Length-mass relationship, histopathology, and parasitism in winter flounder (Pleuronectes americanus) living near a PCB-contaminated naval facility in Newfoundland

Abstract

A study was conducted to ascertain the health of winter flounder (Pleuronectes americanus) sampled near a naval facility contaminated with polychlorinated biphenyls (PCBs), using length-mass relationship, hematological values, histopathology, and parasitism as bioindicators of stress. Samples were collected by SCUBA divers about 2 km (Broad Cove) and 5 km (Fox Harbour) down-current from the dockyard and a reference site (Fox Island) 5 km offshore in Placentia Bay, Newfoundland. Length, mass, and condition factor were significantly greater in both sexes sampled at the reference site than at the two contaminated sites, whereas macroscopic anomalies, including fin necrosis, infestation with ectoparasitic metacercariae of the digenean Cryptocotyle lingua, and histopathological lesions in the liver, kidney, spleen, and gills, were more frequent at the latter locations. A greater variety of prey were consumed by fish taken at Fox Island than at Fox Harbour, while food was absent in several samples from Broad Cove. Three endoparasites, Ceratomyxa acadiensis, Echinorhynchus gadi, and Steringophorus furciger, were less prevalent and abundant in flounder sampled at Broad Cove than at the other two sites. These results suggest a connection between PCB contamination and impaired fish health. In addition, anomalies were more prevalent in samples collected nearest to the contaminated site than in those collected farther away.