Treated Wastewater Contains Compounds that Impair Ecologically Relevant Behavior in Fish

Environmental Monitor –

As the apex predator on the block, it’s not always easy for humans to imagine the heightened awareness and sensitivity to surroundings that allow prey animals to survive. But the feelings of relaxation and reduced anxiety that elevated levels of serotonin in the brain, and many prescription antidepressants, bring humans, aren’t productive in other animals. New research reveals that compounds in treated wastewater—antidepressants in particular—affect behavior in fish enough to render them more vulnerable to predators.

Environment Canada research scientist Jim Sherry, along with researchers Derek Muir and Sigal Balshine, authored the study. The team of researchers view fish living downstream from plants that treat wastewater as “water sentinels” that can warn us of the chemicals present in the water that they’re absorbing.

“Fish have been widely used as early warning ‘canaries’ of problems in aquatic ecosystems,” the researchers explain. “For example, feminization effects in aquatic environments were first observed by roach fishers in England who observed mixed sex organs in fish that they caught. The anglers brought the problem to the attention of scientists who pursued the topic.”

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