Potential connectivity among spatially distinct management zones for Bonefish (Albula vulpes) via larval dispersal

Abstract

The localized scale of most fisheries management does not account for potential regional connectivity, particularly for fish species with prolonged planktonic larval durations (PLD). Although bonefish (Albula vulpes) inhabits shallow coastal habitats from juvenile through adult life stages, it is a strong candidate for population connectivity via larval dispersal with a PLD of 41–71 days. To address this knowledge gap, surface trajectories of particles (“virtual larvae”) released from 26 known and predicted spawning sites of bonefish around the Caribbean Sea, Florida, and Bahamas were simulated for 2009–2015 using a realistic ocean circulation hindcast model coupled with an online particle tracking simulator to study larval transport variations. At each site, 100 surface particles were released twice per month (at full and new moons) from October to April in each year and tracked for 53 days. We then estimated the likelihood that management regions would rely upon larval retention versus larval dispersal from other management zones. Overall, separately managed areas are likely to be connected via larval dispersal rather than entirely self-recruiting. Significant temporal differences in particle dispersal found for new and full moon phases, and between winter and spring, highlight that it is vital to resolve multiscale temporal and spatial variability in circulation transport when studying larval transport and connectivity. Results underscore the need to include the likelihood of population connectivity in fisheries management and conservation strategies, and to ensure that the ontogenetic habitat requirements of bonefish are properly managed at a regional scale.