Search

Search Results

• 1. [Article] Prey dominance shapes trophic structure of the northern California Current pelagic food web: evidence from stable isotopes and diet analysis

  The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/

  Citation × Citation Citation Abstract Copy Title: Prey dominance shapes trophic structure of the northern California Current pelagic food web: evidence from stable isotopes and diet analysis Author: Miller, Todd W., Rau, Greg, Omori, Koji, Brodeur, Richard D. The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/ Title: Prey dominance shapes trophic structure of the northern California Current pelagic food web: evidence from stable isotopes and diet analysis Author: Miller, Todd W., Rau, Greg, Omori, Koji, Brodeur, Richard D. The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/ Close

• 2. [Article] Distribution, structure, and function of marine ecological communities in the northern California Current upwelling ecosystem

  Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification ...

  Citation × Citation Citation Abstract Copy Title: Distribution, structure, and function of marine ecological communities in the northern California Current upwelling ecosystem Author: Reese, Douglas Charles Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area of research. Furthermore, in order to understand how ecosystems function and persist, it is necessary to know how ecological communities are distributed. The overall goal of this study is to provide further understanding regarding the functioning of marine ecosystems in such highly variable environments and to provide information about the distribution and structure of marine communities. Sampling was conducted during June and August of 2000 and 2002 as part of the U.S. GLOBEC mesoscale surveys from Newport, Oregon in the north to Crescent City, California in the south. A geostatistical approach was used to create surfaces used in a GIS to determine the distribution of various community characteristics. Two biological hotspots were identified and determined to persist in space and time, yet differed with respect to biological and physical features and in the amount of area covered. Various community analyses, including nonmetric multidimensional scaling, indicator species analysis, and cluster analysis were used to determine various community properties associated with the hotspots and non-hotspot regions. Results indicate that nekton biological hotspots in the northern California Current persist across differing environmental and biological conditions, although upwelling-based hotspots may be more susceptible to climatic conditions than retention-based hotspots. Analyses of the distribution of the functional groups within the region indicate that the predominant biological activity is spatially nonrandom and occurs within persistent, localized areas. Analyses of species associations suggest a moderate degree of redundancy. The presence of such complementary species within functional groups may confer the stability observed within these systems. The finding that large regional areas are composed of smaller, localized hotspots where a predominant amount of biological activity is occurring, suggests that the evaluation of large marine ecosystems may lead to erroneous or misleading results if they do not consider the more persistent, localized biological hotspots. Title: Distribution, structure, and function of marine ecological communities in the northern California Current upwelling ecosystem Author: Reese, Douglas Charles Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area of research. Furthermore, in order to understand how ecosystems function and persist, it is necessary to know how ecological communities are distributed. The overall goal of this study is to provide further understanding regarding the functioning of marine ecosystems in such highly variable environments and to provide information about the distribution and structure of marine communities. Sampling was conducted during June and August of 2000 and 2002 as part of the U.S. GLOBEC mesoscale surveys from Newport, Oregon in the north to Crescent City, California in the south. A geostatistical approach was used to create surfaces used in a GIS to determine the distribution of various community characteristics. Two biological hotspots were identified and determined to persist in space and time, yet differed with respect to biological and physical features and in the amount of area covered. Various community analyses, including nonmetric multidimensional scaling, indicator species analysis, and cluster analysis were used to determine various community properties associated with the hotspots and non-hotspot regions. Results indicate that nekton biological hotspots in the northern California Current persist across differing environmental and biological conditions, although upwelling-based hotspots may be more susceptible to climatic conditions than retention-based hotspots. Analyses of the distribution of the functional groups within the region indicate that the predominant biological activity is spatially nonrandom and occurs within persistent, localized areas. Analyses of species associations suggest a moderate degree of redundancy. The presence of such complementary species within functional groups may confer the stability observed within these systems. The finding that large regional areas are composed of smaller, localized hotspots where a predominant amount of biological activity is occurring, suggests that the evaluation of large marine ecosystems may lead to erroneous or misleading results if they do not consider the more persistent, localized biological hotspots. Close

• 3. [Article] Summer-time use of west coast US National Marine Sanctuaries by migrating sooty shearwaters (Puffinus griseus)

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Summer-time use of west coast US National Marine Sanctuaries by migrating sooty shearwaters (Puffinus griseus) Author: MacLeod, Catriona, Suryan, Robert M., Harvey, James T., Hyrenbach, K. David, Adams, Josh To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Title: Summer-time use of west coast US National Marine Sanctuaries by migrating sooty shearwaters (Puffinus griseus) Author: MacLeod, Catriona, Suryan, Robert M., Harvey, James T., Hyrenbach, K. David, Adams, Josh To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Close

• 4. [Article] Environmental drivers and reproductive consequences of variation in the diet of a marine predator

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Environmental drivers and reproductive consequences of variation in the diet of a marine predator Author: Horton, Cheryl A., Parrish, Julia K., Gladics, Amanda J., Peterson, William T., Daly, Elizabeth A., Suryan, Robert M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-marine-systems/. Title: Environmental drivers and reproductive consequences of variation in the diet of a marine predator Author: Horton, Cheryl A., Parrish, Julia K., Gladics, Amanda J., Peterson, William T., Daly, Elizabeth A., Suryan, Robert M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-marine-systems/. Close

• 5. [Article] Climate shifts the interaction web of a marine plankton community

  This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons, Inc. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2486. This article ...

  Citation × Citation Citation Abstract Copy Title: Climate shifts the interaction web of a marine plankton community Author: Tolimieri, Nick, Francis, Tessa B., Peterson, William T., Scheuerell, Mark D., Ruzicka, James J., Brodeur, Richard D., Levin, Phillip S. This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons, Inc. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2486. This article is a U.S. Government work and is in the public domain in the U.S.A. Title: Climate shifts the interaction web of a marine plankton community Author: Tolimieri, Nick, Francis, Tessa B., Peterson, William T., Scheuerell, Mark D., Ruzicka, James J., Brodeur, Richard D., Levin, Phillip S. This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons, Inc. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2486. This article is a U.S. Government work and is in the public domain in the U.S.A. Close

• 6. [Article] Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem Author: Reese, Douglas C., Brodeur, Richard D. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-marine-systems/. Title: Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem Author: Reese, Douglas C., Brodeur, Richard D. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-marine-systems/. Close

• 7. [Article] Large medusae in surface waters of the Northern California Current: variability in relation to environmental conditions

  This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springerlink.com/content/0018-8158/. To the best of our knowledge, one or more authors ...

  Citation × Citation Citation Abstract Copy Title: Large medusae in surface waters of the Northern California Current: variability in relation to environmental conditions Author: Emmett, Robert L., Suchman, Cynthia L., Daly, Elizabeth A., Brodeur, Richard D. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springerlink.com/content/0018-8158/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Large medusae in surface waters of the Northern California Current: variability in relation to environmental conditions Author: Emmett, Robert L., Suchman, Cynthia L., Daly, Elizabeth A., Brodeur, Richard D. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springerlink.com/content/0018-8158/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 8. [Article] Trophically transmitted parasites as ecosystem indicators : relationships among parasite community structure, juvenile salmon diet composition, and ocean conditions

  Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition ...

  Citation × Citation Citation Abstract Copy Title: Trophically transmitted parasites as ecosystem indicators : relationships among parasite community structure, juvenile salmon diet composition, and ocean conditions Author: Losee, James P. Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition of zooplankton in the nearshore environment which, in turn, can affect the quality of prey for fish, sea birds and mammals. Interannual variability in the quality and composition of the copepod community in the NCC during early marine residency of some Pacific salmon populations is related to survival to adulthood. However, copepods make up a small portion of the diet of coho and Chinook salmon, and the mechanistic linkages between ocean climate, zooplankton composition and salmon prey remain unclear. Parasite analysis provides a supplement to traditional diet analysis that can describe the foraging history of a host species. Coho salmon (O. kisutch) and Chinook salmon (O. tshawytscha) serve as hosts to an array of marine parasites acquired through consumption of infected intermediate hosts such as copepods, euphausiids, and planktivorous fishes. Causing little or no harm to their salmon host, the presence of trophically transmitted parasites provides information on the dietary history of their salmonid host beyond the 24 hours associated with traditional diet analysis. This study (1) examined differences in feeding behavior of coho and Chinook salmon during their early marine residency using both stomach and parasite community analyses and (2) tested the hypothesis that variability in ocean circulation patterns (measured through the Pacific Decadal Oscillation, sea surface temperature (SST) and Bakun's upwelling index) and copepod species composition are related to variability in the community structure of trophically transmitted marine parasites found in juvenile salmon. I compared the abundance and species composition of parasites recovered from juvenile Columbia River coho and upper Columbia River summer and fall Chinook salmon captured off the coast of Washington from 2002 to 2009. I also compared interannual variability in parasite assemblages to physical and biological indices of ocean conditions. Coho and Chinook salmon consumed similar prey taxa; however, the species richness and abundance of trophically transmitted parasites indicated that Chinook salmon consumed a greater diversity and abundance of infected prey. In addition, differences in the abundance of fish in the diet and Anisakis simplex, a parasitic nematode known to infect salmon through fish consumption, suggest that Chinook salmon consistently consumed more fish prey than coho. In contrast, coho appeared to consume more euphausiids as indicated by stomach content analysis and increased abundance of the euphausiid parasite, Rhadinorhynchus trachuri. Shifts in the parasite community composition of both coho and Chinook salmon were related to interannual variability in SST and the biomass of southern-origin copepods (r > 0.7, P < 0.05). The acanthocephalan R. trachuri and a tetraphyllid cestode were associated with "warm" SSTs and greater biomass of lipid-poor, subtropical copepods while the nematode A. simplex was more abundant in years of "cold" SST and a relatively low biomass of subtropical copepods. These results provide novel insight into differences in the diet of Columbia River coho and Chinook salmon and illustrate linkages between ocean climate, zooplankton community composition and salmon diet during early marine residency. Title: Trophically transmitted parasites as ecosystem indicators : relationships among parasite community structure, juvenile salmon diet composition, and ocean conditions Author: Losee, James P. Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition of zooplankton in the nearshore environment which, in turn, can affect the quality of prey for fish, sea birds and mammals. Interannual variability in the quality and composition of the copepod community in the NCC during early marine residency of some Pacific salmon populations is related to survival to adulthood. However, copepods make up a small portion of the diet of coho and Chinook salmon, and the mechanistic linkages between ocean climate, zooplankton composition and salmon prey remain unclear. Parasite analysis provides a supplement to traditional diet analysis that can describe the foraging history of a host species. Coho salmon (O. kisutch) and Chinook salmon (O. tshawytscha) serve as hosts to an array of marine parasites acquired through consumption of infected intermediate hosts such as copepods, euphausiids, and planktivorous fishes. Causing little or no harm to their salmon host, the presence of trophically transmitted parasites provides information on the dietary history of their salmonid host beyond the 24 hours associated with traditional diet analysis. This study (1) examined differences in feeding behavior of coho and Chinook salmon during their early marine residency using both stomach and parasite community analyses and (2) tested the hypothesis that variability in ocean circulation patterns (measured through the Pacific Decadal Oscillation, sea surface temperature (SST) and Bakun's upwelling index) and copepod species composition are related to variability in the community structure of trophically transmitted marine parasites found in juvenile salmon. I compared the abundance and species composition of parasites recovered from juvenile Columbia River coho and upper Columbia River summer and fall Chinook salmon captured off the coast of Washington from 2002 to 2009. I also compared interannual variability in parasite assemblages to physical and biological indices of ocean conditions. Coho and Chinook salmon consumed similar prey taxa; however, the species richness and abundance of trophically transmitted parasites indicated that Chinook salmon consumed a greater diversity and abundance of infected prey. In addition, differences in the abundance of fish in the diet and Anisakis simplex, a parasitic nematode known to infect salmon through fish consumption, suggest that Chinook salmon consistently consumed more fish prey than coho. In contrast, coho appeared to consume more euphausiids as indicated by stomach content analysis and increased abundance of the euphausiid parasite, Rhadinorhynchus trachuri. Shifts in the parasite community composition of both coho and Chinook salmon were related to interannual variability in SST and the biomass of southern-origin copepods (r > 0.7, P < 0.05). The acanthocephalan R. trachuri and a tetraphyllid cestode were associated with "warm" SSTs and greater biomass of lipid-poor, subtropical copepods while the nematode A. simplex was more abundant in years of "cold" SST and a relatively low biomass of subtropical copepods. These results provide novel insight into differences in the diet of Columbia River coho and Chinook salmon and illustrate linkages between ocean climate, zooplankton community composition and salmon diet during early marine residency. Close