Habitat Features Predict Carrying Capacity of a Recovering Marine Carnivore

The recovery of large carnivore species from over-exploitation can have socioecological effects; thus, reliable estimates potential abundance and distribution represent a valuable tool for developing management objectives criteria. For sea otters (Enhydra lutris), as with many apex predators, equilibrium is not constant across space but rather varies function local habitat quality resource dynamics, thereby complicating the extrapolation carrying capacity (K) one location to another. To overcome this challenge, we developed state-space model density-dependent population dynamics in southern (E. l. nereis), which K estimated continuously varying suite physical, biotic, oceanographic variables, all described at fine spatial scales. We used theta-logistic process that included environmental stochasticity allowed density-independent mortality associated shark bites. Bayesian methods fit time series survey data, augmented by auxiliary data on cause death stranded otters. Our results showed expected density given area be predicted based bathymetry (depth distance shore), benthic substrate composition (rocky vs. soft sediments), presence kelp canopy, net primary productivity, whether or inside an estuary. In addition reductions growth, increased levels shark-bite over last decade also acted limit expansion. functional relationships between variables project values entire historical range California, USA, accounting variation quality. suggest California could eventually support 17,226 (95% CrI = 9,739–30,087). fitted compute candidate optimal sustainable (OSP) regions within California. employed simulation-based approach determine maximum productivity level (MNPL) propose upper quartile MNPL (accounting parameter uncertainty) represents appropriate threshold value OSP. Based analysis, OSP (for California) 10,236, 59.4% projected K. © 2021 Authors. Journal Wildlife Management published Wiley Periodicals LLC behalf Society.