Environmental Toxicology ASSESSMENT OF THE HEALTH STATUS OF WILD FISH FROM THE WHEATLEY HARBOUR AREA OF CONCERN, ONTARIO, CANADA E ` VE A.M. GILROY, y MARK E. MCMASTER, y JOANNE L. PARROTT, y L. MARK HEWITT, y BRADLEY J. PARK, z SCOTT B. BROWN,**y , and JAMES P. SHERRY*y yAquatic Contaminants Research Division, Water, Science, and Technology Directorate, Environment Canada, Burlington, Ontario, Canada zEnvironmental Science Division, Freshwater Institute, Fisheries and Oceans Canada, Winnipeg, Manitoba, Canada (Submitted 29 January 2012; Returned for Revision 22 February 2012; Accepted 13 July 2012) Abstract —The overall health and endocrine function of wild brown bullhead (Ameiurus nebulosus) and goldfish (Carassius auratus) from the Wheatley Harbour Area of Concern (Lake Erie, Ontario, Canada) was assessed using a suite of physiological and biochemical endpoints. Smaller gonads were detected in female brown bullhead and goldfish from Wheatley Harbour compared with Hillman Marsh (Ontario, Canada) reference fish. Female brown bullhead exhibited decreased in vitro synthesis of 17b-estradiol. Female goldfish had decreased plasma vitellogenin concentrations. Plasma testosterone and 11-ketotestosterone were significantly depressed in males of both species. Perturbations in the thyroid status were detected, but varied between sexes and species. Observed differences included lower plasma concentrations of thyroid hormones and/or elevated liver deiodinase activity. Histological evaluation of the thyroid tissue indicated that in the case of female goldfish, those perturbations stimulated the thyroid (as indicated by increased thyroid epithelial cell height) and partially depleted the thyroxine reserves, as indicated by decreased colloid and elevated thyroid activation index. Increased mixed-function oxygenase activity in brown bullhead from Wheatley Harbour was consistent with exposure to planar aromatic contaminants. A principal component analysis of selected variables showed the separation of fish by collection site. The endpoints most strongly associated with the separation were generally those exhibiting significant differences between sites. The results of the present study indicate that the health of fish populations within Wheatley Harbour warrants continued attention. Environ. Toxicol. Chem. 2012;31:2798–2811. # 2012 Crown in the Right of Canada Keywords —Areas of concern Polychlorinated biphenyls Endocrine disruption Brown bullhead Goldfish INTRODUCTION The Great Lakes basin has undergone extensive industrial development and population growth over the last century. Consequently, many areas of the Great Lakes have become degraded due to anthropogenic contamination, habitat loss, and eutrophication [1]. In 1987, a total of 43 specific regions of the Great Lakes were designated as areas of concern (AOCs) under a protocol of the Canada–U.S. Water Quality Agreement, through which both countries committed to the development and implementation of remedial action plans for each AOC [1]. In 2002, Environment Canada initiated a broad effort to assess fish and wildlife health in the Canadian AOCs. The health of sentinel species, as indicated by a variety of characteristics measured in individual fish, reflect the overall condition of the aquatic environment in which those species reside. Hence, a strategy was developed to investigate the health of wild fish populations, using various measures of fish health and endocrine function, which could be perturbed by exposure to contaminants or other stressors. The present study focused on the Wheatley Harbour AOC, located on the northwest shore of Lake Erie, Ontario, Canada, which comprises Wheatley Harbour and the surrounding Muddy Creek wetland. Since the 1970s, Wheatley Harbour has suffered from poor water quality due to industrial discharges, notably from the adjacent fish and vegetable processing plants. The main environmental concerns are sediments contaminated by poly- chlorinated biphenyls (PCBs)—contaminated sediments that are likely due to historical disposal of fish waste and other discharges from the fish processing facility [2,3]—high phos- phorus concentrations, poor water clarity, bacterial contami- nation, and habitat loss [1]. Thyroid abnormalities, mainly observed as hyperplasia and hypertrophy with associated gland enlargement, were observed in salmonids from the Great Lakes more than 30 years ago [4]. Although there are several suggested explanations for thyroid hyperplasia in Great Lakes fish, including iodide deficiency and exposure to organochlorine contaminants [5], a definitive cause has yet to be identified. The potential links between exposure to halogenated aromatic hydrocarbons such as PCBs and their hydroxylated metabolites, and effects on thyroid hormone status in wildlife and in humans, have received attention [6–9]; however, comparatively little attention has been paid to potential effects in fish [10,11]. The objectives of the present study were to assess the health status of two wild fish populations in the Wheatley Harbour AOC — the brown bullhead (Ameiurus nebulosus) and the gold- fish (Carassius auratus) —using measures of health status and a suite of endocrine endpoints, and to test whether the health of these fish populations differed from that of fish from a nearby reference site. The assessment of wild fish health was built on the adult fish survey used within Environment Canada’s Environmental Effects Monitoring program. This survey assesses the health and reproductive status of adult wild fish, and has been used to document endocrine disruption and metabolic disturbances in fish exposed to complex effluents [12]. Adult fish were sampled as recommended in the Environ- mental Effects Monitoring program, which permits the assess- ment of reproductive function and the gathering of information Environmental Toxicology and Chemistry, Vol. 31, No. 12, pp. 2798–2811, 2012 # 2012 Crown in the Right of Canada Printed in the USA DOI: 10.1002/etc.2021 All Supplemental Data may be found in the online version of this article. * To whom correspondence may be addressed (jim.sherry@ec.gc.ca). **Deceased. Published online 1 October 2012 in Wiley Online Library (wileyonlinelibrary.com). 2798