, Elizabeth; Berrendero, Esther; Garcia Pichel, Ferran

    2006-03-01

    The occurrence of carbonate-boring organisms in marine and continental environments is well known and accounts for substantial rates of sediment and sedimentary rock reworking at the geological scale. Many case studies have documented the importance of cyanobacteria in near-surface environments, but nearly all have relied upon morphological descriptions. In this study we applied a polyphasic approach to evaluate euendolithic cyanobacterial assemblages from a variety of carbonaceous marine substrates, using electron microscopy, cultivation, and molecular genetic techniques. The limitations and biases of the different methods became evident: none could be deemed optimal, and each failed to detect much or some of the extant diversity in the samples. In general, SEM tended to underestimate the diversity of morphologically simple community members, and cultivation yielded a very biased view of the community. All approaches, however, congruently detected differences in community structure between soft substrates and hard substrates, with the latter displaying communities of higher complexity. In spite of these differences, the geological and sedimentary imprints of the boring community, exemplified in the formation of well-structured micritic envelopes of re-worked carbonate, were uniform throughout the samples, implying that the mechanism of action is common and most likely universal. Our results speak for the merits of a multidisciplinary approach and provide cautionary implications for paleoenvironmental reconstructions.

  3. The Early Miocene Cape Melville Formation fossil assemblage and the evolution of modern Antarctic marine communities.

    PubMed

    Whittle, Rowan J; Quaglio, Fernanda; Griffiths, Huw J; Linse, Katrin; Crame, J Alistair

    2014-01-01

    The fossil community from the Early Miocene Cape Melville Formation (King George Island, Antarctica) does not show the archaic retrograde nature of modern Antarctic marine communities, despite evidence, such as the presence of dropstones, diamictites and striated rocks, that it was deposited in a glacial environment. Unlike modern Antarctic settings, and the upper units of the Eocene La Meseta Formation on Seymour Island, Antarctica, which are 10 million years older, the Cape Melville Formation community is not dominated by sessile suspension feeding ophiuroids, crinoids or brachiopods. Instead, it is dominated by infaunal bivalves, with a significant component of decapods, similar to present day South American settings. It is possible that the archaic retrograde structure of the modern community did not fully evolve until relatively recently, maybe due to factors such as further cooling and isolation of the continent leading to glaciations, which resulted in a loss of shallow shelf habitats.

  4. Occurrence and Potential Biological Effects of Amphetamine on Stream Communities.

    PubMed

    Lee, Sylvia S; Paspalof, Alexis M; Snow, Daniel D; Richmond, Erinn K; Rosi-Marshall, Emma J; Kelly, John J

    2016-09-06

    The presence of pharmaceuticals, including illicit drugs in aquatic systems, is a topic of environmental significance because of their global occurrence and potential effects on aquatic ecosystems and human health, but few studies have examined the ecological effects of illicit drugs. We conducted a survey of several drug residues, including the potentially illicit drug amphetamine, at 6 stream sites along an urban to rural gradient in Baltimore, Maryland, U.S.A. We detected numerous drugs, including amphetamine (3 to 630 ng L(-1)), in all stream sites. We examined the fate and ecological effects of amphetamine on biofilm, seston, and aquatic insect communities in artificial streams exposed to an environmentally relevant concentration (1 μg L(-1)) of amphetamine. The amphetamine parent compound decreased in the artificial streams from less than 1 μg L(-1) on day 1 to 0.11 μg L(-1) on day 22. In artificial streams treated with amphetamine, there was up to 45% lower biofilm chlorophyll a per ash-free dry mass, 85% lower biofilm gross primary production, 24% greater seston ash-free dry mass, and 30% lower seston community respiration compared to control streams. Exposing streams to amphetamine also changed the composition of bacterial and diatom communities in biofilms at day 21 and increased cumulative dipteran emergence by 65% and 89% during the first and third weeks of the experiment, respectively. This study demonstrates that amphetamine and other biologically active drugs are present in urban streams and have the potential to affect both structure and function of stream communities.

  5. p53 Superfamily proteins in marine bivalve cancer and stress biology.

    PubMed

    Walker, Charles W; Van Beneden, Rebecca J; Muttray, Annette F; Böttger, S Anne; Kelley, Melissa L; Tucker, Abraham E; Thomas, W Kelley

    2011-01-01

    The human p53 tumour suppressor protein is inactivated in many cancers and is also a major player in apoptotic responses to cellular stress. The p53 protein and the two other members of this protein family (p63, p73) are encoded by distinct genes and their functions have been extensively documented for humans and some other vertebrates. The structure and relative expression levels for members of the p53 superfamily have also been reported for most major invertebrate taxa. The functions of homologous proteins have been investigated for only a few invertebrates (specifically, p53 in flies, nematodes and recently a sea anemone). These studies of classical model organisms all suggest that the gene family originally evolved to mediate apoptosis of damaged germ cells or to protect germ cells from genotoxic stress. Here, we have correlated data from a number of molluscan and other invertebrate sequencing projects to provide a framework for understanding p53 signalling pathways in marine bivalve cancer and stress biology. These data suggest that (a) the two identified p53 and p63/73-like proteins in soft shell clam (Mya arenaria), blue mussel (Mytilus edulis) and Northern European squid (Loligo forbesi) have identical core sequences and may be splice variants of a single gene, while some molluscs and most other invertebrates have two or more distinct genes expressing different p53 family members; (b) transcriptional activation domains (TADs) in bivalve p53 and p63/73-like protein sequences are 67-69% conserved with human p53, while those in ecdysozoan, cnidarian, placozoan and choanozoan eukaryotes are ≤33% conserved; (c) the Mdm2 binding site in the transcriptional activation domain is 100% conserved in all sequenced bivalve p53 proteins (e.g. Mya, Mytilus, Crassostrea and Spisula) but is not present in other non-deuterostome invertebrates; (d) an Mdm2 homologue has been cloned for Mytilus trossulus; (e) homologues for both human p53 upstream regulatory and

  6. Pole-to-pole biogeography of surface and deep marine bacterial communities

    PubMed Central

    Ghiglione, Jean-François; Galand, Pierre E.; Pommier, Thomas; Pedrós-Alió, Carlos; Maas, Elizabeth W.; Bakker, Kevin; Bertilson, Stefan; Kirchman, David L.; Lovejoy, Connie; Yager, Patricia L.; Murray, Alison E.

    2012-01-01

    The Antarctic and Arctic regions offer a unique opportunity to test factors shaping biogeography of marine microbial communities because these regions are geographically far apart, yet share similar selection pressures. Here, we report a comprehensive comparison of bacterioplankton diversity between polar oceans, using standardized methods for pyrosequencing the V6 region of the small subunit ribosomal (SSU) rRNA gene. Bacterial communities from lower latitude oceans were included, providing a global perspective. A clear difference between Southern and Arctic Ocean surface communities was evident, with 78% of operational taxonomic units (OTUs) unique to the Southern Ocean and 70% unique to the Arctic Ocean. Although polar ocean bacterial communities were more similar to each other than to lower latitude pelagic communities, analyses of depths, seasons, and coastal vs. open waters, the Southern and Arctic Ocean bacterioplankton communities consistently clustered separately from each other. Coastal surface Southern and Arctic Ocean communities were more dissimilar from their respective open ocean communities. In contrast, deep ocean communities differed less between poles and lower latitude deep waters and displayed different diversity patterns compared with the surface. In addition, estimated diversity (Chao1) for surface and deep communities did not correlate significantly with latitude or temperature. Our results suggest differences in environmental conditions at the poles and different selection mechanisms controlling surface and deep ocean community structure and diversity. Surface bacterioplankton may be subjected to more short-term, variable conditions, whereas deep communities appear to be structured by longer water-mass residence time and connectivity through ocean circulation. PMID:23045668

  7. Decoding Size Distribution Patterns in Marine and Transitional Water Phytoplankton: From Community to Species Level

    PubMed Central

    Roselli, Leonilde; Basset, Alberto

    2015-01-01

    Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from transitional (e.g. coastal lagoons) and coastal water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional waters are characterized by higher resource availability and shallower well-mixed water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape). We tested the hypothesis focusing on resource availability (nutrients and light) and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshwater diatoms, with transitional water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of transitional waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and transitional water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism’s behavior which exploring patch resources in transitional and marine phytoplankton communities. PMID:25974052

  8. Decoding size distribution patterns in marine and transitional water phytoplankton: from community to species level.

    PubMed

    Roselli, Leonilde; Basset, Alberto

    2015-01-01

    Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from transitional (e.g. coastal lagoons) and coastal water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional waters are characterized by higher resource availability and shallower well-mixed water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape). We tested the hypothesis focusing on resource availability (nutrients and light) and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshwater diatoms, with transitional water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of transitional waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and transitional water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism's behavior which exploring patch resources in transitional and marine phytoplankton communities.

  9. Bacterial Community Response to Petroleum Hydrocarbon Amendments in Freshwater, Marine, and Hypersaline Water-Containing Microcosms

    PubMed Central

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida

    2013-01-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination. PMID:23872573

  10. Long-term effects of the antibacterial agent triclosan on marine periphyton communities.

    PubMed

    Eriksson, K Martin; Johansson, C Henrik; Fihlman, Viktor; Grehn, Alexander; Sanli, Kemal; Andersson, Mats X; Blanck, Hans; Arrhenius, Åsa; Sircar, Triranta; Backhaus, Thomas

    2015-09-01

    Triclosan is a widely used antibacterial agent that has become a ubiquitous contaminant in freshwater, estuary, and marine environments. Concerns about potential adverse effects of triclosan have been described in several recent risk assessments. Its effects on freshwater microbial communities have been well studied, but studies addressing effects on marine microbial communities are scarce. In the present study, the authors describe short- and long-term effects of triclosan on marine periphyton (microbial biofilm) communities. Short-term effects on photosynthesis were estimated after 60 min to 210 min of exposure. Long-term effects on photosynthesis, chlorophyll a fluorescence, pigment content, community tolerance, and bacterial carbon utilization were studied after exposing periphyton for 17 d in flow-through microcosms to 0.316 nM to 10,000 nM triclosan. Results from the short-term studies show that triclosan is toxic to periphyton photosynthesis. Half maximal effective concentration (EC50) values of 1080 nM and 3000 nM were estimated using (14)CO2-incorporation and pulse amplitude modulation (PAM) fluorescence measurements, respectively. After long-term triclosan exposure in flow-through microcosms, photosynthesis estimated using PAM fluorometry was not inhibited by triclosan concentrations up to 1000 nM but instead increased with increasing triclosan concentration. Similarly, at exposure concentrations of 31.6 nM and higher, triclosan caused an increase in photosynthetic pigments. At 316 nM triclosan, the pigment amounts were increased by a factor of 1.4 to 1.9 compared with the control level. Pollution-induced community tolerance was observed for algae and cyanobacteria at 100 nM triclosan and higher. Despite the widespread use of triclosan as an antibacterial agent, the compound did not have any effects on bacterial carbon utilization after long-term exposure.

  11. Sulfur-Oxidizing Bacteria Mediate Microbial Community Succession and Element Cycling in Launched Marine Sediment

    PubMed Central

    Ihara, Hideyuki; Hori, Tomoyuki; Aoyagi, Tomo; Takasaki, Mitsuru; Katayama, Yoko

    2017-01-01

    A large amount of marine sediment was launched on land by the Great East Japan earthquake. Here, we employed both on-site and laboratory studies on the launched marine sediment to investigate the succession of microbial communities and its effects on geochemical properties of the sediment. Twenty-two-month on-site survey showed that microbial communities at the uppermost layer (0–2 mm depth) of the sediment changed significantly with time, whereas those at the deeper layer (20–40 mm depth) remained nearly unchanged and kept anaerobic microbial communities. Nine months after the incidence, various sulfur-oxidizing bacteria (SOB) prevailed in the uppermost layer, in which afterwards diverse chemoorganotrophic bacteria predominated. Geochemical analyses indicated that the concentration of metals other than Fe was lower in the uppermost layer than that in the deeper layer. Laboratory study was carried out by incubating the sediment for 57 days, and clearly indicated the dynamic transition of microbial communities in the uppermost layer exposed to atmosphere. SOB affiliated in the class Epsilonproteobacteria rapidly proliferated and dominated at the uppermost layer during the first 3 days, after that Fe(II)-oxidizing bacteria and chemoorganotrophic bacteria were sequentially dominant. Furthermore, the concentration of sulfate ion increased and the pH decreased. Consequently, SOB may have influenced the mobilization of heavy metals in the sediment by metal-bound sulfide oxidation and/or sediment acidification. These results demonstrate that SOB initiated the dynamic shift from the anaerobic to aerobic microbial communities, thereby playing a critical role in element cycling in the marine sediment. PMID:28217124

  12. Bacterial community response to petroleum hydrocarbon amendments in freshwater, marine, and hypersaline water-containing microcosms.

    PubMed

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida; Seldin, Lucy

    2013-10-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination.

  13. Sulfur-Oxidizing Bacteria Mediate Microbial Community Succession and Element Cycling in Launched Marine Sediment.

    PubMed

    Ihara, Hideyuki; Hori, Tomoyuki; Aoyagi, Tomo; Takasaki, Mitsuru; Katayama, Yoko

    2017-01-01

    A large amount of marine sediment was launched on land by the Great East Japan earthquake. Here, we employed both on-site and laboratory studies on the launched marine sediment to investigate the succession of microbial communities and its effects on geochemical properties of the sediment. Twenty-two-month on-site survey showed that microbial communities at the uppermost layer (0-2 mm depth) of the sediment changed significantly with time, whereas those at the deeper layer (20-40 mm depth) remained nearly unchanged and kept anaerobic microbial communities. Nine months after the incidence, various sulfur-oxidizing bacteria (SOB) prevailed in the uppermost layer, in which afterwards diverse chemoorganotrophic bacteria predominated. Geochemical analyses indicated that the concentration of metals other than Fe was lower in the uppermost layer than that in the deeper layer. Laboratory study was carried out by incubating the sediment for 57 days, and clearly indicated the dynamic transition of microbial communities in the uppermost layer exposed to atmosphere. SOB affiliated in the class Epsilonproteobacteria rapidly proliferated and dominated at the uppermost layer during the first 3 days, after that Fe(II)-oxidizing bacteria and chemoorganotrophic bacteria were sequentially dominant. Furthermore, the concentration of sulfate ion increased and the pH decreased. Consequently, SOB may have influenced the mobilization of heavy metals in the sediment by metal-bound sulfide oxidation and/or sediment acidification. These results demonstrate that SOB initiated the dynamic shift from the anaerobic to aerobic microbial communities, thereby playing a critical role in element cycling in the marine sediment.

  14. Meta-analysis reveals complex marine biological responses to the interactive effects of ocean acidification and warming.

    PubMed

    Harvey, Ben P; Gwynn-Jones, Dylan; Moore, Pippa J

    2013-04-01

    Ocean acidification and warming are considered two of the greatest threats to marine biodiversity, yet the combined effect of these stressors on marine organisms remains largely unclear. Using a meta-analytical approach, we assessed the biological responses of marine organisms to the effects of ocean acidification and warming in isolation and combination. As expected biological responses varied across taxonomic groups, life-history stages, and trophic levels, but importantly, combining stressors generally exhibited a stronger biological (either positive or negative) effect. Using a subset of orthogonal studies, we show that four of five of the biological responses measured (calcification, photosynthesis, reproduction, and survival, but not growth) interacted synergistically when warming and acidification were combined. The observed synergisms between interacting stressors suggest that care must be made in making inferences from single-stressor studies. Our findings clearly have implications for the development of adaptive management strategies particularly given that the frequency of stressors interacting in marine systems will be likely to intensify in the future. There is now an urgent need to move toward more robust, holistic, and ecologically realistic climate change experiments that incorporate interactions. Without them accurate predictions about the likely deleterious impacts to marine biodiversity and ecosystem functioning over the next century will not be possible.

  15. Meta-analysis reveals complex marine biological responses to the interactive effects of ocean acidification and warming

    PubMed Central

    Harvey, Ben P; Gwynn-Jones, Dylan; Moore, Pippa J

    2013-01-01

    Ocean acidification and warming are considered two of the greatest threats to marine biodiversity, yet the combined effect of these stressors on marine organisms remains largely unclear. Using a meta-analytical approach, we assessed the biological responses of marine organisms to the effects of ocean acidification and warming in isolation and combination. As expected biological responses varied across taxonomic groups, life-history stages, and trophic levels, but importantly, combining stressors generally exhibited a stronger biological (either positive or negative) effect. Using a subset of orthogonal studies, we show that four of five of the biological responses measured (calcification, photosynthesis, reproduction, and survival, but not growth) interacted synergistically when warming and acidification were combined. The observed synergisms between interacting stressors suggest that care must be made in making inferences from single-stressor studies. Our findings clearly have implications for the development of adaptive management strategies particularly given that the frequency of stressors interacting in marine systems will be likely to intensify in the future. There is now an urgent need to move toward more robust, holistic, and ecologically realistic climate change experiments that incorporate interactions. Without them accurate predictions about the likely deleterious impacts to marine biodiversity and ecosystem functioning over the next century will not be possible. PMID:23610641

  16. Metagenomics reveals that detoxification systems are underrepresented in marine bacterial communities.

    PubMed

    Bengtsson-Palme, Johan; Alm Rosenblad, Magnus; Molin, Mikael; Blomberg, Anders

    2014-09-01

    Environmental shotgun sequencing (metagenomics) provides a new way to study communities in microbial ecology. We here use sequence data from the Global Ocean Sampling (GOS) expedition to investigate toxicant selection pressures revealed by the presence of detoxification genes in marine bacteria. To capture a broad range of potential toxicants we selected detoxification protein families representing systems protecting microorganisms from a variety of stressors, such as metals, organic compounds, antibiotics and oxygen radicals. Using a bioinformatics procedure based on comparative analysis to finished bacterial genomes we found that the amount of detoxification genes present in marine microorganisms seems surprisingly small. The underrepresentation is particularly evident for toxicant transporters and proteins involved in detoxifying metals. Exceptions are enzymes involved in oxidative stress defense where peroxidase enzymes are more abundant in marine bacteria compared to bacteria in general. In contrast, catalases are almost completely absent from the open ocean environment, suggesting that peroxidases and peroxiredoxins constitute a core line of defense against reactive oxygen species (ROS) in the marine milieu. We found no indication that detoxification systems would be generally more abundant close to the coast compared to the open ocean. On the contrary, for several of the protein families that displayed a significant geographical distribution, like peroxidase, penicillin binding transpeptidase and divalent ion transport protein, the open ocean samples showed the highest abundance. Along the same lines, the abundance of most detoxification proteins did not increase with estimated pollution. The low level of detoxification systems in marine bacteria indicate that the majority of marine bacteria have a low capacity to adapt to increased pollution. Our study exemplifies the use of metagenomics data in ecotoxicology, and in particular how anthropogenic

  17. Spatial-temporal feeding dynamics of benthic communities in an estuary-marine gradient

    NASA Astrophysics Data System (ADS)

    Antonio, Emily S.; Kasai, Akihide; Ueno, Masahiro; Ishihi, Yuka; Yokoyama, Hisashi; Yamashita, Yoh

    2012-10-01

    We investigated the fluctuations of carbon and nitrogen stable isotope ratios in benthic consumers and their potential food sources to determine the spatial and temporal variations in the utilization of available organic matter, indicating the origin and pathways of energy from Yura Estuary to Tango Sea, Japan. Field samplings were conducted from the upper estuary to offshore with sampling frequency of twice per season from April (spring) 2006 to February (winter) 2007. The δ13C signatures of the upper and lower estuary benthos showed depleted and in wide range (-28.9‰ to -13.5‰) compared to the enriched and within narrow range signatures of marine benthos (-20.6‰ to -14.0‰) in all seasons. On the contrary, the δ15N signatures of benthic communities showed decreasing trend seaward and summer values were different from the other seasons. Using the dual isotope and multisource mixing models, we estimated the relative contributions of potential food sources to the benthos diet. River POM played an important source of energy for the estuarine benthos, especially in winter when river discharge was high. Marine POM served as an important alternative food for the estuarine benthos from spring to autumn when seawater intruded the bottom estuary. Benthic microalgae were the major food source at the shallow coast throughout the year, while marine POM fueled the deep coast and offshore benthic food webs. Spatial and temporal feeding variations in estuarine benthic communities were driven by the hydrology of the estuary, whereas primary production and transport of food source dictated diet variations of marine benthic communities. The elucidation of the dynamic energy subsidy among aquatic systems highlights the importance of the land-sea transition zones that is crucial for benthic secondary productions.

  18. Key role of selective viral-induced mortality in determining marine bacterial community composition.

    PubMed

    Bouvier, T; del Giorgio, P A

    2007-02-01

    Viral infection is thought to play an important role in shaping bacterial community composition and diversity in aquatic ecosystems, but the strength of this interaction and the mechanisms underlying this regulation are still not well understood. The consensus is that viruses may impact the dominant bacterial strains, but there is little information as to how viruses may affect the less abundant taxa, which often comprise the bulk of the total bacterial diversity. The potential effect of viruses on the phylogenetic composition of marine bacterioplankton was assessed by incubating marine bacteria collected along a North Pacific coastal-open ocean transect in seawater that was greatly depleted of ambient viruses. The ambient communities were dominated by typical marine groups, including alphaproteobacteria and the Bacteroidetes. Incubation of these communities in virus-depleted ambient water yielded an unexpected and dramatic increase in the relative abundance of bacterial groups that are generally undetectable in the in situ assemblages, such as betaproteobacteria and Actinobacteria. Our results suggest that host susceptibility is not necessarily only proportional to its density but to other characteristics of the host, that rare marine bacterial groups may be more susceptible to viral-induced mortality, and that these rare groups may actually be the winners of competition for resources. These observations are not inconsistent with the 'phage kills the winner' hypothesis but represent an extreme and yet undocumented case of this paradigm, where the potential winners apparently never actually develop beyond a very low abundance threshold in situ. We further suggest that this mode of regulation may influence not just the distribution of single strains but of entire phylogenetic groups.

  19. Metagenomic sequencing of marine periphyton: taxonomic and functional insights into biofilm communities

    PubMed Central

    Sanli, Kemal; Bengtsson-Palme, Johan; Nilsson, R. Henrik; Kristiansson, Erik; Alm Rosenblad, Magnus; Blanck, Hans; Eriksson, Karl M.

    2015-01-01

    Periphyton communities are complex phototrophic, multispecies biofilms that develop on surfaces in aquatic environments. These communities harbor a large diversity of organisms comprising viruses, bacteria, algae, fungi, protozoans, and metazoans. However, thus far the total biodiversity of periphyton has not been described. In this study, we use metagenomics to characterize periphyton communities from the marine environment of the Swedish west coast. Although we found approximately ten times more eukaryotic rRNA marker gene sequences compared to prokaryotic, the whole metagenome-based similarity searches showed that bacteria constitute the most abundant phyla in these biofilms. We show that marine periphyton encompass a range of heterotrophic and phototrophic organisms. Heterotrophic bacteria, including the majority of proteobacterial clades and Bacteroidetes, and eukaryotic macro-invertebrates were found to dominate periphyton. The phototrophic groups comprise Cyanobacteria and the alpha-proteobacterial genus Roseobacter, followed by different micro- and macro-algae. We also assess the metabolic pathways that predispose these communities to an attached lifestyle. Functional indicators of the biofilm form of life in periphyton involve genes coding for enzymes that catalyze the production and degradation of extracellular polymeric substances, mainly in the form of complex sugars such as starch and glycogen-like meshes together with chitin. Genes for 278 different transporter proteins were detected in the metagenome, constituting the most abundant protein complexes. Finally, genes encoding enzymes that participate in anaerobic pathways, such as denitrification and methanogenesis, were detected suggesting the presence of anaerobic or low-oxygen micro-zones within the biofilms. PMID:26579098

  20. Jellyfish-associated bacterial communities and bacterioplankton in Indonesian Marine lakes.

    PubMed

    Cleary, Daniel F R; Becking, Leontine E; Polónia, Ana R M; Freitas, Rossana M; Gomes, Newton C M

    2016-05-01

    In the present study, we compared communities of bacteria in two jellyfish species (the 'golden' jellyfish Mastigias cf.papua and the box jellyfish Tripedalia cf.cystophora) and water in three marine lakes located in the Berau region of northeastern Borneo, Indonesia. Jellyfish-associated bacterial communities were compositionally distinct and less diverse than bacterioplankton communities. Alphaproteobacteria, Gammaproteobacteria, Synechococcophycidae and Flavobacteriia were the most abundant classes in water. Jellyfish-associated bacterial communities were dominated by OTUs assigned to the Gammaproteobacteria (family Endozoicimonaceae), Mollicutes, Spirochaetes and Alphaproteobacteria (orders Kiloniellales and Rhodobacterales). Mollicutes were mainly restricted to Mastigias whereas Spirochaetes and the order Kiloniellales were most abundant in Tripedalia hosts. The most abundant OTU overall in jellyfish hosts was assigned to the family Endozoicimonaceae and was highly similar to organisms in Genbank obtained from various hosts including an octocoral, bivalve and fish species. Other abundant OTUs included an OTU assigned to the order Entomoplasmatales and mainly found in Mastigias hosts and OTUs assigned to the Spirochaetes and order Kiloniellales and mainly found in Tripedalia hosts. The low sequence similarity of the Entomoplasmatales OTU to sequences in Genbank suggests that it may be a novel lineage inhabiting Mastigias and possibly restricted to marine lakes.

  1. Divergent ecosystem responses within a benthic marine community to ocean acidification.

    PubMed

    Kroeker, Kristy J; Micheli, Fiorenza; Gambi, Maria Cristina; Martz, Todd R

    2011-08-30

    Ocean acidification is predicted to impact all areas of the oceans and affect a diversity of marine organisms. However, the diversity of responses among species prevents clear predictions about the impact of acidification at the ecosystem level. Here, we used shallow water CO(2) vents in the Mediterranean Sea as a model system to examine emergent ecosystem responses to ocean acidification in rocky reef communities. We assessed in situ benthic invertebrate communities in three distinct pH zones (ambient, low, and extreme low), which differed in both the mean and variability of seawater pH along a continuous gradient. We found fewer taxa, reduced taxonomic evenness, and lower biomass in the extreme low pH zones. However, the number of individuals did not differ among pH zones, suggesting that there is density compensation through population blooms of small acidification-tolerant taxa. Furthermore, the trophic structure of the invertebrate community shifted to fewer trophic groups and dominance by generalists in extreme low pH, suggesting that there may be a simplification of food webs with ocean acidification. Despite high variation in individual species' responses, our findings indicate that ocean acidification decreases the diversity, biomass, and trophic complexity of benthic marine communities. These results suggest that a loss of biodiversity and ecosystem function is expected under extreme acidification scenarios.

  2. Importance of Marine-Derived Nutrients Supplied by Planktivorous Seabirds to High Arctic Tundra Plant Communities

    PubMed Central

    Zwolicki, Adrian; Zmudczyńska-Skarbek, Katarzyna; Richard, Pierre; Stempniewicz, Lech

    2016-01-01

    We studied the relative importance of several environmental factors for tundra plant communities in five locations across Svalbard (High Arctic) that differed in geographical location, oceanographic and climatic influence, and soil characteristics. The amount of marine-derived nitrogen in the soil supplied by seabirds was locally the most important of the studied environmental factors influencing the tundra plant community. We found a strong positive correlation between δ15N isotopic values and total N content in the soil, confirming the fundamental role of marine-derived matter to the generally nutrient-poor Arctic tundra ecosystem. We also recorded a strong correlation between the δ15N values of soil and of the tissues of vascular plants and mosses, but not of lichens. The relationship between soil δ15N values and vascular plant cover was linear. In the case of mosses, the percentage ground cover reached maximum around a soil δ 15N value of 8‰, as did plant community diversity. This soil δ15N value clearly separated the occurrence of plants with low nitrogen tolerance (e.g. Salix polaris) from those predominating on high N content soils (e.g. Cerastium arcticum, Poa alpina). Large colonies of planktivorous little auks have a great influence on Arctic tundra vegetation, either through enhancing plant abundance or in shaping plant community composition at a local scale. PMID:27149113

  3. Divergent ecosystem responses within a benthic marine community to ocean acidification

    PubMed Central

    Kroeker, Kristy J.; Micheli, Fiorenza; Gambi, Maria Cristina; Martz, Todd R.

    2011-01-01

    Ocean acidification is predicted to impact all areas of the oceans and affect a diversity of marine organisms. However, the diversity of responses among species prevents clear predictions about the impact of acidification at the ecosystem level. Here, we used shallow water CO2 vents in the Mediterranean Sea as a model system to examine emergent ecosystem responses to ocean acidification in rocky reef communities. We assessed in situ benthic invertebrate communities in three distinct pH zones (ambient, low, and extreme low), which differed in both the mean and variability of seawater pH along a continuous gradient. We found fewer taxa, reduced taxonomic evenness, and lower biomass in the extreme low pH zones. However, the number of individuals did not differ among pH zones, suggesting that there is density compensation through population blooms of small acidification-tolerant taxa. Furthermore, the trophic structure of the invertebrate community shifted to fewer trophic groups and dominance by generalists in extreme low pH, suggesting that there may be a simplification of food webs with ocean acidification. Despite high variation in individual species’ responses, our findings indicate that ocean acidification decreases the diversity, biomass, and trophic complexity of benthic marine communities. These results suggest that a loss of biodiversity and ecosystem function is expected under extreme acidification scenarios. PMID:21844331

  4. The relationship between regional and local species diversity in marine benthic communities: A global perspective

    PubMed Central

    Witman, Jon D.; Etter, Ron J.; Smith, Franz

    2004-01-01

    The number of species coexisting in ecological communities must be a consequence of processes operating on both local and regional scales. Although a great deal of experimental work has been devoted to local causes of diversity, little is known about the effects of regional processes on local diversity and how they contribute to global diversity patterns in marine systems. We tested the effects of latitude and the richness of the regional species pool on the species richness of local epifaunal invertebrate communities by sampling the diversity of local sites in 12 independent biogeographic regions from 62°S to 63°N latitude. Both regional and local species richness displayed significant unimodal patterns with latitude, peaking at low latitudes and decreasing toward high latitudes. The latitudinal diversity gradient was represented at the scale of local sites because local species richness was positively and linearly related to regional species richness. The richness of the regional species pool explained 73-76% of local species richness. On a global scale, the extent of regional influence on local species richness was nonrandom—the proportion of regional biota represented in local epifaunal communities increased significantly from low to high latitudes. The strong effect of the regional species pool implies that patterns of local diversity in temperate, tropical, and high-latitude marine benthic communities are influenced by processes operating on larger spatiotemporal scales than previously thought. PMID:15501917

  5. Importance of Marine-Derived Nutrients Supplied by Planktivorous Seabirds to High Arctic Tundra Plant Communities.

    PubMed

    Zwolicki, Adrian; Zmudczyńska-Skarbek, Katarzyna; Richard, Pierre; Stempniewicz, Lech

    2016-01-01

    We studied the relative importance of several environmental factors for tundra plant communities in five locations across Svalbard (High Arctic) that differed in geographical location, oceanographic and climatic influence, and soil characteristics. The amount of marine-derived nitrogen in the soil supplied by seabirds was locally the most important of the studied environmental factors influencing the tundra plant community. We found a strong positive correlation between δ15N isotopic values and total N content in the soil, confirming the fundamental role of marine-derived matter to the generally nutrient-poor Arctic tundra ecosystem. We also recorded a strong correlation between the δ15N values of soil and of the tissues of vascular plants and mosses, but not of lichens. The relationship between soil δ15N values and vascular plant cover was linear. In the case of mosses, the percentage ground cover reached maximum around a soil δ 15N value of 8‰, as did plant community diversity. This soil δ15N value clearly separated the occurrence of plants with low nitrogen tolerance (e.g. Salix polaris) from those predominating on high N content soils (e.g. Cerastium arcticum, Poa alpina). Large colonies of planktivorous little auks have a great influence on Arctic tundra vegetation, either through enhancing plant abundance or in shaping plant community composition at a local scale.

  6. Relevance of ammonium oxidation within biological soil crust communities

    USGS Publications Warehouse

    Johnson, S.L.; Budinoff, C.R.; Belnap, J.; Garcia-Pichel, F.

    2005-01-01

    Thin, vertically structured topsoil communities that become ecologically important in arid regions (biological soil crusts or BSCs) are responsible for much of the nitrogen inputs into pristine arid lands. We studied N2 fixation and ammonium oxidation (AO) at subcentimetre resolution within BSCs from the Colorado Plateau. Pools of dissolved porewater nitrate/ nitrite, ammonium and organic nitrogen in wetted BSCs were high in comparison with those typical of aridosoils. They remained stable during incubations, indicating that input and output processes were of similar magnitude. Areal N2 fixation rates (6.5-48 ??mol C2H2 m-2 h -1) were high, the vertical distribution of N2 fixation peaking close to the surface if populations of heterocystous cyanobacteria were present, but in the subsurface if they were absent. Areal AO rates (19-46 ??mol N m-2 h-1) were commensurate with N2 fixation inputs. When considering oxygen availability, AO activity invariably peaked 2-3 mm deep and was limited by oxygen (not ammonium) supply. Most probable number (MPN)-enumerated ammonia-oxidizing bacteria (6.7-7.9 ?? 103 cells g-1 on average) clearly peaked at 2-3 mm depth. Thus, AO (hence nitrification) is a spatially restricted but important process in the nitrogen cycling of BSC, turning much of the biologically fixed nitrogen into oxidized forms, the fate of which remains to be determined.

  7. Atmospheric aerosol deposition influences marine microbial communities in oligotrophic surface waters of the western Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Maki, Teruya; Ishikawa, Akira; Mastunaga, Tomoki; Pointing, Stephen B.; Saito, Yuuki; Kasai, Tomoaki; Watanabe, Koichi; Aoki, Kazuma; Horiuchi, Amane; Lee, Kevin C.; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2016-12-01

    Atmospheric aerosols contain particulates that are deposited to oceanic surface waters. These can represent a major source of nutrients, trace metals, and organic compounds for the marine environment. The Japan Sea and the western Pacific Ocean are particularly affected by aerosols due to the transport of desert dust and industrially derived particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) from continental Asia. We hypothesized that supplementing seawater with aerosol particulates would lead to measurable changes in surface water nutrient composition as well as shifts in the marine microbial community. Shipboard experiments in the Pacific Ocean involved the recovery of oligotrophic oceanic surface water and subsequent supplementation with aerosol particulates obtained from the nearby coastal mountains, to simulate marine particulate input in this region. Initial increases in nitrates due to the addition of aerosol particulates were followed by a decrease correlated with the increase in phytoplankton biomass, which was composed largely of Bacillariophyta (diatoms), including Pseudo-nitzschia and Chaetoceros species. This shift was accompanied by changes in the bacterial community, with apparent increases in the relative abundance of heterotrophic Rhodobacteraceae and Colwelliaceae in aerosol particulate treated seawater. Our findings provide empirical evidence revealing the impact of aerosol particulates on oceanic surface water microbiology by alleviating nitrogen limitation in the organisms.

  8. Submarine groundwater discharges create unique benthic communities in a coastal sandy marine environment

    NASA Astrophysics Data System (ADS)

    Leitão, Francisco; Encarnação, João; Range, Pedro; Schmelz, Rüdiger M.; Teodósio, Maria A.; Chícharo, Luís

    2015-09-01

    In this study we assessed the small-scale effects of submarine groundwater discharges (SGD) on macrofaunal assemblages associated with shallow sandy sediments along the south coast of Portugal. Corer samples were collected in a (1) subtidal seep, (2) at the edge of the seep (periphery) and (3) in the surrounding area. Community structure varied across areas, with diversity, species richness and evenness generally low at seep relatively to the surrounding area. Community composition within the seep was reduced to a small number of taxa, although total abundance was similar between seeps and surrounding areas. The seep was characterized by a distinct hydrological environment, with lower salinity and pH, relative to the surroundings sandy areas. More than 93% of the benthic macrofauna in the seep was dominated by Lumbricillus lineatus (enchytraeid oligochaetes). This study is the first to record the presence of this euryaline species in Portuguese marine waters. In the surrounding area Spionidae Polychaetes and Bathyporeia sp. (Amphipoda) were the most frequent and abundant taxa. These findings provide evidence for a direct association between SGD effect and the composition of benthic marine assemblages. The patchy habitat created by groundwater seep allowed euryhaline species with short and fast recruitment times to occur in a fully marine environment. Whether this pattern is consistent, or only occurs when smooth favorable sea conditions are not superimposed on the groundwater effect remains uncertain.

  9. Microbial community dynamics and biodegradation of polycyclic aromatic hydrocarbons in polluted marine sediments in Hong Kong.

    PubMed

    Wang, Y F; Tam, N F Y

    2011-01-01

    Dynamics of microbial community and biodegradation of polycyclic aromatic hydrocarbons (PAHs) in polluted marine sediments, artificially spiked with a mixture of PAHs (fluorene, phenanthrene, fluoranthene and pyrene), were examined for a period of 60 days. Microbial communities were characterised by bacterial counts, ester-linked fatty acid methyl ester (EL-FAME) analysis and denaturing gradient gel electrophoresis (DGGE). A noted reduction in species diversity occurred only in the high PAH level treatment at onset. Both EL-FAME and DGGE demonstrated a marked shift in microbial community, in all the PAH level treatments, afterwards, with increases in the number of fatty acid degraders, the relative abundance of fatty acid biomarkers for gram-negative bacteria and a decrease in species diversity. The shift was also accompanied by the significant decrease in PAH concentrations. By the end of the experiment, diversity indices, based on both approaches, recovered when PAH concentrations declined to their background levels, except in the high PAH level treatment.

  10. Microbial Community Composition in the Marine Sediments of Jeju Island: Next-Generation Sequencing Surveys.

    PubMed

    Choi, Heebok; Koh, Hyeon-Woo; Kim, Hongik; Chae, Jong-Chan; Park, Soo-Je

    2016-05-28

    Marine sediments are a microbial biosphere with an unknown physiology, and the sediments harbor numerous distinct phylogenetic lineages of Bacteria and Archaea that are at present uncultured. In this study, the structure of the archaeal and bacterial communities was investigated in the surface and subsurface sediments of Jeju Island using a next-generation sequencing method. The microbial communities in the surface sediments were distinct from those in the subsurface sediments; the relative abundance of sequences for Thaumarchaeota, Actinobacteria, Bacteroides, Alphaproteobacteria, and Gammaproteobacteria were higher in the surface than subsurface sediments, whereas the sequences for Euryarchaeota, Acidobacteria, Firmicutes, and Deltaproteobacteria were relatively more abundant in the subsurface than surface sediments. This study presents detailed characterization of the spatial distribution of benthic microbial communities of Jeju Island and provides fundamental information on the potential interactions mediated by microorganisms with the different biogeochemical cycles in coastal sediments.

  11. Molecular tools for investigating microbial community structure and function in oxygen-deficient marine waters.

    PubMed

    Hawley, Alyse K; Kheirandish, Sam; Mueller, Andreas; Leung, Hilary T C; Norbeck, Angela D; Brewer, Heather M; Pasa-Tolic, Ljiljana; Hallam, Steven J

    2013-01-01

    Water column oxygen (O2)-deficiency shapes food-web structure by progressively directing nutrients and energy away from higher trophic levels into microbial community metabolism resulting in fixed nitrogen loss and greenhouse gas production. Although respiratory O2 consumption during organic matter degradation is a natural outcome of a productive surface ocean, global-warming-induced stratification intensifies this process leading to oxygen minimum zone (OMZ) expansion. Here, we describe useful tools for detection and quantification of potential key microbial players and processes in OMZ community metabolism including quantitative polymerase chain reaction primers targeting Marine Group I Thaumarchaeota, SUP05, Arctic96BD-19, and SAR324 small-subunit ribosomal RNA genes and protein extraction methods from OMZ waters compatible with high-resolution mass spectrometry for profiling microbial community structure and functional dynamics.

  12. Herbivore and predator diversity interactively affect ecosystem properties in an experimental marine community.

    PubMed

    Douglass, James G; Duffy, J Emmett; Bruno, John F

    2008-06-01

    Interacting changes in predator and prey diversity likely influence ecosystem properties but have rarely been experimentally tested. We manipulated the species richness of herbivores and predators in an experimental benthic marine community and measured their effects on predator, herbivore and primary producer performance. Predator composition and richness strongly affected several community and population responses, mostly via sampling effects. However, some predators survived better in polycultures than in monocultures, suggesting complementarity due to stronger intra- than interspecific interactions. Predator effects also differed between additive and substitutive designs, emphasizing that the relationship between diversity and abundance in an assemblage can strongly influence whether and how diversity effects are realized. Changing herbivore richness and predator richness interacted to influence both total herbivore abundance and predatory crab growth, but these interactive diversity effects were weak. Overall, the presence and richness of predators dominated biotic effects on community and ecosystem properties.

  13. Adaptive capacity of fishing communities at marine protected areas: a case study from the Colombian Pacific.

    PubMed

    Moreno-Sánchez, Rocío del Pilar; Maldonado, Jorge Higinio

    2013-12-01

    Departing from a theoretical methodology, we estimate empirically an index of adaptive capacity (IAC) of a fishing community to the establishment of marine protected areas (MPAs). We carried out household surveys, designed to obtain information for indicators and sub-indicators, and calculated the IAC. Moreover, we performed a sensitivity analysis to check for robustness of the results. Our findings show that, despite being located between two MPAs, the fishing community of Bazán in the Colombian Pacific is highly vulnerable and that the socioeconomic dimension of the IAC constitutes the most binding dimension for building adaptive capacity. Bazán is characterized by extreme poverty, high dependence on resources, and lack of basic public infrastructure. Notwithstanding, social capital and local awareness about ecological conditions may act as enhancers of adaptive capacity. The establishment of MPAs should consider the development of strategies to confer adaptive capacity to local communities highly dependent on resource extraction.

  14. Short- and long-term conditioning of a temperate marine diatom community to acidification and warming.

    PubMed

    Tatters, Avery O; Roleda, Michael Y; Schnetzer, Astrid; Fu, Feixue; Hurd, Catriona L; Boyd, Philip W; Caron, David A; Lie, Alle A Y; Hoffmann, Linn J; Hutchins, David A

    2013-01-01

    Ocean acidification and greenhouse warming will interactively influence competitive success of key phytoplankton groups such as diatoms, but how long-term responses to global change will affect community structure is unknown. We incubated a mixed natural diatom community from coastal New Zealand waters in a short-term (two-week) incubation experiment using a factorial matrix of warming and/or elevated pCO2 and measured effects on community structure. We then isolated the dominant diatoms in clonal cultures and conditioned them for 1 year under the same temperature and pCO2 conditions from which they were isolated, in order to allow for extended selection or acclimation by these abiotic environmental change factors in the absence of interspecific interactions. These conditioned isolates were then recombined into 'artificial' communities modelled after the original natural assemblage and allowed to compete under conditions identical to those in the short-term natural community experiment. In general, the resulting structure of both the unconditioned natural community and conditioned 'artificial' community experiments was similar, despite differences such as the loss of two species in the latter. pCO2 and temperature had both individual and interactive effects on community structure, but temperature was more influential, as warming significantly reduced species richness. In this case, our short-term manipulative experiment with a mixed natural assemblage spanning weeks served as a reasonable proxy to predict the effects of global change forcing on diatom community structure after the component species were conditioned in isolation over an extended timescale. Future studies will be required to assess whether or not this is also the case for other types of algal communities from other marine regimes.

  15. Short- and long-term conditioning of a temperate marine diatom community to acidification and warming

    PubMed Central

    Tatters, Avery O.; Roleda, Michael Y.; Schnetzer, Astrid; Fu, Feixue; Hurd, Catriona L.; Boyd, Philip W.; Caron, David A.; Lie, Alle A. Y.; Hoffmann, Linn J.; Hutchins, David A.

    2013-01-01

    Ocean acidification and greenhouse warming will interactively influence competitive success of key phytoplankton groups such as diatoms, but how long-term responses to global change will affect community structure is unknown. We incubated a mixed natural diatom community from coastal New Zealand waters in a short-term (two-week) incubation experiment using a factorial matrix of warming and/or elevated pCO2 and measured effects on community structure. We then isolated the dominant diatoms in clonal cultures and conditioned them for 1 year under the same temperature and pCO2 conditions from which they were isolated, in order to allow for extended selection or acclimation by these abiotic environmental change factors in the absence of interspecific interactions. These conditioned isolates were then recombined into ‘artificial’ communities modelled after the original natural assemblage and allowed to compete under conditions identical to those in the short-term natural community experiment. In general, the resulting structure of both the unconditioned natural community and conditioned ‘artificial’ community experiments was similar, despite differences such as the loss of two species in the latter. pCO2 and temperature had both individual and interactive effects on community structure, but temperature was more influential, as warming significantly reduced species richness. In this case, our short-term manipulative experiment with a mixed natural assemblage spanning weeks served as a reasonable proxy to predict the effects of global change forcing on diatom community structure after the component species were conditioned in isolation over an extended timescale. Future studies will be required to assess whether or not this is also the case for other types of algal communities from other marine regimes. PMID:23980240

  16. Biological activities of ethanolic extracts from deep-sea Antarctic marine sponges.

    PubMed

    Turk, Tom; Ambrožič Avguštin, Jerneja; Batista, Urška; Strugar, Gašper; Kosmina, Rok; Čivović, Sandra; Janussen, Dorte; Kauferstein, Silke; Mebs, Dietrich; Sepčić, Kristina

    2013-04-02

    We report on the screening of ethanolic extracts from 33 deep-sea Antarctic marine sponges for different biological activities. We monitored hemolysis, inhibition of acetylcholinesterase, cytotoxicity towards normal and transformed cells and growth inhibition of laboratory, commensal and clinically and ecologically relevant bacteria. The most prominent activities were associated with the extracts from sponges belonging to the genus Latrunculia, which show all of these activities. While most of these activities are associated to already known secondary metabolites, the extremely strong acetylcholinesterase inhibitory potential appears to be related to a compound unknown to date. Extracts from Tetilla leptoderma, Bathydorus cf. spinosus, Xestospongia sp., Rossella sp., Rossella cf. racovitzae and Halichondria osculum were hemolytic, with the last two also showing moderate cytotoxic potential. The antibacterial tests showed significantly greater activities of the extracts of these Antarctic sponges towards ecologically relevant bacteria from sea water and from Arctic ice. This indicates their ecological relevance for inhibition of bacterial microfouling.

  17. Marine biological metapopulation with coupled logistic growth functions: The MSY and quasi MSY

    NASA Astrophysics Data System (ADS)

    Husniah, H.; Supriatna, A. K.

    2014-02-01

    In this paper we develop a mathematical model for a harvested marine biological stock. The stock consists of two discretely separated sub-stocks which are connected by the dispersal of individuals, and hence forms a metapopulation structure. The model assumes that the production function of each stock follows a logistic equation, hence the full system of the stocks governed by a couple of logistic equations. We find the formula of the maximum sustainable yield (MSY) for each sub-stock, which is extendable to a metapopulation with several discretely separated sub-populations. We also give a numerical simulation to illustrate the application of the formula for two-patch case, based on the quasi maximum sustainable yield. The simulation shows that ignoring the existence of the coupling of the system resulting in a lower total harvest from the population. This indicates a financial lost potential arising from an inappropriate recognition of a metapopulation structure in a fishery industry.

  18. Barcodes of marine invertebrates from north Iberian ports: Native diversity and resistance to biological invasions.

    PubMed

    Miralles, L; Ardura, A; Arias, A; Borrell, Y J; Clusa, L; Dopico, E; de Rojas, A Hernandez; Lopez, B; Muñoz-Colmenero, M; Roca, A; Valiente, A G; Zaiko, A; Garcia-Vazquez, E

    2016-11-15

    Ports are gateways for many marine organisms transported by ships worldwide, especially non-indigenous species (NIS). In this study carried out in North Iberian ports (Cantabrian Sea, Bay of Biscay) we have observed 38% of exotic macroinvertebrates. Four species, namely the barnacle Austrominius modestus, the tubeworm Ficopomatus enigmaticus, the Pacific oyster Crassostrea gigas and the pygmy mussel Xenostrobus securis, exhibited clear signs of invasiveness. A total of 671 barcode (cytochrome oxidase subunit I or 18S rRNA) genes were obtained and confirmed the species status of some cryptic NIS. Negative and significant correlation between diversity estimators of native biota and proportion of NIS suggests biotic resistance in ports. This could be applied to management of port biota for contributing to prevent the settlement of biopollutants in these areas which are very sensitive to biological invasions.

  19. Biological Activities of Ethanolic Extracts from Deep-Sea Antarctic Marine Sponges

    PubMed Central

    Turk, Tom; Ambrožič Avguštin, Jerneja; Batista, Urška; Strugar, Gašper; Kosmina, Rok; Čivović, Sandra; Janussen, Dorte; Kauferstein, Silke; Mebs, Dietrich; Sepčić, Kristina

    2013-01-01

    We report on the screening of ethanolic extracts from 33 deep-sea Antarctic marine sponges for different biological activities. We monitored hemolysis, inhibition of acetylcholinesterase, cytotoxicity towards normal and transformed cells and growth inhibition of laboratory, commensal and clinically and ecologically relevant bacteria. The most prominent activities were associated with the extracts from sponges belonging to the genus Latrunculia, which show all of these activities. While most of these activities are associated to already known secondary metabolites, the extremely strong acetylcholinesterase inhibitory potential appears to be related to a compound unknown to date. Extracts from Tetilla leptoderma, Bathydorus cf. spinosus, Xestospongia sp., Rossella sp., Rossella cf. racovitzae and Halichondria osculum were hemolytic, with the last two also showing moderate cytotoxic potential. The antibacterial tests showed significantly greater activities of the extracts of these Antarctic sponges towards ecologically relevant bacteria from sea water and from Arctic ice. This indicates their ecological relevance for inhibition of bacterial microfouling. PMID:23549284

  20. The Index to Marine and Lacustrine Geological Samples (IMLGS): Linking Digital Data to Physical Samples for the Marine Community

    NASA Astrophysics Data System (ADS)

    Stroker, K. J.; Jencks, J. H.; Eakins, B.

    2016-12-01

    The Index to Marine and Lacustrine Geological Samples (IMLGS) is a community designed and maintained resource enabling researchers to locate and request seafloor and lakebed geologic samples curated by partner institutions. The Index was conceived in the dawn of the digital age by representatives from U.S. academic and government marine core repositories and the NOAA National Geophysical Data Center, now the National Centers for Environmental Information (NCEI), at a 1977 meeting convened by the National Science Foundation (NSF). The Index is based on core concepts of community oversight, common vocabularies, consistent metadata and a shared interface. The Curators Consortium, international in scope, meets biennially to share ideas and discuss best practices. NCEI serves the group by providing database access and maintenance, a list server, digitizing support and long-term archival of sample metadata, data and imagery. Over three decades, participating curators have performed the laborious task of creating and contributing metadata for over 205,000 sea floor and lake-bed cores, grabs, and dredges archived in their collections. Some partners use the Index for primary web access to their collections while others use it to increase exposure of more in-depth institutional systems. The IMLGS has a persistent URL/Digital Object Identifier (DOI), as well as DOIs assigned to partner collections for citation and to provide a persistent link to curator collections. The Index is currently a geospatially-enabled relational database, publicly accessible via Web Feature and Web Map Services, and text- and ArcGIS map-based web interfaces. To provide as much knowledge as possible about each sample, the Index includes curatorial contact information and links to related data, information and images : 1) at participating institutions, 2) in the NCEI archive, and 3) through a Linked Data interface maintained by the Rolling Deck to Repository R2R. Over 43,000 International Geo

  1. Enabling a next generation of synthetic biology community organization and leadership.

    PubMed

    Palmer, Megan J; Jewett, Michael C

    2014-03-21

    Synthetic biology seeks to make engineering of complex biological functions more efficient, reliable, and predictable. Advancing the process of engineering biology requires community organization and leadership. As synthetic biology matures into a globally significant enterprise, the community needs to enable a next generation of leaders to organize the field's responsible advancement. We discuss key points raised at a community meeting on these issues at SB6.0--the Sixth International Meeting on Synthetic Biology--and highlight opportunities to carry forward the conversation.

  2. Investigating on the Correlation Between Some Biological Activities of Marine Sponge-Associated Bacteria Extracts and Isolated Diketopiperazines.

    PubMed

    Abd El-Hady, Faten K; Fayad, Walid; Iodice, Carmine; El-Shahid, Zeinab A; Abdel-Aziz, Mohamed S; Crudele, Egle; Tommonaro, Giuseppina

    2017-01-01

    Marine organisms have been considered as the richest sources of novel bioactive metabolites, which can be used for pharmaceutical purposes. In the last years, the interest for marine microorganisms has grown for their enormous biodiversity and for the evidence that many novel compounds isolated from marine invertebrates are really synthesized by their associated bacteria. Nevertheless, the discovery of a chemical communication Quorum sensing (QS) between bacterial cells and between bacteria and host has gained the researchers to expand the aim of their study toward the role of bacteria associated with marine invertebrates, such as marine sponge. In the present paper, we report the evaluation of biological activities of different extracts of bacteria Vibrio sp. and Bacillus sp. associated with marine sponges Dysidea avara and Ircinia variabilis, respectively. Moreover, we evaluated the biological activities of some diketopiperazines (DKPs), previously isolated, and able to activate QS mechanism. The results showed that all extracts, fractions, and DKPs showed low scavenging activity against DPPH and superoxide anion, low cytotoxic and anti-tyrosinase activities, but no antimicrobial and acetylcholinesterase inhibitory activities. One DKP [cyclo-(trans-4-hydroxy-L-prolyl-L-leucine)] has the highest α-glucosidase inhibitory activity even than the standard acarbose.

  3. Enriching distinctive microbial communities from marine sediments via an electrochemical-sulfide-oxidizing process on carbon electrodes

    PubMed Central

    Li, Shiue-Lin; Nealson, Kenneth H.

    2015-01-01

    Sulfide is a common product of marine anaerobic respiration, and a potent reactant biologically and geochemically. Here we demonstrate the impact on microbial communities with the removal of sulfide via electrochemical methods. The use of differential pulse voltammetry revealed that the oxidation of soluble sulfide was seen at +30 mV (vs. SHE) at all pH ranges tested (from pH = 4 to 8), while non-ionized sulfide, which dominated at pH = 4 was poorly oxidized via this process. Two mixed cultures (CAT and LA) were enriched from two different marine sediments (from Catalina Island, CAT; from the Port of Los Angeles, LA) in serum bottles using a seawater medium supplemented with lactate, sulfate, and yeast extract, to obtain abundant biomass. Both CAT and LA cultures were inoculated in electrochemical cells (using yeast-extract-free seawater medium as an electrolyte) equipped with carbon-felt electrodes. In both cases, when potentials of +630 or +130 mV (vs. SHE) were applied, currents were consistently higher at +630 then at +130 mV, indicating more sulfide being oxidized at the higher potential. In addition, higher organic-acid and sulfate conversion rates were found at +630 mV with CAT, while no significant differences were found with LA at different potentials. The results of microbial-community analyses revealed a decrease in diversity for both CAT and LA after electrochemical incubation. In addition, some bacteria (e.g., Clostridium and Arcobacter) not well-known to be capable of extracellular electron transfer, were found to be dominant in the electrochemical cells. Thus, even though the different mixed cultures have different tolerances for sulfide, electrochemical-sulfide removal can lead to major population changes. PMID:25741331

  4. Variability of community interaction networks in marine reserves and adjacent exploited areas

    USGS Publications Warehouse

    Montano-Moctezuma, G.; Li, H.W.; Rossignol, P.A.

    2008-01-01

    Regional and small-scale local oceanographic conditions can lead to high variability in community structure even among similar habitats. Communities with identical species composition can depict distinct networks due to different levels of disturbance as well as physical and biological processes. In this study we reconstruct community networks in four different areas off the Oregon Coast by matching simulated communities with observed dynamics. We compared reserves with harvested areas. Simulations suggested that different community networks, but with the same species composition, can represent each study site. Differences were found in predator-prey interactions as well as non-predatory interactions between community members. In addition, each site can be represented as a set of models, creating alternative stages among sites. The set of alternative models that characterize each study area depicts a sequence of functional responses where each specific model or interaction structure creates different species composition patterns. Different management practices, either in the past or of the present, may lead to alternative communities. Our findings suggest that management strategies should be analyzed at a community level that considers the possible consequences of shifting from one community scenario to another. This analysis provides a novel conceptual framework to assess the consequences of different management options for ecological communities. ?? 2008 Elsevier B.V. All rights reserved.

  5. Marine biotechnologies and synthetic biology, new issues for a fair and equitable profit-sharing commercial use.

    PubMed

    Bloch, Jean-François; Tardieu-Guigues, Elisabeth

    2014-10-01

    The sea will be a source of economic development in the next years. Today the research works in marine biotechnologies supply new products and processes. The introduction in the laboratories of a new technology, synthesis biology, is going to increase the possibilities of creation of new products. Exploitation of product stemming from marine biodiversity has to be made with regard to various rights among which industrial property law, maritime law and the Convention on BioDiversity. All participants involved in the promotion of research in marine biotechnology must address the fair and equitable sharing of any commercial exploitation. Carrying out work involving synthetic biology has increased the number of unanswered questions about how operators should manage in order to avoid any threat of being sued for infringements of IP rights or for alleged bio-piracy. This paper, by no means exhaustive in the field, analyzes some of the issues raised on the modification to the landscape in marine biotechnology by the advent of synthetic biology. Such issues indicate how important the collaboration between researchers, industrialists, lawyers is for allowing proper use of marine biotech.

  6. Propagation of climatic events on ocean stratification, marine biology, and CO2: Case studies over the 1979-1999 period

    NASA Astrophysics Data System (ADS)

    Le QuéRé, Corinne; Aumont, Olivier; Monfray, Patrick; Orr, James

    2003-12-01

    We investigate the propagation of climatic events on ocean stratification, marine biology, and CO2 using a large-scale ocean general circulation model coupled to a simple biogeochemical model of plankton dynamics and the carbon cycle. The model was forced with satellite and reanalysis fields during 1979-1999. We focus on three climatic events: (1) the North Atlantic Oscillation, (2) El Niño events, and (3) the Antarctic Circumpolar Wave. Such climatic events caused variability in ocean stratification, approximated by the mixing depth (MD), from ±20 m in the subtropics to ±100 s of meters at high latitudes. In the subtropics, deepening of the MD resupplied nutrient-impoverished surface waters and increased marine biomass by 20-100%. In contrast, at high latitudes, shoaling of the MD lengthened the growing season (i.e., the length of time that light is available for plankton growth) and increased marine biomass by 10-20%. Variability in marine biology reached global peak-to-peak values of ±0.01 mg m-3 for surface chl a, ±3.4 Pg C yr-1 for primary production, and ±0.3 Pg C yr-1 for export production and its contribution to CO2 fluxes. Our model results suggest that changes in ocean stratification driven by short-term climatic events could be used to understand and quantify the feedbacks from marine biology to CO2 and climate.

  7. Oil-derived marine aggregates - hot spots of polysaccharide degradation by specialized bacterial communities

    NASA Astrophysics Data System (ADS)

    Arnosti, Carol; Ziervogel, Kai; Yang, Tingting; Teske, Andreas

    2016-07-01

    Aggregates generated in the laboratory from incubations of seawater and surface-water oil collected in the initial phase of the Deepwater Horizon oil spill resemble the oil-aggregates observed in situ. Here, we investigated the enzyme activities and microbial community composition of laboratory generated oil-aggregates, focusing on the abilities of these communities to degrade polysaccharides, which are major components of marine organic matter and are abundant constituents of exopolymeric substances (EPS) generated by oil-associated bacteria in response to the presence of oil. The patterns of polysaccharide-hydrolyzing enzyme activities in oil aggregates were very different from those in the water surrounding the aggregates after formation, and in the surface water that did not contain the oil. Specific oil aggregate-associated hydrolysis rates were also considerably higher than in the water surrounding the aggregates. The differences in initial hydrolysis profiles, and in evolution of these profiles with time, points to specialized metabolic abilities among the oil-aggregate communities compared to oil-water and ambient water communities. The composition of the oil-aggregate community indicates a multifunctional microbial assemblage containing primary oil-degrading and exopolysaccharide-producing members of the Gammaproteobacteria, and diverse members of the Alphaproteobacteria, Bacteroidetes and Planktomycetales that most likely participate in the breakdown of oil-derived bacterial biopolymers. Formation and aging of oil-aggregates encourages the growth and transformation of microbial communities that are specialized in degradation of petroleum, as well as their secondary degradation products.

  8. Using community-level metrics to monitor the effects of marine protected areas on biodiversity.

    PubMed

    Soykan, Candan U; Lewison, Rebecca L

    2015-06-01

    Marine protected areas (MPAs) are used to protect species, communities, and their associated habitats, among other goals. Measuring MPA efficacy can be challenging, however, particularly when considering responses at the community level. We gathered 36 abundance and 14 biomass data sets on fish assemblages and used meta-analysis to evaluate the ability of 22 distinct community diversity metrics to detect differences in community structure between MPAs and nearby control sites. We also considered the effects of 6 covariates-MPA size and age, MPA size and age interaction, latitude, total species richness, and level of protection-on each metric. Some common metrics, such as species richness and Shannon diversity, did not differ consistently between MPA and control sites, whereas other metrics, such as total abundance and biomass, were consistently different across studies. Metric responses derived from the biomass data sets were more consistent than those based on the abundance data sets, suggesting that community-level biomass differs more predictably than abundance between MPA and control sites. Covariate analyses indicated that level of protection, latitude, MPA size, and the interaction between MPA size and age affect metric performance. These results highlight a handful of metrics, several of which are little known, that could be used to meet the increasing demand for community-level indicators of MPA effectiveness.

  9. Impact of polymer-coated silver nanoparticles on marine microbial communities: a microcosm study.

    PubMed

    Doiron, K; Pelletier, E; Lemarchand, K

    2012-11-15

    The use of silver nanoparticles (AgNPs) in consumer products is increasing drastically and their potential environmental impacts on aquatic organisms from bacterial communities to vertebrates are not well understood. This study reports on changes in marine bacterial richness using denaturing gradient gel electrophoresis (DGGE), and overall community abundance determined by flow cytometry in marine microcosms exposed to polymer-coated AgNPs (20±5 nm) and ionic silver (Ag(+)). Our study clearly demonstrated that at low concentrations (5 and 50 μg L(-1) total silver), un-aggregated polymer-coated AgNPs and dissolved Ag(+) contamination produced similar effects: a longer lag phase suggesting an adaptation period for microorganisms. As richness decreased in the treated samples, this longer lag phase could correspond to the selection of a fraction of the initial community that is insensitive to silver contamination. Polymer-coated AgNPs preserved their bactericidal properties even under the high ionic strength of estuarine waters.

  10. Preparation of microbial community cDNA for metatranscriptomic analysis in marine plankton.

    PubMed

    Stewart, Frank J

    2013-01-01

    High-throughput sequencing and analysis of microbial community cDNA (metatranscriptomics) are providing valuable insight into in situ microbial activity and metabolism in the oceans. A critical first step in metatranscriptomic studies is the preparation of high-quality cDNA. At the minimum, preparing cDNA for sequencing involves steps of biomass collection, RNA preservation, total RNA extraction, and cDNA synthesis. Each of these steps may present unique challenges for marine microbial samples, particularly for deep-sea samples whose transcriptional profiles may change between water collection and RNA preservation. Because bacterioplankton community RNA yields may be relatively low (<500 ng), it is often necessary to amplify total RNA to obtain sufficient cDNA for downstream sequencing. Additionally, depending on the nature of the samples, budgetary considerations, and the choice of sequencing technology, steps may be required to deplete the amount of ribosomal RNA (rRNA) transcripts in a sample in order to maximize mRNA recovery. cDNA preparation may also involve the addition of internal RNA standards to biomass samples, thereby allowing for absolute quantification of transcript abundance following sequencing. This chapter describes a general protocol for cDNA preparation from planktonic microbial communities, from RNA preservation to final cDNA synthesis, with specific emphasis placed on topics of sampling bias and rRNA depletion. Consideration of these topics is critical for helping standardize metatranscriptomics methods as they become widespread in marine microbiology research.

  11. Impact of Roundup on the marine microbial community, as shown by an in situ microcosm experiment.

    PubMed

    Stachowski-Haberkorn, Sabine; Becker, Beatriz; Marie, Dominique; Haberkorn, Hansy; Coroller, Louis; de la Broise, Denis

    2008-09-29

    The effects of the herbicide Roundup (glyphosate) on natural marine microbial communities were assessed in a 7-day field experiment using microcosms. Bottles were maintained underwater at 6m depth, and 10% of their water content was changed every other day. The comparison of control microcosms and surrounding surface water showed that the microcosm system tested here can be considered as representative of the natural surrounding environment. A temporal temperature gradient gel electrophoresis (TTGE) was run on 16S and 18S rDNA-amplified extracts from the whole microbial community. Cluster analysis of the 16S gel showed differences between control and treatment fingerprints for Roundup at 1 microg L(-1) (ANOSIM, p=0.055; R=0.53), and 10 microg L(-1) (ANOSIM, p=0.086; R=0.40). Flow cytometry analysis revealed a significant increase in the prasinophyte-like population when Roundup concentration was increased to 10 microg L(-1). This study demonstrates that a disturbance was caused to the marine microbial community exposed to 1 microg L(-1) Roundup concentration, a value typical of those reported in coastal waters during a run-off event.

  12. A possible CO2 leakage event: Can the marine microbial community be recovered?

    PubMed

    Borrero-Santiago, A R; Bautista-Chamizo, E; DelValls, T Á; Riba, I

    2017-02-12

    Bacterial communities have been studied to a much lesser degree than macrofauna in the case of a CO2 release. The resistance capacity of marine bacteria is well known, but their possible responses and their ability to recover after a CO2 release has not been investigated. Therefore, this work evaluated the responses of a marine bacterial community after 96h of CO2 exposure under diverse pH treatments (7.8 as control without CO2, 7.0, 6.5, and 6.0) and 24h after CO2 exposure. Results showed that the respiration activity and the diversity of the community were affected in all pH treatments. However, after 24h without CO2 enrichment, the respiration activity and diversity increased, showing a partial recovery. Consequently, bacterial responses have the potential to be used as a monitoring tool for risk assessment related to carbon capture and storage techniques or in any similar CO2 enrichment situations.

  13. Marine Biology: Self-Directed Study Units for Grades K-3 and 4-8, Gifted. Easily Adapted for Regular Classroom Use. Zephyr Learning Project.

    ERIC Educational Resources Information Center

    Tanner, Joey

    Originally designed for the gifted student, these reproducible marine biology units emphasize the use of higher order thinking skills and are appropriate for use in any classroom. Interdisciplinary in content, the units provide a broad view of marine biology. Included are two complete units, one created for the upper elementary gifted student and…

  14. Marine Biology: Self-Directed Study Units for Grades K-3 and 4-8, Gifted. Easily Adapted for Regular Classroom Use. Zephyr Learning Project.

    ERIC Educational Resources Information Center

    Tanner, Joey

    Originally designed for the gifted student, these reproducible marine biology units emphasize the use of higher order thinking skills and are appropriate for use in any classroom. Interdisciplinary in content, the units provide a broad view of marine biology. Included are two complete units, one created for the upper elementary gifted student and…

  15. Learning about Marine Biology. Superific Science Book VI. A Good Apple Science Activity Book for Grades 5-8+.

    ERIC Educational Resources Information Center

    Conway, Lorraine

    Based on the assumption that most students have a natural curiosity about the plant and animal life residing in the oceans, this document provides students in grades five through eight with activities in marine biology. The book provides illustrated information and learning activities dealing with: (1) diatoms; (2) the life cycle of the jellyfish;…

  16. Learning about Marine Biology. Superific Science Book VI. A Good Apple Science Activity Book for Grades 5-8+.

    ERIC Educational Resources Information Center

    Conway, Lorraine

    Based on the assumption that most students have a natural curiosity about the plant and animal life residing in the oceans, this document provides students in grades five through eight with activities in marine biology. The book provides illustrated information and learning activities dealing with: (1) diatoms; (2) the life cycle of the jellyfish;…

  17. Ocean Filmmaking Camp @ Duke Marine Lab: Building Community with Ocean Science for a Better World

    NASA Astrophysics Data System (ADS)

    De Oca, M.; Noll, S.

    2016-02-01

    A democratic society requires that its citizens are informed of everyday's global issues. Out of all issues those related to ocean conservation can be hard to grasp for the general public and especially so for disadvantaged racial and ethnic groups. Opportunity-scarce communities generally have more limited access to the ocean and to science literacy programs. The Ocean Filmmaking Camp @ Duke Marine Lab (OFC@DUML) is an effort to address this gap at the level of high school students in a small coastal town. We designed a six-week summer program to nurture the talents of high school students from under-represented communities in North Carolina with training in filmmaking, marine science and conservation. Our science curriculum is especially designed to present the science in a locally and globally-relevant context. Class discussions, field trips and site visits develop the students' cognitive abilities while they learn the value of the natural environment they live in. Through filmmaking students develop their voice and their media literacy, while connecting with their local community, crossing class and racial barriers. By the end of the summer this program succeeds in encouraging students to engage in the democratic process on ocean conservation, climate change and other everyday affairs affecting their local communities. This presentation will cover the guiding principles followed in the design of the program, and how this high impact-low cost program is implemented. In its first year the program was co-directed by a graduate student and a local high school teacher, who managed more than 20 volunteers with a total budget of $1,500. The program's success was featured in the local newspaper and Duke University's Environment Magazine. This program is an example of how ocean science can play a part in building a better world, knitting diverse communities into the fabric of the larger society with engaged and science-literate citizens living rewarding lives.

  18. Recent trends in biological extraction of chitin from marine shell wastes: a review.

    PubMed

    Kaur, Surinder; Dhillon, Gurpreet Singh

    2015-03-01

    The natural biopolymer chitin and its deacetylated product chitosan are widely used in innumerable applications ranging from biomedicine, pharmaceuticals, food, agriculture and personal care products to environmental sector. The abundant and renewable marine processing wastes are commercially exploited for the extraction of chitin. However, the traditional chitin extraction processes employ harsh chemicals at elevated temperatures for a prolonged time which can harm its physico-chemical properties and are also held responsible for the deterioration of environmental health. In view of this, green extraction methods are increasingly gaining popularity due to their environmentally friendly nature. The bioextraction of chitin from crustacean shell wastes has been increasingly researched at the laboratory scale. However, the bioextraction of chitin is not currently exploited to its maximum potential on the commercial level. Bioextraction of chitin is emerging as a green, cleaner, eco-friendly and economical process. Specifically in the chitin extraction, microorganisms-mediated fermentation processes are highly desirable due to easy handling, simplicity, rapidity, controllability through optimization of process parameters, ambient temperature and negligible solvent consumption, thus reducing environmental impact and costs. Although, chitin production from crustacean shell waste through biological means is still at its early stage of development, it is undergoing rapid progress in recent years and showing a promising prospect. Driven by reduced energy, wastewater or solvent, advances in biological extraction of chitin along with valuable by-products will have high economic and environmental impact.

  19. Numerical and experimental hydrodynamic analysis of suction cup bio-logging tag designs for marine mammals

    NASA Astrophysics Data System (ADS)

    Murray, Mark; Shorter, Alex; Howle, Laurens; Johnson, Mark; Moore, Michael

    2012-11-01

    The improvement and miniaturization of sensing technologies has made bio-logging tags, utilized for the study of marine mammal behavior, more practical. These sophisticated sensing packages require a housing which protects the electronics from the environment and provides a means of attachment to the animal. The hydrodynamic forces on these housings can inadvertently remove the tag or adversely affect the behavior or energetics of the animal. A modification to the original design of a suction cup bio-logging tag housing was desired to minimize the adverse forces. In this work, hydrodynamic loading of two suction cup tag designs, original and modified designs, were analyzed using computational fluid dynamics (CFD) models and validated experimentally. Overall, the simulation and experimental results demonstrated that a tag housing that minimized geometric disruptions to the flow reduced drag forces, and that a tag housing with a small frontal cross-sectional area close to the attachment surface reduced lift forces. Preliminary results from experimental work with a common dolphin cadaver indicates that the suction cups used to attach the tags to the animal provide sufficient attachment force to resist failure at predicted drag and lift forces in 10 m/s flow.

  20. Reproductive biology of two marine catfishes (Siluriformes, Ariidae) in the Sepetiba Bay, Brazil.

    PubMed

    Gomes, Iracema David; Araújo, Francisco Gerson

    2004-03-01

    Marine catfish are abundant in the Sepetiba Bay, a 305 km2 area in Southeast Brazilian coast (Lat. 22 degrees 54' - 23 degrees 04' S: Long. 43 degrees 44' - 44 degrees 10' W), but the knowledge on their biology is still scanty. The reproductive biology of Sciadeichthys luniscutis (Valenciennes 1840) and Genidens genidens (Valenciennes 1839) was studied through monthly sampling, from October 1998 to September 1999. Fishes were caught with a standardized otter trawl, in the interior of Sepetiba Bay, and near to the confluence with a major freshwater contributor. Six gonadal stages were described, based on macroscopic observations of gonad form, size, weight, color and oocyte diameter, and microscopic observations of differences in size and staining in the nucleus and cytoplasm structures, as viewed through a light microscope. Changes in the gonadosomatic index (GSI) and in stages of gonadal development showed what S. luniscutis spawned in Spring, while G. genidens spawned in Summer. Total spawning was shown for both species as indicated by high concentration of post-ovulatory follicles in spent stages. Fecundity was low (14-38 vitellogenic oocytes for S. luniscutis and 6-24 for G. genidens). when compared with other teleosts. Low fecundity and separation in spawning period suggest that both species are k-strategist, able to avoid interspecific competition in early stages of life cycle to optimize the use of the available niche.

  1. Temporal Stability of the Microbial Community in Sewage-Polluted Seawater Exposed to Natural Sunlight Cycles and Marine Microbiota

    PubMed Central

    Sassoubre, Lauren M.; Yamahara, Kevan M.

    2015-01-01

    Billions of gallons of untreated wastewater enter the coastal ocean each year. Once sewage microorganisms are in the marine environment, they are exposed to environmental stressors, such as sunlight and predation. Previous research has investigated the fate of individual sewage microorganisms in seawater but not the entire sewage microbial community. The present study used next-generation sequencing (NGS) to examine how the microbial community in sewage-impacted seawater changes over 48 h when exposed to natural sunlight cycles and marine microbiota. We compared the results from microcosms composed of unfiltered seawater (containing naturally occurring marine microbiota) and filtered seawater (containing no marine microbiota) to investigate the effect of marine microbiota. We also compared the results from microcosms that were exposed to natural sunlight cycles with those from microcosms kept in the dark to investigate the effect of sunlight. The microbial community composition and the relative abundance of operational taxonomic units (OTUs) changed over 48 h in all microcosms. Exposure to sunlight had a significant effect on both community composition and OTU abundance. The effect of marine microbiota, however, was minimal. The proportion of sewage-derived microorganisms present in the microcosms decreased rapidly within 48 h, and the decrease was the most pronounced in the presence of both sunlight and marine microbiota, where the proportion decreased from 85% to 3% of the total microbial community. The results from this study demonstrate the strong effect that sunlight has on microbial community composition, as measured by NGS, and the importance of considering temporal effects in future applications of NGS to identify microbial pollution sources. PMID:25576619

  2. Temporal stability of the microbial community in sewage-polluted seawater exposed to natural sunlight cycles and marine microbiota.

    PubMed

    Sassoubre, Lauren M; Yamahara, Kevan M; Boehm, Alexandria B

    2015-03-01

    Billions of gallons of untreated wastewater enter the coastal ocean each year. Once sewage microorganisms are in the marine environment, they are exposed to environmental stressors, such as sunlight and predation. Previous research has investigated the fate of individual sewage microorganisms in seawater but not the entire sewage microbial community. The present study used next-generation sequencing (NGS) to examine how the microbial community in sewage-impacted seawater changes over 48 h when exposed to natural sunlight cycles and marine microbiota. We compared the results from microcosms composed of unfiltered seawater (containing naturally occurring marine microbiota) and filtered seawater (containing no marine microbiota) to investigate the effect of marine microbiota. We also compared the results from microcosms that were exposed to natural sunlight cycles with those from microcosms kept in the dark to investigate the effect of sunlight. The microbial community composition and the relative abundance of operational taxonomic units (OTUs) changed over 48 h in all microcosms. Exposure to sunlight had a significant effect on both community composition and OTU abundance. The effect of marine microbiota, however, was minimal. The proportion of sewage-derived microorganisms present in the microcosms decreased rapidly within 48 h, and the decrease was the most pronounced in the presence of both sunlight and marine microbiota, where the proportion decreased from 85% to 3% of the total microbial community. The results from this study demonstrate the strong effect that sunlight has on microbial community composition, as measured by NGS, and the importance of considering temporal effects in future applications of NGS to identify microbial pollution sources.

  3. Community-driven computational biology with Debian Linux.

    PubMed

    Möller, Steffen; Krabbenhöft, Hajo Nils; Tille, Andreas; Paleino, David; Williams, Alan; Wolstencroft, Katy; Goble, Carole; Holland, Richard; Belhachemi, Dominique; Plessy, Charles

    2010-12-21

    The Open Source movement and its technologies are popular in the bioinformatics community because they provide freely available tools and resources for research. In order to feed the steady demand for updates on software and associated data, a service infrastructure is required for sharing and providing these tools to heterogeneous computing environments. The Debian Med initiative provides ready and coherent software packages for medical informatics and bioinformatics. These packages can be used together in Taverna workflows via the UseCase plugin to manage execution on local or remote machines. If such packages are available in cloud computing environments, the underlying hardware and the analysis pipelines can be shared along with the software. Debian Med closes the gap between developers and users. It provides a simple method for offering new releases of software and data resources, thus provisioning a local infrastructure for computational biology. For geographically distributed teams it can ensure they are working on the same versions of tools, in the same conditions. This contributes to the world-wide networking of researchers.

  4. Community-driven computational biology with Debian Linux

    PubMed Central

    2010-01-01

    Background The Open Source movement and its technologies are popular in the bioinformatics community because they provide freely available tools and resources for research. In order to feed the steady demand for updates on software and associated data, a service infrastructure is required for sharing and providing these tools to heterogeneous computing environments. Results The Debian Med initiative provides ready and coherent software packages for medical informatics and bioinformatics. These packages can be used together in Taverna workflows via the UseCase plugin to manage execution on local or remote machines. If such packages are available in cloud computing environments, the underlying hardware and the analysis pipelines can be shared along with the software. Conclusions Debian Med closes the gap between developers and users. It provides a simple method for offering new releases of software and data resources, thus provisioning a local infrastructure for computational biology. For geographically distributed teams it can ensure they are working on the same versions of tools, in the same conditions. This contributes to the world-wide networking of researchers. PMID:21210984

  5. The bacterial community structure of hydrocarbon-polluted marine environments as the basis for the definition of an ecological index of hydrocarbon exposure.

    PubMed

    Lozada, Mariana; Marcos, Magalí S; Commendatore, Marta G; Gil, Mónica N; Dionisi, Hebe M

    2014-09-17

    The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities.

  6. The Bacterial Community Structure of Hydrocarbon-Polluted Marine Environments as the Basis for the Definition of an Ecological Index of Hydrocarbon Exposure

    PubMed Central

    Lozada, Mariana; Marcos, Magalí S.; Commendatore, Marta G.; Gil, Mónica N.; Dionisi, Hebe M.

    2014-01-01

    The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities. PMID:24964812

  7. Marine bacterial community structure resilience to changes in protist predation under phytoplankton bloom conditions.

    PubMed

    Baltar, Federico; Palovaara, Joakim; Unrein, Fernando; Catala, Philippe; Horňák, Karel; Šimek, Karel; Vaqué, Dolors; Massana, Ramon; Gasol, Josep M; Pinhassi, Jarone

    2016-03-01

    To test whether protist grazing selectively affects the composition of aquatic bacterial communities, we combined high-throughput sequencing to determine bacterial community composition with analyses of grazing rates, protist and bacterial abundances and bacterial cell sizes and physiological states in a mesocosm experiment in which nutrients were added to stimulate a phytoplankton bloom. A large variability was observed in the abundances of bacteria (from 0.7 to 2.4 × 10(6) cells per ml), heterotrophic nanoflagellates (from 0.063 to 2.7 × 10(4) cells per ml) and ciliates (from 100 to 3000 cells per l) during the experiment (∼3-, 45- and 30-fold, respectively), as well as in bulk grazing rates (from 1 to 13 × 10(6) bacteria per ml per day) and bacterial production (from 3 to 379 μg per C l per day) (1 and 2 orders of magnitude, respectively). However, these strong changes in predation pressure did not induce comparable responses in bacterial community composition, indicating that bacterial community structure was resilient to changes in protist predation pressure. Overall, our results indicate that peaks in protist predation (at least those associated with phytoplankton blooms) do not necessarily trigger substantial changes in the composition of coastal marine bacterioplankton communities.

  8. Competition and facilitation between the marine nitrogen-fixing cyanobacterium Cyanothece and its associated bacterial community.

    PubMed

    Brauer, Verena S; Stomp, Maayke; Bouvier, Thierry; Fouilland, Eric; Leboulanger, Christophe; Confurius-Guns, Veronique; Weissing, Franz J; Stal, LucasJ; Huisman, Jef

    2014-01-01

    N2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N2-fixing cyanobacterium Cyanothece sp. Miami BG043511 and its associated free-living chemotrophic bacteria at different concentrations of nitrate and dissolved organic carbon and different temperatures. High temperature strongly stimulated the growth of Cyanothece, but had less effect on the growth and community composition of the chemotrophic bacteria. Conversely, nitrate and carbon addition did not significantly increase the abundance of Cyanothece, but strongly affected the abundance and species composition of the associated chemotrophic bacteria. In nitrate-free medium the associated bacterial community was co-dominated by the putative diazotroph Mesorhizobium and the putative aerobic anoxygenic phototroph Erythrobacter and after addition of organic carbon also by the Flavobacterium Muricauda. Addition of nitrate shifted the composition toward co-dominance by Erythrobacter and the Gammaproteobacterium Marinobacter. Our results indicate that Cyanothece modified the species composition of its associated bacteria through a combination of competition and facilitation. Furthermore, within the bacterial community, niche differentiation appeared to play an important role, contributing to the coexistence of a variety of different functional groups. An important implication of these findings is that changes in nitrogen and carbon availability due to, e.g., eutrophication and climate change are likely to have a major impact on the species composition of the bacterial community associated with N2-fixing cyanobacteria.

  9. The role of habitat heterogeneity in structuring the community of intertidal free-living marine nematodes.

    PubMed

    Gingold, Ruth; Mundo-Ocampo, Manuel; Holovachov, Oleksandr; Rocha-Olivares, Axayácatl

    2010-01-01

    The role of habitat complexity has been widely neglected in the study of meiofaunal community patterns. We studied the intertidal nematode community of a structurally complex macrotidal beach exhibiting contrasting microhabitats (sandbars and runnels) to understand the influence of environmental gradients and habitat heterogeneity in the community structure. We tested whether topographical complexity affected (1) the zonation pattern in terms of abundance and diversity, and (2) local diversity by promoting compartmentalization into distinct faunal groups. Our analyses revealed three major faunal assemblages along the exposure gradient associated to differences in mean grain size and chlorophyll a. Diversity patterns involved a mid-intertidal peak, consistent with the intermediate disturbance hypothesis, and another peak at the limit with the subtidal region, consistent with the transition zone. These results highlight the predominance of environmental gradients in establishing intertidal zonation. However, microhabitats differed in environmental conditions and possessed significantly distinct nematofaunal communities. Runnels featured higher levels of taxonomic and functional diversity, many unique genera, and the community differed from the assemblage at the limit to the subtidal, stressing their role as distinct microhabitats. The nematofauna of the structurally complex beach was more diverse than the one from a homogeneous beach nearby, supporting the hypothesis that structural heterogeneity promotes diversity by compartmentalization and highlighting the importance of microhabitats in the assessment of biodiversity. Contrary to previous predictions, our results indicate potentially high regional marine nematode diversity in the Upper Gulf of California.

  10. Seasonal and spatial diversity of microbial communities in marine sediments of the South China Sea.

    PubMed

    Du, Jikun; Xiao, Kai; Huang, Yali; Li, Huixian; Tan, Hongming; Cao, Lixiang; Lu, Yongjun; Zhou, Shining

    2011-10-01

    This study was conducted to characterize the diversity of microbial communities in marine sediments of the South China Sea by means of 16S rRNA gene clone libraries. The results revealed that the sediment samples collected in summer harboured a more diverse microbial community than that collected in winter, Deltaproteobacteria dominated 16S rRNA gene clone libraries from both seasons, followed by Gammaproteobacteria, Acidobacteria, Nitrospirae, Planctomycetes, Firmicutes. Archaea phylotypes were also found. The majority of clone sequences shared greatest similarity to uncultured organisms, mainly from hydrothermal sediments and cold seep sediments. In addition, the sedimentary microbial communities in the coastal sea appears to be much more diverse than that of the open sea. A spatial pattern in the sediment samples was observed that the sediment samples collected from the coastal sea and the open sea clustered separately, a novel microbial community dominated the open sea. The data indicate that changes in environmental conditions are accompanied by significant variations in diversity of microbial communities at the South China Sea.

  11. Invasion rates increase with species richness in a marine epibenthic community by two mechanisms.

    PubMed

    Dunstan, Piers K; Johnson, Craig R

    2004-01-01

    It is widely believed that, when extrinsic conditions are similar, the likelihood of species invading established assemblages decreases with increasing species richness of the recipient community. Here we show that, for a sessile marine invertebrate community, invasion of patches increases with richness of the patch. We show that invasions can increase with local species richness by two distinct mechanisms. In the first, opportunistic colonisers with traits typical of invasive species colonise species-rich patches at higher rates because speciose patches are dominated by small colonies and mortality rates of small colonies are greater than that of large ones. Thus, mortality provides bare space for opportunists to colonise more frequently in species-rich patches. In the second, some species avoid colonising open areas of free space but preferentially associate with established colonies of particular other species, and a given preferred associate is more likely to occur in species-rich than in species-poor patches. These patterns are the result of particular properties of individual species and local species dynamics, and show that reduced risk of invasion is not necessarily an intrinsic property of species-rich communities. We conclude that resistance to invasion will be determined by the properties of the particular component species and emergent dynamics of the recipient community, and not by an aggregate community property such as richness.

  12. Marine bacterial community structure resilience to changes in protist predation under phytoplankton bloom conditions

    PubMed Central

    Baltar, Federico; Palovaara, Joakim; Unrein, Fernando; Catala, Philippe; Horňák, Karel; Šimek, Karel; Vaqué, Dolors; Massana, Ramon; Gasol, Josep M; Pinhassi, Jarone

    2016-01-01

    To test whether protist grazing selectively affects the composition of aquatic bacterial communities, we combined high-throughput sequencing to determine bacterial community composition with analyses of grazing rates, protist and bacterial abundances and bacterial cell sizes and physiological states in a mesocosm experiment in which nutrients were added to stimulate a phytoplankton bloom. A large variability was observed in the abundances of bacteria (from 0.7 to 2.4 × 106 cells per ml), heterotrophic nanoflagellates (from 0.063 to 2.7 × 104 cells per ml) and ciliates (from 100 to 3000 cells per l) during the experiment (∼3-, 45- and 30-fold, respectively), as well as in bulk grazing rates (from 1 to 13 × 106 bacteria per ml per day) and bacterial production (from 3 to 379 μg per C l per day) (1 and 2 orders of magnitude, respectively). However, these strong changes in predation pressure did not induce comparable responses in bacterial community composition, indicating that bacterial community structure was resilient to changes in protist predation pressure. Overall, our results indicate that peaks in protist predation (at least those associated with phytoplankton blooms) do not necessarily trigger substantial changes in the composition of coastal marine bacterioplankton communities. PMID:26262814

  13. Identification of Carbohydrate Metabolism Genes in the Metagenome of a Marine Biofilm Community Shown to Be Dominated by Gammaproteobacteria, Bacteroidetes

    PubMed Central

    Edwards, Jennifer L.; Smith, Darren L.; Connolly, John; McDonald, James E.; Cox, Michael J.; Joint, Ian; Edwards, Clive; McCarthy, Alan J.

    2010-01-01

    Polysaccharides are an important source of organic carbon in the marine environment, degradation of the insoluble, globally abundant cellulose is a major component of the marine carbon cycle. Although a number of species of cultured bacteria are known to degrade crystalline cellulose, little is known of the polysaccharide hydrolases expressed by cellulose-degrading microbial communities, particularly in the marine environment. Next generation 454 Pyrosequencing was applied to analyze the microbial community that colonizes, degrades insoluble polysaccharides in situ in the Irish Sea. The bioinformatics tool MG-RAST was used to examine the randomly sampled data for taxonomic markers, functional genes,, showed that the community was dominated by members of the Gammaproteobacteria, Bacteroidetes. Furthermore, the identification of 211 gene sequences matched to a custom-made database comprising the members of nine glycoside hydrolase families revealed an extensive repertoire of functional genes predicted to be involved in cellulose utilization. This demonstrates that the use of an in situ cellulose baiting method yielded a marine microbial metagenome considerably enriched in functional genes involved in polysaccharide degradation. The research reported here is the first designed to specifically address the bacterial communities that colonize, degrade cellulose in the marine environment, to evaluate the glycoside hydrolase (cellulase, chitinase) gene repertoire of that community, in the absence of the biases associated with PCR-based molecular techniques. PMID:24710093

  14. Fungal communities from methane hydrate-bearing deep-sea marine sediments in South China Sea.

    PubMed

    Lai, Xintian; Cao, Lixiang; Tan, Hongming; Fang, Shu; Huang, Yali; Zhou, Shining

    2007-12-01

    To elucidate fungal diversity in methane hydrate-bearing deep-sea marine sediments in the South China Sea, internal transcribed spacer (ITS) regions of rRNA genes from five different sediment DNA samples were amplified and phylogenetically analyzed. Total five ITS libraries were constructed and 413 clones selected randomly were grouped into 24 restriction patterns by Amplified Ribosomal DNA Restriction Analysis (ARDRA). ITS sequences of 44 representative clones were determined and compared with the GenBank database using gapped-BLAST. The phylogenetic analysis showed that the ITS sequences (71-97% similarity) were similar to those of Phoma, Lodderomyces, Malassezia, Cryptococcus, Cylindrocarpon, Hortaea, Pichia, Aspergillus and Candida. The remaining sequences were not associated to any known fungi or fungal sequences in the public database. The results suggested that methane hydrate-bearing deep-sea marine sediments harbor diverse fungi. This is the first report on fungal communities from methane hydrate-bearing deep-sea marine sediments in South China Sea.

  15. Protection Enhances Community and Habitat Stability: Evidence from a Mediterranean Marine Protected Area

    PubMed Central

    Fraschetti, Simonetta; Guarnieri, Giuseppe; Bevilacqua, Stanislao; Terlizzi, Antonio; Boero, Ferdinando

    2013-01-01

    Rare evidences support that Marine Protected Areas (MPAs) enhance the stability of marine habitats and assemblages. Based on nine years of observation (2001–2009) inside and outside a well managed MPA, we assessed the potential of conservation and management actions to modify patterns of spatial and/or temporal variability of Posidonia oceanica meadows, the lower midlittoral and the shallow infralittoral rock assemblages. Significant differences in both temporal variations and spatial patterns were observed between protected and unprotected locations. A lower temporal variability in the protected vs. unprotected assemblages was found in the shallow infralittoral, demonstrating that, at least at local scale, protection can enhance community stability. Macrobenthos with long-lived and relatively slow-growing invertebrates and structurally complex algal forms were homogeneously distributed in space and went through little fluctuations in time. In contrast, a mosaic of disturbed patches featured unprotected locations, with small-scale shifts from macroalgal stands to barrens, and harsh temporal variations between the two states. Opposite patterns of spatial and temporal variability were found for the midlittoral assemblages. Despite an overall clear pattern of seagrass regression through time, protected meadows showed a significantly higher shoot density than unprotected ones, suggesting a higher resistance to local human activities. Our results support the assumption that the exclusion/management of human activities within MPAs enhance the stability of the structural components of protected marine systems, reverting or arresting threat-induced trajectories of change. PMID:24349135

  16. Trace elements at the intersection of marine biological and geochemical evolution

    USGS Publications Warehouse

    Robbins, Leslie J.; Lalonde, Stefan V.; Planavsky, Noah J.; Partin, Camille A.; Reinhard, Christopher T.; Kendall, Brian; Scott, Clinton T.; Hardisty, Dalton S.; Gill, Benjamin C.; Alessi, Daniel S.; Dupont, Christopher L.; Saito, Mak A.; Crowe, Sean A.; Poulton, Simon W.; Bekker, Andrey; Lyons, Timothy W.; Konhauser, Kurt O.

    2016-01-01

    Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies.

  17. Overview on Biological Activities and Molecular Characteristics of Sulfated Polysaccharides from Marine Green Algae in Recent Years

    PubMed Central

    Wang, Lingchong; Wang, Xiangyu; Wu, Hao; Liu, Rui

    2014-01-01

    Among the three main divisions of marine macroalgae (Chlorophyta, Phaeophyta and Rhodophyta), marine green algae are valuable sources of structurally diverse bioactive compounds and remain largely unexploited in nutraceutical and pharmaceutical areas. Recently, a great deal of interest has been developed to isolate novel sulfated polysaccharides (SPs) from marine green algae because of their numerous health beneficial effects. Green seaweeds are known to synthesize large quantities of SPs and are well established sources of these particularly interesting molecules such as ulvans from Ulva and Enteromorpha, sulfated rhamnans from Monostroma, sulfated arabinogalactans from Codium, sulfated galacotans from Caulerpa, and some special sulfated mannans from different species. These SPs exhibit many beneficial biological activities such as anticoagulant, antiviral, antioxidative, antitumor, immunomodulating, antihyperlipidemic and antihepatotoxic activities. Therefore, marine algae derived SPs have great potential for further development as healthy food and medical products. The present review focuses on SPs derived from marine green algae and presents an overview of the recent progress of determinations of their structural types and biological activities, especially their potential health benefits. PMID:25257786

  18. Overview on biological activities and molecular characteristics of sulfated polysaccharides from marine green algae in recent years.

    PubMed

    Wang, Lingchong; Wang, Xiangyu; Wu, Hao; Liu, Rui

    2014-09-25

    Among the three main divisions of marine macroalgae (Chlorophyta, Phaeophyta and Rhodophyta), marine green algae are valuable sources of structurally diverse bioactive compounds and remain largely unexploited in nutraceutical and pharmaceutical areas. Recently, a great deal of interest has been developed to isolate novel sulfated polysaccharides (SPs) from marine green algae because of their numerous health beneficial effects. Green seaweeds are known to synthesize large quantities of SPs and are well established sources of these particularly interesting molecules such as ulvans from Ulva and Enteromorpha, sulfated rhamnans from Monostroma, sulfated arabinogalactans from Codium, sulfated galacotans from Caulerpa, and some special sulfated mannans from different species. These SPs exhibit many beneficial biological activities such as anticoagulant, antiviral, antioxidative, antitumor, immunomodulating, antihyperlipidemic and antihepatotoxic activities. Therefore, marine algae derived SPs have great potential for further development as healthy food and medical products. The present review focuses on SPs derived from marine green algae and presents an overview of the recent progress of determinations of their structural types and biological activities, especially their potential health benefits.

  19. The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts

    PubMed Central

    Vergés, Adriana; Steinberg, Peter D.; Hay, Mark E.; Poore, Alistair G. B.; Campbell, Alexandra H.; Ballesteros, Enric; Heck, Kenneth L.; Booth, David J.; Coleman, Melinda A.; Feary, David A.; Figueira, Will; Langlois, Tim; Marzinelli, Ezequiel M.; Mizerek, Toni; Mumby, Peter J.; Nakamura, Yohei; Roughan, Moninya; van Sebille, Erik; Gupta, Alex Sen; Smale, Dan A.; Tomas, Fiona; Wernberg, Thomas; Wilson, Shaun K.

    2014-01-01

    Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to ‘barrens’ when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs. PMID:25009065

  20. The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts.

    PubMed

    Vergés, Adriana; Steinberg, Peter D; Hay, Mark E; Poore, Alistair G B; Campbell, Alexandra H; Ballesteros, Enric; Heck, Kenneth L; Booth, David J; Coleman, Melinda A; Feary, David A; Figueira, Will; Langlois, Tim; Marzinelli, Ezequiel M; Mizerek, Toni; Mumby, Peter J; Nakamura, Yohei; Roughan, Moninya; van Sebille, Erik; Gupta, Alex Sen; Smale, Dan A; Tomas, Fiona; Wernberg, Thomas; Wilson, Shaun K

    2014-08-22

    Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to 'barrens' when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs.

  1. Effects of marine reserves versus nursery habitat availability on structure of reef fish communities.

    PubMed

    Nagelkerken, Ivan; Grol, Monique G G; Mumby, Peter J

    2012-01-01

    No-take marine fishery reserves sustain commercial stocks by acting as buffers against overexploitation and enhancing fishery catches in adjacent areas through spillover. Likewise, nursery habitats such as mangroves enhance populations of some species in adjacent habitats. However, there is lack of understanding of the magnitude of stock enhancement and the effects on community structure when both protection from fishing and access to nurseries concurrently act as drivers of fish population dynamics. In this study we test the separate as well as interactive effects of marine reserves and nursery habitat proximity on structure and abundance of coral reef fish communities. Reserves had no effect on fish community composition, while proximity to nursery habitat only had a significant effect on community structure of species that use mangroves or seagrass beds as nurseries. In terms of reef fish biomass, proximity to nursery habitat by far outweighed (biomass 249% higher than that in areas with no nursery access) the effects of protection from fishing in reserves (biomass 21% lower than non-reserve areas) for small nursery fish (≤ 25 cm total length). For large-bodied individuals of nursery species (>25 cm total length), an additive effect was present for these two factors, although fish benefited more from fishing protection (203% higher biomass) than from proximity to nurseries (139% higher). The magnitude of elevated biomass for small fish on coral reefs due to proximity to nurseries was such that nursery habitats seem able to overrule the usually positive effects on fish biomass by reef reserves. As a result, conservation of nursery habitats gains importance and more consideration should be given to the ecological processes that occur along nursery-reef boundaries that connect neighboring ecosystems.

  2. The influence of the biological pump on ocean chemistry: implications for long-term trends in marine redox chemistry, the global carbon cycle, and marine animal ecosystems.

    PubMed

    Meyer, K M; Ridgwell, A; Payne, J L

    2016-05-01

    The net export of organic matter from the surface ocean and its respiration at depth create vertical gradients in nutrient and oxygen availability that play a primary role in structuring marine ecosystems. Changes in the properties of this 'biological pump' have been hypothesized to account for important shifts in marine ecosystem structure, including the Cambrian explosion. However, the influence of variation in the behavior of the biological pump on ocean biogeochemistry remains poorly quantified, preventing any detailed exploration of how changes in the biological pump over geological time may have shaped long-term shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure. Here, we use a 3-dimensional Earth system model of intermediate complexity to quantitatively explore the effects of the biological pump on marine chemistry. We find that when respiration of sinking organic matter is efficient, due to slower sinking or higher respiration rates, anoxia tends to be more prevalent and to occur in shallower waters. Consequently, the Phanerozoic trend toward less bottom-water anoxia in continental shelf settings can potentially be explained by a change in the spatial dynamics of nutrient cycling rather than by any change in the ocean phosphate inventory. The model results further suggest that the Phanerozoic decline in the prevalence ocean anoxia is, in part, a consequence of the evolution of larger phytoplankton, many of which produce mineralized tests. We hypothesize that the Phanerozoic trend toward greater animal abundance and metabolic demand was driven more by increased oxygen concentrations in shelf environments than by greater food (nutrient) availability. In fact, a lower-than-modern ocean phosphate inventory in our closed system model is unable to account for the Paleozoic prevalence of bottom-water anoxia. Overall, these model simulations suggest that the changing spatial distribution of photosynthesis and respiration in the oceans has

  3. Predicting the offshore distribution and abundance of marine birds with a hierarchical community distance sampling model.

    PubMed

    Goyert, Holly F; Gardner, Beth; Sollmann, Rahel; Veit, Richard R; Gilbert, Andrew T; Connelly, Emily E; Williams, Kathryn A

    2016-09-01

    Proposed offshore wind energy development on the Atlantic Outer Continental Shelf has brought attention to the need for baseline studies of the distribution and abundance of marine birds. We compiled line transect data from 15 shipboard surveys (June 2012-April 2014), along with associated remotely sensed habitat data, in the lower Mid-Atlantic Bight off the coast of Delaware, Maryland, and Virginia, USA. We implemented a recently developed hierarchical community distance sampling model to estimate the seasonal abundance of 40 observed marine bird species. Treating each season separately, we included six oceanographic parameters to estimate seabird abundance: three static (distance to shore, slope, sediment grain size) and three dynamic covariates (sea surface temperature [SST], salinity, primary productivity). We expected that avian bottom-feeders would respond primarily to static covariates that characterize seafloor variability, and that surface-feeders would respond more to dynamic covariates that quantify surface productivity. We compared the variation in species-specific and community-level responses to these habitat features, including for rare species, and we predicted species abundance across the study area. While several protected species used the study area in summer during their breeding season, estimated abundance and observed diversity were highest for nonbreeding species in winter. Distance to shore was the most common significant predictor of abundance, and thus useful in estimating the potential exposure of marine birds to offshore development. In many cases, our expectations based on feeding ecology were confirmed, such as in the first winter season, when bottom-feeders associated significantly with the three static covariates (distance to shore, slope, and sediment grain size), and surface-feeders associated significantly with two dynamic covariates (SST, primary productivity). However, other cases revealed significant relationships between

  4. High Risk Behaviors in Marine Mammals: Linking Behavioral Responses to Anthropogenic Disturbance to Biological Consequences

    DTIC Science & Technology

    2014-09-30

    improving the protection of marine mammals during naval operations. OBJECTIVES We are testing the hypothesis that extreme behaviors requiring...arrhythmias and physiological instability in diving marine mammals . Specifically, we will determine which factors or combination of factors act as the primary...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. High Risk Behaviors in Marine Mammals : Linking

  5. Is benthic food web structure related to diversity of marine macrobenthic communities?

    NASA Astrophysics Data System (ADS)

    Sokołowski, A.; Wołowicz, M.; Asmus, H.; Asmus, R.; Carlier, A.; Gasiunaité, Z.; Grémare, A.; Hummel, H.; Lesutiené, J.; Razinkovas, A.; Renaud, P. E.; Richard, P.; Kędra, M.

    2012-08-01

    Numerical structure and the organisation of food webs within macrozoobenthic communities has been assessed in the European waters (Svalbard, Barents Sea, Baltic Sea, North Sea, Atlantic Ocean and the Mediterranean Sea) to address the interactions between biodiversity and ecosystem functioning. Abundance and classical species diversity indices (S, H', J) of macrofaunal communities were related to principal attributes of food webs (relative trophic level and food chain length, FCL) that were determined from carbon and nitrogen stable isotope values. Structure of marine macrobenthos varies substantially at a geographical scale; total abundance ranges from 63 ind. m-2 to 34,517 ind. m-2, species richness varies from 3 to 166 and the Shannon-Weaver diversity index from 0.26 to 3.26 while Pielou's evenness index is below 0.73. The major source of energy for macrobenthic communities is suspended particulate organic matter, consisting of phytoplankton and detrital particles, sediment particulate organic matter, and microphytobenthos in varying proportions. These food sources support the presence of suspension- and deposit-feeding communities, which dominate numerically on the sea floor. Benthic food webs include usually four to five trophic levels (FCL varies from 3.08 to 4.86). Most species are assigned to the second trophic level (primary consumers), fewer species are grouped in the third trophic level (secondary consumers), and benthic top predators are the least numerous. Most species cluster primarily at the lowest trophic level that is consistent with the typical organization of pyramidal food webs. Food chain length increases with biodiversity, highlighting a positive effect of more complex community structure on food web organisation. In more diverse benthic communities, energy is transferred through more trophic levels while species-poor communities sustain a shorter food chain.

  6. Assessing the complex sponge microbiota: core, variable and species-specific bacterial communities in marine sponges.

    PubMed

    Schmitt, Susanne; Tsai, Peter; Bell, James; Fromont, Jane; Ilan, Micha; Lindquist, Niels; Perez, Thierry; Rodrigo, Allen; Schupp, Peter J; Vacelet, Jean; Webster, Nicole; Hentschel, Ute; Taylor, Michael W

    2012-03-01

    Marine sponges are well known for their associations with highly diverse, yet very specific and often highly similar microbiota. The aim of this study was to identify potential bacterial sub-populations in relation to sponge phylogeny and sampling sites and to define the core bacterial community. 16S ribosomal RNA gene amplicon pyrosequencing was applied to 32 sponge species from eight locations around the world's oceans, thereby generating 2567 operational taxonomic units (OTUs at the 97% sequence similarity level) in total and up to 364 different OTUs per sponge species. The taxonomic richness detected in this study comprised 25 bacterial phyla with Proteobacteria, Chloroflexi and Poribacteria being most diverse in sponges. Among these phyla were nine candidate phyla, six of them found for the first time in sponges. Similarity comparison of bacterial communities revealed no correlation with host phylogeny but a tropical sub-population in that tropical sponges have more similar bacterial communities to each other than to subtropical sponges. A minimal core bacterial community consisting of very few OTUs (97%, 95% and 90%) was found. These microbes have a global distribution and are probably acquired via environmental transmission. In contrast, a large species-specific bacterial community was detected, which is represented by OTUs present in only a single sponge species. The species-specific bacterial community is probably mainly vertically transmitted. It is proposed that different sponges contain different bacterial species, however, these bacteria are still closely related to each other explaining the observed similarity of bacterial communities in sponges in this and previous studies. This global analysis represents the most comprehensive study of bacterial symbionts in sponges to date and provides novel insights into the complex structure of these unique associations.

  7. Marine Subsurface Microbial Community Shifts Across a Hydrothermal Gradient in Okinawa Trough Sediments

    PubMed Central

    2016-01-01

    Sediments within the Okinawa back-arc basin overlay a subsurface hydrothermal network, creating intense temperature gradients with sediment depth and potential limits for microbial diversity. We investigated taxonomic changes across 45 m of recovered core with a temperature gradient of 3°C/m from the dynamic Iheya North Hydrothermal System. The interval transitions sharply from low-temperature marine mud to hydrothermally altered clay at 10 meters below seafloor (mbsf). Here, we present taxonomic results from an analysis of the 16S rRNA gene that support a conceptual model in which common marine subsurface taxa persist into the subsurface, while high temperature adapted archaeal taxa show localized peaks in abundances in the hydrothermal clay horizons. Specifically, the bacterial phylum Chloroflexi accounts for a major proportion of the total microbial community within the upper 10 mbsf, whereas high temperature archaea (Terrestrial Hot Spring Crenarchaeotic Group and methanotrophic archaea) appear in varying local abundances in deeper, hydrothermal clay horizons with higher in situ temperatures (up to 55°C, 15 mbsf). In addition, geochemical evidence suggests that methanotrophy may be occurring in various horizons. There is also relict DNA (i.e., DNA preserved after cell death) that persists in horizons where the conditions suitable for microbial communities have ceased. PMID:28096736

  8. Marine Subsurface Microbial Community Shifts Across a Hydrothermal Gradient in Okinawa Trough Sediments.

    PubMed

    Brandt, Leah D; House, Christopher H

    2016-01-01

    Sediments within the Okinawa back-arc basin overlay a subsurface hydrothermal network, creating intense temperature gradients with sediment depth and potential limits for microbial diversity. We investigated taxonomic changes across 45 m of recovered core with a temperature gradient of 3°C/m from the dynamic Iheya North Hydrothermal System. The interval transitions sharply from low-temperature marine mud to hydrothermally altered clay at 10 meters below seafloor (mbsf). Here, we present taxonomic results from an analysis of the 16S rRNA gene that support a conceptual model in which common marine subsurface taxa persist into the subsurface, while high temperature adapted archaeal taxa show localized peaks in abundances in the hydrothermal clay horizons. Specifically, the bacterial phylum Chloroflexi accounts for a major proportion of the total microbial community within the upper 10 mbsf, whereas high temperature archaea (Terrestrial Hot Spring Crenarchaeotic Group and methanotrophic archaea) appear in varying local abundances in deeper, hydrothermal clay horizons with higher in situ temperatures (up to 55°C, 15 mbsf). In addition, geochemical evidence suggests that methanotrophy may be occurring in various horizons. There is also relict DNA (i.e., DNA preserved after cell death) that persists in horizons where the conditions suitable for microbial communities have ceased.

  9. Molecular characterization of acquired phototrophs and their plastids in marine communities

    NASA Astrophysics Data System (ADS)

    Johnson, M. D.; Beaudoin, D. J.; Moeller, H.

    2016-02-01

    Acquired phototrophy is a form of mixotrophy that involves host associations with prey chloroplasts or intact algal cells as symbionts. In marine ecosystems, acquired phototrophy is widespread and alters community interactions by increasing the size class of primary production. The impact of this shift varies from enhancing growth efficiency of host cells (e.g. plastidic oligotrichs) to fueling highly productive bloom events (e.g. Mesodinium rubrum). Here we test the hypothesis that certain acquired phototrophs (e.g. M. rubrum) have species-specific prey and plastid associations, while others (e.g. plastidic oligotrichs) are generalists. Using single cell PCR and taxon-specific primers, we characterized the diversity of acquired phototrophs and their plastids in a variety of coastal marine ecosystems. In certain cases we also compare these data to community plankton diversity, using next-generation sequencing approaches. We demonstrate that Mesodinium blooms may be attributed to several clades from the M. rubrum complex, as well as M. major, and that all of these bloom events are dominated by T. amphioxeia plastids. In contrast, analysis of single M. rubrum cells from non-bloom situations can yield a more complex picture of cryptophyte associations. We also present results on host and plastid diversity of Dinophysis sp., Perispira sp., and Tontonia sp. Our results reveal that while certain species of acquired phototrophs are plastid specialists, cryptic diversity of plastid genes revealed by single cell PCR also implies some level of flexibility in prey uptake.

  10. Distribution of Sulfate-Reducing Communities from Estuarine to Marine Bay Waters.

    PubMed

    Colin, Yannick; Goñi-Urriza, Marisol; Gassie, Claire; Carlier, Elisabeth; Monperrus, Mathilde; Guyoneaud, Rémy

    2017-01-01

    Estuaries are highly dynamic ecosystems in which freshwater and seawater mix together. Depending on tide and river inflows, particles originating from rivers or from the remobilization of sediments accumulate in the water column. Due to the salinity gradient and the high heterotrophic activity in the estuarine plume, hypoxic and anoxic microniches may form in oxygenated waters, sustaining favorable conditions for resuspended anaerobic microorganisms. In this context, we tested the hypothesis that anaerobic sulfate-reducing prokaryotes may occur in the water column of the Adour River. Using 16S ribosomal RNA (rRNA) and dsrAB-based terminal restriction fragment length polymorphism (T-RFLP) techniques, we characterized total prokaryotic and sulfate-reducing communities along a gradient from estuarine to marine bay waters. Sulfate-reducing prokaryotes were further characterized by the description of dsrB genes and the cultivation of sulfidogenic anaerobic microorganisms. As a result, physical-chemical parameters had a significant effect on water bacterial diversity and community structure along the studied gradient. The concentration of cultured sulfidogenic microorganisms ranged from 1 to 60 × 10(3) cells l(-1) in the water column. Sulfate-reducing prokaryotes occurring in estuarine waters were closely related to microorganisms previously detected in freshwater sediments, suggesting an estuarine origin, mainly by the remobilization of the sediments. In the marine bay station, sediment-derived sulfate-reducing prokaryotes were not cultured anymore, probably due to freshwater dilution, increasing salinity and extended oxic stress. Nevertheless, isolates related to the type strain Desulfovibrio oceani were cultured from the diluted plume and deep marine waters, indicating the occurrence of autochthonous sulfate-reducing bacteria offshore.

  11. Environmental Drivers of Inter-annual Variability in Beaufort Sea Marine Fish Community Structure

    NASA Astrophysics Data System (ADS)

    Majewski, A.; Atchison, S.; Eert, J.; Dempsey, M.; MacPhee, S.; Michel, C.; Reist, J.

    2016-02-01

    The Beaufort Sea is a complex and dynamic system influenced by a wide suite of oceanic and riverine inputs that affect the ecosystem. Interactions within the resulting water masses are largely driven by factors such as precipitation, wind, and ice cover. Thus, the Beaufort Sea environment is highly variable in both space and time, and this variability is reflected in the habitats of biota. Inherent system variability must be factored into baselines designed to detect changes resulting from anthropogenic stressors and natural drivers. Between 2012 and 2014, Fisheries and Oceans Canada conducted the first baseline survey of offshore marine fishes, their habitats, and ecological relationships in the Canadian Beaufort Sea. In 2012, benthic trawling was conducted at 28 stations spanning 20-1000 m depths across shelf and slope habitats, and selected stations were re-sampled in 2013 and 2014. Concurrent sampling of oceanographic parameters and sediment composition was conducted at each station. We examine the stability of marine fish assemblages over a three-year period, and compare results for shelf stations to previous research to develop longer-term perspectives. Oceanographic (e.g., salinity), physical (e.g., depth and sediment grain size) and geographic (e.g., distance from shore) parameters, and proxies for local productivity (i.e., water-column and benthic chlorophyll) are explored as explanatory variables affecting fish community structure among years. Establishing knowledge baselines and understanding variability in the community structure and habitat associations of Beaufort Sea marine fishes will support mitigation and conservation efforts by enhancing our ability to predict, detect and monitor the effects of hydrocarbon development and climate change on this pivotal ecosystem component.

  12. Marine reserves reestablish lost predatory interactions and cause community changes in rocky reefs.

    PubMed

    Guidetti, Paolo

    2006-06-01

    In the last decades, marine reserves have dramatically increased in number worldwide. Here I examined the potential of no-take marine reserves to reestablish lost predatory interactions and, in turn, cause community-wide changes in Mediterranean rocky reefs. Protected locations supported higher density and size of the most effective fish preying on sea urchins (the sea breams Diplodus sargus and D. vulgaris) than unprotected locations. Density of sea urchins (Paracentrotus lividus and Arbacia lixula) was lower at protected than at unprotected locations. Size structure of P. lividus was bimodal (a symptom of predation on medium-sized urchins) only at the protected locations. Coralline barrens were less extended at protected than at unprotected locations, whereas turf-forming and erect-branched algae showed an opposite pattern. Erect-unbranched and erect-calcified algae and conspicuous zoobenthic organisms did not show any pattern related to protection. Tethering experiments showed that predation impact on urchins was (1) higher at protected than at unprotected locations, (2) higher on P. lividus than on A. lixula, and (3) higher on medium-sized (2-3.5 cm test diameter) than large-sized (>3.5 cm) urchins. Sea urchins preyed on by fish in natural conditions were smaller at unprotected than at protected locations. The analysis of sea urchin remains found in Diplodus fish stomachs revealed that medium-sized P. lividus were the most frequently preyed upon urchins and that size range of consumed sea urchins expanded with increasing size of Diplodus fish. These results suggest that (1) depletion and size reduction of predatory fish caused by fishing alter patterns of predation on sea urchins, and that (2) fishing bans (e.g., within no-take marine reserves) may reestablish lost interactions among strongly interactive species in temperate rocky reefs with potential community-wide effects.

  13. Early detection of eukaryotic communities from marine biofilm using high-throughput sequencing: an assessment of different sampling devices.

    PubMed

    Pochon, Xavier; Zaiko, Anastasija; Hopkins, Grant A; Banks, Jonathan C; Wood, Susanna A

    2015-01-01

    Marine biofilms are precursors for colonization by larger fouling organisms, including non-indigenous species (NIS). In this study, high-throughput sequencing (HTS) of 18S rRNA metabarcodes was used to investigate four sampling methods (modified syringe, sterilized sponge, underwater tape and sterilized swab) for characterizing eukaryotic communities in marine biofilms. Perspex™ plates were sampled in and out of water. DNA collected with tape did not amplify. Otherwise, there were no statistical differences in communities among the remaining three sampling devices or between the two environments. Sterilized sponges are recommended for ease of use underwater. In-depth HTS analysis identified diverse eukaryotic communities, dominated by Metazoa and Chromoalveolata. Among the latter, diatoms (Bacillariophyceae) were particularly abundant (33% of reads assigned to Chromalveolata). The NIS Ciona savignyi was detected in all samples. The application of HTS in marine biofilm surveillance could facilitate early detection of NIS, improving the probability of successful eradication.

  14. Protist communities in a marine oxygen minimum zone off Costa Rica by 454 pyrosequencing

    NASA Astrophysics Data System (ADS)

    Jing, H.; Rocke, E.; Kong, L.; Xia, X.; Liu, H.; Landry, M. R.

    2015-08-01

    Marine planktonic protists, including microalgae and protistan grazers, are an important contributor to global primary production and carbon and mineral cycles, however, little is known about their population shifts along the oxic-anoxic gradient in the water column. We used 454 pyrosequencing of the 18S rRNA gene and gene transcripts to study the community composition of whole and active protists throughout a water column in the Costa Rica Dome, where a stable oxygen minimum zone (OMZ) exists at a depth of 400~700 m. A clear shift of protist composition from photosynthetic Dinoflagellates in the surface to potential parasitic Dinoflagellates and Ciliates in the deeper water was revealed along the vertical profile at both rRNA and rDNA levels. Those protist groups recovered only at the rDNA level represent either lysed aggregates sinking from the upper waters or potential hosts for parasitic groups. UPGMA clustering demonstrated that total and active protists in the anoxic core of OMZ (550 m) were distinct from those in other water depths. The reduced community diversity and presence of a parasitic/symbiotic trophic lifestyle in the OMZ, especially the anoxic core, suggests that OMZs can exert a selective pressure on protist communities. Such changes in community structure and a shift in trophic lifestyle could result in a modulation of the microbial loop and associated biogeochemical cycling.

  15. mdRNA-Seq analysis of marine microbial communities from the northern Red Sea

    PubMed Central

    Hou, Shengwei; Pfreundt, Ulrike; Miller, Dan; Berman-Frank, Ilana; Hess, Wolfgang R.

    2016-01-01

    Metatranscriptomic differential RNA-Seq (mdRNA-Seq) identifies the suite of active transcriptional start sites at single-nucleotide resolution through enrichment of primary transcript 5′ ends. Here we analyzed the microbial community at 45 m depth at Station A in the northern Gulf of Aqaba, Red Sea, during 500 m deep mixing in February 2012 using mdRNA-Seq and a parallel classical RNA-Seq approach. We identified promoters active in situ for five different pico-planktonic genera (the SAR11 clade of Alphaproteobacteria, Synechococcus of Cyanobacteria, Euryarchaeota, Thaumarchaeota, and Micromonas as an example for picoeukaryotic algae), showing the applicability of this approach to highly diverse microbial communities. 16S rDNA quantification revealed that 24% of the analyzed community were group II marine Euryarchaeota in which we identified a highly abundant non-coding RNA, Tan1, and detected very high expression of genes encoding intrinsically disordered proteins, as well as enzymes for the synthesis of specific B vitamins, extracellular peptidases, carbohydrate-active enzymes, and transport systems. These results highlight previously unknown functions of Euryarchaeota with community-wide relevance. The complementation of metatranscriptomic studies with mdRNA-Seq provides substantial additional information regarding transcriptional start sites, promoter activities, and the identification of non-coding RNAs. PMID:27759035

  16. The identification of a new Giardia duodenalis assemblage in marine vertebrates and a preliminary analysis of G. duodenalis population biology in marine systems.

    PubMed

    Lasek-Nesselquist, Erica; Welch, David Mark; Sogin, Mitchell L

    2010-08-01

    Giardia duodenalis is an intestinal parasite of many vertebrates. The presence of G. duodenalis in the marine environment due to anthropogenic and wildlife activity is well documented, including the contributions from untreated sewage and storm water, agricultural run-off and droppings from terrestrial animals. Recently, studies have detected this protistan parasite in the faeces of marine vertebrates such as whales, dolphins, seals and shore birds. To explore the population biology of G. duodenalis in marine life, we determined the prevalence of G. duodenalis in two species of seal (Halichoerus grypus, Phoca vitulina vitulina and Phoca vitulina richardsi) from the east and west coasts of the USA, sequenced two loci from G. duodenalis-positive samples to assess molecular diversity and examined G. duodenalis distribution amongst these seals and other marine vertebrates along the east coast. We found a significant difference in the presence of G. duodenalis between east and west coast seal species. Only the zoonotic lineages of G. duodenalis, Assemblages A and B and a novel lineage, which we designated as Assemblage H, were identified in marine vertebrates. Assemblages A and B are broadly distributed geographically and show a lack of host specificity. Only grey seal (Halichoerus grypus) samples and one gull sample (Larus argentatus) from a northern location of Cape Cod, Massachusetts, USA, showed the presence of Assemblage H haplotypes; only one other study of harbour seals from the Puget Sound region of Washington, USA previously recorded the presence of an Assemblage H haplotype. Assemblage H sequences form a monophyletic clade that appears as divergent from the other seven Assemblages of G. duodenalis as these assemblages are from each other. The discovery of a previously uncharacterised lineage of G. duodenalis suggests that this parasite has more genetic diversity and perhaps a larger host range than previously believed.

  17. Human pharmaceuticals in the marine environment: Focus on exposure and biological effects in animal species.

    PubMed

    Fabbri, Elena; Franzellitti, Silvia

    2016-04-01

    Marine waters have been poorly investigated for the occurrence of pharmaceutical contamination. Recent data confirm that pharmaceuticals occur widely in marine and coastal environments; therefore, assessment of potential risk to marine species needs further efforts. The present study represents the first extensive review of pharmaceutical contamination in marine environments addressing the effects on the marine biota analyzed at the molecular, cellular, and individual levels. Because pharmaceuticals differ from conventional pollutants, being designed to interact with specific physiological pathways at low doses, the most recent evidence on modes of action and physiological alterations on marine animal species are discussed. Data on spatial distributions of pharmaceuticals in waters and sediments, as well as bioaccumulation rates, are also presented. The present review also seeks to expand knowledge of how the quality of coastal and marine environments could be efficiently monitored to anticipate possible health and environmental risks. © 2015 SETAC.

  18. Biology in Context: Teachers' Professional Development in Learning Communities

    ERIC Educational Resources Information Center

    Elster, Doris

    2009-01-01

    Biology in Context ("bik") is a project that aims to improve biology teaching in lower secondary schools in Germany. Based on a theoretical framework derived from the National Educational Standards, four competence areas should be fostered in biology education: subject knowledge; inquiry acquisition; subject-related communication; and…

  19. Sponsorship of the Society for Marine Mammalogy’s 19th Biennial Conference on the Biology of Marine Mammals

    DTIC Science & Technology

    2011-09-30

    response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing...and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information...Number: N00014110559 http://www.marinemammalscience.org/ LONG-TERM GOALS The Society for Marine Mammalogy ( SMM ), the world’s premier

  20. Environmental assessment of a large industrial marine complex based on a community of benthic filter-feeders.

    PubMed

    Carballo, José Luis; Naranjo, Santiago

    2002-07-01

    Biological quality in a bay affected by man's activities was evaluated by means of the composition of assemblages of sponges and ascidians. Our results showed that the structure of these two groups of filter-feeders aided in discriminating between undisturbed and disturbed areas, establishing different "environmental health categories" from moderately to strongly disturbed areas, and in ascertaining the extension of the area of each "health category". We were able to divide the bay into four zones based on type of disturbance or anthropogenic source: (1) stations free of any source of disturbance, (2) stations under moderate disturbance, located close to industrial ports, millworks, etc., (3) stations that are under the direct influence of industrial wastes such as a power station and oil refinery, and (4) stations near strongly disturbed areas, influenced directly by harmful steelworks activities. We differentiated clearly between four large species assemblages, and related the composition of these assemblages to different kinds of disturbances. Thus, these species could be used to manage the marine environment in this bay by comparing the observed fauna, with expected fauna in an unstressed site. Moreover, the joint presence of the sponge Cliona vastifica and tunicate Policitor adriaticum seems always to indicate a more or less pristine environmental situation, functioning as bioindicators of normal conditions. We think that the use of specific bioindicators for monitoring disturbance is a valid tool to establish baselines to predict impacts associated with industrial development in many marine ecosystems. The advantages to monitoring communities on hard rocks versus sandy or muddy bottoms are also commented upon.

  1. Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica: a regional comparison.

    PubMed

    Stark, Jonathan S; Kim, Stacy L; Oliver, John S

    2014-01-01

    The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are

  2. Humpback Whale Populations Share a Core Skin Bacterial Community: Towards a Health Index for Marine Mammals?

    PubMed Central

    Apprill, Amy; Robbins, Jooke; Eren, A. Murat; Pack, Adam A.; Reveillaud, Julie; Mattila, David; Moore, Michael; Niemeyer, Misty; Moore, Kathleen M. T.; Mincer, Tracy J.

    2014-01-01

    Microbes are now well regarded for their important role in mammalian health. The microbiology of skin – a unique interface between the host and environment - is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of humpback whales (Megaptera novaeangliae), and examine the potential for a core bacterial community and its variability with host (endogenous) or geographic/environmental (exogenous) specific factors. Skin biopsies or freshly sloughed skin from 56 individuals were sampled from populations in the North Atlantic, North Pacific and South Pacific oceans and bacteria were characterized using 454 pyrosequencing of SSU rRNA genes. Phylogenetic and statistical analyses revealed the ubiquity and abundance of bacteria belonging to the Flavobacteria genus Tenacibaculum and the Gammaproteobacteria genus Psychrobacter across the whale populations. Scanning electron microscopy of skin indicated that microbial cells colonize the skin surface. Despite the ubiquity of Tenacibaculum and Psychrobater spp., the relative composition of the skin-bacterial community differed significantly by geographic area as well as metabolic state of the animals (feeding versus starving during migration and breeding), suggesting that both exogenous and endogenous factors may play a role in influencing the skin-bacteria. Further, characteristics of the skin bacterial community from these free-swimming individuals were assembled and compared to two entangled and three dead individuals, revealing a decrease in the central or core bacterial community members (Tenacibaculum and Psychrobater spp.), as well as the emergence of potential pathogens in the latter cases. This is the first discovery of a cross-population, shared skin bacterial community. This research suggests that the skin bacteria may be connected to humpback health and immunity and could possibly

  3. Community- and government-managed marine protected areas increase fish size, biomass and potential value.

    PubMed

    Chirico, Angelica A D; McClanahan, Timothy R; Eklöf, Johan S

    2017-01-01

    Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government- and community-managed MPAs on the density, size and biomass of seagrass- and coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km2 in size, ≤ 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby

  4. Host ontogeny and the temporal decay of similarity in parasite communities of marine fish.

    PubMed

    Timi, Juan T; Luque, José L; Poulin, Robert

    2010-07-01

    Geographical distances between host populations are key determinants of how many parasite species they share. In principle, decay in similarity should also occur with increasing distance along any other dimension that characterizes some form of separation between communities. Here, we apply the biogeographical concept of distance decay in similarity to ontogenetic changes in the metazoan parasite communities of three species of marine fish from the Atlantic coast of South America. Using differences in body length between all possible pairs of size classes as measures of ontogenetic distances, we find that, using an index of similarity (Bray-Curtis) that takes into account the abundance of each parasite species, the similarity in parasite communities showed a very clear decay pattern; using an index (Jaccard) based on presence/absence of species only, we obtained slightly weaker but nevertheless similar patterns. As we predicted, the slope of the decay relationship was significantly steeper in the fish Cynoscion guatucupa, which goes through clear ontogenetic changes in diet and therefore in exposure to parasites, than in the other species, Engraulis anchoita and Micropogonias furnieri, which maintain a roughly similar diet throughout their lives. In addition, we found that for any given ontogenetic distance, i.e. for a given length difference between two size classes, the similarity in parasite communities was almost always higher if they were adult size classes, and almost always lower if they were juvenile size classes. This, combined with comparisons among individual fish within size classes, shows that parasite communities in juvenile fish are variable and subject to stochastic effects. We propose the distance decay approach as a rigorous and quantitative method to measure rates of community change as a function of host age, and for comparisons across host species to elucidate the role of host ecology in the development of parasite assemblages. 2010 Australian

  5. Anthropogenic Disturbance and Biodiversity of Marine Benthic Communities in Antarctica: A Regional Comparison

    PubMed Central

    Stark, Jonathan S.; Kim, Stacy L.; Oliver, John S.

    2014-01-01

    The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are

  6. Humpback whale populations share a core skin bacterial community: towards a health index for marine mammals?

    PubMed

    Apprill, Amy; Robbins, Jooke; Eren, A Murat; Pack, Adam A; Reveillaud, Julie; Mattila, David; Moore, Michael; Niemeyer, Misty; Moore, Kathleen M T; Mincer, Tracy J

    2014-01-01

    Microbes are now well regarded for their important role in mammalian health. The microbiology of skin--a unique interface between the host and environment--is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of humpback whales (Megaptera novaeangliae), and examine the potential for a core bacterial community and its variability with host (endogenous) or geographic/environmental (exogenous) specific factors. Skin biopsies or freshly sloughed skin from 56 individuals were sampled from populations in the North Atlantic, North Pacific and South Pacific oceans and bacteria were characterized using 454 pyrosequencing of SSU rRNA genes. Phylogenetic and statistical analyses revealed the ubiquity and abundance of bacteria belonging to the Flavobacteria genus Tenacibaculum and the Gammaproteobacteria genus Psychrobacter across the whale populations. Scanning electron microscopy of skin indicated that microbial cells colonize the skin surface. Despite the ubiquity of Tenacibaculum and Psychrobater spp., the relative composition of the skin-bacterial community differed significantly by geographic area as well as metabolic state of the animals (feeding versus starving during migration and breeding), suggesting that both exogenous and endogenous factors may play a role in influencing the skin-bacteria. Further, characteristics of the skin bacterial community from these free-swimming individuals were assembled and compared to two entangled and three dead individuals, revealing a decrease in the central or core bacterial community members (Tenacibaculum and Psychrobater spp.), as well as the emergence of potential pathogens in the latter cases. This is the first discovery of a cross-population, shared skin bacterial community. This research suggests that the skin bacteria may be connected to humpback health and immunity and could possibly serve

  7. Community- and government-managed marine protected areas increase fish size, biomass and potential value

    PubMed Central

    Chirico, Angelica A. D.; McClanahan, Timothy R.; Eklöf, Johan S.

    2017-01-01

    Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government- and community-managed MPAs on the density, size and biomass of seagrass- and coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km2 in size, ≤ 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby

  8. Seasonal and interannual variability of the marine bacterioplankton community throughout the water column over ten years

    PubMed Central

    Cram, Jacob A; Chow, Cheryl-Emiliane T; Sachdeva, Rohan; Needham, David M; Parada, Alma E; Steele, Joshua A; Fuhrman, Jed A

    2015-01-01

    Microbial activities that affect global oceanographic and atmospheric processes happen throughout the water column, yet the long-term ecological dynamics of microbes have been studied largely in the euphotic zone and adjacent seasonally mixed depths. We investigated temporal patterns in the community structure of free-living bacteria, by sampling approximately monthly from 5 m, the deep chlorophyll maximum (∼15–40 m), 150, 500 and 890 m, in San Pedro Channel (maximum depth 900 m, hypoxic below ∼500 m), off the coast of Southern California. Community structure and biodiversity (inverse Simpson index) showed seasonal patterns near the surface and bottom of the water column, but not at intermediate depths. Inverse Simpson's index was highest in the winter in surface waters and in the spring at 890 m, and varied interannually at all depths. Biodiversity appeared to be driven partially by exchange of microbes between depths and was highest when communities were changing slowly over time. Meanwhile, communities from the surface through 500 m varied interannually. After accounting for seasonality, several environmental parameters co-varied with community structure at the surface and 890 m, but not at the intermediate depths. Abundant and seasonally variable groups included, at 890 m, Nitrospina, Flavobacteria and Marine Group A. Seasonality at 890 m is likely driven by variability in sinking particles, which originate in surface waters, pass transiently through the middle water column and accumulate on the seafloor where they alter the chemical environment. Seasonal subeuphotic groups are likely those whose ecology is strongly influenced by these particles. This surface-to-bottom, decade-long, study identifies seasonality and interannual variability not only of overall community structure, but also of numerous taxonomic groups and near-species level operational taxonomic units. PMID:25203836

  9. Integrating Distributed Physical and Biological Marine data using OGC Web Services

    NASA Astrophysics Data System (ADS)

    Gemmell, A. L.; Blower, J. D.; Haines, K.; Price, M.; Millard, K.; Harpham, Q.

    2008-12-01

    Earth scientists use highly diverse sources of data, including in-situ measurements, remotely-sensed information and the results of numerical simulations. The ability to access, visualize, combine and compare these datasets is at the core of scientific investigation, but such tasks have hitherto been very difficult or impossible due to a fundamental lack of harmonization of data products. As a result, much valuable data remains underused. We present a web portal that visualizes and compares physical and biological marine data from both numerical models and in-situ observations. The model data are obtained via an Open Geospatial Consortium (OGC)-compatible Web Map Service (WMS), and the observed data are obtained via an OGC Web Feature Service (WFS). The physical model WMS, the biological model WMS and the WFS are located at three different institutes. This ability to display in-situ point observations alongside model data facilitates much valuable work on model validation. As models become increasingly complex, and sources of observed data become more numerous, it is important to be able to access and compare this growing amount of data efficiently, to ensure cross-checking and consistency between models and observations. The web portal is being applied in a large European operational oceanography project (ECOOP), where it is used to provide support to ecosystem modellers, and specifically to aid detection of potentially harmful algal blooms in coastal areas. The development of this system has been enabled by the conceptual framework of the Climate Science Modelling Language (CSML), which provides a common view onto all these datasets, independent of their storage format or physical location. CSML is based upon emerging international standards, enabling interoperability with other standards-based infrastructures. By creating a reusable Java library that embodies the CSML concepts we are able to apply these techniques to a number of other projects.

  10. Biological N2O Fixation in the Eastern South Pacific Ocean and Marine Cyanobacterial Cultures

    PubMed Central

    Farías, Laura; Faúndez, Juan; Fernández, Camila; Cornejo, Marcela; Sanhueza, Sandra; Carrasco, Cristina

    2013-01-01

    Despite the importance of nitrous oxide (N2O) in the global radiative balance and atmospheric ozone chemistry, its sources and sinks within the Earth’s system are still poorly understood. In the ocean, N2O is produced by microbiological processes such as nitrification and partial denitrification, which account for about a third of global emissions. Conversely, complete denitrification (the dissimilative reduction of N2O to N2) under suboxic/anoxic conditions is the only known pathway accountable for N2O consumption in the ocean. In this work, it is demonstrated that the biological assimilation of N2O could be a significant pathway capable of directly transforming this gas into particulate organic nitrogen (PON). N2O is shown to be biologically fixed within the subtropical and tropical waters of the eastern South Pacific Ocean, under a wide range of oceanographic conditions and at rates ranging from 2 pmol N L−1 d− to 14.8 nmol N L−1 d−1 (mean ± SE of 0.522±1.06 nmol N L−1 d−1, n = 93). Additional assays revealed that cultured cyanobacterial strains of Trichodesmium (H-9 and IMS 101), and Crocosphaera (W-8501) have the capacity to directly fix N2O under laboratory conditions; suggesting that marine photoautotrophic diazotrophs could be using N2O as a substrate. This metabolic capacity however was absent in Synechococcus (RCC 1029). The findings presented here indicate that assimilative N2O fixation takes place under extreme environmental conditions (i.e., light, nutrient, oxygen) where both autotrophic (including cyanobacteria) and heterotrophic microbes appear to be involved. This process could provide a globally significant sink for atmospheric N2O which in turn affects the oceanic N2O inventory and may also represent a yet unexplored global oceanic source of fixed N. PMID:23717516

  11. Lessons from the past and charting the future of marine natural products drug discovery and chemical biology

    PubMed Central

    Gerwick, William H.; Moore, Bradley S.

    2012-01-01

    Summary Marine life forms are an important source of structurally-diverse and biologically-active secondary metabolites, several of which have inspired the development of new classes of therapeutic agents. These success stories have had to overcome difficulties inherent to natural products-derived drugs, such as adequate sourcing of the agent and issues related to structural complexity. Nevertheless, several marine-derived agents are now approved, most as `first-in-class' drugs, with 5 of 7 appearing in the past few years. Additionally, there is a rich pipeline of clinical and pre-clinical marine compounds to suggest their continued application in human medicine. Understanding of how these agents are biosynthetically assembled has accelerated in recent years, especially through interdisciplinary approaches, and innovative manipulations and re-engineering of some of these gene clusters are yielding novel agents of enhanced pharmaceutical properties compared with the natural product. PMID:22284357

  12. Effects of Trophic Skewing of Species Richness on Ecosystem Functioning in a Diverse Marine Community

    PubMed Central

    Reynolds, Pamela L.; Bruno, John F.

    2012-01-01

    Widespread overharvesting of top consumers of the world’s ecosystems has “skewed” food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey species richness, affect ecosystem functioning. We experimentally measured the effects of trophic skew on production in an estuarine food web by manipulating ratios of species richness across three trophic levels in experimental mesocosms. After 24 days, increasing macroalgal richness promoted both plant biomass and grazer abundance, although the positive effect on plant biomass disappeared in the presence of grazers. The strongest trophic cascade on the experimentally stocked macroalgae emerged in communities with a greater ratio of prey to predator richness (bottom-rich food webs), while stronger cascades on the accumulation of naturally colonizing algae (primarily microalgae with some early successional macroalgae that recruited and grew in the mesocosms) generally emerged in communities with greater predator to prey richness (the more top-rich food webs). These results suggest that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions. PMID:22693549

  13. Impact of environmental bacterial communities on fish health in marine recirculating aquaculture systems.

    PubMed

    Xue, Shuxia; Xu, Wei; Wei, Junli; Sun, Jinsheng

    2017-05-01

    Marine cultured fish diseases caused by bacteria in recirculating aquaculture systems (RASs) greatly threaten fish aquaculture. To date, the dynamics of bacterial populations in RAS and their impacts to fish health remain largely unknown. In the present study, the bacterial communities in the water from two different marine RASs were analyzed using pyrosequencing technique. Fish disease syndromes and mortality had been reported from one RAS (RAS-d) while the fish in the other RAS remained healthy (RAS-h). The diversity of bacteria in each RAS and the abundance of each bacterium were identified based on sequencing the V4 hypervariable region of the 16S rRNA gene. A total number of 107,476 effective sequences were obtained from the pyrosequencing results. 640 and 844 operational taxonomic units (OTUs) were identified in RAS-d and RAS-h, respectively. In order level, tags annotation showed that Vibrionales and Flavobacteriales were the predominant strains in RAS-d with a relative abundance 50.5% and 36.5%, respectively. In contrast, the bacterial community in RAS-h contained 35.8% Vibrionales, 17.3% Alteromonadales, 10.7% Rhodobacterales, 7.43% Kordiimonadales, and 6.26% Oceanospirillales. In addition, the Vibrionaceae in the RAS-d represented 6.98% of the population which was significantly higher than that in RAS-h (0.40%). More potential pathogenic bacteria in fish, such as Vibrio harveyi, Vibrio rotiferianus were also found in the bacterial population in RAS-d. The results also showed that the bacteria community in RAS-h was more diverse and balanced than in RAS-d. These findings of this study suggested a potential correlation between fish diseases and environmental bacterial populations. Copyright © 2017. Published by Elsevier B.V.

  14. Effects of trophic skewing of species richness on ecosystem functioning in a diverse marine community.

    PubMed

    Reynolds, Pamela L; Bruno, John F

    2012-01-01

    Widespread overharvesting of top consumers of the world's ecosystems has "skewed" food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey species richness, affect ecosystem functioning. We experimentally measured the effects of trophic skew on production in an estuarine food web by manipulating ratios of species richness across three trophic levels in experimental mesocosms. After 24 days, increasing macroalgal richness promoted both plant biomass and grazer abundance, although the positive effect on plant biomass disappeared in the presence of grazers. The strongest trophic cascade on the experimentally stocked macroalgae emerged in communities with a greater ratio of prey to predator richness (bottom-rich food webs), while stronger cascades on the accumulation of naturally colonizing algae (primarily microalgae with some early successional macroalgae that recruited and grew in the mesocosms) generally emerged in communities with greater predator to prey richness (the more top-rich food webs). These results suggest that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions.

  15. Oxygen limitations on marine animal distributions and the collapse of epibenthic community structure during shoaling hypoxia.

    PubMed

    Chu, Jackson W F; Tunnicliffe, Verena

    2015-08-01

    Deoxygenation in the global ocean is predicted to induce ecosystem-wide changes. Analysis of multidecadal oxygen time-series projects the northeast Pacific to be a current and future hot spot of oxygen loss. However, the response of marine communities to deoxygenation is unresolved due to the lack of applicable data on component species. We repeated the same benthic transect (n = 10, between 45 and 190 m depths) over 8 years in a seasonally hypoxic fjord using remotely operated vehicles equipped with oxygen sensors to establish the lower oxygen levels at which 26 common epibenthic species can occur in the wild. By timing our surveys to shoaling hypoxia events, we show that fish and crustacean populations persist even in severe hypoxia (<0.5 mL L(-1) ) with no mortality effects but that migration of mobile species occurs. Consequently, the immediate response to hypoxia expansion is the collapse of community structure; normally partitioned distributions of resident species coalesced and localized densities increased. After oxygen renewal and formation of steep oxygen gradients, former ranges re-established. High frequency data from the nearby VENUS subsea observatory show the average oxygen level at our site declined by ~0.05 mL L(-1) year(-1) over the period of our study. The increased annual duration of the hypoxic (<1.4 mL L(-1) ) and severely hypoxic periods appears to reflect the oxygen dynamics demonstrated in offshore source waters and the adjacent Strait of Georgia. Should the current trajectory of oxygen loss continue, community homogenization and reduced suitable habitat may become the dominant state of epibenthic systems in the northeast Pacific. In situ oxygen occurrences were not congruent with lethal and sublethal hypoxia thresholds calculated across the literature for major taxonomic groups indicating that research biases toward laboratory studies on Atlantic species are not globally applicable. Region-specific hypoxia thresholds are necessary to

  16. Diversity and community structure within anoxic sediment from marine salinity meromictic lakes and a coastal meromictic marine basin, Vestfold Hilds, Eastern Antarctica.

    PubMed

    Bowman, J P; Rea, S M; McCammon, S A; McMeekin, T A

    2000-04-01

    16S rDNA clone library analysis was used to examine the biodiversity and community structure within anoxic sediments of several marine-type salinity meromictic lakes and a coastal marine basin located in the Vestfolds Hills area of Eastern Antarctica. From 69 to 130 (555 total) 16S rDNA clones were analysed from each sediment sample, and restriction fragment length polymorphism (RFLP) and sequence analysis grouped the clones into 202 distinct phylotypes (a clone group with sequence similarity of >0.98). A number of phylotypes and phylotype groups predominated in all libraries, with a group of 10 phylotypes (31% of clones) forming a novel deep branch within the low G+C Gram-positive division. Other abundant phylotypes detected in several different clone libraries grouped with Prochlorococcus cyanobacteria, diatom chloroplasts, delta proteobacteria (Desulfosarcina group, Syntrophus and Geobacterl Pelobacter/Desulphuromonas group), order Chlamydiales (Parachlamydiaceae) and Spirochaetales (wall-less Antarctic spirochaetes). Most archaeal clones detected (3.1% of clones) belonged to a highly diverged group of Euryarchaeota clustering with clones previously detected in rice soil, aquifer sediments and hydrothermal vent material. Little similarity existed between the phylotypes detected in this study and other clone libraries based on marine sediment, suggesting that an enormous prokaryotic diversity occurs within marine and marine-derived sediments.

  17. Structures, biological activities and phylogenetic relationships of terpenoids from marine ciliates of the genus Euplotes.

    PubMed

    Guella, Graziano; Skropeta, Danielle; Di Giuseppe, Graziano; Dini, Fernando

    2010-07-08

    In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i) euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii) raikovenals, built on the bicyclo[3.2.0]heptane ring system; (iii) rarisetenolides and focardins containing an octahydroazulene moiety; and (iv) vannusals, with a unique C30 backbone. Their complex structures have been elucidated through a combination of nuclear magnetic resonance spectroscopy, mass spectrometry, molecular mechanics and quantum chemical calculations. Despite the limited number of biosynthetic experiments having been performed, the large diversity of ciliate terpenoids has facilitated the proposal of biosynthetic pathways whereby they are produced from classical linear precursors. Herein, the similarities and differences emerging from the comparison of the classical chemotaxonomy approach based on secondary metabolites, with species phylogenesis based on genetic descriptors (SSU-rDNA), will be discussed. Results on the interesting ecological and biological properties of ciliate terpenoids are also reported.

  18. Estimation of biologically damaging UV levels in marine surface waters with DNA and viral dosimeters.

    PubMed

    Wilhelm, Steven W; Jeffrey, Wade H; Suttle, Curtis A; Mitchell, David L

    2002-09-01

    We have surveyed the biologically harmful radiation penetrating the water column along a transect in the western Gulf of Mexico using dosimeters consisting of intact viruses or naked calf-thymus DNA (ctDNA). The indigenous marine bacteriophage PWH3a-P1, which lytically infects the heterotrophic bacterium Vibrio natriegens (strain PWH3a), displayed decay rates for infectivity approaching 1.0 h(-1) in surface waters when deployed in a seawater-based dosimeter. The accumulation of pyrimidine dimers in ctDNA dosimeters provided a strong correlation to these results, with pyrimidine dimers representing more than 0.3% (up to ca 3800 dimers Mb(-1) DNA) of the total DNA in dosimeters exposed to sea surface levels of solar radiation. The results demonstrate a strong correlation between the dimer formation in the DNA dosimeters, the decay rates of viral infectivity and the penetration of UVB radiation into the water column. The decay of viral infectivity attenuated with depth in a manner similar to the decay of solar radiation and was still significant at 10 m in offshore oligotrophic water and at dimer frequencies less than 0.1% (ca 200-300 dimers Mb(-1) DNA).

  19. Chemical synthesis and biological activities of 3-alkyl pyridinium polymeric analogues of marine toxins

    PubMed Central

    Houssen, Wael E.; Lu, Zhibao; Edrada-Ebel, RuAngelie; Chatzi, Christina; Tucker, Steven J.; Sepčić, Kristina; Turk, Tom; Zovko, Ana; Shen, Sanbing

    2010-01-01

    Two new large poly-1,3-dodecylpyridinium salts, APS12 and APS12-2 of 12.5- and 14.7-kDa size, respectively, were synthesised and tested for their pore-forming and transfection capabilities in HEK 293 and undifferentiated mouse ES cells using patch-clamp recording, Ca2+ imaging and flow cytometry. Polymerisation reactions were enhanced by microwaves, and the product sizes were controlled by altering the irradiation time. This method can also be applied to obtain polymers with variable linking chains as shown by the preparation of poly-(1,3-octylpyridinium) salt of 11.9-kDa size. Molecular weights of the final products were determined using ESIMS analysis, which also indicated the products to be amongst the largest macro-cycles ever recorded, up to a 900-membered ring. Anti-bacterial, haemolytic and anti-acetylcholinesterase activities were also reported for the two dodecyl pyridinium polymers. These biological activities are characteristic to the structurally related marine toxin, poly-APS. Electronic supplementary material The online version of this article (doi:10.1007/s12154-010-0036-4) contains supplementary material, which is available to authorized users. PMID:21326630

  20. Seawater Incursion Events in a Cretaceous Paleo-lake Revealed by Specific Marine Biological Markers

    PubMed Central

    Hu, J. F.; Peng, P. A.; Liu, M. Y.; Xi, D. P.; Song, J. Z.; Wan, X. Q.; Wang, C. S.

    2015-01-01

    Many large paleo-lakes in North China were formed after the Triassic Era. Seawater incursion events (SWIEs) in these lakes have been extensively discussed in the literature, yet lack reliable methodology and solid evidence, which are essential for reconstructing and confirming SWIEs. The present study employs specific marine biological markers (24-n-propyl and 24-isopropyl cholestanes) to trace SWIEs in a dated core taken from the Songliao Basin (SLB). Two SWIEs were identified. The first SWIE from 91.37 to 89.00 Ma, was continuous and variable but not strong, while the second SWIE from 84.72 to 83.72 Ma was episodic and strong. SWIEs caused high total organic carbon (TOC) and negative δ13Corg values in the sediments, which were interpreted as an indication of high productivity in the lake, due to the enhancement of nutrient supplies as well as high levels of aqueous CO2, due to the mixing of alkaline seawater and acidic lake water. The SWIEs in SLB were controlled by regional tectonic activity and eustatic variation. Movement direction changes of the Izanagi/Kula Plate in 90 Ma and 84 Ma created faults and triggered SWIEs. A high sea level, from 90 to 84 Ma, also facilitated the occurrence of SWIEs in SLB. PMID:25946976

  1. Structures, Biological Activities and Phylogenetic Relationships of Terpenoids from Marine Ciliates of the Genus Euplotes

    PubMed Central

    Guella, Graziano; Skropeta, Danielle; Di Giuseppe, Graziano; Dini, Fernando

    2010-01-01

    In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i) euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii) raikovenals, built on the bicyclo[3.2.0]heptane ring system; (iii) rarisetenolides and focardins containing an octahydroazulene moiety; and (iv) vannusals, with a unique C30 backbone. Their complex structures have been elucidated through a combination of nuclear magnetic resonance spectroscopy, mass spectrometry, molecular mechanics and quantum chemical calculations. Despite the limited number of biosynthetic experiments having been performed, the large diversity of ciliate terpenoids has facilitated the proposal of biosynthetic pathways whereby they are produced from classical linear precursors. Herein, the similarities and differences emerging from the comparison of the classical chemotaxonomy approach based on secondary metabolites, with species phylogenesis based on genetic descriptors (SSU-rDNA), will be discussed. Results on the interesting ecological and biological properties of ciliate terpenoids are also reported. PMID:20714425

  2. The utility of two marine community indices to assess the environmental degradation of lotic systems using fish communities.

    PubMed

    Stojković Piperac, Milica; Milošević, Djuradj; Simić, Snežana; Simić, Vladica

    2016-05-01

    Multimetric approaches are commonly used to evaluate the ecological status of aquatic ecosystems. However, it has been recommended that the sensitivity of existing methods be improved through the investigation of the potential of new metrics to detect environmental disturbances. In this study we tested the effectiveness of two community indices (Taxonomic distinctness index (TDI) and Abundance biomass comparison (ABC) method), primarily proposed for marine ecosystems, to identify sites with different levels of environmental degradation in lotic systems using fish community data. Fish samples were collected over the period 2003-2011 at 131 sampling stations. To generate water and habitat quality classes, a self-organizing map (SOM) based on environmental data was applied. Gradients over the SOM map were investigated for the values of the TDI and ABC indices. The results of this study reveal that the values of both the TDI and ABC indices are highly correlated with water and habitat quality gradients. However, despite the observed correlation, the utility of TDI as a potential metric in bioassessment programs is rather limited, due to its lack of discriminatory power. In contrast, the ABC method could be proposed as a novel metric, but can only be applied in type-specific multimetric approaches. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Fatty acids from lipids of marine organisms: molecular biodiversity, roles as biomarkers, biologically active compounds, and economical aspects.

    PubMed

    Bergé, Jean-Pascal; Barnathan, Gilles

    2005-01-01

    Because of their characteristic living environments, marine organisms produce a variety of lipids. Fatty acids constitute the essential part of triglycerides and wax esters, which are the major components of fats and oils. Nevertheless, phospholipids and glycolipids have considerable importance and will be taken into account, especially the latter compounds that excite increasing interest regarding their promising biological activities. Thus, in addition to the major polyunsaturated fatty acids (PUFA) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, a great number of various fatty acids occur in marine organisms, e.g. saturated, mono- and diunsaturated, branched, halogenated, hydroxylated, methoxylated, non-methylene-interrupted. Various unprecedented chemical structures of fatty acids, and lipid-containing fatty acids, have recently been discovered, especially from the most primitive animals such as sponges and gorgonians. This review of marine lipidology deals with recent advances in the field of fatty acids since the end of the 1990s. Different approaches will be followed, mainly developing biomarkers of trophic chains in marine ecosystems and of chemotaxonomic interest, reporting new structures, especially those with biological activities or biosynthetic interest. An important part of this review will be devoted to the major PUFA, their relevance to health and nutrition, their biosynthesis, their sources (usual and promising) and market.

  4. Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use

    DTIC Science & Technology

    2009-09-30

    beluga whales at the Barren Islands, Alaska, the Bering Sea Acoustic Report, Marine Mammal Monitoring for NW Fisheries, and Monitoring killer whale ...distribution, physical oceanographic process, and sound levels to marine mammal habitat use on the eastern Bering Sea shelf. Integrated data such...individual parameters. 3) A mixed-model analysis will be performed to identify relationships between marine mammal presence and environmental sound

  5. Quantifying Stress in Marine Mammals: Measuring Biologically Active Cortisol in Cetaceans and Pinnipeds

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Quantifying Stress in Marine Mammals: Measuring...boonstra/ LONG-TERM GOALS This research will improve our ability to measure stress in marine mammals. Stress hormones (glucocorticoids...are best estimated by measuring “free glucocorticoid” levels (i.e. that hormone not bound by CBG). This project will improve the capacity of marine

  6. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities

    PubMed Central

    Williamson, David H; Ceccarelli, Daniela M; Evans, Richard D; Jones, Geoffrey P; Russ, Garry R

    2014-01-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery. PMID:24634720

  7. Analyses of sublittoral macrobenthic community change in a marine nature reserve using similarity profiles (SIMPROF).

    PubMed

    Somerfield, P J; Burton, M; Sanderson, W G

    2014-12-01

    Sublittoral macrobenthic communities in the Skomer Marine Nature Reserve (SMNR), Pembrokeshire, Wales, were sampled at 10 stations in 1993, 1996, 1998, 2003, 2007 and 2009 using a Day grab and a 0.5 mm mesh. The time series is analysed using Similarities Profiles (SIMPROF) tests and associated methods. Q-mode analysis using clustering with Type 1 SIMPROF addresses multivariate structure among samples, showing that there is clear structure associated with differences among years. Inverse (r-mode) analysis using Type 2 SIMPROF decisively rejects a hypothesis that species are not associated with each other. Clustering of the variables (species) with Type 3 SIMPROF identifies groups of species which covary coherently through the time-series. The time-series is characterised by a dramatic decline in abundances and diversity between the 1993 and 1996 surveys. By 1998 there had been a shift in community composition from the 1993 situation, with different species dominating. Communities had recovered in terms of abundance and species richness, but different species dominated the community. No single factor could be identified which unequivocally explained the dramatic changes observed in the SMNR. Possible causes were the effects of dispersed oil and dispersants from the Sea Empress oil spill in February 1996 and the cessation of dredge-spoil disposal off St Annes Head in 1995, but the most likely cause was severe weather. With many species, and a demonstrable recovery from an impact, communities within the SMNR appear to be diverse and resilient. If attributable to natural storms, the changes observed here indicate that natural variability may be much more important than is generally taken into account in the design of monitoring programmes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Competition and facilitation between the marine nitrogen-fixing cyanobacterium Cyanothece and its associated bacterial community

    PubMed Central

    Brauer, Verena S.; Stomp, Maayke; Bouvier, Thierry; Fouilland, Eric; Leboulanger, Christophe; Confurius-Guns, Veronique; Weissing, Franz J.; Stal, LucasJ.; Huisman, Jef

    2014-01-01

    N2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N2-fixing cyanobacterium Cyanothece sp. Miami BG043511 and its associated free-living chemotrophic bacteria at different concentrations of nitrate and dissolved organic carbon and different temperatures. High temperature strongly stimulated the growth of Cyanothece, but had less effect on the growth and community composition of the chemotrophic bacteria. Conversely, nitrate and carbon addition did not significantly increase the abundance of Cyanothece, but strongly affected the abundance and species composition of the associated chemotrophic bacteria. In nitrate-free medium the associated bacterial community was co-dominated by the putative diazotroph Mesorhizobium and the putative aerobic anoxygenic phototroph Erythrobacter and after addition of organic carbon also by the Flavobacterium Muricauda. Addition of nitrate shifted the composition toward co-dominance by Erythrobacter and the Gammaproteobacterium Marinobacter. Our results indicate that Cyanothece modified the species composition of its associated bacteria through a combination of competition and facilitation. Furthermore, within the bacterial community, niche differentiation appeared to play an important role, contributing to the coexistence of a variety of different functional groups. An important implication of these findings is that changes in nitrogen and carbon availability due to, e.g., eutrophication and climate change are likely to have a major impact on the species composition of the bacterial community associated with N2-fixing cyanobacteria. PMID:25642224

  9. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities.

    PubMed

    Williamson, David H; Ceccarelli, Daniela M; Evans, Richard D; Jones, Geoffrey P; Russ, Garry R

    2014-02-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery.

  10. Combined Carbohydrates Support Rich Communities of Particle-Associated Marine Bacterioplankton

    PubMed Central

    Sperling, Martin; Piontek, Judith; Engel, Anja; Wiltshire, Karen H.; Niggemann, Jutta; Gerdts, Gunnar; Wichels, Antje

    2017-01-01

    Carbohydrates represent an important fraction of labile and semi-labile marine organic matter that is mainly comprised of exopolymeric substances derived from phytoplankton exudation and decay. This study investigates the composition of total combined carbohydrates (tCCHO; >1 kDa) and the community development of free-living (0.2–3 μm) and particle-associated (PA) (3–10 μm) bacterioplankton during a spring phytoplankton bloom in the southern North Sea. Furthermore, rates were determined for the extracellular enzymatic hydrolysis that catalyzes the initial step in bacterial organic matter remineralization. Concentrations of tCCHO greatly increased during bloom development, while the composition showed only minor changes over time. The combined concentration of glucose, galactose, fucose, rhamnose, galactosamine, glucosamine, and glucuronic acid in tCCHO was a significant factor shaping the community composition of the PA bacteria. The richness of PA bacteria greatly increased in the post-bloom phase. At the same time, the increase in extracellular β-glucosidase activity was sufficient to explain the observed decrease in tCCHO, indicating the efficient utilization of carbohydrates by the bacterioplankton community during the post-bloom phase. Our results suggest that carbohydrate concentration and composition are important factors in the multifactorial environmental control of bacterioplankton succession and the enzymatic hydrolysis of organic matter during phytoplankton blooms. PMID:28197132

  11. Ocean warming increases threat of invasive species in a marine fouling community.

    PubMed

    Sorte, Cascade J B; Williams, Susan L; Zerebecki, Robyn A

    2010-08-01

    We addressed the potential for climate change to facilitate invasions and precipitate shifts in community composition by testing effects of ocean warming on species in a marine fouling community in Bodega Harbor, Bodega Bay, California, USA. First, we determined that introduced species tolerated significantly higher temperatures than natives, suggesting that climate change will have a disproportionately negative impact on native species. Second, we assessed the temperature dependence of survival and growth by exposing juveniles to an ambient control temperature and increased temperatures predicted by ocean warming scenarios (+3 degrees C and +4.5 degrees C) in laboratory mesocosms. We found that responses differed between species, species origins, and demographic processes. Based on the temperature tolerance, survival, and growth results, we predict that, as ocean temperatures increase, native species will decrease in abundance, whereas introduced species are likely to increase in this system. Facilitation of invasions by climate change may already be underway; locally, invasive dominance has increased concurrent with ocean warming over the past approximately 40 years. We suggest that the effects of climate change on communities can occur via both direct impacts on the diversity and abundance of native species and indirect effects due to increased dominance of introduced species.

  12. The Brachyura and Anomura fauna (Decapoda; Crustacea) in the Arvoredo Marine Biological Reserve on the southern Brazilian coast.

    PubMed

    Bouzon, J L; Freire, A S

    2007-05-01

    Eight species of Brachyura and two species of Anomura were registered for the first time on the Santa Catarina coast, in the waters around the Arvoredo Marine Biological Reserve. The animals were collected by scuba divers, between 3 and 22 meters depth, from September 2001 to February 2003. A total of 31 decapod species were collected, and most of the new occurrences had already been registered in the adjacent northern waters.

  13. Analysis of a marine picoplankton community by 16S rRNA gene cloning and sequencing.

    PubMed Central

    Schmidt, T M; DeLong, E F; Pace, N R

    1991-01-01

    The phylogenetic diversity of an oligotrophic marine picoplankton community was examined by analyzing the sequences of cloned ribosomal genes. This strategy does not rely on cultivation of the resident microorganisms. Bulk genomic DNA was isolated from picoplankton collected in the north central Pacific Ocean by tangential flow filtration. The mixed-population DNA was fragmented, size fractionated, and cloned into bacteriophage lambda. Thirty-eight clones containing 16S rRNA genes were identified in a screen of 3.2 x 10(4) recombinant phage, and portions of the rRNA gene were amplified by polymerase chain reaction and sequenced. The resulting sequences were used to establish the identities of the picoplankton by comparison with an established data base of rRNA sequences. Fifteen unique eubacterial sequences were obtained, including four from cyanobacteria and eleven from proteobacteria. A single eucaryote related to dinoflagellates was identified; no archaebacterial sequences were detected. The cyanobacterial sequences are all closely related to sequences from cultivated marine Synechococcus strains and with cyanobacterial sequences obtained from the Atlantic Ocean (Sargasso Sea). Several sequences were related to common marine isolates of the gamma subdivision of proteobacteria. In addition to sequences closely related to those of described bacteria, sequences were obtained from two phylogenetic groups of organisms that are not closely related to any known rRNA sequences from cultivated organisms. Both of these novel phylogenetic clusters are proteobacteria, one group within the alpha subdivision and the other distinct from known proteobacterial subdivisions. The rRNA sequences of the alpha-related group are nearly identical to those of some Sargasso Sea picoplankton, suggesting a global distribution of these organisms. Images PMID:2066334

  14. Structure and variability of the marine-bird community in the northeastern Chukchi Sea

    NASA Astrophysics Data System (ADS)

    Gall, Adrian E.; Day, Robert H.; Weingartner, Thomas J.

    2013-09-01

    We examined the seasonal and interannual variation in the marine-bird community and its relationship to physical oceanography in the northeastern Chukchi Sea in 2008-2010 as part of a multi-year, interdisciplinary study. We sampled 3 study areas, each ∼3000 km2, located in the offshore northeastern Chukchi Sea: Klondike, Burger, and Statoil. We quantified the marine habitat by measuring strength of stratification, depth of the mixed layer, and temperature and salinity in the upper mixed layer. The total density of seabirds was the highest in 2009, when warm (5-6 °C), moderately saline (31-31.5) Bering Sea Water (BSW) extended across Burger and Klondike at all depths. Bird density was generally higher in Klondike than in Burger in 2008 and 2009; densities did not differ significantly among study areas in 2010, when BSW covered all 3 study areas. The relative abundance of alcids in all study areas combined increased from 2008 to 2010. Klondike was numerically dominated by alcids and tubenoses in all years, whereas Burger was numerically dominated by larids and tubenoses in 2008 and by alcids in 2009 and 2010; Statoil also was numerically dominated by alcids in 2010. Least auklets, crested auklets, and northern fulmars were positively associated with strong stratification and high salinity (>31) in the upper mixed layer, characteristics that indicated the presence of BSW. Phalaropes were positively associated with salinity but negatively associated with stratification, suggesting that well-mixed water provides better foraging opportunities for these surface-feeding planktivores. The distribution and abundance of marine birds, particularly the planktivorous species, is influenced by advective processes that transport oceanic species of zooplankton from the Bering Sea to the Chukchi Sea. This transport apparently differed among years and resulted in a broader northeastward intrusion of Bering Sea Water and greater total abundance of planktivorous seabirds in the

  15. Macroalgal blooms alter community structure and primary productivity in marine ecosystems.

    PubMed

    Lyons, Devin A; Arvanitidis, Christos; Blight, Andrew J; Chatzinikolaou, Eva; Guy-Haim, Tamar; Kotta, Jonne; Orav-Kotta, Helen; Queirós, Ana M; Rilov, Gil; Somerfield, Paul J; Crowe, Tasman P

    2014-09-01

    Eutrophication, coupled with loss of herbivory due to habitat degradation and overharvesting, has increased the frequency and severity of macroalgal blooms worldwide. Macroalgal blooms interfere with human activities in coastal areas, and sometimes necessitate costly algal removal programmes. They also have many detrimental effects on marine and estuarine ecosystems, including induction of hypoxia, release of toxic hydrogen sulphide into the sediments and atmosphere, and the loss of ecologically and economically important species. However, macroalgal blooms can also increase habitat complexity, provide organisms with food and shelter, and reduce other problems associated with eutrophication. These contrasting effects make their overall ecological impacts unclear. We conducted a systematic review and meta-analysis to estimate the overall effects of macroalgal blooms on several key measures of ecosystem structure and functioning in marine ecosystems. We also evaluated some of the ecological and methodological factors that might explain the highly variable effects observed in different studies. Averaged across all studies, macroalgal blooms had negative effects on the abundance and species richness of marine organisms, but blooms by different algal taxa had different consequences, ranging from strong negative to strong positive effects. Blooms' effects on species richness also depended on the habitat where they occurred, with the strongest negative effects seen in sandy or muddy subtidal habitats and in the rocky intertidal. Invertebrate communities also appeared to be particularly sensitive to blooms, suffering reductions in their abundance, species richness, and diversity. The total net primary productivity, gross primary productivity, and respiration of benthic ecosystems were higher during macroalgal blooms, but blooms had negative effects on the productivity and respiration of other organisms. These results suggest that, in addition to their direct social and

  16. Microbial community composition of anoxic marine sediments in the Bay of Cádiz (Spain).

    PubMed

    Köchling, Thorsten; Lara-Martín, Pablo; González-Mazo, Eduardo; Amils, Ricardo; Sanz, José Luis

    2011-09-01

    The composition of the microbial community inhabiting the anoxic coastal sediments of the Bay of Cádiz (southern Spain) was investigated using a molecular approach consisting of PCR cloning and denaturing gradient gel electrophoresis (DGGE), based on 16S rRNA sequences. The total cell count was 1-5 × 10⁸ cells/g sediment and, as determined by catalyzed reporter deposition-fluorescent in situ hybridization (CARD-FISH), the proportion of Bacteria to Archaea was about 70:30. The analysis of 16S-rRNA gene sequences revealed a wide spectrum of microorganisms, which could be grouped into 111 operational taxonomic units (OTUs). Many of the OTUs showed high phylogenetic similarity to microorganisms living in marine sediments of diverse geographic origin. The phylogenetic groups that were predominantly detected were Firmicutes, Deltaproteobacteria, and Gammaproteobacteria, accounting for 23, 15, and 14% of the clones, respectively. Diversity in the domain Archaea was significantly lower than in the domain Bacteria. The majority of the archaeal OTUs belonged to the Crenarchaeota phylum. Since most of the sequences could not be identified precisely at the genus/species level, the functional roles of the microorganisms in the ecosystem could not be inferred. However, seven OTUs affiliated with the Delta- and Epsilonproteobacteria were identified down to the genus level, with all of the identified genera known to occur in sulfate-rich marine environments.

  17. Community change within a Caribbean coral reef Marine Protected Area following two decades of local management.

    PubMed

    Noble, Mae M; van Laake, Gregoor; Berumen, Michael L; Fulton, Christopher J

    2013-01-01

    Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs). While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP). Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth) closed to fishing, this did not hold for deeper (15 m) habitats, and there was a widespread decline (38% decrease) in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management.

  18. Semi-continuous methane production from undiluted brown algae using a halophilic marine microbial community.

    PubMed

    Miura, Toyokazu; Kita, Akihisa; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nakashimada, Yutaka

    2016-01-01

    Acclimated marine sediment-derived culture was used for semi-continuous methane production from materials equivalent to raw brown algae, without dilution of salinity and without nutrient supply, under 3 consecutive conditions of varying organic loading rates (OLRs) and hydraulic retention time (HRT). Methane production was stable at 2.0gVS/kg/day (39-day HRT); however, it became unstable at 2.9gVS/kg/day (28-day HRT) due to acetate and propionate accumulation. OLR subsequently decreased to 1.7gVS/kg/day (46-day HRT), stabilizing methane production beyond steady state. Methane yield was above 300mL/g VS at all OLRs. These results indicated that the acclimated marine sediment culture was able to produce methane semi-continuously from raw brown algae without dilution and nutrient supply under steady state. Microbial community analysis suggested that hydrogenotrophic methanogens predominated among archaea during unstable methane production, implying a partial shift of the methanogenic pathway from acetoclastic methanogenesis to acetate oxidation.

  19. Components of breeding productivity in a marine bird community: key factors and concordance

    USGS Publications Warehouse

    Hatch, Scott A.; Hatch, Martha A.

    1990-01-01

    We estimated components of annual breeding productivity for eight species of marine birds on the Semidi Islands in the western Gulf of Alaska. Mortality of eggs and young, caused primarily by avian predators, accounted for most of the annual variation in productivity. Failure to produce eggs, clutch size variation, and the hatchability of eggs were generally less important. The stage of breeding at which annual productivity was most strongly regulated differed among species. In murres, chick-rearing success accounted for the largest share of annual variation in overall productivity, whereas incubation success was the key factor in fulmars, kittiwakes, and puffins. Although avian predators were the dominant proximate cause of egg and chick losses in some species, food supply seemed ultimately responsible for variation in all the major components of productivity. Concordance of productivity among species was low for the marine bird community as a whole, but selected pairs of species exhibited a greater tendency for high and low productivities to occur in the same years. Compared with the same or similar species outside Alaska, Semidi Islands birds were in one of three categories: (i) species whose productivity was about the same as reported from other areas (fulmars and gulls), (ii) species with comparatively low productivity (murres, puffins, kittiwakes), and (iii) species with similar mean productivity but greater annual variation (cormorants). These patterns suggest that specialized consumers of forage fish experienced food shortages at the Semidi Islands and that surface feeders were more severely affected than divers.

  20. The Influence of Predator-prey Interactions on Climate-induced Range Shifts in Marine Communities

    NASA Astrophysics Data System (ADS)

    Selden, R. L.; Batt, R. D.; Morley, J. W.; Pinsky, M. L.

    2016-02-01

    Trawl surveys conducted over the last 40 years have provided evidence of widespread shifts in the distribution of marine species in the coastal United States. For many species, the shift in their distribution matched the shift in their preferred temperatures. However, some species, notably American lobster, Homarus americanus, shifted poleward substantially faster than would be predicted from climate alone, while others lagged significantly behind. We investigated the degree to which ecological interactions could alter climate-induced range shifts in marine communities, focusing specifically on American lobster and its key predators. Parallel analysis of the changes in distribution and abundance of lobster, cod, and black sea bass revealed that the increase in lobster abundance and northeastern shift in the center of its range occurred in conjunction with a decline in cod biomass in the northern part of its range. The contraction of the southern lobster range limit was tracked by the northward expansion of its southern predator, black sea bass. These results suggest that predator release in the Gulf of Maine in conjunction with predator invasion at the southern limit may have contributed to the accelerated response of lobster to ocean warming.

  1. Communities of the Biological Crossroads: An Extraordinary Outdoor Classroom.

    ERIC Educational Resources Information Center

    Maier, Charles R.

    1992-01-01

    Provides rich description of the biological diversity found in a 30-mile section of Nebraska known as the "biological crossroads." Argues that the seven major associations of the Niobrara River valley provide a great classroom. Includes a complete listing of plant species. (DDR)

  2. Epilithic cyanobacterial communities of a marine tropical beach rock (Heron Island, Great Barrier Reef): diversity and diazotrophy.

    PubMed

    Díez, Beatriz; Bauer, Karolina; Bergman, Birgitta

    2007-06-01

    The diversity and nitrogenase activity of epilithic marine microbes in a Holocene beach rock (Heron Island, Great Barrier Reef, Australia) with a proposed biological calcification "microbialite" origin were examined. Partial 16S rRNA gene sequences from the dominant mat (a coherent and layered pink-pigmented community spread over the beach rock) and biofilms (nonstratified, differently pigmented microbial communities of small shallow depressions) were retrieved using denaturing gradient gel electrophoresis (DGGE), and a clone library was retrieved from the dominant mat. The 16S rRNA gene sequences and morphological analyses revealed heterogeneity in the cyanobacterial distribution patterns. The nonheterocystous filamentous genus Blennothrix sp., phylogenetically related to Lyngbya, dominated the mat together with unidentified nonheterocystous filaments of members of the Pseudanabaenaceae and the unicellular genus Chroococcidiopsis. The dominance and three-dimensional intertwined distribution of these organisms were confirmed by nonintrusive scanning microscopy. In contrast, the less pronounced biofilms were dominated by the heterocystous cyanobacterial genus Calothrix, two unicellular Entophysalis morphotypes, Lyngbya spp., and members of the Pseudanabaenaceae family. Cytophaga-Flavobacterium-Bacteroides and Alphaproteobacteria phylotypes were also retrieved from the beach rock. The microbial diversity of the dominant mat was accompanied by high nocturnal nitrogenase activities (as determined by in situ acetylene reduction assays). A new DGGE nifH gene optimization approach for cyanobacterial nitrogen fixers showed that the sequences retrieved from the dominant mat were related to nonheterocystous uncultured cyanobacterial phylotypes, only distantly related to sequences of nitrogen-fixing cultured cyanobacteria. These data stress the occurrence and importance of nonheterocystous epilithic cyanobacteria, and it is hypothesized that such epilithic cyanobacteria are

  3. 30 CFR 550.247 - What biological, physical, and socioeconomic information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the MMPA, sensitive underwater features, marine sanctuaries, critical habitat designated under the ESA, or other areas of biological concern. (b) Physical environment reports. Site-specific...

  4. 30 CFR 550.247 - What biological, physical, and socioeconomic information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the MMPA, sensitive underwater features, marine sanctuaries, critical habitat designated under the ESA, or other areas of biological concern. (b) Physical environment reports. Site-specific...

  5. 30 CFR 550.247 - What biological, physical, and socioeconomic information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information on chemosynthetic communities, federally listed threatened or endangered species, marine mammals protected under the MMPA, sensitive underwater features, marine sanctuaries, critical habitat designated under the ESA, or other areas of biological concern. (b) Physical environment reports. Site-specific...

  6. Mycosporine-like amino acids are multifunctional molecules in sea hares and their marine community

    PubMed Central

    Kicklighter, Cynthia E.; Kamio, Michiya; Nguyen, Linh; Germann, Markus W.; Derby, Charles D.

    2011-01-01

    Molecules of keystone significance are relatively rare, yet mediate a variety of interactions between organisms. They influence the distribution and abundance of species, the transfer of energy across multiple trophic levels, and thus they play significant roles in structuring ecosystems. Despite their potential importance in facilitating our understanding of ecological systems, only three molecules thus far have been proposed as molecules of keystone significance: saxitoxin and dimethyl sulfide in marine communities and tetrodotoxin in riparian communities. In the course of studying the neuroecology of chemical defenses, we identified three mycosporine-like amino acids (MAAs)—N-ethanol palythine (= asterina-330), N-isopropanol palythine (= aplysiapalythine A), and N-ethyl palythine (= aplysiapalythine B)—as intraspecific alarm cues for sea hares (Aplysia californica). These alarm cues are released in the ink secretion of sea hares and cause avoidance behaviors in neighboring conspecifics. Further, we show that these three bioactive MAAs, two [aplysiapalythine A (APA) and -B (APB)] being previously unknown molecules, are present in the algal diet of sea hares and are concentrated in their defensive secretion as well as in their skin. MAAs are known to be produced by algae, fungi, and cyanobacteria and are acquired by many aquatic animals through trophic interactions. MAAs are widely used as sunscreens, among other uses, but sea hares modify their function to serve a previously undocumented role, as intraspecific chemical cues. Our findings highlight the multifunctionality of MAAs and their role in ecological connectivity, suggesting that they may function as molecules of keystone significance in marine ecosystems. PMID:21709250

  7. Polychlorinated biphenyl (PCB) anaerobic degradation in marine sediments: microcosm study and role of autochthonous microbial communities.

    PubMed

    Matturro, Bruna; Ubaldi, Carla; Grenni, Paola; Caracciolo, Anna Barra; Rossetti, Simona

    2016-07-01

    Polychlorobiphenyl (PCB) biodegradation was followed for 1 year in microcosms containing marine sediments collected from Mar Piccolo (Taranto, Italy) chronically contaminated by this class of hazardous compounds. The microcosms were performed under strictly anaerobic conditions with or without the addition of Dehalococcoides mccartyi, the main microorganism known to degrade PCBs through the anaerobic reductive dechlorination process. Thirty PCB congeners were monitored during the experiments revealing that the biodegradation occurred in all microcosms with a decrease in hepta-, hexa-, and penta-chlorobiphenyls (CBs) and a parallel increase in low chlorinated PCBs (tri-CBs and tetra-CBs). The concentrations of the most representative congeners detected in the original sediment, such as 245-245-CB and 2345-245-CB, and of the mixture 2356-34-CB+234-245-CB, decreased by 32.5, 23.8, and 46.7 %, respectively, after only 70 days of anaerobic incubation without any bioaugmentation treatment. Additionally, the structure and population dynamics of the microbial key players involved in the biodegradative process and of the entire mixed microbial community were accurately defined by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) in both the original sediment and during the operation of the microcosm. The reductive dehalogenase genes of D. mccartyi, specifically involved in PCB dechlorination, were also quantified using real-time PCR (qPCR). Our results demonstrated that the autochthonous microbial community living in the marine sediment, including D. mccartyi (6.32E+06 16S rRNA gene copy numbers g(-1) sediment), was able to efficiently sustain the biodegradation of PCBs when controlled anaerobic conditions were imposed.

  8. Diversity patterns, ecology and biological activities of fungal communities associated with the endemic macroalgae across the Antarctic peninsula.

    PubMed

    Furbino, Laura E; Godinho, Valéria M; Santiago, Iara F; Pellizari, Franciane M; Alves, Tânia M A; Zani, Carlos L; Junior, Policarpo A S; Romanha, Alvaro J; Carvalho, Amanda G O; Gil, Laura H V G; Rosa, Carlos A; Minnis, Andrew M; Rosa, Luiz H

    2014-05-01

    We surveyed diversity patterns and engaged in bioprospecting for bioactive compounds of fungi associated with the endemic macroalgae, Monostroma hariotii and Pyropia endiviifolia, in Antarctica. A total of 239 fungal isolates were obtained, which were identified to represent 48 taxa and 18 genera using molecular methods. The fungal communities consisted of endemic, indigenous and cold-adapted cosmopolitan taxa, which displayed high diversity and richness, but low dominance indices. The extracts of endemic and cold-adapted fungi displayed biological activities and may represent sources of promising prototype molecules to develop drugs. Our results suggest that macroalgae along the marine Antarctic Peninsula provide additional niches where fungal taxa can survive and coexist with their host in the extreme conditions. We hypothesise that the dynamics of richness and dominance among endemic, indigenous and cold-adapted cosmopolitan fungal taxa might be used to understand and model the influence of climate change on the maritime Antarctic mycota.

  9. Icecolors`93: Biological weighting function for the ultraviolet inhibition of carbon fixation in a natural antarctic phytoplankton community

    SciTech Connect

    Boucher, N.; Prezelin, B.B.; Evens, T.

    1994-12-31

    The goals of the Icecolors 1993 expedition were (1) to develop a space/time climatology of incident and penetrating spectral irradiance for the southern oceans, (2) to quantify the ultraviolet (UV) dependency of primary production for pelagic and substrate-associated antarctic phytoplankton communities, and (3) to determine the UV inhibition effects on key target sites. The study was conducted at Palmer Station, Antarctica, prior to the opening of the ozone `hole` and during the onset of depletion of ozone, the most severe ever recorded over the Antarctic Peninsula. This paper discusses results from an experiment designed to estimate a biological weight function for primary production inhibition in Antarctic phytoplankton under natural irradiance. The newly derived function is presented and it is shown that the sensitivity of in situ phytoplankton to ambient UV-B at the end of winter was greater than that measured under artificial light conditions for temperate marine phytoplankton and terrestrial plants. 18 refs., 3 figs.

  10. Major National Societal Trends Likely to Affect the Marin Community Colleges through the Year 2000. Societal Factors Affecting Education.

    ERIC Educational Resources Information Center

    Stetson, Nancy E.

    Societal trends likely to affect the Marin Community Colleges (MCC) through the year 2000 are examined in this study of college planning for the next 5 years. Following information on the background, significance, and procedures of the study, a review is presented of six publications, selected for their particular relevance to the community…

  11. Biological Significance of Marine Actinobacteria of East Coast of Andhra Pradesh, India.

    PubMed

    Kavitha, Alapati; Savithri, Handanahal S

    2017-01-01

    An attempt was made to identify actinobacterial strains present in the marine soil of East Coast regions viz., Chirala, Bapatla, and Peddaganjam, Andhra Pradesh; Kanyakumari, Tamil Nadu and Goa, Goa along with the study of their antimicrobial potential. Eight out of 73 actinobacterial strains isolated from these regions showed strong antimicrobial activity against Gram positive bacteria, Gram negative bacteria, and Candida albicans. Molecular identification (16S rRNA analysis) of the eight strains revealed that they belong to Dietzia sp., Kocuria sp., Nocardiopsis sp., and Streptomyces spp. ISP (International Streptomyces project) -1, ISP-2 and starch casein media supported high antimicrobial potential after 5-6 days of growth. Production of antimicrobials by the strains varied significantly with different carbon and nitrogen sources. Gas chromatography mass spectrometry (GCMS) analysis of volatile compounds produced by the strains illustrated an array of antimicrobial compounds such as 1, 2-benzene dicarboxylic acid, 2-piperidinone, pyrrolo[1,2-a]pyrazine-1,4-dion, phenyl ethyl alcohol, 3-phenyl propionic acid etc. Ours is the first report on the study and detection of above mentioned antimicrobial metabolites from Dietzia sp. (A3), Kocuria sp. (A5), and Nocardiopsis sp. (A7). By sequence based analysis for secondary metabolites, non-ribosomal peptide synthetase (NRPS) gene cluster was noticed in six strains (A2, A3, A4, A6, A7, and A8) and none of them had polyketide synthase (PKS) system. The present study intimates the biological potentiality of the actinobacterial strains isolated from East Coast of Andhra Pradesh, India which reveals further scope to investigate new bioactive compounds from them by employing both natural product chemistry and modern biotechnological aspects.

  12. Satellite Tracking of Sympatric Marine Megafauna Can Inform the Biological Basis for Species Co-Management

    PubMed Central

    Gredzens, Christian; Marsh, Helene; Fuentes, Mariana M. P. B.; Limpus, Colin J.; Shimada, Takahiro; Hamann, Mark

    2014-01-01

    Context Systematic conservation planning is increasingly used to identify priority areas for protection in marine systems. However, ecosystem-based approaches typically use density estimates as surrogates for animal presence and spatial modeling to identify areas for protection and may not take into account daily or seasonal movements of animals. Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective. This study aims to demonstrate an evidence-based method to inform the biological basis for co-management of two sympatric species, dugongs and green sea turtles. This approach can then be used in conservation planning to delineate areas to maximize species protection. Methodology/Results Fast-acquisition satellite telemetry was used to track eleven dugongs and ten green turtles at two geographically distinct foraging locations in Queensland, Australia to evaluate the inter- and intra-species spatial relationships and assess the efficacy of existing protection zones. Home-range analysis and bathymetric modeling were used to determine spatial use and compared with existing protection areas using GIS. Dugong and green turtle home-ranges significantly overlapped in both locations. However, both species used different core areas and differences existed between regions in depth zone use and home-range size, especially for dugongs. Both species used existing protection areas in Shoalwater Bay, but only a single tracked dugong used the existing protection area in Torres Strait. Conclusions/Significance: Fast-acquisition satellite telemetry can provide evidence-based information on individual animal movements to delineate relationships between dugongs and green turtles in regions where they co-occur. This information can be used to increase the efficacy of conservation planning and complement more broadly based survey information. These species also use similar habitats, making complimentary co-management possible, but

  13. Biological Significance of Marine Actinobacteria of East Coast of Andhra Pradesh, India

    PubMed Central

    Kavitha, Alapati; Savithri, Handanahal S.

    2017-01-01

    An attempt was made to identify actinobacterial strains present in the marine soil of East Coast regions viz., Chirala, Bapatla, and Peddaganjam, Andhra Pradesh; Kanyakumari, Tamil Nadu and Goa, Goa along with the study of their antimicrobial potential. Eight out of 73 actinobacterial strains isolated from these regions showed strong antimicrobial activity against Gram positive bacteria, Gram negative bacteria, and Candida albicans. Molecular identification (16S rRNA analysis) of the eight strains revealed that they belong to Dietzia sp., Kocuria sp., Nocardiopsis sp., and Streptomyces spp. ISP (International Streptomyces project) -1, ISP-2 and starch casein media supported high antimicrobial potential after 5–6 days of growth. Production of antimicrobials by the strains varied significantly with different carbon and nitrogen sources. Gas chromatography mass spectrometry (GCMS) analysis of volatile compounds produced by the strains illustrated an array of antimicrobial compounds such as 1, 2-benzene dicarboxylic acid, 2-piperidinone, pyrrolo[1,2-a]pyrazine-1,4-dion, phenyl ethyl alcohol, 3-phenyl propionic acid etc. Ours is the first report on the study and detection of above mentioned antimicrobial metabolites from Dietzia sp. (A3), Kocuria sp. (A5), and Nocardiopsis sp. (A7). By sequence based analysis for secondary metabolites, non-ribosomal peptide synthetase (NRPS) gene cluster was noticed in six strains (A2, A3, A4, A6, A7, and A8) and none of them had polyketide synthase (PKS) system. The present study intimates the biological potentiality of the actinobacterial strains isolated from East Coast of Andhra Pradesh, India which reveals further scope to investigate new bioactive compounds from them by employing both natural product chemistry and modern biotechnological aspects. PMID:28729856

  14. Satellite tracking of sympatric marine megafauna can inform the biological basis for species co-management.

    PubMed

    Gredzens, Christian; Marsh, Helene; Fuentes, Mariana M P B; Limpus, Colin J; Shimada, Takahiro; Hamann, Mark

    2014-01-01

    Systematic conservation planning is increasingly used to identify priority areas for protection in marine systems. However, ecosystem-based approaches typically use density estimates as surrogates for animal presence and spatial modeling to identify areas for protection and may not take into account daily or seasonal movements of animals. Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective. This study aims to demonstrate an evidence-based method to inform the biological basis for co-management of two sympatric species, dugongs and green sea turtles. This approach can then be used in conservation planning to delineate areas to maximize species protection. Fast-acquisition satellite telemetry was used to track eleven dugongs and ten green turtles at two geographically distinct foraging locations in Queensland, Australia to evaluate the inter- and intra-species spatial relationships and assess the efficacy of existing protection zones. Home-range analysis and bathymetric modeling were used to determine spatial use and compared with existing protection areas using GIS. Dugong and green turtle home-ranges significantly overlapped in both locations. However, both species used different core areas and differences existed between regions in depth zone use and home-range size, especially for dugongs. Both species used existing protection areas in Shoalwater Bay, but only a single tracked dugong used the existing protection area in Torres Strait. Fast-acquisition satellite telemetry can provide evidence-based information on individual animal movements to delineate relationships between dugongs and green turtles in regions where they co-occur. This information can be used to increase the efficacy of conservation planning and complement more broadly based survey information. These species also use similar habitats, making complimentary co-management possible, but important differences exist between locations making it

  15. Enriching a cellulose hydrogel with a biologically active marine exopolysaccharide for cell-based cartilage engineering.

    PubMed

    Rederstorff, E; Rethore, G; Weiss, P; Sourice, S; Beck-Cormier, S; Mathieu, E; Maillasson, M; Jacques, Y; Colliec-Jouault, S; Fellah, B H; Guicheux, J; Vinatier, C

    2017-04-01

    The development of biologically and mechanically competent hydrogels is a prerequisite in cartilage engineering. We recently demonstrated that a marine exopolysaccharide, GY785, stimulates the in vitro chondrogenesis of adipose stromal cells. In the present study, we thus hypothesized that enriching our silated hydroxypropyl methylcellulose hydrogel (Si-HPMC) with GY785 might offer new prospects in the development of scaffolds for cartilage regeneration. The interaction properties of GY785 with growth factors was tested by surface plasmon resonance (SPR). The biocompatibility of Si-HPMC/GY785 towards rabbit articular chondrocytes (RACs) and its ability to maintain and recover a chondrocytic phenotype were then evaluated in vitro by MTS assay, cell counting and qRT-PCR. Finally, we evaluated the potential of Si-HPMC/GY785 associated with RACs to form cartilaginous tissue in vivo by transplantation into the subcutis of nude mice for 3 weeks. Our SPR data indicated that GY785 was able to physically interact with BMP-2 and TGFβ. Our analyses also showed that three-dimensionally (3D)-cultured RACs into Si-HPMC/GY785 strongly expressed type II collagen (COL2) and aggrecan transcripts when compared to Si-HPMC alone. In addition, RACs also produced large amounts of extracellular matrix (ECM) containing glycosaminoglycans (GAG) and COL2. When dedifferentiated RACs were replaced in 3D in Si-HPMC/GY785, the expressions of COL2 and aggrecan transcripts were recovered and that of type I collagen decreased. Immunohistological analyses of Si-HPMC/GY785 constructs transplanted into nude mice revealed the production of a cartilage-like extracellular matrix (ECM) containing high amounts of GAG and COL2. These results indicate that GY785-enriched Si-HPMC appears to be a promising hydrogel for cartilage tissue engineering. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Marine pollution

    SciTech Connect

    Albaiges, J. )

    1989-01-01

    This book covers the following topics: Transport of marine pollutants; Transformation of pollutants in the marine environment; Biological effects of marine pollutants; Sources and transport of oil pollutants in the Persian Gulf; Trace metals and hydrocarbons in Syrian coastal waters; and Techniques for analysis of trace pollutants.

  17. A novel approach to the assess biotic oxygen consumption in marine sediment communities

    NASA Astrophysics Data System (ADS)

    Baranov, Victor; Queiros, Ana; Widdicombe, Stephen; Stephens, Nick; Lessin, Gennadi; Krause, Stefan; Lewandowski, Joerg

    2016-04-01

    Bioturbation , the mixing of the sediment matrix by burrowing animals impacts sediment metabolism, including respiration through redistribution of particulate organics, changes in bacterial biota diversity and acitivity, as well as via burrowing fauna's own metabolism. Bioturbation, reflecting faunal activity, is also a proxy for the general sedimentary ecosystem health, and can be impacted by many of emerging marine environmental issues such as ocean acidification, warming and the occurrence of heat waves. Sedimentary oxygen consumption is often taken as a proxy for the activity of bioturbating fauna, but determining baselines can be difficult because of the confounding effects of other fauna and microbes present in sediments, as well as irnorganic processes that consume oxygen. Limitations therefore exist in current methodologies, and numerous confounding factors are hampering progress in this area. Here, we present novel method for the assessment of sediment respiration which is expected to be affected only by the biogenic oxygen consumption (namely aerobic respiration). As long as tracer reduction "immune" to inorganic oxygen consumption, so that measurements using this method can be used, alongside traditional methods, to decouple biological respiration from inorganic oxygen consumption reactions. The tracer is easily detectable, non-toxic and can be applied in systems with constant oxygen supply. The latter allow for incubation without the need to to work with unsealed experimental units, bringing procedural advantage over traditional methods. Consequently assessed bioturbating fauna is not exposed to hypoxia and additional stress. Here, we had applied system for the first time to investigate impacts of a common North-Atlantic bioturbator, the brittle star Amphiura filiformis, - on respiration of marine sediments. Two series of experiments were conducted with animals and sediment collected from Cawsand Bay, Plymouth, UK Preliminary results show that tracer

  18. Functional genomics to assess biological responses to marine pollution at physiological and evolutionary timescales: toward a vision of predictive ecotoxicology.

    PubMed

    Reid, Noah M; Whitehead, Andrew

    2016-09-01

    Marine pollution is ubiquitous, and is one of the key factors influencing contemporary marine biodiversity worldwide. To protect marine biodiversity, how do we surveil, document and predict the short- and long-term impacts of pollutants on at-risk species? Modern genomics tools offer high-throughput, information-rich and increasingly cost-effective approaches for characterizing biological responses to environmental stress, and are important tools within an increasing sophisticated kit for surveiling and assessing impacts of pollutants on marine species. Through the lens of recent research in marine killifish, we illustrate how genomics tools may be useful for screening chemicals and pollutants for biological activity and to reveal specific mechanisms of action. The high dimensionality of transcriptomic responses enables their usage as highly specific fingerprints of exposure, and these fingerprints can be used to diagnose environmental problems. We also emphasize that molecular pathways recruited to respond at physiological timescales are the same pathways that may be targets for natural selection during chronic exposure to pollutants. Gene complement and sequence variation in those pathways can be related to variation in sensitivity to environmental pollutants within and among species. Furthermore, allelic variation associated with evolved tolerance in those pathways could be tracked to estimate the pace of environmental health decline and recovery. We finish by integrating these paradigms into a vision of how genomics approaches could anchor a modernized framework for advancing the predictive capacity of environmental and ecotoxicological science. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Impact of geoengineering with olivine dissolution on the carbon cycle and marine biology

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Abrams, J.; Völker, C.; Wolf-Gladrow, D. A.; Hartmann, J.

    2012-04-01

    We investigate the potential of a specific geoengineering technique: the carbon sequestration by artificially enhanced silicate weathering via the dissolution of olivine. This approach would not only operate against rising temperatures but would also oppose ocean acidification. If details of the marine chemistry are taken into consideration, a new mass ratio of CO2 sequestration per olivine dissolution of about 1 is achieved, 20% smaller than previously assumed. We calculate that this approach has the potential to sequestrate up to 1 Pg of C per year directly, if olivine is distributed as fine powder over land areas of the humid tropics, but this rate is limited by the saturation concentration of silicic acid. These upper limit sequestration rates come at the environmental cost of pH values in the rivers rising to 8.2 in examples for the rivers Amazon and Congo (Köhler et al., 2010). The secondary effects of the input of silicic acid connected with this approach leads in an ecosystem model (ReCOM2.0 in MITgcm) to species shifts aways from the calcifying species towards diatoms, thus altering the biological carbon pumps. Open ocean dissolution of olivine would sequestrate about 1 Pg CO2 per Pg olivine from which about 8% are caused by changes in the biological pumps (increase export of organic matter, decreased export of CaCO3). The chemical impact of open ocean dissolution of olivine (the increased alkalinity input) is therefore less efficient than dissolution on land, but leads due to different chemical impacts to a higher surface ocean pH enhancement to counteract ocean acidification. We finally investigate open ocean dissolution rates of up to 10 Pg olivine per year corresponding to geoengineering rates which might be of interest in the light of expected future emission (e.g. A2 scenario with emissions rising to 30 PgC/yr in 2100 AD). Those rates would still sequestrate only less than 20% of the emission until 2100, but would require that the nowadays available

  20. Modeling ecological drivers in marine viral communities using comparative metagenomics and network analyses

    PubMed Central

    Hurwitz, Bonnie L.; Westveld, Anton H.; Brum, Jennifer R.; Sullivan, Matthew B.

    2014-01-01

    Long-standing questions in marine viral ecology are centered on understanding how viral assemblages change along gradients in space and time. However, investigating these fundamental ecological questions has been challenging due to incomplete representation of naturally occurring viral diversity in single gene- or morphology-based studies and an inability to identify up to 90% of reads in viral metagenomes (viromes). Although protein clustering techniques provide a significant advance by helping organize this unknown metagenomic sequence space, they typically use only ∼75% of the data and rely on assembly methods not yet tuned for naturally occurring sequence variation. Here, we introduce an annotation- and assembly-free strategy for comparative metagenomics that combines shared k-mer and social network analyses (regression modeling). This robust statistical framework enables visualization of complex sample networks and determination of ecological factors driving community structure. Application to 32 viromes from the Pacific Ocean Virome dataset identified clusters of samples broadly delineated by photic zone and revealed that geographic region, depth, and proximity to shore were significant predictors of community structure. Within subsets of this dataset, depth, season, and oxygen concentration were significant drivers of viral community structure at a single open ocean station, whereas variability along onshore–offshore transects was driven by oxygen concentration in an area with an oxygen minimum zone and not depth or proximity to shore, as might be expected. Together these results demonstrate that this highly scalable approach using complete metagenomic network-based comparisons can both test and generate hypotheses for ecological investigation of viral and microbial communities in nature. PMID:25002514

  1. Modeling ecological drivers in marine viral communities using comparative metagenomics and network analyses.

    PubMed

    Hurwitz, Bonnie L; Westveld, Anton H; Brum, Jennifer R; Sullivan, Matthew B

    2014-07-22

    Long-standing questions in marine viral ecology are centered on understanding how viral assemblages change along gradients in space and time. However, investigating these fundamental ecological questions has been challenging due to incomplete representation of naturally occurring viral diversity in single gene- or morphology-based studies and an inability to identify up to 90% of reads in viral metagenomes (viromes). Although protein clustering techniques provide a significant advance by helping organize this unknown metagenomic sequence space, they typically use only ∼75% of the data and rely on assembly methods not yet tuned for naturally occurring sequence variation. Here, we introduce an annotation- and assembly-free strategy for comparative metagenomics that combines shared k-mer and social network analyses (regression modeling). This robust statistical framework enables visualization of complex sample networks and determination of ecological factors driving community structure. Application to 32 viromes from the Pacific Ocean Virome dataset identified clusters of samples broadly delineated by photic zone and revealed that geographic region, depth, and proximity to shore were significant predictors of community structure. Within subsets of this dataset, depth, season, and oxygen concentration were significant drivers of viral community structure at a single open ocean station, whereas variability along onshore-offshore transects was driven by oxygen concentration in an area with an oxygen minimum zone and not depth or proximity to shore, as might be expected. Together these results demonstrate that this highly scalable approach using complete metagenomic network-based comparisons can both test and generate hypotheses for ecological investigation of viral and microbial communities in nature.

  2. Development of a cost-effective metabarcoding strategy for analysis of the marine phytoplankton community

    PubMed Central

    Yoon, Tae-Ho; Kang, Hye-Eun; Kang, Chang-Keun; Lee, Sang Heon; Ahn, Do-Hwan

    2016-01-01

    We developed a cost-effective metabarcoding strategy to analyze phytoplankton community structure using the Illumina MiSeq system. The amplicons (404–411 bp) obtained by end-pairing of two reads were sufficiently long to distinguish algal species and provided barcode data equivalent to those generated with the Roche 454 system, but at less than 1/20th of the cost. The original universal primer sequences targeting the 23S rDNA region and the PCR strategy were both modified, and this resulted in higher numbers of eukaryotic algal sequences by excluding non-photosynthetic proteobacterial sequences supporting effectiveness of this strategy. The novel strategy was used to analyze the phytoplankton community structure of six water samples from the East/Japan Sea: surface and 50 m depths at coastal and open-sea sites, with collections in May and July 2014. In total, 345 operational taxonomic units (OTUs) were identified, which covered most of the prokaryotic and eukaryotic algal phyla, including Dinophyta, Rhodophyta, Ochrophyta, Chlorophyta, Streptophyta, Cryptophyta, Haptophyta, and Cyanophyta. This highlights the importance of plastid 23S primers, which perform better than the currently used 16S primers for phytoplankton community surveys. The findings also revealed that more efforts should be made to update 23S rDNA sequences as well as those of 16S in the databases. Analysis of algal proportions in the six samples showed that community structure differed depending on location, depth and season. Across the six samples evaluated, the numbers of OTUs in each phylum were similar but their relative proportions varied. This novel strategy would allow laboratories to analyze large numbers of samples at reasonable expense, whereas this has not been possible to date due to cost and time. In addition, we expect that this strategy will generate a large amount of novel data that could potentially change established methods and tools that are currently used in the realms of

  3. Development of a cost-effective metabarcoding strategy for analysis of the marine phytoplankton community.

    PubMed

    Yoon, Tae-Ho; Kang, Hye-Eun; Kang, Chang-Keun; Lee, Sang Heon; Ahn, Do-Hwan; Park, Hyun; Kim, Hyun-Woo

    2016-01-01

    We developed a cost-effective metabarcoding strategy to analyze phytoplankton community structure using the Illumina MiSeq system. The amplicons (404-411 bp) obtained by end-pairing of two reads were sufficiently long to distinguish algal species and provided barcode data equivalent to those generated with the Roche 454 system, but at less than 1/20th of the cost. The original universal primer sequences targeting the 23S rDNA region and the PCR strategy were both modified, and this resulted in higher numbers of eukaryotic algal sequences by excluding non-photosynthetic proteobacterial sequences supporting effectiveness of this strategy. The novel strategy was used to analyze the phytoplankton community structure of six water samples from the East/Japan Sea: surface and 50 m depths at coastal and open-sea sites, with collections in May and July 2014. In total, 345 operational taxonomic units (OTUs) were identified, which covered most of the prokaryotic and eukaryotic algal phyla, including Dinophyta, Rhodophyta, Ochrophyta, Chlorophyta, Streptophyta, Cryptophyta, Haptophyta, and Cyanophyta. This highlights the importance of plastid 23S primers, which perform better than the currently used 16S primers for phytoplankton community surveys. The findings also revealed that more efforts should be made to update 23S rDNA sequences as well as those of 16S in the databases. Analysis of algal proportions in the six samples showed that community structure differed depending on location, depth and season. Across the six samples evaluated, the numbers of OTUs in each phylum were similar but their relative proportions varied. This novel strategy would allow laboratories to analyze large numbers of samples at reasonable expense, whereas this has not been possible to date due to cost and time. In addition, we expect that this strategy will generate a large amount of novel data that could potentially change established methods and tools that are currently used in the realms of

  4. Size distributions of organic nitrogen and carbon in remote marine aerosols: Evidence of marine biological origin based on their isotopic ratios

    NASA Astrophysics Data System (ADS)

    Miyazaki, Yuzo; Kawamura, Kimitaka; Sawano, Maki

    2010-03-01

    Size-segregated aerosol samples were collected over the western North Pacific in summer 2008 for the measurements of organic nitrogen (ON) and organic carbon (OC). ON and OC showed bimodal size distributions. Their concentrations showed positive correlation with those of biogenic tracers, methanesulfonic acid (MSA) and azelaic acid (C9). We found that average ON and OC concentrations were twice greater in aerosols collected in the oceanic region with higher biological productivity than in the regions with lower productivity. The average ON/OC ratios are higher (0.49 ± 0.11) in more biologically influenced aerosols than those (0.35 ± 0.10) in less influenced aerosols. Stable carbon isotopic analysis indicates that marine-derived carbon accounted for ˜46-72% of total carbon in more biologically influenced aerosols. These results provide evidence that organic aerosols in this region are enriched in ON that is linked to oceanic biological activity and the subsequent emissions to the atmosphere.

  5. Phylogeny, phylogeography, phylobetadiversity and the molecular analysis of biological communities

    PubMed Central

    Emerson, Brent C.; Cicconardi, Francesco; Fanciulli, Pietro P.; Shaw, Peter J. A.

    2011-01-01

    There has been much recent interest and progress in the characterization of community structure and community assembly processes through the application of phylogenetic methods. To date most focus has been on groups of taxa for which some relevant detail of their ecology is known, for which community composition is reasonably easily quantified and where the temporal scale is such that speciation is not likely to feature. Here, we explore how we might apply a molecular genetic approach to investigate community structure and assembly at broad taxonomic and geographical scales, where we have little knowledge of species ecology, where community composition is not easily quantified, and where speciation is likely to be of some importance. We explore these ideas using the class Collembola as a focal group. Gathering molecular evidence for cryptic diversity suggests that the ubiquity of many species of Collembola across the landscape may belie greater community complexity than would otherwise be assumed. However, this morphologically cryptic species-level diversity poses a challenge for attempts to characterize diversity both within and among local species assemblages. Recent developments in high throughput parallel sequencing technology, combined with mtDNA barcoding, provide an advance that can bring together the fields of phylogenetic and phylogeographic analysis to bear on this problem. Such an approach could be standardized for analyses at any geographical scale for a range of taxonomic groups to quantify the formation and composition of species assemblages. PMID:21768154

  6. The Biology of HIV/AIDS: A Case Study in Community Engagement

    ERIC Educational Resources Information Center

    Caccavo, Frank, Jr.

    2008-01-01

    This article describes a project for the Biology of HIV/AIDS course for undergraduate biology majors. This project challenged science students to engage the community on two different levels. They first had to interact directly and personally with HIV/AIDS activists. The proposal then encouraged them to think about and describe ways of engaging a…

  7. The Biology of HIV/AIDS: A Case Study in Community Engagement

    ERIC Educational Resources Information Center

    Caccavo, Frank, Jr.

    2008-01-01

    This article describes a project for the Biology of HIV/AIDS course for undergraduate biology majors. This project challenged science students to engage the community on two different levels. They first had to interact directly and personally with HIV/AIDS activists. The proposal then encouraged them to think about and describe ways of engaging a…

  8. Stronger predation in the tropics shapes species richness patterns in marine communities.

    PubMed

    Freestone, Amy L; Osman, Richard W; Ruiz, Gregory M; Torchin, Mark E

    2011-04-01

    Species interactions are widely assumed to be stronger at lower latitudes, but surprisingly few experimental studies test this hypothesis, and none ties these processes to observed patterns of species richness across latitude. We report here the first experimental field test that predation is both stronger and has a disproportionate effect on species richness in the tropics relative to the temperate zone. We conducted predator-exclusion experiments on communities of sessile marine invertebrates in four regions, which span 32 degrees latitude, in the western Atlantic Ocean and Caribbean Sea. Over a three-month timescale, predation had no effect on species richness in the temperate zone. In the tropics, however, communities were from two to over ten times more species-rich in the absence of predators than when predators were present. While micro-and macro-predators likely compete for the limited prey resource in the tropics, micropredators alone were able to exert as much pressure on the invertebrate communities as the full predator community. This result highlights the extent to which exposure to even a subset of the predator guild can significantly impact species richness in the tropics. Patterns were consistent in analyses that included relative and total species abundances. Higher species richness in the absence of predators in the tropics was also observed when species occurrences were pooled across two larger spatial scales, site and region, demonstrating a consistent scaling relationship. These experimental results show that predation can both limit local species abundances and shape patterns of regional coexistence in the tropics. When preestablished diverse tropical communities were then exposed to predation for different durations, ranging from one to several days, species richness was always reduced. These findings confirmed that impacts of predation in the tropics are strong and consistent, even in more established communities. Our results offer empirical

  9. Bacterial Exopolysaccharides from Extreme Marine Habitats: Production, Characterization and Biological Activities

    PubMed Central

    Poli, Annarita; Anzelmo, Gianluca; Nicolaus, Barbara

    2010-01-01

    Many marine bacteria produce exopolysaccharides (EPS) as a strategy for growth, adhering to solid surfaces, and to survive adverse conditions. There is growing interest in isolating new EPS producing bacteria from marine environments, particularly from extreme marine environments such as deep-sea hydrothermal vents characterized by high pressure and temperature and heavy metal presence. Marine EPS-producing microorganisms have been also isolated from several extreme niches such as the cold marine environments typically of Arctic and Antarctic sea ice, characterized by low temperature and low nutrient concentration, and the hypersaline marine environment found in a wide variety of aquatic and terrestrial ecosystems such as salt lakes and salterns. Most of their EPSs are heteropolysaccharides containing three or four different monosaccharides arranged in groups of 10 or less to form the repeating units. These polymers are often linear with an average molecular weight ranging from 1 × 105 to 3 × 105 Da. Some EPS are neutral macromolecules, but the majority of them are polyanionic for the presence of uronic acids or ketal-linked pyruvate or inorganic residues such as phosphate or sulfate. EPSs, forming a layer surrounding the cell, provide an effective protection against high or low temperature and salinity, or against possible predators. By examining their structure and chemical-physical characteristics it is possible to gain insight into their commercial application, and they are employed in several industries. Indeed EPSs produced by microorganisms from extreme habitats show biotechnological promise ranging from pharmaceutical industries, for their immunomodulatory and antiviral effects, bone regeneration and cicatrizing capacity, to food-processing industries for their peculiar gelling and thickening properties. Moreover, some EPSs are employed as biosurfactants and in detoxification mechanisms of petrochemical oil-polluted areas. The aim of this paper is to give

  10. Bacterial exopolysaccharides from extreme marine habitats: production, characterization and biological activities.

    PubMed

    Poli, Annarita; Anzelmo, Gianluca; Nicolaus, Barbara

    2010-06-03

    Many marine bacteria produce exopolysaccharides (EPS) as a strategy for growth, adhering to solid surfaces, and to survive adverse conditions. There is growing interest in isolating new EPS producing bacteria from marine environments, particularly from extreme marine environments such as deep-sea hydrothermal vents characterized by high pressure and temperature and heavy metal presence. Marine EPS-producing microorganisms have been also isolated from several extreme niches such as the cold marine environments typically of Arctic and Antarctic sea ice, characterized by low temperature and low nutrient concentration, and the hypersaline marine environment found in a wide variety of aquatic and terrestrial ecosystems such as salt lakes and salterns. Most of their EPSs are heteropolysaccharides containing three or four different monosaccharides arranged in groups of 10 or less to form the repeating units. These polymers are often linear with an average molecular weight ranging from 1 x 10(5) to 3 x 10(5) Da. Some EPS are neutral macromolecules, but the majority of them are polyanionic for the presence of uronic acids or ketal-linked pyruvate or inorganic