Big Indiana Bass

Mortality of hybrid striped bass following catch-and-release angling
Matt Petersen, Indiana Department of Natural Resources
Phillip Bettoli, Tennessee Technological University

Hybrid striped bass ("wipers"), a cross between a female striped bass and a male white bass, have been stocked into many Indiana reservoirs (Monroe being the most notable), as well as in reservoirs throughout the southeastern U.S. since the late 1960s, and have become pretty popular sportfish in some places. Bass anglers frequently try and release inadvertently caught hybrids when they are landed, but experience suggests that many times, a hard fought fish will die anyway. Researchers in this study wanted to quantify the successful release rate, as well as correlate it to a variety of variables.

They experimentally angled (a fancy term for 'went fishing and caught') 56 hybrid striped bass greater than 15" in length in a Tennessee reservoir using traditional angling gear in water temperatures ranging from 55^oF to 90^oF. To each fish caught they externally attached an ultra-sonic transmitter equipped with a float, then immediately released and tracked all fish multiple times during the first 10 days following release.

In the fall and spring when water temperatures were cool, mortality of caught and released hybrids was very low (average 3.6%). However in summer, when water temperatures exceeded 79^oF, the mortality rate increased to nearly 40%. Evidence was very strong in favor of water temperature being the only critical variable to explain the difference in mortality rates. While the hybrids in this study experienced lower catch and release mortality than pure striped bass in other systems, the 40% rate during summer is still problematic. Many authorities suggest that if you catch a hybrid striped bass during the warmer water months and want to release it, you keep your eyes open for a period of time to see if the fish comes floating back to the surface. If so, you might consider collecting the fish and taking it home for the table instead of leaving it to die.