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Abstract
Changes in food web dynamics and ocean productivity over the past 4500 years are investigated using stable isotope analysis of nitrogen and carbon in collagen from animal bones preserved in coastal archeological middens on Sanak Island, along the eastern edge of the Aleutian archipelgo. Samples included Steller sea lions, Harbor seals, Northern fur seals, sea otters, Pacific cod and sockeye salmon. Sea otters had the highest δ13C (−11.9 ± 0.7‰) and lowest δ15N values (14.5 ± 1.4‰), Northern fur seals had the lowest δ13C values (−13.6 ± 1.4‰), and Steller sea lions had the highest δ15N values (18.4 ± 1.4‰) of the marine mammals. Cod isotope values were consistent with those of demersal organisms from near shore habitats (−12.5 ± 0.9‰ δ13C, 16.1 ± 1.4‰ δ15N), while salmon values were consistent with those of organisms existing in an open ocean habitat and at a lower trophic level (−15.2 ± 1.4‰ δ13C, 11.5 ± 1.7‰ δ15N). When comparing six different prehistoric time periods, two time periods had significantly different δ 13C for salmon. Otters had significantly different δ15N values in two out of the six prehistoric time periods but no differences in δ13C. The mean δ13C, corrected for the oceanic Suess Effect, of modern specimens of all species (except Northern fur seals) were significantly lower than prehistoric animals. Several hypotheses are explored to explain these differences including a reduction in productivity during the twentieth century in this region of the Gulf of Alaska. If true, this suggests that North Pacific climate regimes experienced during the twentieth century may not be good analogs of North Pacific marine ecosystems during the late Holocene.
|
Alaska Department of Fish and Game 2006: Westward Region salmon escapement survey database. ADFG, Division of Commercial Fisheries, 10. Google Scholar | |
|
Albers, W.D. and Anderson, P.J. 1985: Diet of Pacific cod, Gadus macrocephalus, and predation on the northern pink shrimp, Pandalus borealis, in Pavlof Bay, Alaska. Fishery Bulletin 83, 601-10. Google Scholar | ISI | |
|
Alverson, D.L. 1992: A review of commercial fisheries and the Stellar sea lion (Eumatopias jubatus): the conflict arena. Reviews in Aquatic Sciences 6, 203-56. Google Scholar | ISI | |
|
Ambrose, S.H. and Norr, L. 1993: Experimental evidence for the relationship of the carbon isotope ratios of whole diet and dietary protein to those of bone collagen and carbonate. In Lambert, J.B. and Grupe, G., editors, Prehistoric human bone: archaeology at the molecular level. Springer-Verlag, 1-38. Google Scholar | Crossref | |
|
Anderson, P.J. and Piatt, J.F. 1999: Community reorganization in the Gulf of Alaska following ocean climate regime shift. Marine Ecology-Progress Series 189, 117-23. Google Scholar | Crossref | ISI | |
|
Atkinson, S. , Calkins, D. , Burkanov, V. , Castellini, M. , Hennen, D. and Inglis, S. 2008: Impact of changing diet regimes on Steller sea lion body condition. Marine Mammal Science 24, 276-89. Google Scholar | Crossref | ISI | |
|
Beamish, R.J. 1993: Climate and exceptional fish production off the west coast of North America. Canadian Journal of Fisheries and Aquatic Sciences 50, 2270-91. Google Scholar | Crossref | ISI | |
|
Beamish, R.J. and Bouillon, D.R. 1993: Pacific salmon production trends in relation to climate . Canadian Journal of Fisheries and Aquatic Sciences 50, 1002-16. Google Scholar | Crossref | ISI | |
|
Beamish, R.J. , Noakes, D.J. , McFarlane, G.A. , Klyashtorin, L. , Ivanov, V.V. and Kurashov, V. 1999: The regime concept and natural trends in the production of Pacific salmon. Canadian Journal of Fisheries and Aquatic Sciences 56, 516-26. Google Scholar | Crossref | ISI | |
|
Benson, A.J. and Trites, A.W. 2002: Ecological effects of regime shifts in the Bering Sea and Eastern North Pacific Ocean. Fish and Fisheries 3, 95-113. Google Scholar | Crossref | ISI | |
| Betts, M., Maschner, H. and Clark, D.W. 2009a: Zooarchaeology of the ‘Fish that Stops’: using archaeofaunas to construct long-term time series of Atlantic and Pacific cod populations. In Moss, M. and Cannon, A., editors, The archaeology of North Pacific fisheries. University of Alaska Press, in press. Google Scholar | |
| Betts, M., Maschner, H.D.G. and Lech, V. 2009b: A 4500 year time-series of Otariid abundance on Sanak Island, Western Gulf of Alaska. In Braje T. and Rick, T., editors, Sea dogs of the North Pacific: the archaeology and historical ecology of seals, sea lions, sea cows, and sea otters. University of California Press, in press. Google Scholar | |
|
Bligh, E.G. and Dyer, W.J. 1959: A rapid method of total lipid extraction and purification . Canadian Journal of Biochemistry and Physiology 37, 911-17. Google Scholar | Crossref | Medline | |
|
Bodkin, J.L. , Esslinger, G.G. and Monson, D.H. 2004: Foraging depths of sea otters and implications to coastal marine communities. Marine Mammal Science 20, 305-21. Google Scholar | Crossref | ISI | |
|
Botsford, L.W. , Castilla, J.C. and Peterson, C.H. 1997: The management of fisheries and marine ecosystems. Science 277, 509-15. Brodeur, R.D. and Ware, D.M. 1992: Long-term variability in zooplankton biomass in the subarctic Pacific Ocean. Fisheries Oceanography 1, 32-38 . Google Scholar | Crossref | ISI | |
|
Burgner, R. 1991: Life history of sockeye salmon (Oncorhyncus nerka). In Groot, C. and Margolis, L. , editors, Pacific salmon life histories. UBC Press, 1-118. Google Scholar | |
|
Burton, R.K. and Koch, P.L. 1999: Isotopic tracking of foraging and long-distance migration in northeastern Pacific pinnipeds. Oecologia 119, 578-85. Google Scholar | Crossref | Medline | ISI | |
|
Burton, R.K. , Snodgrass, J.J. , Gifford-Gonzalez, D. , Guilderson, T. , Brown, T. and Koch, P.L. 2001: Holocene changes in the ecology of northern fur seals: insights from stable isotopes and archaeofauna. Oecologia 128, 107-15. Google Scholar | Crossref | Medline | ISI | |
|
Burton, R.K. , Gifford-Gonzalez, D. , Snodgrass, J.J. and Koch, P.L. 2002: Isotopic tracking of prehistoric pinniped foraging and distribution along the central California coast: preliminary results. International Journal of Osteoarchaeology 12, 4-11. Google Scholar | Crossref | ISI | |
|
Call, K.A. and Loughlin, T.R. 2005: An ecological classification of Alaskan Steller sea lion (Eumetopias jubatus) rookeries: a tool for conservation/management. Fisheries Oceanography 14, 212-22. Google Scholar | Crossref | ISI | |
|
Causey, D. , Corbett, D.G. , Lefevre, C. , West, D.L. , Savinetsky, A.B. , Kiseleva, N.K. and Khassanov, B.F. 2005: The palaeoenvironment of humans and marine birds of the Aleutian Islands: three millennia of change. Fisheries Oceanography 14, 259-76. Google Scholar | Crossref | ISI | |
|
Childers, A.R. , Whitledge, T.E. and Stockwell, D.A. 2005: Seasonal and interannual variability in the distribution of nutrients and chlorophyll a across the Gulf of Alaska shelf: 1998-2000 . Deep-Sea Research Part II-Topical Studies in Oceanography 52, 193-216. Google Scholar | |
|
Coyle, K.O. 2005: Zooplankton distribution, abundance and biomass relative to water masses in eastern and central Aleutian Island passes. Fisheries Oceanography 14, 77-92. Google Scholar | Crossref | ISI | |
| D’Arrigo, R. , Mashig, E. , Frank, D. , Wilson, R. and Jacoby, G. 2005: Temperature variability over the past millennium inferred from Northwestern Alaska tree rings. Climate Dynamics 24, 227-36. Google Scholar | Crossref | ISI | |
|
Dayton, P.K. 1985: Ecology of kelp communities. Annual Review of Ecology and Systematics 16, 215-45. Google Scholar | Crossref | |
|
DeNiro, M. and Epstein, S. 1981: Influence of diet on the distribution of nitrogen isotopes in animals. Geochimica et Cosmochimica Acta 45, 341-51. Google Scholar | Crossref | ISI | |
|
Doucett, R.R. , Power, G. , Barton, D.R. , Drimmie, R.J. and Cunjak, R.A. 1996: Stable isotope analysis of nutrient pathways leading to Atlantic salmon. Canadian Journal of Fisheries and Aquatic Sciences 53, 2058-66. Google Scholar | Crossref | ISI | |
|
Duggins, D.O. , Simenstad, C.A. and Estes, J.A. 1989: Magnification of secondary production by kelp detritus in coastal marine ecosystems. Science 245, 170-73. Google Scholar | Crossref | Medline | ISI | |
|
El-Sabaawi, R. 2008: Trophic dynamics of copepods in the Strait of Georgia. PhD Thesis, Department of Biology, University of Victoria . Google Scholar | |
|
Estes, J.A. and Duggins, D.O. 1995: Sea otters and kelp forests in Alaska - generality and variation in a community ecological paradigm. Ecological Monographs 65, 75-100. Google Scholar | Crossref | ISI | |
|
Estes, J.A. , Riedman, M.L. , Staedler, M.M. , Tinker, M.T. and Lyon, B.E. 2003: Individual variation in prey selection by sea otters: patterns, causes and implications. Journal of Animal Ecology 72, 144-55. Google Scholar | Crossref | ISI | |
|
Fadely, B.S. , Robson, B.W. , Sterling, J.T. , Greig, A. and Call, K.A. 2005: Immature Steller sea lion (Eumetopias jubatus) dive activity in relation to habitat features of the eastern Aleutian Islands. Fisheries Oceanography 14, 243-58. Google Scholar | Crossref | ISI | |
|
Finney, B.P. , Gregory-Eaves, I. , Sweetman, J. , Dougas, M.S.V. and Smol, J.P. 2000: Impacts of climatic change and fishing on Pacific salmon abundance over the past 300 years. Science 290, 795-99. Google Scholar | Crossref | Medline | ISI | |
|
Finney, B.P. , Gregory-Eaves, I. , Douglas, M.S.V. and Smol, J.P. 2002: Fisheries productivity in the northeastern Pacific Ocean over the past 2,200 years. Nature 416, 729-33. Google Scholar | |
|
Finney, B.P. , Alheit, J. , Emeis, K.C. , Field, D.B. , Guitierrez, D. and Struck, U. 2009: Paleoecological studies on variability in marine fish populations: A long-term perspective on the impacts of climate change on marine fisheries. Journal of Marine Systems GLOBEC Special Issue, doi: 10.1016/j.jmarsys. 2008.12.010. Google Scholar | |
|
Fisher, D.A. , Wake, C. , Kreutz, K. , Yalcin, K. , Steig, E. , Mayewski, P. , Anderson, L. , Zheng, J. , Rupper, S. , Zdanowicz, C. , Demuth, M. , Waszkiewicz, M. , Dahl-Jensen, D. , Goto-Azuma, K. , Bourgeois, J.B. and Koerner, R.M. 2004: Stable isotope records from Mount Logan, Eclipse ice cores and nearby Jellybean Lake. Water cycle of the North Pacific over 2000 years: sudden shifts and tropical connections. Geographie physique et Quaternaire 58, 337-52. Google Scholar | Crossref | |
|
Francis, R.C. and Hare, S.R. 1994: Decadal-scale regime shifts in the large marine ecosystems of the Northeast Pacific: a case for historical science. Fisheries Oceanography 3, 279-91. Google Scholar | Crossref | |
|
Frost, K.J. , Lowry, L.F. and VerHoef, J.M. 1999: Monitoring the trend of harbor seals in Prince William Sound, Alaska, after the Exxon Valdez oil spill. Marine Mammal Science 15, 494-506. Google Scholar | Crossref | ISI | |
|
Fry, B. and Sherr, E.B. 1984. δ13C measurements as indicators of carbon flow in marine and freshwater ecosystems. Contributions to Marine Science 27, 13-47. Google Scholar | ISI | |
|
Gargett, A.E. 1997: The optimal stability ‘window’: a mechanism underlying decadal fluctuations in North Pacific salmon stocks? Fisheries Oceanography 6, 109-17. Google Scholar | Crossref | ISI | |
|
Gentry, R.L. 1998: Behavior and ecology of the northern fur seal. Princeton University Press. Google Scholar | |
|
Grayson, D.K. 1984: Quantitative zooarchaeology: topics in the analysis of archaeological faunas. Academic Press, Inc. Google Scholar | |
|
Gruber, N. , Keeling, C.D. , Bacastow, R.B. , Guenther, P.R. , Lueker, T.J. , Wahlen, M. , Meijer, H.A.J. , Mook, W.G. and Stocker, T.F. 1999: Spatiotemporal patterns of carbon-13 in the global surface oceans and the oceanic Suess effect. Global Biogeochemical Cycles 13, 307-35. Google Scholar | Crossref | ISI | |
|
Guilderson, T.P. , Roark, E.B. , Quay, P.D. , Page, S.R.F. and Moy, C. 2006: Seawater radiocarbon evolution in the Gulf of Alaska: 2002 observations. Radiocarbon 48, 1-15. Google Scholar | Crossref | ISI | |
|
Hare, S.R. and Francis, R.C. 1995: Climate change and salmon production in the Northeast Pacific Ocean. In Beamish, R.J. , editor, Climate change and northern fish populations. Canada Special Publication of Fisheries and Aquatic Sciences, 357-72. Google Scholar | |
|
Hare, S.R. and Mantua, N.J. 2000: Empirical evidence for North Pacific regime shifts in 1977 and 1989. Progress in Oceanography 47, 103-45. Google Scholar | Crossref | ISI | |
|
Hare, S.R. , Mantua, N.J. and Francis, R.C. 1999: Inverse production regimes: Alaska and west coast Pacific salmon. Fisheries 24, 6-14. Google Scholar | Crossref | ISI | |
|
Hedges, R.E. , Stevens, R.E. and Koch, P.L. 2005: Isotopes in bones and teeth. In Leng, M. J. , editor, Isotopes in palaeoenvironmental research . Springer, 117-45. Google Scholar | |
|
Hilton, G.M. , Thompson, D.R. , Sagar, P.M. , Cuthbert, R.J. , Cherel, Y. and Bury, S.J. 2006: A stable isotopic investigation into the causes of decline in a sub-Antarctic predator, the rockhopper penguin Eudyptes chrysocome. Global Change Biology 12, 611-25. Google Scholar | Crossref | ISI | |
|
Hirons, A.C. 2001: Trophic dynamics of pinniped populations in Alaska using stable carbon and nitrogen isotope ratios. PhD Thesis, Institute of Marine Science, University of Alaska. Google Scholar | |
|
Hirons, A.C. , Schell, D.M. and Finney, B.P. 2001: Temporal records of δ13C and δ15N in North Pacific pinnipeds: inferences regarding environmental change and diet. Oecologia 129, 591-601. Google Scholar | Crossref | Medline | ISI | |
|
Hobson, K.A. and Welch, H.E. 1992: Determination of trophic relationships within a high Arctic marine food web using δ13C and δ15N analysis. Marine Ecology-Progress Series 84, 9-18. Google Scholar | Crossref | ISI | |
|
Hobson, K.A. , Schell, D.M. , Renouf, D. and Noseworthy, E. 1996: Stable carbon and nitrogen isotopic fractionation between diet and tissues of captive seals: implications for dietary reconstructions involving marine mammals. Canadian Journal of Fisheries and Aquatic Sciences 53, 528-33. Google Scholar | Crossref | ISI | |
|
Hobson, K.A. , Sease, J.L. , Merrick, R.L. and Piatt, J.F. 1997: Investigating trophic relationships of pinnipeds in Alaska and Washington using stable isotope ratios of nitrogen and carbon. Marine Mammal Science 13, 114-32. Google Scholar | Crossref | ISI | |
|
Hobson, K.A. , Sinclair, E.H. , York, A.E. , Thomason, J.R. and Merrick, R.E. 2004: Retrospective isotopic analyses of Steller sea lion tooth annuli and seabird feathers: a cross-taxa approach to investigating regime and dietary shifts in the Gulf of Alaska. Marine Mammal Science 20, 621-38. Google Scholar | Crossref | ISI | |
|
Hollowed, A.B. and Wooster, W.S. 1992: Variability of winter ocean conditions and strong year classes of Northeast Pacific groundfish. ICES Marine Science Symposia 195, 433-44. Google Scholar | |
|
Hunt, G.L. and Stabeno, P.J. 2005: Oceanography and ecology of the Aleutian Archipelago: spatial and temporal variation. Fisheries Oceanography 14, 292-306. Google Scholar | Crossref | ISI | |
|
Iverson, S.J. , Frost, K.J. and Lowry, L.F. 1997: Fatty acid signatures reveal fine scale structure of foraging distribution of harbor seals and their prey in Prince William Sound, Alaska . Marine Ecology-Progress Series 151, 255-71. Google Scholar | Crossref | ISI | |
|
Kenyon, K.W. 1969: The sea otter in the Eastern Pacific Ocean. Dover Publications. Google Scholar | Crossref | |
|
Kim, J.H. , Rimbu, N. , Lorenz, S.J. , Lohmann, G. , Nam, S.I. , Schouten, S. , Ruhlemann, C. and Schneider, R.R. 2004: North Pacific and North Atlantic sea-surface temperature variability during the Holocene. Quaternary Science Reviews 23, 2141-54. Google Scholar | Crossref | ISI | |
|
Koch, P.L. , Fogel, M.L. and Tuross, N. 1994: Tracing the diets of fossil animals using stable isotopes . In Lajtha, K. and Michener, R.H. , editors, Stable isotopes in ecology and environmental science. Blackwell Scientific Publications , 63-92. Google Scholar | |
|
Kvitek, R.G. and Oliver, J.S. 1992: Influence of sea otters on soft-bottom prey communities in Southeast Alaska. Marine Ecology-Progress Series 82, 103-13. Google Scholar | Crossref | ISI | |
|
Ladd, C. , Hunt, G.L. , Mordy, C.W. , Salo, S.A. and Stabeno, P.J. 2005: Marine environments of the eastern and central Aleutian Islands. Fisheries Oceanography 14, 22-38. Google Scholar | Crossref | ISI | |
|
Lambert, J.B. and Grupe, G. 1993: Prehistoric human bone: archaeology at the molecular level . Springer-Verlag. Google Scholar | Crossref | |
|
Laws, E.A. , Popp, B.N. , Bidigare, R.R. , Kennicutt, M.C. and Macko, S.A. 1995: Dependence of phytoplankton carbon isotopic composition on growth-rate and CO2aq - theoretical considerations and experimental results . Geochimica et Cosmochimica Acta 59, 1131-38. Google Scholar | Crossref | ISI | |
|
Laws, E.A. , Popp, B.N. , Cassar, N. and Tanimoto, J. 2002: C-13 discrimination patterns in oceanic phytoplankton: likely influence of CO2 concentrating mechanisms, and implications for palaeoreconstructions . Functional Plant Biology 29, 323-33. Google Scholar | Crossref | ISI | |
| Lech, V., Betts, M. and Maschner, H. 2009: An analysis of seal, sea lion, and sea otter consumption patterns on Sanak Island, Alaska: a 4500 year record on Aleut consumer behavior. In Braje, T. and Rick, T., editors, Sea dogs of the North Pacific: the archaeology and historical ecology of seals, sea lions, sea cows, and sea otters. University of California Press, in press. Google Scholar | |
|
Liu, H.B. , Suzuki, K. and Saino, T. 2002: Phytoplankton growth and microzooplankton grazing in the subarctic Pacific Ocean and the Bering Sea during summer 1999. Deep-Sea Research Part I-Oceanographic Research Papers 49, 363-75. Google Scholar | |
|
Logerwell, E.A. , Aydin, K. , Barbeaux, S. , Brown, E. , Conners, M.E. , Lowe, S. , Orr, J.W. , Ortiz, I. , Reuter, R. and Spencer, P. 2005: Geographic patterns in the demersal ichthyofauna of the Aleutian Islands. Fisheries Oceanography 14, 93-112. Google Scholar | Crossref | ISI | |
|
MacDonald, G.M. and Case, R.A. 2005: Variations in the Pacific decadal oscillation over the past millennium. Geophysical Research Letters 32, L08703, doi: 10.1029/2005GL022378. Google Scholar | Crossref | ISI | |
|
Maniscalco, J.M. , Matkin, C.O. , Maldini, D. , Calkins, D.G. and Atkinson, S. 2007: Assessing killer whale predation on Steller sea lions from field observations in Kenai Fjords, Alaska. Marine Mammal Science 23, 306-21. Google Scholar | Crossref | ISI | |
|
Mantua, N. 2004: Methods for detecting regime shifts in large marine ecosystems: a review with approaches applied to North Pacific data. Progress in Oceanography 60, 165-82. Google Scholar | Crossref | ISI | |
|
Mantua, N.J. and Hare, S.R. 2002: The Pacific decadal oscillation. Journal of Oceanography 58, 35-44. Google Scholar | Crossref | ISI | |
|
Maschner, H. 2000: Catastrophic change and regional interaction: the southern Bering Sea in a dynamic world system. In Appelt, M., Berglund, J. and Gullov, H.C., editors, Identities and cultural contacts in the Arctic: proceedings from a conference at the Danish National Museum, November 30-December 2, 1999. Danish National Museum, 252-65. Google Scholar | |
|
Maschner, H. , Betts, M. , Cornell, J. , Dunne, J. , Finney, B.P. , Huntley, N. , Jordan, J.W. , King, A. , Misarti, N. , Reedy-Maschner, K.L. , Russell, R. , Tews, A.M. , Wood, S. and Benson, B. 2009a: An introduction to the biocomplexity of Sanak Island, western Gulf of Alaska. Pacific Science 63, 673-709. Google Scholar | Crossref | ISI | |
| Maschner, H., Finney, B.P., Jordan, J.W., Tews, A.M., Misarti, N. and Knudsen, G. 2009b: Did the North Pacific ecosystem collapse in AD 1000? In Maschner, H., Mason, O.W. and McGhee, R., editors, The northern world AD 900-1400. University of Utah Press, in press. Google Scholar | |
|
Matheus, P.E. 1995: Diet and co-ecology of Pleistocene short-faced bears and brown bears in Eastern Beringia. Quaternary Research 44, 447-53. Google Scholar | Crossref | ISI | |
| -- 1997: Laboratory procedures for extracting and purifying collagen from fossil and modern bone. PhD Thesis, Institute of Marine Science, University of Alaska-Fairbanks. Google Scholar | |
|
McRoy, C.P. , Gradinger, R. , Springer, A.M. , Bluhm, B. , Iverson, S.J. and Budge, S. 2004: Stable isotopes reveal food web shifts due to arctic sea ice decline. AGU Joint Assembly, 17-24 May 2004, Montreal, Canada. Google Scholar | |
|
Michener, R.H. and Schell, D.M. 1994: Stable isotope ratios as tracers in marine aquatic food webs. In Lajtha, K. and Michener, R.H. , editors, Stable isotopes in ecology and environmental science. Blackwell Scientific Publications, 136-56. Google Scholar | |
|
Misarti, N. 2007: Six thousand years of change in the Northeast Pacific: an interdisciplinary view of maritime ecosystems. PhD Thesis, Institute of Marine Science, Fairbanks: University of Alaska Fairbanks, 210 pp. Google Scholar | |
|
Mueter, F.J. and Norcross, B.L. 2002: Spatial and temporal patterns in the demersal fish community on the shelf and upper slope regions of the Gulf of Alaska. Fishery Bulletin 100, 559-81. Google Scholar | ISI | |
|
National Research Council 2003: Decline of the Stellar sea lion in Alaskan waters: untangling food webs and fishing nets. National Academy of Sciences Press. Google Scholar | |
|
Newsome, S.D., Koch, P.L., Etnier, M.A. and Aurioles-Gambao, D. 2006: Using carbon and nitrogen isotope values to investigate maternal strategies in northeast Pacific otariids. Marine Mammal Science 22, 556-72. Google Scholar | Crossref | ISI | |
|
Newsome, S.D., Etnier, M.A., Kurle, C.M., Waldbauer, J.R., Chamberlain, C.P. and Koch, P.L. 2007a: Historic decline in primary productivity in the western Gulf of Alaska and eastern Bering Sea: isotopic analysis of northern fur seal teeth. Marine Ecology-Progress Series 332, 211-24. Google Scholar | Crossref | ISI | |
|
Newsome, S.D. , Etnier, M.A. , Gifford-Gonzalez, D. , Phillips, D.L. , van Tuinen, M., Hadly, E.A., Costa, D.P., Kennett, D.J., Guilderson, T.P. and Koch, P.L. 2007b: The shifting baseline of northern fur seal ecology in the northeast Pacific Ocean. Proceedings of the National Academy of Sciences of the United States of America 104, 9709-14. Google Scholar | |
|
Niebauer, H.J. 1998: Variability in Bering Sea ice cover as affected by a regime shift in the North Pacific in the period 1947-1996. Journal of Geophysical Research-Oceans 103, 27 717-37. Google Scholar | Crossref | ISI | |
|
Ortiz, J.D. , Mix, A.C. , Wheeler, P.A. and Key, R.M. 2000: Anthropogenic CO2 invasion into the northeast Pacific based on concurrent δ13C (DIC) and nutrient profiles from the California Current. Global Biogeochemical Cycles 14, 917-29. Google Scholar | Crossref | ISI | |
|
Overland, J.E. and Stabeno, P.J. 2004: Is the climate of the Bering Sea warming and affecting the ecosystem? EOS 85, 309-16. Google Scholar | Crossref | |
|
Overland, J.E. , Adams, J.M. and Bond, N.A. 1999: Decadal variability of the Aleutian low and its relation to high-latitude circulation. Journal of Climate 12, 1542-48. Google Scholar | Crossref | ISI | |
|
Parkinson, C.L. and Cavalieri, D.J. 2002: A 21 year record of Arctic sea-ice extents and their regional, seasonal and monthly variability and trends. Annals of Glaciology 34, 441-46. Google Scholar | Crossref | ISI | |
|
Pitcher, K.W. 1980a: Food of the harbor seal, Phoca vitulina in the Gulf of Alaska. Fishery Bulletin 78, 544-49. Google Scholar | ISI | |
| -- 1980b: Stomach contents and feces as indicators of harbor seal, Phoca vitulina, foods in the Gulf of Alaska. Fishery Bulletin 78, 797-98. Post, D.M. 2002: Using stable isotopes to estimate trophic position: models, methods, and assumptions. Ecology 83, 703-18. Google Scholar | ISI | |
|
Quay, P. , Sonnerup, R. , Westby, T. , Stutsman, J. and McNichol, A. 2003: Changes in the C-13/C-12 of dissolved inorganic carbon in the ocean as a tracer of anthropogenic CO2 uptake. Global Biogeochemical Cycles 17, 1004-23. Google Scholar | Crossref | ISI | |
|
Quay, P.D. , Tilbrook, B. and Wong, C.S. 1992: Oceanic uptake of fossil-fuel CO2 - C-13 evidence. Science 256, 74-79. Google Scholar | Crossref | Medline | ISI | |
|
Reimer, P.J. , Baillie, M.G.L. , Bard, E. , Bayliss, A. , Beck, J.W. , Bertrand, C.J.H. , Blackwell, P.G. , Buck, C.E. , Burr, G.S. , Cutler, K.B. , Damon, P.E. , Edwards, R.L. , Fairbanks, R.G. , Friedrich, M. , Guilderson, T.P. , Hogg, A.G. , Hughen, K.A. , Kromer, B. , McCormac, G. , Manning, S. , Ramsey, C.B. , Reimer, R.W. , Remmele, S. , Southon, J.R. , Stuiver, M. , Talamo, S. , Taylor, F.W. , van der Plicht, J. and Weyhenmeyer, C.E. 2004 : IntCal04 terrestrial radiocarbon age calibration, 0-26 cal kyr BP. Radiocarbon 46, 1026-58. Google Scholar | |
|
Reisewitz, S.E. , Estes, J.A. and Simenstad, C.A. 2006: Indirect food web interactions: sea otters and kelp forest fishes in the Aleutian archipelago. Oecologia 146, 623-31. Google Scholar | Crossref | Medline | ISI | |
|
Rodionov, S.N. , Overland, J.E. and Bond, N.A. 2005: Spatial and temporal variability of the Aleutian climate . Fisheries Oceanography 14, 3-21. Roemmich, D. and McGowan, J. 1995: Climatic warming and the decline of zooplankton in the California current. Science 267, 1324-26. Google Scholar | Crossref | ISI | |
|
Satterfield, F.R. 2000: A comparison of sockeye salmon (Oncorhyncis nerka) in two climate regimes in the North Pacific Ocean using stable carbon and nitrogen isotope ratios. Masters Thesis, Institute of Marine Science, University of Alaska. Google Scholar | |
|
Satterfield, F.R. and Finney, B.P. 2002: Stable isotope analysis of Pacific salmon: insight into trophic status and oceanographic conditions over the last 30 years. Progress in Oceanography 53, 231-46. Google Scholar | Crossref | ISI | |
|
Schell, D.M. 2000: Declining carrying capacity in the Bering Sea: isotopic evidence from whale baleen. Limnology and Oceanography 45, 459-62. Google Scholar | Crossref | ISI | |
| -- 2001: Carbon isotope ratio variations in Bering Sea biota: the role of anthropogenic carbon dioxide. Limnology and Oceanography 46, 999-1000. Google Scholar | Crossref | ISI | |
|
Schell, D.M. , Barnett, B.A. and Vinette, K.A. 1998: Carbon and nitrogen isotope ratios in zooplankton of the Bering, Chukchi and Beaufort seas. Marine Ecology-Progress Series 162, 11-23. Google Scholar | Crossref | ISI | |
|
Schoeninger, M.J. and DeNiro, M. 1984: Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals. Geochimica et Cosmochimica Acta 48, 625-39. Google Scholar | Crossref | ISI | |
|
Simenstad, C.A. , Estes, J.A. and Kenyon, K.W. 1978: Aleuts, sea otters and alternative stable-state communities . Science 200, 403-11. Google Scholar | Crossref | Medline | ISI | |
|
Sinclair, E.H. and Zeppelin, T.K. 2002: Seasonal and spatial differences in diet in the western stock of Steller sea lions (Eumetopias jubatus). Journal of Mammalogy 83, 973-90. Google Scholar | Crossref | ISI | |
|
Smith, T.M. and Reynolds, R.W. 2003: Extended reconstruction of global sea surface temperatures based on COADS data (1854-1997). Journal of Climate 16, 1495-510. Google Scholar | Crossref | ISI | |
|
Springer, A.M. , Estes, J.A. , van Vliet, G.B., Williams, T.M., Doak, D.F., Danner, E.M., Forney, K.A. and Pfister, B. 2003: Sequential megafaunal collapse in the North Pacific Ocean: an ongoing legacy of industrial whaling? Proceedings of the National Academy of Sciences of the United States of America 100, 12 223-28. Google Scholar | |
|
Springer, A.M. , Estes, J.A. , van Vliet, G.B., Williams, T.M., Doak, D.F., Danner, E.M. and Pfister, B. 2008: Mammal-eating killer whales, industrial whaling, and the sequential megafaunal collapse in the North Pacific Ocean: a reply to critics of Springer et al. 2003. Marine Mammal Science 24, 414-42. Google Scholar | |
|
Stabeno, P.J. , Hunt, G.L. and Macklin, S.A. 2005: Introduction to processes controlling variability in productivity and ecosystem structure of the Aleutian Archipelago. Fisheries Oceanography 14, 1-2. Google Scholar | Crossref | ISI | |
|
Steneck, R.S. , Graham, M.H. , Bourque, B.J. , Corbett, D. , Erlandson, J.M. , Estes, J.A. and Tegner, M.J. 2002: Kelp forest ecosystems: biodiversity, stability, resilience and future. Environmental Conservation 29, 436-59. Google Scholar | Crossref | ISI | |
|
Strom, S.L. , Olson, M.B. , Macri, E.L. and Mordy, C.W. 2006: Cross-shelf gradients in phytoplankton community structure, nutrient utilization, and growth rate in the coastal Gulf of Alaska. Marine Ecology-Progress Series 328, 75-92. Google Scholar | Crossref | ISI | |
|
Sugimoto, T. and Tadokoro, K. 1998: Interdecadal variations of plankton biomass and physical environment in the North Pacific. Fisheries Oceanography 7, 289-99. Google Scholar | Crossref | ISI | |
|
Takahashi, T. , Sutherland, S.C. , Feely, R.A. and Wanninkhof, R. 2006: Decadal change of the surface water pCO2 in the North Pacific: a synthesis of 35 years of observations. Journal of Geophysical Research-Oceans 111, 1-20. Google Scholar | Crossref | Medline | ISI | |
|
Tanaka, T. , Watanabe, Y.W. , Watanabe, S. , Noriki, S. , Tsurushima, N. and Nojiri, Y. 2003: Oceanic suess effect of delta C13 in subpolar region: the North Pacific. Geophysical Research Letters 30, 2159-63. Google Scholar | Crossref | ISI | |
|
Tews, A.M. 2005: Prehistoric eastern Aleut subsistence; 5,000 years of faunal variations. Masters Thesis, Department of Anthropology, Idaho State University, 243 pp. Google Scholar | |
|
Trites, A.W. , Deecke, V.B. , Gregr, E.J. , Ford, J.K.B. and Olesiuk, P.F. 2007a: Killer whales, whaling, and sequential megafaunal collapse in the North Pacific: a comparative analysis of the dynamics of marine mammals in Alaska and British Columbia following commercial whaling. Marine Mammal Science 23, 751-65. Google Scholar | Crossref | ISI | |
|
Trites, A.W. , Miller, A.J. , Maschner, H.D.G. , Alexander, M.A. , Bograd, S.J. , Calder, J.A. , Capotondi, A. , Coyle, K.O. , Di Lorenzo, E. , Finney, B.P. , Gregr, E.J. , Grosch, C.E. , Hare, S.R. , Hunt, G.L. , Jahncke, J. , Kachel, N.B. , Kim, H.J. , Ladd, C. , Mantua, N.J. , Marzban, C. , Maslowski, W. , Mendelssohn, R. , Neilson, D.J. , Okkonen, S.R. , Overland, J.E. , Reedy-Maschner, K.L. , Royer, T.C. , Schwing, F.B. , Wang, J.X.L. and Winship, A.J. 2007b: Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatas) in Alaska: assessing the ocean climate hypothesis. Fisheries Oceanography 16, 46-67. Google Scholar | Crossref | ISI | |
|
Tuross, N. , Fogel, M.L. and Hare, P.E. 1988: Variability in the preservation of the isotopic composition of collagen from fossil bone. Geochimica et Cosmochimica Acta 52, 929-35. Google Scholar | Crossref | ISI | |
|
Venrick, E.L. , McGowan, J.A. , Cayan, D.R. and Hayward, T.L. 1987: Climate and chlorophyll-a - long-term trends in the central North Pacific Ocean. Science 238, 70-72. Google Scholar | Crossref | Medline | ISI | |
|
Wada, E. , Mizutani, H. and Minagawa, M. 1991: The use of stable isotopes for food web analysis. Critical Reviews in Food Science and Nutrition 30, 361-71. Google Scholar | Crossref | Medline | ISI | |
|
Wade, P.R. , Burkanov, V.N. , Dahlheim, M.E. , Friday, N.A. , Fritz, L.W. , Loughlin, T.R. , Mizroch, S.A. , Muto, M.M. , Rice, D.W. , Barrett-Lennard, L.G. , Black, N.A. , Burdin, A.M. , Calambokidis, J. , Cerchio, S. , Ford, J.K.B. , Jacobsen, J.K. , Matkin, C.O. , Matkin, D.R. , Mehta, A.V. , Small, R.J. , Straley, J.M. , McCluskey, S.M. , VanBlaricom, G.R. and Clapham, P.J. 2007: Killer whales and marine mammal trends in the North Pacific - a re-examination of evidence for sequential megafauna collapse and the prey-switching hypothesis. Marine Mammal Science 23, 766-802. Google Scholar | Crossref | ISI | |
|
Ware, D.M. 1995: A century and a half of change in the climate of the NE Pacific. Fisheries Oceanography 4, 267-77. Google Scholar | Crossref | ISI | |
|
Ware, D.M. and Thomson, R.E. 1991: Link between long-term variability in upwelling and fish production in the Northeast Pacific Ocean. Canadian Journal of Fisheries and Aquatic Sciences 48, 2296-306. Google Scholar | Crossref | ISI | |
|
Watt, J. , Siniff, D.B. and Estes, J.A. 2000: Inter-decadal patterns of population and dietary change in sea otters at Amchitka Island, Alaska. Oecologia 124, 289-98. Google Scholar | Crossref | Medline | ISI | |
|
Weiss, R.F. 1974: Carbon dioxide in water and seawater: the solubility of a non-ideal gas. Marine Chemistry 2, 203-15. Google Scholar | Crossref | |
|
Welch, D.W. and Parsons, T.R. 1993: δ13C-δ15N values as indicators of trophic position and competitive overlap for Pacific salmon (Oncorhynchus spp.). Fisheries Oceanography 2, 11-23. Google Scholar | Crossref | |
|
Welch, D.W. , Ishida, Y. and Nagasawa, K. 1998: Thermal limits and ocean migrations of sockeye salmon (Oncorhynchus nerka): long-term consequences of global warming. Canadian Journal of Fisheries and Aquatic Sciences 55, 937-48. Google Scholar | Crossref | ISI | |
|
Williams, B. , Risk, M. , Stone, R. , Sinclair, D. and Ghaleb, B. 2007: Oceanographic changes in the North Pacific Ocean over the past century recorded in deep-water gorgonian corals. Marine Ecology-Progress Series 335, 85-94. Google Scholar | Crossref | ISI | |
|
Willis, R.H. and Ball, E.M. 1930: Statistical review of the Alaska salmon fisheries part I: Bristol Bay and the Alaska Peninsula. Bulletin of the United States Bureau of Fisheries XLIV, 673. Google Scholar | |
|
Wynne, K. and Foy, R. 2002: Is it food now? Gulf Apex Predator-Prey study. In DeMaster, D. and Atkinson, S., editors, Steller sea lion decline: is it food II? University of Alaska Sea Grant Program, 80. Google Scholar | |
|
Yang, M.S. 2004: Diet changes of Pacific cod (Gadus macrocephalus) in Pavlof Bay associated with climate changes in the Gulf of Alaska between 1980 and 1995. Fishery Bulletin 102, 400-405. Google Scholar | ISI | |
|
York, A.E. 1995: The relationship of several environmental indices to the survival of juvenile male northern fur seals (Callorhinus ursinus) from the Pribilof Islands. In Beamish, R.J. , editor, Climate change and northern fish populations. Canadian Special Publication of Fisheries and Aquatic Sciences, 317-27. Google Scholar |
