The spotted seatrout is one of the most prized targets of saltwater recreational fisheries in Texas. The sport fishing industry overall generates more than $2 billion in the state and supports thousands of jobs along the Gulf Coast.

Keeping this industry strong requires understanding the trout’s reproductive patterns and habitat needs. With mature trout, some of the best fishing areas are also good spawning habitats, but preserving areas that are the best locations for them to reproduce will help maintain a stable population.

Mapping these locations is difficult because of the darker green waters of the Gulf.

Although seatrout are generally known to aggregate and spawn in estuaries and bays along the coast of Texas from April through September each year, the specific locations and distribution of critical spawning habitats have not been identified or characterized. This lack of knowledge limits the ability of state and federal agencies to monitor, assess and manage this ecologically and economically valuable fishery.

Researchers at The University of Texas Marine Science Institute have come up with a creative solution to this problem.

“Waters in Texas are extremely full of life, from turtles and fish down to microscopic plants and animals. But all this life creates murky water and makes it hard to see,” says marine science Ph.D. candidate Chris Biggs.

Fortunately, Biggs points out, the spotted seatrout is not a member of the trout family but is a drum fish. “They actually make noises underwater,” says Biggs. “We can use underwater microphones to study them and figure out what’s going on.”