State and federal biologists have released more than 100 endangered mussels into the Green River by Mammoth Cave National Park.The pink mucket mussel is a federally endangered species. The mussels used to be abundant in the Green River, but pollution and human interference with the water’s flow decimated the population. Now, scientists hope they can reestablish the population.Monte McGregor is an aquatic scientist with the Kentucky Department of Fish and Wildlife. He says while freshwater mussels may be underappreciated by the general public, they’re very important to a river ecosystem and act as a barometer of a river’s general health“They filter gallons and gallons of water a day,” he said. “They take all the little tiny particles of bacteria, algae, and they concentrate the stuff they don’t want on the bottom. And all these insects that live on the bottom of these streams, they’re able to get the food they can’t normally get to because the mussels are there.”McGregor says when asked to name an endangered species in Kentucky, most people can’t.“So one of the things we do is try to educate folks that the pink mucket mussel is just as rare as that lion or tiger or other African species that they’re familiar with, yet it’s in their backyard,” he said. “And it’s in the water that they’re drinking.”The scientists hope the mussels they placed on the riverbed will burrow down, grow, and eventually reproduce.