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

Migrating Trees

Three-quarters of American tree species have shifted to the West since 1980 due to dryer conditions in the East and changing rainfall patterns.

Plutonium Problem

To safely dispose of 56 million gallons of nuclear waste dating back to the Second World War, the Department of Energy might replace a glass-log encasement plan with a cement option.

Bat Banter

Computer algorithms helped Israeli researchers decode the language of Egyptian fruit bats and discover that bats exchange information about specific problems.

Tuna Turnaround

Levels of toxic mercury in Atlantic Bluefin tuna declined 19 percent between 2004 and 2012, a drop that scientists attribute to a shift from coal to natural gas and renewable energy.

Buzzing RoboBees

Harvard researchers have invented tiny robotic bees that may be able to eventually pollinate the crops that are under threat because of vanishing bee colonies.
Edit ModuleShow Tags
Edit ModuleShow Tags