Bioenergetics of Brown Bullheads in a Changing Climate

Much of the fisheries climate change research has focused on cool and coldwater species.  However, warming temperatures can have unintended consequences even when they do not exceed a species lethal limit.  Brown Bullheads Ameiurus nebulosus are known to have high incidence of liver and skin tumors related to exposure to PAH’s in the Great Lakes.  We expect that PAH exposure will increase due to higher consumption associated with warming temperatures, potentially inducing tumors at earlier ages and resulting in truncated age structure.  To explore this we developed a bioenergetics model for Brown Bullhead based upon consumption and metabolism measurements in the laboratory.  Independent laboratory experiments were used to validate model predictions. Applying the model to Bullhead populations in the lower Great Lakes suggest fish will indeed reach contaminant levels associated with carcinogenesis at earlier ages leading to lower life expectancy. Similar contaminant-related modeling with other species will likely yield insights into other consequences of climate change at the individual/population or community level.