There are about 50 different species of freshwater (a.k.a., pearly) mussels in the lakes, streams and rivers of New York. Let’s learn a little bit about these fascinating creatures and why they are so important for the environment.

Why are freshwater mussels also known as pearly mussels? The answer comes from the colorful, shiny coating inside their shells known of as “mother-of-pearl”. The coating is formed to smooth out the rough surface of the inside of the shell, just like oysters coat grains of sand to create pearls.

Mother-of-pearl has been used for decorative purposes throughout history. It was valued by native people here in North America. Fancy buttons have been made from it. I have a couple of pocketknives that use mother-of-pearl for the handles. They are beautiful.

Pearly mussels spend most of their lives in the sediment at the bottom of the rivers, lakes and streams where they live. Most of us (myself included) don’t realize how many of them are there because they are almost always hidden.

They are what biologists call filter feeders and get their food by removing microscopic organisms from water. They filter large quantities and improve the overall quality of the water as a result.

As you might suspect, they end up filtering out a lot of bad stuff, such as PCBs, in addition to the organisms that they eat. While that’s good for the water, it’s bad for the mussels. It’s also bad for animals like river otters that eat them.

Pollutants in the water are not the only hazards that pearly mussels face. Overharvest, habitat alteration, agricultural runoff and many other things threaten them. The invasive zebra mussel attaches to them and kills them.

Freshwater mussels often live a very long time. Some species can pass the century mark. Mussels have one simple foot that allows them to move very slowly across the bottom and dig burrows in the sediment. Because they move around so slowly, it takes a long time for them to establish a new colony.

It takes about seven years for freshwater mussels to be old enough to reproduce. When they do, they release their golchidia (larvae) which attach to the gills of fish and live as a parasite off their host for a short period before dropping off. Unlike most parasites, this process does no harm to the fish.

Pearly mussels have some very unique names (e.g., pink heelsplitter, fragile papershell, plain pocketbook and creeper). They are actually quite fascinating, and I encourage folks to read more about these natural water purifiers. Perhaps I will get a chance to write about a couple of the most interesting ones in the future.

Let’s all enjoy the outdoors!

John S. Van Etten is the current president of the Federation of Sportsmen’s Clubs of Sullivan County, Inc.