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