Poisoned Poisson

Fish Rendered Scentless by Pollution




Fish living in lakes tainted with metals are losing their sense of smell, prompting worries about dwindling populations, because when dissolved metals contact fish nostrils, their neurons shut down to protect the brain. Fish use their sense of smell to navigate murky waters, find mates and food, and avoid predators.

The effect of metals has been linked to impaired reproduction and growth, but this secondary, “covert toxic” effect is described by Keith Tierney, a University of Alberta assistant professor, this way: “If you can’t smell food or avoid predators, you’re more likely to die.”

The good news from Canadian researchers, as reported in the journal Ecotoxicology and Environment Safety, is that such harm to fish can be reversed. When study co-author Greg Pyle, a professor at Alberta’s University of Lethbridge, and his research team relocated yellow perch from Ontario lakes contaminated with mercury, nickel, copper, iron and manganese to a cleaner lake, the fish regained their sense of smell within 24 hours.

Most of the contaminated lakes involved have a metallic mix, making it hard to determine precisely which pollutants are to blame. Copper is high on the list of suspects; its agricultural and manufacturing use has more than doubled in the United States over the past three decades, according to the Copper Development Association.


Source: Environmental Health News

Edit ModuleShow Tags

More from Natural Awakenings

Tree Tally

By digitalizing photographs and other museum records, scientists are closing in on the number of tree species left to be discovered in the Amazon rainforest.

Tiny Baubles

As many as 51 trillion particles of discarded plastic lie on the ocean floor, threatening marine life globally.

Landfill Eulogy

Sweden’s waste-to-energy plants are so efficient that it has closed many landfills and actually imports trash to burn from other European countries.

Humpback Holler

Humpback whales that leap out of the water are making a big splash to communicate with distant pods, Australian researchers have found.

Window Pain

As many as one billion migrating birds die annually when they collide with glass windows in the United States.
Edit ModuleShow Tags
Edit ModuleShow Tags