Become a Local Expert
Because of their constant filtering, Unionids are the heavy-duty in-stream providers of “water quality,” and unlike fish, they can’t get out of the way and then quickly swim back to recolonize a site. Stream projects should avoid disturbing the streambed where they’re abundant, since the mussels mature slowly, and mature individuals can keep providing improved water quality for several decades. Water level fluctuations in impoundments can make
vast areas of the bottom behind dams uninhabitable.
To become the local unionid expert, search shores & bottoms of streams, and shores & shallows of lakes, concentrating on clear-water habitats and on riffles, and especially on streams right below lake outlets, where phytoplanktonic food from the still water flows like a perpetual buffet. Some species are wedged into the mucky banks of streams. Muskrats accumulate shell piles beside stumps and rocks on the bank, which you’ll find easily once you begin to think like a Muskrat. Flood waters concentrate shells at the foot of bars, or in eddies. It’s important to examine lots of animals and collect lots of shells, because many species are superficially hard to tell apart and many are rare. Since you can collect dead shells without harming the populations, it’s possible to gather material documentation of the occurrence of species, and their variation.