In a recently issued draft biological opinion (PDF) , the National Marine Fisheries Service (Service) has concluded that EPA’s registration of products containing the herbicides oryzalin, pendimethalin, and tricluralin is likely to jeopardize the survival of approximately half of the Pacific salmonid populations listed under the Endangered Species Act (ESA).

The draft biological opinion is the latest milestone in a series of controversial ESA section 7 consultations between the Environmental Protection Agency (EPA) and the Service regarding EPA’s registration of 37 pesticides for agricultural and residential use that EPA has determined "may affect" listed salmonid species.  The draft opinion also reinforces the conclusion that Pacific salmon and steelhead are suffering the effects of a host of stressors, including pesticide exposure, reached by the National Research Council Committee in its recent report titled Sustainable Water and Environmental Management in the California Bay-Delta.

As explained in a previous blog entry, the consultations are not only the product of litigation accusing the EPA of failing to comply with the ESA with respect to pesticide registrations, they are generating new litigation, and they are drawing criticism from members of Congress.

Lawmakers in agricultural regions are concerned that the Service is imposing overly protective buffers around water bodies where the pesticides could not be applied, which, in their view may dramatically reduce crop yield with no discernible benefit to listed species.

The draft biological opinion for oryzalin, pendimethalin, and tricluralin is likely to be controversial.  As part of the reasonable and prudent alternative the Service has proposed to avoid jeopardy, the aerial application of any pesticide containing any of the three active ingredients within 300 feet of any surface water that connects with salmonid-bearing waters will be prohibited.  In contrast, this is less than a third the size of the buffer required in the 2008 Biological Opinion for the Registration of Pesticides Containing Chlorpyrifos, Diazinon, and Malathion (PDF), which required 1,000-foot wide buffers for aerial applications and 20-foot buffers of non-crop plantings along surface waters that connect to salmonid-bearing waters.

EPA is soliciting comments regarding the Service’s proposed measures included in the reasonable and prudent alternative on its Endangered Species Effects Determinations and Consultations and Biological Opinions web page until April 30, 2012 .  EPA will forward comments to the Service for its consideration.

Under the current schedule, the biological opinions for all 37 active ingredients are to be completed on or before June 30, 2013.