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  • 1
    Online-Ressource
    Online-Ressource
    Dordrecht :Springer Netherlands,
    Schlagwort(e): Oceanography. ; Environmental sciences. ; Marine ecology -- Arctic Ocean. ; Electronic books.
    Materialart: Online-Ressource
    Seiten: 1 online resource (461 pages)
    Ausgabe: 1st ed.
    ISBN: 9789401788632
    DDC: 577.82091632
    Sprache: Englisch
    Anmerkung: Intro -- Contents -- Contributors -- Chapter 1: The Pacific Arctic Region: An Introduction -- 1.1 Introduction -- 1.2 The Pacific Arctic Region -- 1.3 Physical Processes, Hydrography and Sea Ice: Field and Modeling -- 1.4 Atmospheric Forcing and Sea Ice -- 1.5 Physical Processes and Modeling -- 1.6 Carbon Transformations and Cycling -- 1.7 Lower and Upper Trophic Levels and Ecosystem Modeling -- 1.8 Summary -- References -- Chapter 2: Recent and Future Changes in the Meteorology of the Pacific Arctic -- 2.1 Introduction -- 2.2 Climatological Fields -- 2.3 Storms and Temporal Variability -- 2.4 The Differences of the Pacific Sector Relative to the Larger Arctic System -- 2.5 The Future Climate of the Pacific Arctic -- 2.6 Summary -- References -- Chapter 3: Recent Variability in Sea Ice Cover, Age, and Thickness in the Pacific Arctic Region -- 3.1 Introduction -- 3.2 Sea Ice Cover -- 3.2.1 Trends in Sea Ice Cover -- 3.2.2 Interannual Variability in Sea Ice Cover -- 3.3 Sea Ice Age -- 3.3.1 Sea Ice Age Data and Analysis -- 3.3.2 Recent Variability in Sea Ice Age -- 3.4 Sea Ice Thickness -- 3.4.1 Sea Ice Thickness Data and Background -- 3.4.2 Sea Ice Thickness Model Description -- 3.4.3 Sea Ice Thickness Model Validation -- 3.4.4 Recent Variability in Modeled Sea Ice Thickness -- 3.4.5 Potential Mechanisms of Sea Ice Thinning -- 3.5 Implications and Possible Future States -- 3.6 Summary -- References -- Chapter 4: Abrupt Climate Changes and Emerging Ice- Ocean Processes in the Pacific Arctic Region and the Bering Sea -- 4.1 Introduction -- 4.2 Data and Methods -- 4.3 Leading Climate Forcing: Arctic Dipole (DA) Pattern -- 4.4 Investigating Mechanisms Responsible for Arctic Sea Ice Minima Using PIOMAS -- 4.5 Bering Strait Heat Transport and the DA -- 4.6 Modeling the Bering Sea Cold Pool Using CIOM. , 4.7 Modeling Landfast Ice in the Beaufort-Chukchi Seas Using CIOM -- 4.8 Possible Air-Ice-Sea Feedback Loops in the Western Arctic -- 4.9 Summary -- References -- Chapter 5: The Large Scale Ocean Circulation and Physical Processes Controlling Pacific-Arctic Interactions -- 5.1 Introduction -- 5.2 The Northern North Pacific, Gulf of Alaska, and Alaskan Stream -- 5.3 Western Subarctic Gyre -- 5.4 Bering Sea -- 5.5 Chukchi Sea -- 5.6 Beaufort Sea -- 5.7 Heat/Freshwater Content and Sea Ice -- 5.8 Summary -- References -- Chapter 6: Shelf-Break Exchange in the Bering, Chukchi and Beaufort Seas -- 6.1 Introduction -- 6.2 The Bering Shelf-Break -- 6.3 The Chukchi and Beaufort Shelf-Break -- 6.3.1 Shelf-Basin Connections -- 6.3.2 Instabilities of the Shelf-Break Jet -- 6.3.3 Wind-Driven Exchange -- 6.4 Undersea Canyons of the Chukchi and Beaufort Shelves -- 6.4.1 Herald Canyon -- 6.4.2 Barrow Canyon -- 6.4.3 Mackenzie Trough -- 6.5 Polynya-Formed Dense Shelf Water -- 6.6 Summary -- 6.6.1 Bering Shelf-Break -- 6.6.2 Chukchi/Beaufort Shelf-Break -- References -- Chapter 7: On the Flow Through Bering Strait: A Synthesis of Model Results and Observations -- 7.1 Introduction -- 7.2 Model Descriptions -- 7.2.1 Bering Ecosystem Study Ice-Ocean Modeling and Assimilation System (BESTMAS) -- 7.2.2 Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) -- 7.2.3 Naval Postgraduate School Arctic Modeling Effort (NAME) -- 7.2.4 Nucleus for European Modelling of the Ocean (NEMO) with ORCA Configuration -- 7.2.5 Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) -- 7.3 Bering Strait Observational Mooring Data -- 7.4 Results -- 7.5 Discussion -- 7.6 Summary -- References -- Chapter 8: Carbon Fluxes Across Boundaries in the Pacific Arctic Region in a Changing Environment -- 8.1 Introduction -- 8.2 Geographic and Water Mass Features. , 8.2.1 Geographic Definition and Description -- 8.2.2 Water-Mass Characterizations -- 8.3 Pacific Ocean Inflow -- 8.4 Fluxes Across the Arctic Land-Sea Interface -- 8.5 CO 2 Flux Across the Air-Sea Boundary -- 8.5.1 Sea Surface p CO 2 Distribution -- 8.5.2 Air-Sea CO 2 Flux -- 8.6 Impact of Seasonal Sea-Ice Cycle -- 8.7 Overall DIC Budget -- 8.8 Summary -- References -- Chapter 9: Carbon Biogeochemistry of the Western Arctic: Primary Production, Carbon Export and the Controls on Ocean Acidification -- 9.1 Introduction -- 9.2 Primary Production -- 9.2.1 Northern Bering Sea -- 9.2.2 Chukchi Sea -- 9.2.3 Deep Canada Basin -- 9.3 DOC Production -- 9.3.1 Spatial Variability -- 9.3.2 The Use of DOC/Salinity Relationships -- 9.3.3 Dynamical Characterization of tDOC-Inputs & -- Sinks -- 9.4 Export Flux of Particulate Organic Carbon -- 9.4.1 Regional Case Studies -- 9.4.1.1 Chukchi Sea: The Shelf Basin Interaction Study (SBI-II) -- 9.4.1.2 Mackenzie Shelf: Canadian Arctic Shelf Exchange Study (CASES) -- 9.4.1.3 Laptev Sea, Northern Baffin Bay and the Beaufort Sea Shelves -- 9.4.1.4 Eastern and Central Arctic Ocean: Polarstern ARK-XXII/2 Expedition -- 9.4.2 Conclusions -- 9.5 Grazing -- 9.6 Benthic Carbon Cycling -- 9.6.1 Sediment Nutrient Efflux -- 9.7 Contribution of Heterotrophic Bacteria to Carbon Cycling -- 9.7.1 Respiration by Heterotrophic Bacteria -- 9.7.2 Biomass Production by Heterotrophic Bacteria and Phytoplankton -- 9.7.3 Growth Efficiency in the Arctic Ocean -- 9.7.4 Implications for Shelf-Basin Exchange -- 9.8 Ocean Acidification -- 9.8.1 The Bering Sea -- 9.8.2 The Western Arctic Ocean -- 9.9 Summary -- References -- Chapter 10: Biodiversity and Biogeography of the Lower Trophic Taxa of the Pacific Arctic Region: Sensitivities to Climate Change -- 10.1 General Introduction -- 10.2 Phytoplankton in the PAR -- 10.2.1 Introduction. , 10.2.2 Phytoplankton and Sea Ice Algae: An Overview -- 10.2.3 Latitudinal Variation of Phytoplankton Biodiversity and Community Composition in the Western Arctic Ocean -- 10.2.4 Synechococcus -- 10.2.5 Sensitivities to Habitat Changes -- 10.3 Heterotrophic Microbes in the PAR -- 10.3.1 Introduction -- 10.3.2 Viruses -- 10.3.3 Bacterial Diversity -- 10.3.4 Bacterial and Archaeal Diversity Levels in the Arctic Ocean Versus Lower-Latitude Oceans -- 10.3.5 Diversity and Distribution of Heterotrophic Protists -- 10.3.5.1 Diversity of Heterotrophic Protists Assessed by Microscopy -- 10.3.5.2 Diversity of Heterotrophic Protists Assessed by Molecular Genetics -- 10.3.5.3 Biogeographical and Depth Distribution of Heterotrophic Protists -- 10.3.5.4 Heterotrophic Microbes: Future Research -- 10.4 Benthic Fauna of the PAR -- 10.4.1 Introduction -- 10.4.2 Benthic Fauna of the Northern Bering, Chukchi, and Western Beaufort Seas -- 10.4.2.1 Environmental Setting -- 10.4.2.2 General Biogeography -- 10.4.3 Benthic Invertebrate Patterns in the Canadian Beaufort Sea Shelf -- 10.4.3.1 Environmental Setting -- 10.4.3.2 General Biogeography and Biodiversity -- 10.4.4 Deep-Sea Benthos -- 10.4.5 Effect of Climate Change on Benthic Fauna of the PAR -- 10.5 Sea Ice Associated Diversity and Production in the PAR -- 10.5.1 Introduction -- 10.5.2 Primary Producers: Diversity, Abundance and Activity -- 10.5.3 Sea Ice Meiofauna Abundance and Diversity -- 10.5.4 Effects of Climate Change -- 10.6 Biodiversity and Biogeography of Metazoan Zooplankton of the PAR -- 10.6.1 Introduction -- 10.6.2 Species Diversity -- 10.6.3 Zooplankton Advection: Expatriate Analysis -- 10.6.4 Horizontal Zooplankton Community Structure -- 10.6.5 Vertical Distribution of Zooplankton in the Deep Waters of the PAR -- 10.6.6 Long-Term Change -- 10.7 Summary -- References. , Chapter 11: Marine Fishes, Birds and Mammals as Sentinels of Ecosystem Variability and Reorganization in the Pacific Arctic Region -- 11.1 Introduction -- 11.1.1 Ecological Scale -- 11.2 Overview: Ecology of Upper Trophic Level (UTL) Species -- 11.2.1 Fishes and Crabs -- 11.2.1.1 Northern Bering and Chukchi Seas -- 11.2.1.2 Beaufort Sea -- 11.2.2 Marine Birds -- 11.2.2.1 At-Sea Distribution -- 11.2.2.2 Breeding Colonies -- 11.2.2.3 Seasonal Dynamics -- 11.2.3 Marine Mammals -- 11.2.3.1 Core Arctic Species -- 11.2.3.2 Seasonally Migrant Species -- 11.3 Case Studies: Responses of UTL Species to Environmental Variability -- 11.3.1 Fishes and Crabs -- 11.3.1.1 Salmon and Forage Fish in the Northern Bering Sea -- 11.3.1.2 Snow Crab in the Chukchi Sea -- 11.3.1.3 Demersal Fish and Crab in the Beaufort Sea -- 11.3.2 Marine Birds -- 11.3.2.1 Nesting Auklets and the Anadyr Current -- 11.3.3 Eiders During Winter and Migration -- 11.3.4 Marine Mammals -- 11.3.4.1 Timing and Relative Abundance of Bowhead Whales Feeding in the Canadian Beaufort Sea -- 11.3.4.2 Body Condition of Ringed Seals in the Western Canadian Arctic -- 11.3.4.3 Changes in Life-History and Diet of Walruses and Seals in the Northern Bering and Chukchi Seas -- 11.4 UTL Species as Ecosystem Sentinels -- 11.4.1 UTL-Focused Research Framework -- 11.4.1.1 Trophic Interactions -- 11.4.1.2 Foraging Dynamics -- 11.4.1.3 Species Composition -- 11.5 Summary -- 11.5.1 Tracking Biological Responses in an Era of Rapid Change and Extreme Events -- 11.5.2 Integration of Science and Local Knowledge -- 11.6 Personal Communications -- References -- Chapter 12: Progress and Challenges in Biogeochemical Modeling of the Pacific Arctic Region -- 12.1 Introduction -- 12.2 PAR Characteristics Particularly Relevant for Biogeochemical Modeling -- 12.3 A Brief History of PAR Biogeochemical Models. , 12.4 Modeling PAR in 1-D: Introduction and Locations.
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  • 2
    Schlagwort(e): Oceanography ; Forschungsbericht ; oceanography ; Arctic Ocean ; Aufsatzsammlung ; Nordpolarmeer ; Meereskunde
    Materialart: Buch
    Seiten: VII, 287 S , Ill., graph. Darst , 25 cm
    ISBN: 0875902634
    Serie: Coastal and estuarine studies 49
    DDC: 551.46/8
    Sprache: Englisch
    Anmerkung: Includes bibliographical references
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  • 3
    Publikationsdatum: 2020-02-05
    Beschreibung: A coordinated effort involving trailblazing science — and icebreaking ships — from many nations is needed to fill gaps in our understanding of the Arctic Ocean and how it’s changing.
    Materialart: Article , PeerReviewed
    Format: text
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  • 4
    Publikationsdatum: 2023-02-08
    Beschreibung: Continental slopes – steep regions between the shelf break and abyssal ocean – play key roles in the climatology and ecology of the Arctic Ocean. Here, through review and synthesis, we find that the narrow slope regions contribute to ecosystem functioning disproportionately to the size of the habitat area (∼6% of total Arctic Ocean area). Driven by inflows of sub-Arctic waters and steered by topography, boundary currents transport boreal properties and particle loads from the Atlantic and Pacific Oceans along-slope, thus creating both along and cross-slope connectivity gradients in water mass properties and biomass. Drainage of dense, saline shelf water and material within these, and contributions of river and meltwater also shape the characteristics of the slope domain. These and other properties led us to distinguish upper and lower slope domains; the upper slope (shelf break to ∼800 m) is characterized by stronger currents, warmer sub-surface temperatures, and higher biomass across several trophic levels (especially near inflow areas). In contrast, the lower slope has slower-moving currents, is cooler, and exhibits lower vertical carbon flux and biomass. Distinct zonation of zooplankton, benthic and fish communities result from these differences. Slopes display varying levels of system connectivity: (1) along-slope through property and material transport in boundary currents, (2) cross-slope through upwelling of warm and nutrient rich water and down-welling of dense water and organic rich matter, and (3) vertically through shear and mixing. Slope dynamics also generate separating functions through (1) along-slope and across-slope fronts concentrating biological activity, and (2) vertical gradients in the water column and at the seafloor that maintain distinct physical structure and community turnover. At the upper slope, climatic change is manifested in sea-ice retreat, increased heat and mass transport by sub-Arctic inflows, surface warming, and altered vertical stratification, while the lower slope has yet to display evidence of change. Model projections suggest that ongoing physical changes will enhance primary production at the upper slope, with suspected enhancing effects for consumers. We recommend Pan-Arctic monitoring efforts of slopes given that many signals of climate change appear there first and are then transmitted along the slope domain.
    Materialart: Article , PeerReviewed
    Format: text
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  • 5
    Publikationsdatum: 2014-03-01
    Beschreibung: With changing climate, delineation of protected areas for sensitive species must account for long-term variability and geographic shifts of key habitat elements. Projecting the future adequacy of protected areas requires knowing major factors that drive such changes, and how readily the animals adjust to altered resources. In the Arctic, the viability of habitats for marine birds and mammals often depends on sea ice to dissipate storm waves and provide platforms for resting. However, some wind conditions (including weak winds during extreme cold) can consolidate pack ice into cover so dense that air-breathing divers are excluded from the better feeding areas. Spectacled Eiders (Somateria fischeri) winter among leads (openings) in pack ice in areas where densities of their bivalve prey are quite high. During winter 2009, however, prevailing winds created a large region of continuous ice with inadequate leads to allow access to areas of dense preferred prey. Stable isotope and fatty acid biomarkers indicated that, under these conditions, the eiders did not diversify their diet to include abundant non-bivalve taxa but did add a smaller, less preferred, bivalve species. Consistent with a computer model of eider energy balance, the body fat of adult eiders in 2009 was 33?35% lower than on the same date (19 March) in 2001 when ice conditions allowed access to higher bivalve densities. Ice cover data suggest that the eiders were mostly excluded from areas of high bivalve density from January to March in about 30% of 14 winters from 1998 to 2011. Thus, even without change in total extent of ice, shifts in prevailing winds can alter the areal density of ice to reduce access to important habitats. Because changes in wind-driven currents can also rearrange the dispersion of prey, the potential for altered wind patterns should be an important concern in projecting effects of climate change on the adequacy of marine protected areas for diving endotherms in the Arctic. # doi:10.1890/13-0411.1
    Print ISSN: 1051-0761
    Digitale ISSN: 1939-5582
    Thema: Biologie
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  • 6
    Publikationsdatum: 2014-09-01
    Beschreibung: Climate warming in seasonally ice-covered seas is expected to reduce the extent and duration of annual sea ice. Resulting changes in sea ice related blooms of ice algae or phytoplankton may in turn alter the timing, magnitude, or quality of organic matter inputs to the sea floor. If benthic taxa rely differently on direct consumption of settling fresh microalgae for growth and reproduction, altered blooms may lead to reorganization of deposit-feeding assemblages. To assess the potential for such changes, we examined the diets of five abundant deposit-feeders (three infaunal bivalves, a polychaete, and a brittle star) with different feeding modes over the course of the spring bloom in May?June 2007 in the north-central Bering Sea (30?90 m depth). Short-term data from gut contents reflected feeding modes, with the bivalves Macoma calcarea, Ennucula tenuis, and Nuculana radiata, and the brittle star Ophiura sarsi, responding more quickly to deposition of fresh algae than did the head-down polychaete Pectinaria hyperborea. Fatty acid biomarkers also indicated rapid ingestion of settling algae by the bivalves (especially Macoma) and the brittle star, while Pectinaria continued to ingest mainly bacteria. Fatty acid biomarkers did not indicate any unique dietary importance of ice algae released from melting ice. Longer-term inference from stable isotopes suggested that fresh microalgae contributed little to overall carbon assimilated by any of these species. Instead, deposit-feeders appeared to select a consistent fraction from the pool of sediment organic matter, probably heterotrophic microbes, microbial products, and reworked phytodetritus that form a longer-term sediment ?food bank.? Redistribution of settled organic matter via scouring and accumulation by currents, as well as the multi-year life spans of macroinvertebrates, may further overwhelm effects of short-term variations in the timing, magnitude, and dispersion of blooms in the water column. More diet data are needed from midsummer to account for any lag in assimilation of fresh microalgae at these cold temperatures. Nevertheless, our results suggest that if annual sea ice cover is reduced, increased production of phytoplankton during longer ice-free periods could replace inputs of ice-associated microalgae to the sediment food bank used by deposit-feeders. # doi:10.1890/13-0486.1
    Print ISSN: 1051-0761
    Digitale ISSN: 1939-5582
    Thema: Biologie
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  • 7
    Publikationsdatum: 2020-07-15
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
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  • 8
    Publikationsdatum: 2020-07-07
    Beschreibung: Rapid Arctic warming drives profound change in the marine environment that have significant socio-economic impacts within the Arctic and beyond, including climate and weather hazards, food security, transportation, infrastructure planning and resource extraction. These concerns drive efforts to understand and predict Arctic environmental change and motivate development of an Arctic Region Component of the Global Ocean Observing System (ARCGOOS) capable of collecting the broad, sustained observations needed to support these endeavors. This paper provides a roadmap for establishing the ARCGOOS. ARCGOOS development must be underpinned by a broadly endorsed framework grounded in high-level policy drivers and the scientific and operational objectives that stem from them. This should be guided by a transparent, internationally accepted governance structure with recognized authority and organizational relationships with the national agencies that ultimately execute network plans. A governance model for ARCGOOS must guide selection of objectives, assess performance and fitness-to-purpose, and advocate for resources. A requirements-based framework for an ARCGOOS begins with the Societal Benefit Areas (SBAs) that underpin the system. SBAs motivate investments and define the system�s science and operational objectives. Objectives can then be used to identify key observables and their scope. The domains of planning/policy, strategy, and tactics define scope ranging from decades and basins to focused observing with near real time data delivery. Patterns emerge when this analysis is integrated across an appropriate set of SBAs and science/operational objectives, identifying impactful variables and the scope of the measurements. When weighted for technological readiness and logistical feasibility, this can be used to select Essential ARCGOOS Variables, analogous to Essential Ocean Variables of the Global Ocean Observing System. The Arctic presents distinct needs and challenges, demanding novel observing strategies. Cost, traceability and ability to integrate region-specific knowledge have to be balanced, in an approach that builds on existing and new observing infrastructure. ARCGOOS should benefit from established data infrastructures following the Findable, Accessible, Interoperable, Reuseable Principles to ensure preservation and sharing of data and derived products. Linking to the Sustaining Arctic Observing Networks (SAON) process and involving Arctic stakeholders, for example through liaison with the International Arctic Science Committee (IASC), can help ensure success.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
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  • 9
    Publikationsdatum: 2018-05-06
    Beschreibung: Polar marine regions are facing rapid changes induced by climate change, with consequences for local faunal populations, but also for overall ecosystem functioning, goods and services. Yet given the complexity of polar marine ecosystems, predicting the mode, direction and extent of these consequences remains challenging. Trait-based approaches are increasingly adopted as a tool by which to explore changes in functioning, but trait information is largely absent for the high latitudes. Some understanding of trait–function relationships can be gathered from studies at lower latitudes, but given the uniqueness of polar ecosystems it is questionable whether these relationships can be directly transferred. Here we discuss the challenges of using trait-based approaches in polar regions and present a roadmap of how to overcome them by following six interlinked steps: (1) forming an active, international research network, (2) standardizing terminology and methodology, (3) building and crosslinking trait databases, (4) conducting coordinated trait-function experiments, (5) implementing traits into models, and finally, (6) providing advice to management and stakeholders. The application of trait-based approaches in addition to traditional species-based methods will enable us to assess the effects of rapid ongoing changes on the functioning of marine polar ecosystems. Implementing our roadmap will make these approaches more easily accessible to a broad community of users and consequently aid understanding of the future polar oceans.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev , info:eu-repo/semantics/article
    Format: application/pdf
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  • 10
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    Unbekannt
    PERGAMON-ELSEVIER SCIENCE LTD
    In:  EPIC3Deep-Sea Research Part II-Topical Studies in Oceanography, PERGAMON-ELSEVIER SCIENCE LTD, online, pp. 1-14, ISSN: 0967-0645
    Publikationsdatum: 2017-12-31
    Beschreibung: The snow crab Chionoecetes opilio and Arctic lyre crab Hyas coarctatus are prominent members of the Chukchi Sea epifaunal community. A better understanding of their life history will aid in determining their role in this ecosystem in light of the changing climate and resource development. In this study, the size frequency distribution, growth, and mortality of these two crab species was examined in 2009, 2010, 2012, and 2013 to determine temporal and spatial patterns within the eastern Chukchi Sea, and to identify potential environmental drivers of the observed patterns. Temporally, the mean size of both sexes of C. opilio and H. coarctatus decreased significantly from 2009 to 2013, with the number of rare maximum sized organisms decreasing significantly to near absence in the latter two study years. Spatially, the mean size of male and female crabs of both species showed a latitudinal trend, decreasing from south to north in the investigation area. Growth of both sexes of C. opilio and H. coarctatus was linear over the sampled size range, and mortality was highest in the latter two study years. Life history features of both species related to different environmental parameters in different years, ranging from temperature, the sediment carbon to nitrogen ratio of the organic content, and sediment grain size distribution. Likely explanations for the observed temporal and spatial variability are ontogenetic migrations of mature crabs to warmer areas possibly due to cooler water temperatures in the latter two study years, or interannual fluctuations, which have been reported for C. opilio populations in other areas where successful waves of recruitment were estimated to occur in eight year intervals. Further research is suggested to determine if the spatial and temporal patterns found in this study are part of the natural variability in this system or if they are an indication of long-term trends.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
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