Native fish on the Missouri National Recreational River (MNRR) are relatively productive and dominated by cool and warmwater species, including catfish, sauger, suckers, and naturally reproducing populations of paddlefish. Fisheries are significant but different in species composition and total number from the pre-dam Missouri River.
The Endangered Pallid Surgeon & Scaleshell Mussel
Both reaches of the park are recovery priority areas for the endangered pallid sturgeon. The United States Geological Survey recently completed a multi-year reconnaissance level survey of available pallid sturgeon spawning habitat between Gavins Point Dam and St. Louis.
The report and maps are available here.
The scaleshell mussel was listed as an endangered species by the US Fish & Wildlife Service in 2001 because of a number of factors including habitat degradation due to dam construction and changes in land use patterns.
Problems & Issues Affecting MNRR Fisheries
Native fish have declined in the park because of migration blockage, loss and change in habitat, decreased turbidity, and competition from new species, all primarily due to the river regulation effect of the mainstem dams. These regulatory practices have resulted in a less turbid river and an annual cycle of riverflows (hydrograph) that causes lower than normal river elevations during critical months for fish breeding.
The mainstem dams have affected fisheries in other ways. The dams have controlled flooding, making development possible in the old erosion zone near the river, which was the best fish and wildlife habitat. While native fish numbers have declined, invasive alien species such as bighead and silver carp thrive, usurping much of the remaining habitat and food supply.