According to a recent study in Ecological Monographs, predicting the impact of climate change on organisms is much more complicated than simply looking at species northern and southern range limits. Studying the ecologically important California Sea Mussel (Mytilus californianus), Brian Helmuth (University of South Carolina) and colleagues from the University of California - Santa Barbara, the University of British Columbia Vancouver, and Oregon State University measured body temperatures of this mussel along most of its range, from Washington to Southern California. "Mosaic patterns of thermal stress in the rocky intertidal zone: Implications for climate change," suggests that conserving areas based on a few similarities including location, may not be enough, as variations in temperature and other variables can turn what would seem like an ideal and "typical" environment into one that's decidedly different from nearby sites.

As global climate changes occur, "the role of organism temperature in driving species distribution patterns has assumed a further sense of urgency," say the authors.

Like terrestrial ectotherms (organisms that can not regulate their body temperature only through outside sources such as the sun), the body temperatures of intertidal invertebrates are driven by multiple factors in their environment. Solar radiation, wind speed, humidity, air and ground temperatures, along with the organisms' own shape, color and mass affect its body temperature.

"In many cases, science has a poor understanding of how physiologically relevant environmental factors vary in space and time. We know little of how 'climate' is translated into patterns of body temperature, especially at scales important to organisms," says Helmuth.

Mussel distribution and physiology is known to be negatively affected by high-temperature stress.

"The thermal environment must be considered from the perspective of the organism's interacti
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Contact: Annie Drinkard
annie@esa.org
Ecological Society of America
14-Nov-2006