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The influence of climate change on populations and communitiesThermal tolerance, species interactions, and climate change Many predictions have focused on how climate change might impact species through the direct effects of environmental stress on demographic rates. These models treat species as independent units and often neglect the fact that organisms are embedded within complex webs of interacting species. We are intrigued by the possibility that some of the most immediate and important impacts of climate change could arise through changes in key species interactions. Using field and laboratory experiments, we have shown that the effect of a keystone predator, the sea star Pisaster ochraceus, is influenced by small changes in ocean temperature (~3°C). Thus, long-term shifts in cold-water upwelling patterns could generate community-level effects through impacts on this keystone predator. More recently, we have also investigated how the feeding and growth of Pisaster is influenced by exposure to aerial conditions during low tide. In other projects, we are examining the extent to which populations of marine species (including intertidal snails and copepods) are locally adapted to biogeographic variation in temperature. This work includes the use of selection experiments to test the capacity of tidepool copepods to adapt to future increases in temperature.
Sea stars (Pisaster ochraceus) feeding on mussels. Click here to watch a 30-minute special on climate change, broadcast on KQED-TV in April 2009. This program includes Eric Sanford and other scientists discussing the impacts of climate change on natural communities in California. Bodega Ocean Acidification Research (BOAR) In collaboration with Drs. Brian Gaylord, Tessa Hill, and Ann Russell, we are examining the influence of ocean acidification on ecologically and economically important species in northern California (with a focus on the Sonoma coast and Tomales Bay). Our interdisciplinary research combines moored and shipboard measurements of seawater chemistry with laboratory and field studies of the biological effects of ocean acidification. To date, our experiments on the native oyster (Ostrea lurida) indicate that oyster larvae and juveniles may be quite vulnerable to decreasing pH and changes in the calcium carbonate saturation state. See Bodega Ocean Acidification Research (BOAR) >
System at BML to manipulate CO2 in larval cultures (left), and magnified view of oyster larvae (right). The location of Bodega Marine Laboratory within a major upwelling center, and the lab's research strengths in coastal oceanography (Bodega Ocean Observing Node), make this an ideal place to explore links between oceanographic processes and the dynamics of benthic marine communities. In addition to understanding the effects of changing temperature and ocean chemistry, our lab continues to be interested in how variation in bottom-up forces affects invertebrate reproduction, recruitment, and growth. Selected publications: Pincebourde, S., E. Sanford, and B. Helmuth. An intertidal sea star adjusts thermal inertia to avoid extreme body temperatures. American Naturalist, in press. Kuo, E.S.L. and E. Sanford. 2009. Geographic variation in the upper thermal limits of an intertidal snail: implications for climate envelope models. Marine Ecology Progress Series, in press. Pincebourde, S., E. Sanford, and B. Helmuth. 2008. Body temperature during low tide alters the feeding performance of a top intertidal predator. Limnology and Oceanography 53: 1562–1573. Sanford, E. 2002. Water temperature, predation, and the neglected role of physiological rate effects in rocky intertidal communities. Integrative and Comparative Biology 42: 881–891. Sanford, E. and B.A. Menge. 2001. Spatial and temporal variation in barnacle growth in a coastal upwelling system. Marine Ecology Progress Series 209: 143–157. Sanford, E. 1999. Regulation of keystone predation by small changes in ocean temperature. Science 283: 2095–2097. |
