PNNL

Abstract

We have been investigating the potential for variations in ocean temperature and carbon dioxide to affect nearshore vegetated communities in the Pacific Northwest. Experimental studies as well as long-term monitoring suggest that these communities will respond to climate change and that alterations in their functions may impact fisheries resources. This paper addresses the effects of sea level rise on coastal communities; temperature variations on eelgrass; carbon dioxide-enriched seawater on photosynthetic rates of mudflats, seagrasses, and bull kelp; and of increased climate variability on primary production. Conclusions show there is a clear need to focus investigations on the potential effects of a warmer and CO2-rich environment on Puget Sound's nearshore ecosystem. Experimental data as well as filed studies strongly indicate that temperature is a major factor controlling benthic primary production, respiration and community production in Pacific Northwest estuarine ecosystems. A shift in temperature will predictably affect these processes. The actual amount of effect, the complexities of change and the ultimate impact on fisheries resources are unquantified and highly speculative at this time.