Daily News Archive
From August 24, 2005
Grizzlies Contaminated with Pesticides Due to Salmon Diet
The study compared fat and hair samples from coastal and inland bears. Coastal grizzly bears have a diet rich in salmon; consuming spawning salmon almost exclusively between the late summer and the fall. Inland bears, in contrast, subsist on a completely salmon free diet. The results of the study showed significantly higher levels of pesticides and other toxins in the coastal bears.
The coastal grizzly bears showed levels of chemicals in one gram of fat that were as high, in some cases, as 20 parts per billion (ppb) of DDT, 43 ppb for PCBs, and 53 ppb for PBDEs. While the grizzly bears are not as severely contaminated as other salmon-eating animals including polar bears and orcas, scientists do raise concern that the high levels of pesticides will have an effect on the reproductive abilities of young females.
The report noted that, due to the fact that some of the pesticides found in the fat samples were endocrine disruptors combined with the low reproductive rates and cyclical hibernation of bears, “adult female grizzly bears may supply elevated concentrations of endocrine-disrupting chemicals to their young.”
in the Pacific Northwest has long been
recognized as a problem with several campaigns to regulate and protect
the wild salmon. Yet even with national regulations curbing pesticide
practices that prove fatal to salmon, the North Pacific remains a threat.
“The North Pacific is a sink for these contaminants, which are
probably introduced through the atmosphere . . . from Asia. It reminds
us once again that our planet is a small one,” commented Dr. Peter
Ross, one of the co-authors of the report published about the study
Globe and Mail).