Poisoned Poisson Fish Rendered Scentless


by Pollution


Fish living in lakes tainted with met- als 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 Tier- ney, 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 jour- nal 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 Develop- ment Association.


Source: Environmental Health News natural awakenings July 2013 23


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64