Primary productivity and the carrying capacity for herring in NE Pacific marine ecosystems

Abstract The carrying capacity for Pacific herring ( Clupea pallasi ) and its relationship to primary productivity was examined for eight populations in the NE Pacific and eastern Bering Sea. Data on biomass (ages 3 and older) and catches of herring in British Columbia (Georgia Strait, west coast Vancouver Island, Central Coast, Queen Charlotte Islands, Prince Rupert) and Alaska (Sitka, Prince William Sound, eastern Bering Sea) during the second half of the 20th Century derived from analytical stock assessments were used to calculate annual surplus production of herring. There was considerable interannual variability in herring productivity among all populations, however, only three (Georgia Strait, Prince Rupert, Prince William Sound) showed significant differences in mean productivity on decadal time scales (productivity regimes). Carrying capacity for the most recent productivity regime for each population was estimated using the Schaefer surplus production model. Mean annual primary productivity was estimated from remotely-sensed (SeaWiFS) chlorophyll data for British Columbia and Sitka ecosystems, and from in situ chlorophyll data for Prince William Sound and the eastern Bering Sea. The carrying capacity for herring populations in the NE Pacific ranged from 28,000 to 250,000 tonnes, and to 325,000 tonnes in the eastern Bering Sea. When considered on the basis of their distributional area, the west coast of Vancouver Island and Georgia Strait populations had the highest carrying capacity per unit area (9.3–13.8 tonnes km −2 ) and the eastern Bering Sea had the lowest (0.7 tonnes km −2 ). There is a significant positive linear relationship between the productivity of herring populations at carrying capacity and primary productivity on a per unit area basis. Although similar direct relationships have been observed between phytoplankton standing stock (as chlorophyll biomass) and total catches of resident fish populations from these regions, such a direct relationship was unexpected between primary productivity and herring carrying capacity because of multiple trophic pathways and other factors (e.g. spawning habitat) which should limit the carrying capacity for individual populations of particular species of fish. These results may be used to forecast potential responses of herring in NE Pacific ecosystems to global changes in ocean productivity.

[1]  K. Coyle,et al.  Annual cycle of zooplankton abundance, biomass and production on the northern Gulf of Alaska shelf, October 1997 through October 2000 , 2003 .

[2]  R. Beamish,et al.  Climate change and northern fish populations , 1995 .

[3]  R. Beamish,et al.  Effects of ocean variability on recruitment and an evaluation of parameters used in stock assessment models , 2004, Reviews in Fish Biology and Fisheries.

[4]  Paul J. Harrison,et al.  Review of the Biological Oceanography of the Strait of Georgia: Pelagic Environment , 1983 .

[5]  C. Robinson.  The influence of ocean climate on coastal plankton and fish production , 1994 .

[6]  E. Williams,et al.  Pacific herring, Clupea pallasi, recruitment in the Bering Sea and north‐east Pacific Ocean, I: relationships among different populations , 2000 .

[7]  R. Hopcroft,et al.  The paradox of Metridia spp. egg production rates: a new technique and measurements from the coastal Gulf of Alaska , 2005 .

[8]  T. Parsons,et al.  Levels of Production in the Pelagic Environment of the Strait of Georgia, British Columbia: A Review , 1970 .

[9]  José A. A. De Oliveira,et al.  Surplus production, variability, and climate change in the great sardine and anchovy fisheries , 2001 .

[10]  Bernard A. Megrey,et al.  Using multi-species surplus production models to estimate ecosystem-level maximum sustainable yields , 2006 .

[11]  Paul G. Falkowski,et al.  A consumer's guide to phytoplankton primary productivity models , 1997 .

[12]  D. Pauly,et al.  Primary production required to sustain global fisheries , 1995, Nature.

[13]  P. Falkowski.  Light-shade adaptation and assimilation numbers , 1981 .

[14]  D. Ware,et al.  Bottom-Up Ecosystem Trophic Dynamics Determine Fish Production in the Northeast Pacific , 2005, Science.

[15]  J. King.  REPORT OF THE STUDY GROUP ON FISHERIES AND ECOSYSTEM RESPONSES TO RECENT REGIME SHIFTS , 2005 .

[16]  J. Stockner,et al.  Phytoplankton Ecology of the Strait of Georgia, British Columbia , 1979 .

[17]  Scott W. Nixon,et al.  Physical energy inputs and the comparative ecology of lake and marine ecosystems , 1988 .

[18]  K. Rose,et al.  Geographic variation in North Pacific herring populations: Pan-Pacific comparisons and implications for climate change impacts , 2008 .

[19]  R. Brodeur,et al.  Food habits and diet overlap of various eastern Bering Sea fishes , 1988 .

[20]  M. Sinclair.  Marine Populations: An Essay on Population Regulation and Speciation , 1988 .

[21]  K. Tadokoro,et al.  Interannual–interdecadal variations in zooplankton biomass, chlorophyll concentration and physical environment in the subarctic Pacific and Bering Sea , 1997 .

[22]  J. Overland,et al.  Application of a sequential regime shift detection method to the Bering Sea ecosystem , 2005 .

[23]  M. Perry,et al.  Seasonal and inter-annual variability of SeaWiFS-derived chlorophyll a concentrations in waters off the Washington and Vancouver Island coasts, 1998–2002 , 2004 .

[24]  Patricia A. Livingston,et al.  Ecosystem Change and the Decline of Marine Mammals in the Eastern Bering Sea : Testing the Ecosystem Shift and Commercial Whaling Hypotheses , 1999 .

[25]  E. Sala,et al.  Marine, Estuarine, and Diadromous Fish Stocks at Risk of Extinction in North America (Exclusive of Pacific Salmonids) , 2000 .

[26]  Yasuhiro Yamanaka,et al.  Simulated herring growth responses in the Northeastern Pacific to historic temperature and zooplankton conditions generated by the 3-dimensional NEMURO nutrient-phytoplankton-zooplankton model , 2007 .

[27]  Scott C. Doney,et al.  Response of ocean ecosystems to climate warming , 2004 .