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Biophysical larval dispersal models of observed bonefish (Albula vulpes) spawning events in Abaco, The Bahamas: An assessment of population connectivity and ocean dynamics

Citation

Lombardo, Steven M. et al. (2022), Biophysical larval dispersal models of observed bonefish (Albula vulpes) spawning events in Abaco, The Bahamas: An assessment of population connectivity and ocean dynamics, Dryad, Dataset, https://doi.org/10.5061/dryad.g4f4qrft7

Abstract

Biophysical models are a powerful tool for assessing population connectivity of marine organisms that broadcast spawn. Albula vulpes is a species of bonefish that is an economically and culturally important sportfish found throughout the Caribbean and that exhibits genetic connectivity among geographically distant populations. We created ontogenetically relevant biophysical models for bonefish larval dispersal based upon multiple observed spawning events in Abaco, The Bahamas in 2013, 2018, and 2019. Biological parameterizations were informed through active acoustic telemetry, CTD casts, captive larval rearing, and field collections of related albulids and anguillids. Ocean conditions were derived from the Regional Navy Coastal Ocean Model American Seas dataset. Each spawning event was simulated 100 times using the program Ichthyop. Ten thousand particles were released at observed and putative spawning locations and were allowed to disperse for the full 71-day pelagic larval duration for A. vulpes. Settlement densities in defined settlement zones were assessed along with interactions with oceanographic features. The prevailing Northern dispersal paradigm exhibited strong connectivity with Grand Bahama, the Berry Islands, Andros, and self-recruitment to lower and upper Abaco. Ephemeral gyres and flow direction within Northwest and Northeast Providence Channels were shown to have important roles in larval retention to the Bahamian Archipelago. Larval development environments for larvae settling upon different islands showed few differences and dispersal was closely associated with the thermocline. Settlement patterns informed the suggestion for expansion of conservation parks in Grand Bahama, Abaco, and Andros, and the creation of a park in Eleuthera and the Berry Islands to protect fisheries. Further observation of spawning events and the creation of biophysical models will help to maximize protection for bonefish spawning locations and nursery habitat, and may help to predict year-class strength for bonefish stocks throughout the Greater Caribbean.

Methods

These data are bonefish Albula vulpes larval dispersal model outputs from the program Ichthyop (Lett et al. 2008). The Ichthyop model intakes support data that are included in this repository: Navy Coastal Ocean Model American Seas (NCOM AmSeas) — publicly available at https://www.ncei.noaa.gov/thredds-coastal/catalog/amseas/catalog.html — interpolated over an orthogonal grid created in ROMS (https://www.myroms.org/) that span the 2013–2014, 2018–2019, and 2019–2020 spawning seasons, settlement zone shapefiles created in ArcMap and adjusted to align with the orthogonal grid, a particle density schedule that represents bonefish larval development based upon the Japanese eel Anguilla japonica

Usage Notes

The Ichthyop output NetCDF files were analyzed in R, and all support files can be opened and inspected in R. Ichthyop was used to run the simulation.

Funding

Bonefish & Tarpon Trust, Award: 49072

National Fish and Wildlife Foundation, Award: 49072