Feeding the mummichog (Fundulus heteroclitus) a diet spiked with non‐ortho‐ and mono‐ortho‐substituted Polychlorinated biphenyls: Accumulation and effects

A laboratory model was developed to predict exposure effects in the field. Accumulation of non-ortho- and mono-ortho-substituted PCBs in liver tissue and their effects on mummichogs (Fundulus heteroclitus) were investigated. An artificial diet spiked with a mixture of eight PCB congeners was fed to mummichogs in the laboratory. Ratios of the congeners were similar to those measured in livers of mummichogs indigenous to the PCB Superfund site, New Bedford Harbor, Massachusetts, USA. Nominal dietary concentrations were high (54.3 μg/g wet body weight), medium (10.9 μg/g), low (2.2 μg/g), and a control. Accumulation of PCBs was consistent with exposure; however, lower levels of congener 77 were detected in liver tissue (0.2–0.8% of total PCBs) than in the spiked diets (3.3–4.6%). Significant (p ≤ 0.05) mortality occurred in mummichogs fed high and medium doses relative to the control. Mortality was higher and growth was lower with increasing toxic equivalent concentration of dietary PCB concentration and accumulation of PCBs in liver tissue. Mummichogs exhibited an exposure response in congener accumulation and biological effects with increasing dietary PCB concentration. Unlike fish from New Bedford Harbor, clean fish exposed to PCBs appear to have either slower uptake or higher metabolism of congener 77, indicating possible adaptation of mummichogs inhabiting polluted environments.