Prey capture ability of mummichogs (Fundulus heteroclitus) as a behavioral biomarker for contaminants in estuarine systems

Abstract

Prey capture was evaluated as a behavioral biomarker of contamination by examining feeding behavior of adult mummichogs (Fundulus heteroclitus) from 13 sites. Prey capture ability was related to sediment and tissue contaminant levels and with previous genetic analyses. The levels of contaminants at a site were highly correlated with each other, confounding the impacts of individual contaminants. The number of prey (grass shrimp) captured was highest in three of the cleanest sites. Sites with the lowest capture rates were generally more contaminated. The number of captures at all sites was highly variable, with both high and low efficiencies in highly contaminated populations. A significant relationship exists between the Mdh-A(a) allele and captures, with higher captures in the southern populations. Gut content analysis of field-collected fish had grass shrimp as the largest proportion of the diet at sites whose fish had the highest laboratory capture rates. Thus, prey capture as a behavioral biomarker is ecologically relevant and corresponds to diet in the field. However, it is not especially sensitive due to great variability at each site. Behavioral differences related to overall contaminant levels rather than to specific toxicants.