Estimating Post-Release Survival of Tournament-Caught Black Bass Using T-Bar Tagging and Tag-Recovery Models

Black bass (Micropterus spp.) are one of the most sought-after freshwater sport fish in North America. Lake Champlain (on the border of U.S. states of New York and Vermont, and the Canadian province of Quebec) is consistently ranked one of the top 25 bass fishing lakes in the United States, boasting large populations of both largemouth (M. salmoides) and smallmouth bass (M. dolomieu). In 2008, Lake Champlain hosted 95 bass fishing tournaments. Because of the size of the lake, bass may be transported upwards of 100 km in a livewell, increasing their risk of injury. A high-profile fish kill at Plattsburgh, NY, in 2009 raised concerns about harm inflicted on fish due to handling practices at these catch-and-release events. We assessed bass for 11 physical indicators of stress at nine tournaments in 2011 and 2012, and 983 largemouth bass and 1008 smallmouth bass were tagged with plastic t-bar tags. Tag recovery models were used to assess variation in post-release survival based on observed indicators of stress. Minor indicators of stress (e.g. hook wounds) were not significantly related to survival; however, compounded stressors inferred from the presence of multiple stress indicators (e.g. barotrauma, absence of reflexes) were negatively associated with survival.