Michigan’s Endangered Species: The Rayed Bean and the Snuffbox

By Annie Perry, MNA Intern

A female rayed bean. Photo: Angela Boyer, USFWS

A female rayed bean. Photo: Angela Boyer, USFWS

Almost one year ago, two of Michigan’s native mussels, the rayed bean and the snuffbox, were listed as endangered under the Endangered Species Act. The rayed bean and the snuffbox aren’t the largest species—both are smaller than 3 inches—but threats to these small organisms can indicate big problems for the environment.

North America has the highest diversity of freshwater mussels in the world, with 300 species found on the continent. Of those species, 38 have recently gone extinct and another 77 are considered “critically imperiled,” according to the U.S. Fish and Wildlife Service. Mussels tend to be long-lived because they can close their shells for protection. As a result, they respond to long-term ecological disturbances rather than short-term disturbances. Some call mussels the “canary in the land mine” in terms of water quality because mussel disappearances show long-term trends that are harming our waterways.

The rayed bean and snuffbox have each suffered significant declines from their original ranges. According to the U.S. Fish and Wildlife Service, the rayed bean, which was once found in 115 streams and lakes, has experienced a 73 percent range decline. The snuffbox has seen a 62 percent decline in occupied streams, but this range decline coupled with population losses show an actual range and population decline of at least 90 percent.

Some MNA sanctuaries contain the rivers and streams these endangered mussels could still occupy, including the Stephen M. Polovich Memorial Nature Sanctuary and the James & Alice Brennan Memorial Nature Sanctuary, both in St. Clair County.

The greatest threat to the remaining freshwater mussels is habitat loss and degradation, much of which is caused by pollution from point and non-point sources. There are some ways you can help conserve the rayed bean, snuffbox and other endangered species in Michigan:

  • Learn more about endangered species and wildlife conservation, especially the endangered species in your area. For information on the protected species in Michigan, check out the U.S. Fish and Wildlife Service or one of our past blog posts on endangered species.
  • Get involved with a conservation organization in your community. MNA hosts regular volunteer days at its sanctuaries, many of which take action to protect the sanctuary’s native and endangered species. For a list of MNA’s upcoming volunteer days, check out our events calendar.
  • Limit use of pesticides or lawn-care chemicals. This will help prevent runoff—a type of non-point source pollution—into nearby lakes and streams.
  • Plant trees and plants to help control soil erosion and avoid runoff into freshwater areas.
  • While boating, follow the rules created to help prevent the spread of exotic pests like zebra mussels. Zebra mussels and other exotic creatures act as another threat to the state’s native mussels.
  • Speak up! The Michigan Department of Natural Resources has a hotline you can call if you see someone illegally hunting, trapping or fishing a protected species.