Is it bad to be crooked? Assessing fluctuating asymmetry's usefulness as a bioindicator for harbor porpoises (Phocoena phocoena )

Conservation biologists have been utilizing fluctuating asymmetry (FA) as a bioindicator of individual and population health, however, surprisingly few FA studies have been conducted on marine mammals despite the myriad of stresses impacting them. In this study, we assessed FA expression in harbor porpoises at three levels: within individuals; between individuals of differing health within a population; and between individuals of two populations experiencing different stress levels. Significant differences in FA expression throughout the body and between old and young porpoises were detected, but no relationships were detected between groups of differing health or environmental stress. Therefore, it appears that the current stresses impacting harbor porpoises are not detrimentally affecting individual or population quality. Our results highlight the need to examine multiple traits throughout the body as there is little correlation in FA expression among traits, and the need to establish a direct link between FA expression and individual quality.