Connectivity and Larval Dispersal Pathways of Panulirus argus in the Gulf of Mexico: A Numerical Study

The connectivity among subpopulations of Panulirus argus in the Gulf of Mexico is evaluated using a particle-tracking model coupled to a realistic hydrodynamic simulation generated with the Hybrid Coordinate Ocean Model. In 12 potential subpopulations of the Gulf of Mexico, virtual larvae were released daily from March 21 to June 18, 2006–2010. Virtual propagules were tracked for a maximum of 198 days and programmed to undergo vertical migrations and to eventually “die” according to an exponential decay function. The subpopulations that were the most inter-connected and had the highest values of self-settlement were those from the Bay of Campeche (Campeche, Southern Veracruz, Central Veracruz, and Northern Veracruz). This pattern can be explained by the recirculation resulting from the semi-permanent cyclonic gyre in the Bay of Campeche and the back and forth behaviour of the shelf currents at Veracruz. Self-settlement was low at Quintana Roo, Southern Florida, and Northwestern Cuba, because the Loop Current quickly transported the larvae away from those areas. Southern Florida received a considerable number of settlers coming from almost all other subpopulations mainly by means of the Loop Current. Larvae from Yucatan may be transported to subpopulations in the Bay of Campeche by means of both westward Loop Current Eddies and the westward inner-shelf current in the Campeche Bank. The continental shelf of the Bay of Campeche, particularly the islands and cays in the western edge of the Campeche Bank, emerged as both important settlement areas and larval dispersal pathways. A program for the protection of the species in these areas may help increase the population size of P. argus in the Gulf of Mexico, potentially favouring local fisheries.