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Fish Olfaction

A growing body of research has scientists concerned that fish are losing their sense of smell because of exposure to pesticides and copper runoff in rivers, lakes and streams.

Fish rely heavily on their sense of smell to find food, detect danger, find a healthy mate, and return home to spawn. But studies show that chemicals found in common pesticides, such as Roundup, and in the copper that leaks from aging car brake pads can essentially block a fish’s ability to smell properly. Even short-term exposures of just a few hours are sufficient to interfere with the olfactory system, studies show.

The results can be devastating. Female salmon with impaired olfaction choose unhealthy mates, interfering with their ability to reproduce. Those that can’t detect danger, such as predators, fail to hide from them and get eaten. Others can’t find food or detect the familiar smells that help them find their way home to spawn. What’s more, research shows that other species, such as leeches and water fleas, experience the same problems when exposed to chemical pollutants.

So what can be done about it? Better regulation of pesticides would help reduce runoff into water sources. Switching to natural pesticides would be even more effective, where possible. And properly maintaining car brake pads would not only reduce copper runoff, it would make driving your car safer.

For more information about this story, visit Science News.

To read more about this and other environmental health issues, go to: www.environmentalhealthnews.org, www.ourstolenfuture.org, or www.healthandenvironment.org