GERMLINE MUTATIONS AND REPRODUCTIVE EFFECTS IN FATHEAD MINNOWS EXPOSED TO CONTAMINATED SEDIMENTS FROM RANDLE REEF, HAMILTON HARBOUR

Abstract

<p>Sediments at Randle Reef, Hamilton Harbour are highly contaminated with coal tar, a complex mixture of polycyclic aromatic hydrocarbons (PAH's). Studies there have demonstrated adverse effects in fish, including elevated mortalities and increased incidences of tumors. However, reproductive effects and heritable genetic alterations have not been evaluated. We exposed sub-adult fathead minnow (<em>Pimephales promelas</em>) to contaminated water and sediments at Randle Reef, Hamilton Harbour using two approaches. In the first, fish were caged at Randle Reef for six weeks, and in the second fish were exposed in-lab to whole sediments for three weeks. Fish from both studies were transferred to clean aquaria and evaluated for reproductive impairment immediately following exposures. We also determined germline mutation rates in fish exposed in-lab, using microsatellite DNA markers. Overall, we found no evidence to support our initial expectation that fish exposed to the highly contaminated sediments at Randle Reef would experience elevated germline mutations and reproductive impairment. This finding was unexpected, given the large number of studies that have reported effects following exposure to PAH's and PAH-contaminated sediments, including sediments contaminated with coal tar. A number of factors that may have contributed to results obtained are discussed.</p>