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Fish and freshwater mussels can be found in every permanent type and size of water body in the state. Even floodplain ponds and wetlands and intermittent streams can become surprisingly full of a rich diversity of fish and some species of freshwater mussels if they can maintain water for several consecutive years. The diversity of fish and freshwater mussels that might inhabit a certain water body can be affected by size, location in the state, diversity of habitats, past and present water quality or habitat disturbances, non-native species impacts, and impediments to dispersal within the watershed, among other factors. While aquatic species are not always as easily observed as terrestrial species, Indiana waters contain an amazing diversity of them.
Indiana’s aquatic habitats are currently home to about 200 species of fish and 60 species of freshwater mussels. While many are common and distributed throughout much of the state, several species are rare and restricted to a single stream, lake, or watershed. Twenty-two species of fish and 25 species of freshwater mussels are listed as a Species of Greatest Conservation Need (SGCN) by the Indiana DNR.
Habitat management and conservation programs for these species are supported through the generosity of Hoosiers who donate to the Indiana Nongame Wildlife Fund. No state tax dollars are used to manage these species. Consider donating today.
Monitoring Fish and Freshwater Mussels Populations
Indiana DNR nongame aquatic biologists conduct research and monitoring to better understand the status and distribution of Indiana’s fish and freshwater mussel species. Some monitoring is more general and exploratory in nature and may employ a wide range of techniques to sample areas of the state where fish and freshwater mussel information is lacking. Other activities are more targeted toward SGCN and may involve very specialized techniques. SGCN currently being studied and monitored include lake sturgeon, longnose dace, pugnose shiner, trout-perch, western sand darter, channel darter, and all mussel species.
- Monitoring Lake Sturgeon
Indiana’s East Fork White River contains the last remaining native population of lake sturgeon in the Ohio River drainage. Nongame aquatic biologists have been monitoring this population since 1996. During this time, more than 100 individual fish have been captured and tagged, and about 40 of them have been tracked for varying lengths of time using radio telemetry techniques. Lake sturgeon is listed as an endangered species by the Indiana DNR and it is currently under review for federal listing by the U.S. Fish & Wildlife Service.
- Statewide Fish Monitoring
Indiana DNR nongame aquatic biologists conduct general surveys for fish throughout the state on an annual basis. A variety of methods including electrofishing and/or seining, trawling, gill/trammel netting, dip-netting, and other methods are used to collect all fish species inhabiting the sampled stretch of river, stream, lake, or other aquatic habitat. This helps biologists find SGCN in locations where they were previously unknown, detect declines in species that may need to be considered for listing, and gather information on fish species that are unlisted but are important host species for mussel reproduction.
- Statewide Mussel Monitoring
Indiana DNR nongame aquatic biologists conduct general surveys for freshwater mussels throughout the state on an annual basis. Surveys are normally conducted using a timed search approach. This approach takes a section of a stream that is visually (if possible) and physically (such as searching through the stream bottom with shoed-feet, hands, or specialized rakes) searched for live mussels and other shell material while recording the amount of time that is exerted.