Dispersal Patterns of Coastal Largemouth Bass in Response to Tournament Displacement

Tournament displacement, stockpiling near release points, and handling stress are major concerns for managers of sport fisheries in the southeastern USA. We examined the effects of transport distance and tournament handling stress on dispersal of 40 Largemouth Bass Micropterus salmoides via telemetry from May 2012 to September 2013 in the Albemarle Sound system of eastern North Carolina. Largemouth Bass were captured from four tributaries of Albemarle Sound and transported 16.5-45 km to a central release point before being acoustically tagged and released. Movement data from an array of passive receivers was used to calculate rates of dispersal from the release point, emigration from the study area and return to capture location over time. Blood cortisol concentration, collected from our tagged Largemouth Bass and those captured in an actual tournament, was used to determine the effect of stress on potential postrelease movement and survival. Our findings indicate little evidence of long-term stockpiling (i.e., fish remaining close to release point; Richardson-Heft et al. 2000); 57% of displaced Largemouth Bass dispersed more than 500 m from the release point within 7 d and 87% within 21 d postrelease. Half of those that emigrated from Edenton Bay returned to their capture location. However, no Largemouth Bass displaced 35-45 km returned to their capture locations, suggesting that long-distance displacement inhibits return. Fishing (2.8%) and nonharvest mortality (0.5%) were low throughout this study except for peaks observed during late spring (42.9%) and early summer (25.1%) of 2013. Mean cortisol concentrations were similar in Largemouth Bass collected during our simulated tournament (126.7 ng/mL) and an actual tournament (118.4 ng/mL). However, cortisol concentrations were unrelated to survival, postrelease dispersal, or return of tagged individuals to their capture location. Largemouth Bass appear to be able to cope with current tournament practices; however, restrictions on displacement distance may increase return rates.