Larval Dynamics in the Gulf of Mexico: Using Ontogentic Vertical Migration Patterns to Inform Larval Trajectories and Assess Ecosystem Impacts

Understanding movements of early life stages is a key part of managing exploited fish populations. Position in the water column can impact larval dispersal since it determines which currents larvae are exposed to. Ontogenetic vertical migration patterns for a range of age classes and taxa of major commercial and recreational fishes in the Gulf of Mexico were predicted using generalized additive models built using a suite of environmental variables. The models were built using a training data set and validation was done using a testing data set. These ontogenetic vertical migration patterns are used in combination with circulation data from the West Florida Coastal Ocean Model (WFCOM) to predict larval trajectories in the Gulf of Mexico. These trajectories can be used to build a larval source and sink matrix for the Gulf of Mexico, which will illuminate potential spawning and rearing areas as well as areas where larvae may be lost to unfavorable physical conditions. This source and sink matrix informs the Atlantis Gulf of Mexico ecosystem model, which contains physical, biogeochemical, and food web interactions and can be used to test management strategies. Atlantis can be used to identify the impact of larval source and sink dynamics on fisheries and trophic dynamics. This project lies at the intersection of predictive statistical modeling, hydrodynamic modeling, and ecosystem modeling and represents an interdisciplinary approach to understanding larval dynamics and the impacts that they have on ecosystems.