The U.S. Fish and Wildlife Service (FWS) has proposed listing the northwestern pond turtle (Actinemys marmorata) and the southwestern pond turtle (Actinemys pallida) as threatened species under the federal Endangered Species Act (ESA), with a final listing decision likely to occur next year. Listing the turtles would affect large swaths of California, Oregon, Washington, and parts of Nevada — the northwestern pond currently inhabits portions of Washington, Oregon, Nevada, as well as northern and central California, and the southwestern pond turtle is found in central and southern California from northern Monterey County into Baja California, Mexico. The turtles rely on aquatic habitats such as streams, ponds, and adjacent uplands, and they are found from cool coastal regions to the Mojave River watershed.

Source: 88 FR 68370, 68374.

While climate change, habitat loss, and habitat modification, including altered hydrology through wetland conversion, stream channelization, water diversions, and water regulation for flood risk management are primary drivers of the species’ decline, the FWS also cites managed stream flows below dams as a threat to the turtles. According to the FWS’ listing proposal, reduced water temperatures, increased sedimentation, and high canopy cover all have a negative effect on the species’ habitat and are likely contributing to the turtles’ slower growth rate, smaller juvenile population, and lower recruitment. This may very well present a conundrum for dam operators and other water managers that engage in voluntary, and oftentimes mandatory, water releases that purposefully reduce summer water temperatures for the benefit of listed salmonids.

The FWS’ proposal does not identify critical habitat for the species, but would generally prohibit “take” wherever the species are found. The FWS has until October 3, 2024 to either publish a final rule listing one or both of the turtles, withdraw the proposed listing, or extend the proposed listing for an additional six months.