The U.S. Fish and Wildlife Service has teamed up with FishBrain, the Swedish company behind a social network and an angler app that tracks weather, wind direction, water quality and other data points of interest to people who fish. Or who just want to observe wildlife. Now that app will include a feature to identify species of fish and other creatures that live near water, that are deemed to be threatened or endangered.

Users can log up to 50 “at-risk species” as they fish in an effort to help conservationists and researchers figure out where the animals live, what sort of habitat they need and perhaps the reasons for their decline.

The FWS provided a list of threatened or endangered species as well as possible candidates for protection under the Endangered Species Act that live in, or around, lakes, streams, estuaries, or other bodies of water. At risk species include the shortnose sturgeon, whooping crane, Kemp’s ridley sea turtle, and the California red-legged frog.

It might seem odd to view anglers who, after all, hunt fish, as a formidable force for conservation, but then again, the last thing a fisherman wants is a lack of fish. Preserving species is important for them. And, many who fish release what they catch.

As Gary Frazer, assistant director of the FWS’ Ecological Services Program said in a statement:

“Anglers are extremely important to protecting and maintaining healthy aquatic habitats. This is a unique opportunity to synthesize recreational anglers’ information and knowledge in local waterways and expand our understanding of various species.”

The updated app is available for Apple and Android devices.

Sign up for Data Sheet, Fortune’s daily morning newsletter about the business of technology.