Native Freshwater Mussels

Freshwater mussels belong to the phylum Mollusca, the second most diverse group of animals in the world in terms of number of described species. The phylum consists of approximately 100,000 freshwater, marine, and terrestrial species and includes mussels, snails, octopi, squid, as well as several other less familiar groups. Although freshwater mussels are distributed throughout the world, they reach their great-est diversity in North America, east of the Mississippi River. United States mussel populations have been in decline since the late 1800s for a number of reasons. Currently, nearly three-quarters of North America’s native freshwater mussel species are considered endangered, threatened, or species of special concern, and some researchers believe that as many as 35 species (12%) are already extinct.

The objective of this leaflet is to raise awareness about the decline of freshwater mussels in North America, their life history requirements, and the important ecological role they play in aquatic habitats. In addition, this leaflet provides a number of practical habitat management considerations to help protect freshwater mussel populations. Freshwater mussels can also be referred to as freshwater clams or bivalves. However, for the sake of consistency, they are referred to as freshwater mussels throughout this leaflet.

Freshwater mussels were once an important natural resource for Native Americans, particularly the mound-building tribes of the Midwest. While it seems that they were gathered primarily for use as a food source, their shells were also valued and used for tempering pottery and making tools, utensils, and jewelry. It was not until the late 1800s, however, that the commercial value of freshwater mussels was recognized by the newly born American button industry.

This, coupled with loss and degradation of freshwater habitats associated with the America’s rapid industrialization, contributed to the first major declines in freshwater mussel populations in the United States. By 1912, nearly 200 button factories were operating in towns all over the country; pearly shells of harvested mussels were used for buttons and their soft tissues for livestock feed. The button industry declined with the advent of plastics in the 1950s.By the 1950s, however, the Japanese had found a new market for freshwater mussels as a source material for cultured pearls. Mussels harvested for this purpose are sorted and steamed or cooked to remove the soft parts. The shells are then cut and finished into beads for insertion into oysters to serve as nuclei for cultured pearls. Thousands of tons of mussel shells are processed and exported to Japan each year to supply the cultured pearl industry. Additional commercial and medical uses for freshwater mussels are under consideration. For example, recent research suggests that some mussels may be resistant to certain types of cancer and that the extraction of cancer-curing drugs from mussels may be feasible in the future.

Read entire article here:
https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_054084.pdf