Some of the most at risk animals in North America might appear to look like a rock at the bottom of a creek.  You might walk past them, not necessarily because they are scarce but because they blend so well into their surroundings.  The animal at risk is the freshwater mussel! Over harvesting for bait, loss of fish needed for reproduction, reduction of forests along streams (the trees cool the water), toxic spills, the building of dams and polluted water have all played a role in the decline of the freshwater mussel both in species diversity and numbers of animals. No matter what the cause, a stream without mussels is at a serious disadvantage.  Mussels strengthen streambeds by keeping the bottom soils in place and provide food and habitat for other animals and plants.  Mussels are “filter feeders” so they clean water.  They suck in water, trap dirt, algae, and other pollutants and then release the filtered cleaner water back into the stream.   One mussel can filter several gallons of water each day. Freshwater mussels need our help because there are over 300 species of freshwater mussels native to North America.   Close to 75% are defined as of “concern” by state and federal governments and many are listed as endangered or threatened. If you live in or around the Delaware Estuary and you would like to help protect freshwater mussels contact the Partnership for the Delaware Estuary: http://www.delawareestuary.org/Mussel-Survey-Program