The National Academy of Science Review

At the request of Congress and the U.S. Departments of the Interior, Commerce and the National Research Council (NRC), the operating arm of the National Academy of Sciences (NAS) has undertaken a review of the scientific basis of the "biological opinions" issued by the US Fish & Wildlife in 2008 and the National Marine Fisheries Service in 2009.

Developed from scientific review of 30 years of existing data on the Delta and its resident fish species, these biological opinions - or "BiOps" as they are referred to - determined that pelagic and salmon fish species in the Delta are being harmed by the continued water exports and identified what actions are needed to minimize that harm. The BiOps' findings led to pumping restrictions imposed on Delta water exporters.

The first report, released in March 2010, found that actions to reduce water diversions to protect endangered Delta species were scientifically justified. It also determined that the standard of environmental triggers is not as supported when determining levels of water diversions. The second report was expected by the end of November 2011, but it has not yet been released.