Abstract

Larval fish and invertebrate advection modeling in the northern Gulf of Mexico (Gulf), particularly the Mississippi Bight, and the Mississippi Sound (Sound) show poor shallow water life history validation. Connectivity within the Sound and offshore Gulf waters is not well delineated, leaving immigration and emigration transport pathways associated with reproductive dynamics undefined. Major difficulties are with approaches to shallow waters. The principal difficulty is in cross-isobath flow as the coastline is approached, especially in low current areas. Higher resolution, finite volume models have not adequately matched known early life history dispersal and retention characteristics. The suspected difficulty is with wave produced flux of momentum toward the boundaries that does not capture the downward flux of wind momentum used in finite difference models. This lack of information is a critical issue for management and conservation of Mississippi fishery species that have connective pathways between offshore Gulf waters and the Sound as an essential component of their early life history. Wave models are available and applicable to the shallow regions, and near-surface GPS drifters are available for validation. We propose the extensive deployment of near-surface drifters with GPS trackers in the Sound and nearby barrier island waters that will simulate movement of surface-dwelling larvae in conjunction with a modeling effort to describe coastal boundary conditions. The purpose of this research is to identify transport pathways, improve shallow water operational models, and resolve issues of larval connectivity in the Sound and adjacent Gulf.