Giant appetites: exploring the trophic ecology of California’s largest kelp forest predator, the giant sea bass Stereolepis gigas

Abstract

The recovery of endangered predators has the potential to influence the ecosystems they inhabit. After suffering severe population declines due to fishing pressure, giant sea bass Stereolepis gigas in southern California, USA, are beginning to recover. As large-bodied predators often associated with the kelp forest and rocky reef environments of southern California and Baja California, Mexico, the local recovery of this species could influence trophic dynamics in these systems. Here we leverage stable isotope and gut content analysis to describe the trophic ecology of adult giant sea bass. We found that they are generalist predators, with larger individuals relying more heavily on macroalgae-derived carbon, occupying a larger trophic niche, and obtaining higher trophic positions. Using these results, we speculate about the relationship between giant sea bass and kelp forest ecosystems, a vulnerable yet key habitat, including the impact of the return of these predators, as well as how contemporary threats to kelp forests might mediate their continued recovery.