Endangered mussels are reproducing again in the Cedar River in Minnesota for the first time in decades. The Department of Natural Resources has been making efforts to spur the reproduction of mucket and black sandshell mussels in the river. In the past three years, the department released thousands of sand shells and mucket mussels into the river in the hope that they will start reproducing in the waterway.

 

The Cedar River endured devastating human activities for the past few decades, driving away the once-thriving population of mussels. Excessive pollution and overharvesting have already depleted most of its shells and the mussels themselves. The efforts to repopulate the tiny animals are now paying off.

 

Among the important roles that mussels play in the river include water filtration of bacteria such as E. coli. They also sequester chemicals and poisons by depositing them into their shells. Their shells are one of the popular ways of removing chemicals from water since they are not eaten by any other species in the food chain.

 

“That’s what’s so unique about mussels,” said Madeline Pletta, DNR biologist. “If they die out, their shells are still there, maybe for 100 years. So we know exactly where they were. If a fish dies, how would you ever even know it was there?”

 

On top of overharvesting, mussels became endangered after growing cities dumped raw sewage into rivers. With dams being built, it also separate their populations.

 

With the help of the Soil and Water Conservation District, several large earthen berms to protect shorelines and store stormwater have been installed. The city of Austin also have ongoing plants to replace wastewater treatment plants to reduce phosphorous pollution. And now thousands of mussels are doing their magic filtering the water and holding it in place. (inhabitat via Star Tribune)