Here is a link that might help you, not sure. But from what I can see these help to clean the river. http://www.umesc.usgs.gov/aquatic/native_mussels/5004455.html
Type: Posts; User: tater03
Here is a link that might help you, not sure. But from what I can see these help to clean the river. http://www.umesc.usgs.gov/aquatic/native_mussels/5004455.html