Separate Biological Review Teams (BRTs) were convened by NOAA Fisheries to assess the best available information concerning the status of bearded, ringed, ribbon, and spotted seals along with past, present, and future threats to each of these species in response to petitions filed by the Center for Biological Diversity. The petitions sought to list these ice-associated seals as threatened or endangered under the U.S. Endangered Species Act, primarily due to concern about threats to the species' habitat from climate warming and diminishing ice cover.