Estimating Recreational Effort in the Gulf of Mexico Red Snapper Fishery Using Boat Ramp Cameras: Reduction in Federal Season Length Does Not Proportionally Reduce Catch

摘要

Estimating fishing effort is of critical importance in assessing population trends of exploited species. We used video camera footage collected by surveillance cameras to estimate effort during the federal recreational seasons for Red Snapper Lutjanus campechanus during 2012-2015 in coastal Alabama. For 2012 (40 d in duration) and 2013 (28 d in duration), we randomly sampled 20% of days within the season and counted the number of boats launched and number of potential anglers (total number of people) on each vessel during randomly chosen 5-min blocks of time during each daylight or dusk hour. For 2014 and 2015, the seasons were considerably shorter, 9 and 10 d, respectively, and we were able to count the number of boats launched and potential anglers during randomly chosen 5-min intervals every daylight or dusk hour of each day. Using hourly weather observations (wind and precipitation), day of the week (weekend versus weekday), boat launch site, and year, general linear models were constructed to predict potential Red Snapper anglers per hour. For all years combined, the model had an R-2 of 0.62, with a higher R-2 (0.71) for the same variables using just 2014 and 2015 data. Applying the model, we were able to predict total offshore anglers by summing the hourly predictions over the season. We then estimated total number and weight of Red Snapper harvested for this group of anglers. Reductions in season length were not proportional to catch reductions due to changes in angler behavior. Red Snapper catch (in pounds) were reduced by 26% with a 75% reduction in season length. Our findings demonstrate the utility of dockside cameras for estimating marine recreational fishing effort and demonstrate the nonstatic response of anglers to management changes.