On October 31, 2023, the U.S. Fish and Wildlife Service (Service) proposed listing the oblong rocksnail (Leptoxis compacta) as an endangered species under the Endangered Species Act (ESA). The freshwater snail exists only in the Cahaba River in central Alabama and subsists on algae growing on the riverbed. The oblong rocksnail was declared extinct in 2000 after several decades without a confirmed specimen observation and multiple river surveys. In 2011, a population was discovered which inhabits a 5.6 river mile stretch of the Cahaba River about 10 miles south of Birmingham. Following that discovery, the Center for Biological Diversity and the Cahaba Riverkeeper petitioned the Service to list the oblong rocksnail under the ESA in 2016, and in December 2017 the Service determined that listing may be warranted and began investigating further.

Before the population of oblong rocksnail plummeted in the 1930s, the gastropod was found abundantly across 50 river miles of the Cahaba River between Birmingham and Selma, Alabama. According to the Federal Register notice, the species’ population decline was likely precipitated by chemical contamination in the Cahaba River from urban development and coal mining activities upstream of the snail’s range. In 2022, the Service’s species status assessment (SSA) concluded that the oblong rocksnail’s current range is only 11% of its known historical range. The SSA emphasized that the oblong rocksnail’s range must expand within the Cahaba River and its tributaries to avoid “stochastic and catastrophic events” that could “eliminate” the entire population of the species.

The Federal Register notices states that the Service will accept comments on the proposed listing of the oblong rocksnail until January 2, 2024. The proposed listing notice and supporting documents are available on the Federal Register and at www.regulations.gov under Docket No. FWS–R4–ES–2023–0171.