Benthic Habitats and the Effects of Fishing

Symposium Abstract: Fishing Effects on Habitat: The Potential Consequences of Removing such Habitat Engineers as Red Grouper Epinephelus morio

F. C. Coleman, C. C. Koenig, M. W. Miller, S. A. Heppell, and K. Scanlon

doi: https://doi.org/10.47886/9781888569605.ch40

Mass removal of species that restructure the architecture of habitat and thus increase its complexity can have multiple effects on ecosystems, including loss of biodiversity and altered biogeochemical pathways. In this paper, we report on the contributions made to habitat heterogeneity by the engineering capabilities of red grouper, Epinephelus morio, throughout its life. We demonstrate that this fish starts excavating habitat at first settlement, provides important structure and enhances biodiversity in nearshore communities of the west Florida shelf as juveniles, and contributes significantly to the structure of low-relief continental shelf edge areas as adults. We discuss the potential benefits of using side-scan sonar imagery to track grouper-induced changes in habitat over time (developing a time-series of images both within marine reserves and in nearby reference sites). We also discuss the implications of red grouper fishery removals to overall productivity of the continental shelf of the northeastern Gulf of Mexico and the particular management problems presented by knowledge of this behavior. Current management decisions to move the longline grouper fishery further offshore may increase pressure on red grouper and other excavating species, such as tilefish, have a significant negative influence on habitat heterogeneity, with potential to cause cascading problems throughout shelf-edge communities.