Ice-fishing handling practices and their effects on the short-term post-release behaviour of Largemouth bass

Abstract

Numerous studies have investigated the impacts of catch-and-release on the post-release behaviour of fish during periods characterized by warm air and water temperatures. Comparatively little is known about the post-release behaviour of fish caught while ice fishing. Largemouth bass (LMB), a popular sportfish in North America, is sometimes encountered during ice fishing and is often released due to angler conservation ethic or to comply with regulations. To examine the impacts of ice angling on the post-release behaviour of LMB, we exposed them to a range of handling practices and assessed their skin temperatures prior to release, as well as short-term post-release swimming activity using biologgers equipped with a tri-axial accelerometer, temperature and pressure sensors. Skin temperature of LMB had a significant positive relationship with windchill temperature. Generally, the longer that LMB were exposed to air or placed on the ice, the colder their skin became. Overall, water depth and water temperature selected by LMB increased with time during the post-release period. Overall dynamic body acceleration (ODBA), a proxy for locomotory activity, decreased as time progressed in the release period, while ODBA decreased with increasing depth and water temperatures. LMB with warmer skin temperatures had lower locomotory activity compared to those with colder skin temperatures. Further, the effect of skin temperature on locomotory activity became more amplified with increasing depth and warming water temperatures selected by LMB post-release. Anglers practicing catch-and-release angling during the winter should adopt best handling practices by reducing the time fish are removed from the water when windchill temperatures are sub-freezing to avoid alteration in post-release behaviour.