Chemicals Are 'feminizing' Canadian Fish

CALGARY, Alberta, July 29 (UPI) — Chemicals found in two Alberta rivers are causing some “gender bending” in fish, making males show characteristic of females, Canadian researchers say.

University of Calgary researchers say a cocktail of chemicals is skewing sex ratios of fish populations in the Red Deer and Oldman rivers in southern Alberta, a university release said Thursday.


Organic contaminants, many with hormone-like activity, were found in the water of both rivers, researchers said.

Compounds detected included synthetic estrogens from birth control pill compounds and hormone therapy drugs, Bisphenol A, a chemical used in making plastics, and certain types of natural and synthetic steroids that are byproducts of agricultural run-off and cattle farming.

Testing a native minnow, the longnose dace, scientists found that in 14 of 15 tested locations males showed elevated levels of a protein normally only found in females and involved in the production of eggs.

The results downstream of two local cities were striking, one of the study’s authors said.

“We saw a significant increase in … the presence of compounds with estrogen-like activity in areas downstream, south of Fort Macleod and Lethbridge,” Hamid Habibi said.

“Our results showed females make up 85 per cent of the population of longnose dace. In the upstream locations, females comprise 55 per cent of the population,” Habibi said.

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Categorized | Chemicals, Fish, Other
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