Gag Grouper

Using Video Surveys to Examine the Effect of Habitat

on the Occurrence of Gag Grouper

GA Alvarez | DA Gandy | BJ Irwin | CA Jennings | AG Fox

The economically important Gag (Mycteroperca microlepis) fishery was declared overfished in the Gulf of Mexico in 2009. Although Gag are no longer listed as overfished, fisheries managers are concerned that stocks may not be recovering. Our objective was to identify habitat characteristics important to Gag, and their effect on Gag occurrence throughout the West Florida Shelf (WFS). We obtained data from three separate fisheries-independent video surveys that occurred in the WFS from 2010-2017. We ran a separate mixed effects logistic regression for each survey, and used AIC to determine the best fitting models. Our results indicate that increased rock coverage, relief, latitude, and depth had an overall positive effect on Gag occurrence, as did the coverage of sea whip. Managers may be able to help Gag and encourage their recovery by using these data to establish or expand protected areas that contain favorable characteristics.