On March 31, the U.S. District Court for the District of Columbia denied an appeal filed by the Natural Resources Defense Council (NRDC) and other conservation groups seeking to overturn a National Marine Fisheries Service (NMFS) decision not to protect two types of river herring, alewife, and blueback herring under the Endangered Species Act (ESA). The appeal sought to have NMFS list both species as threatened. A listing of river herring would have a significant impact on hydropower projects, as dams were identified as one of the primary threats to river herring populations.

NMFS previously determined in 2013 that listing alewife and blueback herring, which are prevalent throughout the Eastern United States, was not warranted. That decision was challenged and resulted in the court vacating the listing decision and remanding it back to NMFS for further review. In 2019, NMFS issued an updated determination, again finding that listing was not warranted. NRDC then appealed NMFS’s 2019 determination. One of the arguments asserted by NRDC is that the listing determination did not adequately address the impacts of climate change on river herring. One of the considerations in making a threatened listing is whether the population is likely to become endangered in the “foreseeable future.” NRDC argued that NMFS chose too proximate a time period to evaluate the “foreseeable future,” particularly given longer-term projections on climate change impacts. The court found that the more proximate time period chosen by NMFS was not arbitrary and capricious and was based on the best science available.

Currently, there is no definition of “foreseeable future” in the ESA regulations, but this is one of the topics that is likely to be addressed in the ESA rulemakings expected later this year.

Though the court denied NRDC’s petition and left the listing decision it place, it did direct NMFS to provide additional explanation regarding its determination on blueback herring populations in New England. Specifically, the court directed NMFS to explain its finding that this group was not a distinct population segment and why NMFS did not assess that population under the agency’s “significant portion of its range” policy. The court’s memorandum opinion is available here.