Matthew Wagner, a biologist from the U.S. Fish and Wildlife Service, holds a threatened pearl darter fish, which haven't lived in the Pearl River system for 50 years, as they are released in the Strong River, a tributary of the Pearl River, in Pinola, Miss., Monday, July 31, 2023. Wildlife experts say a number of pollution and habitat problems likely contributed to the disappearance of pearl darter from the Pearl River system. (AP Photo/Gerald Herbert)
