ETWP; Final Rule To List the Illinois Cave Amphipod as Endangered

The U.S. Fish and Wildlife Service (Service) determines the Illinois cave amphipod (Gammarus acherondytes) to be an endangered species pursuant to the Endangered Species Act (Act) of 1973, as amended. Historically, the Illinois cave amphipod was known from six cave streams in Monroe and St. Clair counties, Illinois. This amphipod is a cave-dependent species living in the dark zone of cave entrances. Recent surveys have found the species at only three of the original six sites, although one of the six sites is no longer accessible for surveys. This species is believed to be threatened primarily by degraded groundwater quality resulting from various sources, such as the application of agricultural and residential pesticides and fertilizers in cave stream recharge areas, and contamination from human and animal wastes from residential septic systems and livestock feedlots. This action implements the Federal protection of the Act for the Illinois cave amphipod.