The National Marine Fisheries Service has been studying the effects of chemical pesticides on threatened and endangered salmon species, and I have to say that I’m impressed with the thorough approach to this scientific challenge.
Not everyone is so impressed, however, and pesticide manufacturers have filed a federal lawsuit to block implementation of protection measures proposed by NMFS, but more about that in a moment.
Risk analysis is always a tricky subject, but it appears that the NMFS researchers have taken a step-by-step approach, turning over every stone.
The latest “biological opinion” (PDF 11.7 mb) is a 600-page report covering pesticides containing carbaryl, carbofuran and methomyl. Like the previous biological opinion (PDF 11 mb) on diazinon, chlorpyrifos and malathion, the agency has determined that the pesticides pose a significant risk of extinction for listed salmon and outline further restrictions on their use.
Read my story in Wednesday’s Kitsap Sun and a well-written piece by Associated Press reporter Phuong Le.
NMFS scientists have been looking at how much of each pesticide can get into a stream under various kinds of applications. In the water, these neurotoxins can affect a fish directly — if not by killing them, by impairing their response to predators, their ability to get food, their ability to find their natal streams or their ability to connect with a mate.
Even if a fish is not harmed directly, these insecticides can affect fish simply by doing their job very well — killing off all or a significant portion of the insects that a fish needs to eat, grow and survive.
As if measuring all these effects are not enough, now we learn that chemicals may exhibit synergistic effects — making it necessary to look not just at the effects of a single chemical but how multiple chemicals in the water work together.
