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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.
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