Freshwater Mussels Freshwater mussels, which are often called clams, are found in many of Alaska's rivers, ponds, and lakes. Mussels belong to a group of invertebrates known as mollusks, and have two shells fastened together by a hinge. Mussels can open and close their shells by way of an internal muscle, and usually spent their days on the bottom of the water, feeding with their shells partly open.
Mussels are filter feeders.
They pull water into their bodies, strain out the microscopic food, and then spit the water back out. It is because of this simple yet efficient way of eating that mussels are in trouble today. Some of these species began disappearing as far back as the mid-1800's. These early disappearances coincided with mussel shells being made into buttons. Later disappearances are due to the land use changes within their ecosystems such as clear- cutting forests, dam building, and water pollution.