In the 1980s, internal and external tumours and deformities in fish in the Detroit River were found at elevated rates. These deformities can be caused by pollution and sediment contamination. Although contaminants are still present in sediments in the Detroit River Area of Concern (AOC), the prevalence of tumours in brown bullhead (our indicator species) are decreasing. In part, this is due to legislation introduced by both Canadian and U.S. authorities to restrict the discharge of many pollutants into the river. Researchers from the Great Lakes Institute of Environmental Research (GLIER) examined liver tumours in brown bullhead caught in the Detroit River. Results show that liver tumours in brown bullhead have decreased to less than 1% (1 of 112) - a rate that is lower than the Great Lakes background of 2%. These results indicate that liver tumours in the Detroit River are no more prevalent than other Great Lakes sites, and the Fish Tumours and Other Deformities beneficial use is no longer considered impaired for the Canadian side of the Detroit River.
6 дек 2022
