Meeting Abstract

P2.116  Thursday, Jan. 5  Parameterizing a Dynamic Energy Budget Model for the keystone predator Pisaster ochraceus MONACO, C. J.; University of South Carolina monacocj@email.sc.edu

Ecological literature offers a number of examples revealing the overarching importance of keystone predators on their systems. By driving prey dynamics, these key players can define the structure and functioning of entire communities. Mechanistic studies have shown that the relative importance of predator species on their communities is largely determined by their sensitivity to varying body temperature and food conditions. Despite widespread recognition of keystone predators’ critical ecological role, few predictive frameworks have been developed that account for interactive effects of varying prey availability and temperature on their foraging performance. Pure experimental studies are usually unable to capture the interaction of multiple factors. Pure theoretical approaches, in turn, consider inherently complex environments, but are often criticized for lacking realism. By merging these approaches, current efforts are providing a deeper understanding of the ways in which individuals’ physiological condition varies under constantly fluctuating environmental signals. Dynamic Energy Budget Models (DEBM) rise as powerful tools, capable of integrating such signals to shed light on the organism’s fitness throughout its life-history. I show work-in-progress aimed towards estimating standard DEBM parameters for the sea star Pisaster ochraceus, an emblematic keystone predator inhabiting rocky-intertidal shores along the west coast of North America. Besides relying on computer simulations and literature surveys, the model parameterization is strongly supported by empirical observations. Preliminary outputs are shown, where Pisaster’s foraging behavior and fitness are contrasted under different temperature and food conditions.