By the mid 1960s, the Japanese cultured pearl industry began to expand. Today, thousands of mussels are legally harvested from North American rivers for this multi-million dollar enterprise. On the rise for the same purpose is the illegal harvest of the mussels. Ecologically, mussels are extremely important to freshwater ecosystems because they form a critical middle link in the food chain. Mussels continuously siphon water from their surroundings, filtering phytoplankton and other microscopic organisms for food that is then converted to tissue.
Mussels are excellent biological indicators in part because of their key position in energy cycling.
As a result of their filtering abilities, mussels help to maintain water quality by filtering contaminants, sediments, and nutrients from the water column. The abundance and distribution of mussels can reveal important facts about the overall health of freshwater ecosystems. Additionally, the shells of mollusks can be analyzed to determine whether and when toxic chemicals were accumulated. The presence and abundance of mussels or their absence in their historical range are a reflection of the water and habitat quality in an area. As such, mussels are an important ecological component of the nation s lakes and rivers and excellent indicators of water quality.