MEPS 548:11-30 (2016)  -  DOI: https://doi.org/10.3354/meps11651

Projecting the effects of climate-driven changes in organic matter supply on benthic food webs in the northern Bering Sea

James R. Lovvorn1,*, Christopher A. North2,5, Jason M. Kolts2,6, Jacqueline M. Grebmeier3, Lee W. Cooper3, Xuehua Cui4

1Department of Zoology and Center for Ecology, Southern Illinois University, Carbondale, Illinois 62901, USA
2Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
3Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, Maryland 20688, USA
4Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996, USA
5Present address: Department of Botany, University of Wyoming, Laramie, Wyoming 82071, USA
6Present address: Department of Biology, Metropolitan State University of Denver, Denver, Colorado 80217, USA
*Corresponding author:

ABSTRACT: Climate-driven changes in seasonal sea ice are expected to affect the timing, magnitude, and fate of phytoplankton production. Production may be increased by longer ice-free periods, or decreased by reduced stratification of the water column without freshwater input from melting ice. Benthic deposit-feeders may experience changes in organic matter (OM) supply owing to altered phytoplankton production, increased zooplankton grazing, or redistribution of settling phytodetritus. Where most benthic taxa subsist on a longer-term pool of sediment OM and bacteria, communities may be partially buffered against varied inputs of phytodetritus. We used network models of benthic food webs in 3 sectors of the northern Bering Sea to simulate effects of changes in OM supply. In the models, sediment OM content, which integrates longer-term inputs of microalgae, was gradually reduced or increased over 10 yr to the lowest or highest levels observed among sampling stations. In both samples and model predictions, decreased sediment OM was linked to quite variable declines among trophic groups, with effective loss of some taxa. Increased sediment OM was coupled with moderate to dramatic increases of different taxa, sometimes with lagged peaks and declines of prey and predators. In the models, meiofauna, protists, and bacteria responded quickly, while macrofauna exhibited 2 yr delays, suggesting short-term but limited buffering by the sediment OM pool. Our results indicate that climate-related changes in phytodetrital inputs can lead to important shifts in benthic biomass, community structure, and functional diversity, with loss of various common taxa.


KEY WORDS: Benthic communities · Deposit-feeders · Food web limitation · Food web models · Network models · Phytodetritus · Sediment organic matter


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Cite this article as: Lovvorn JR, North CA, Kolts JM, Grebmeier JM, Cooper LW, Cui X (2016) Projecting the effects of climate-driven changes in organic matter supply on benthic food webs in the northern Bering Sea. Mar Ecol Prog Ser 548:11-30. https://doi.org/10.3354/meps11651

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