Critters, great and small


The Rivanna hosts a number of species of wildlife, from mammals like beaver, otter and mink to birds like heron, osprey and the bald eagle, and, of course, fish, with bass and perch chief among them. Of all the species, the most treasured is the James River spiny mussel. Globally rare and federally endangered, the spiny mussel occurs in the headwater streams of the Rivanna, which is considered one of its best habitats, due to the availability and quality of habitat and presence of all eight of its host fishes. Historically, the lower Rivanna mainstem was the home for the mussel but has been degraded over the past 30 years due to sedimentation and pollution. Other globally rare mussels occur in the mainstem Rivanna, including the Atlantic pigtoe and the green floater.