Wah-Tut-Ca Magazine February 2014 - Page 3

Showing Our Mussels The Endless Job Of Keeping Northwood Lake Clean There are over a million of them. They live off the shores of Wah-Tut-Ca at the bottom of Northwood Lake. There they work tirelessly keeping the water clear and clean. They’ve been working on this job for over 240 million years. They are freshwater mussels. Freshwater Mussels are part of the mollusk family. There are more species of mussels in North America than any place on earth and New Hampshire is home to at least 10 varieties. They can live up to 100 years of age. They spend most of their lives as stationary filter feeders burrowed beneath the sand and gravel at the bottom of the lake. They not only contribute to keeping the water clean but also provide an indication of the health of the lake. Mussels continuously filter water through their fine gills and eat bacteria, protozoans and other organic materials for food. “If it’s in the water, it’s in the mollusk”, so the saying goes. This fact is one of the most important attributes of the mussels. They are especially susceptible to pollutants and contaminants. This means that the presence of mussels can indicate healthy water quality. It also means that any decline in mussel population can indicate a water quality problem. In fact, mussels can tell us of a water quality problem long before even the most sophisticated scientific equipment. For this reason mussels are an excellent indicator species. For century’s humans have used freshwater mussels for tools, jewelry and sometimes food. Although not as tasty as their saltwater cousins Native Americans did eat them as a supplemental food source. However other members of the food chain, including raccoons and aquatic birds, eagerly consume them. Their 24/7 filtering operations also make the environment suitable for other freshwater life. The reproductive cycle is interesting. They form a unique symbiotic relationship with fish. The mussel larvae attach themselves to a fish host, where they develop into juveniles. Eventually they drop off the host and sink to the bottom of the water and begin to develop into full-grown mussels. This has no significant negative effect on the fish but is critical to the survival of the young mussel. Recently it has been estimated that 70% of all freshwater mussel species in North America are threatened or endangered. Two of them live in New Hampshire. Because they are sensitive to pollution, sedimentation and increasing water temperatures habit for these mollusks is shrinking. To our good fortune freshwater mussels thrive at the bottom of Northwood Lake. By the millions they cover the lakebed. They keep the lake clean and let us know that all is well with the water we swim in and boat on. Extra Content Click Below To Watch Northwood Lake Underwater Video Of Freshwater Mussels