The Control of West Florida Continental Shelf Material Property Distributions by a Combination of Deep-Ocean and Local Forcing

Often described as oligotrophic, the west Florida continental shelf supports abundant fisheries and experiences inter-annual blooms of the harmful alga, Karenia brevis. Through a coordinated program of coastal ocean observing and modeling, the ecology of the west Florida shelf is shown to be governed by a combination of deep-ocean interactions with the shelf slope and local forcing, each of which alters material properties. Local forcing primarily influences the inner shelf, but deep-ocean forcing, under certain conditions, may set the entire shelf in motion, resulting in injections of new inorganic nutrients by upwelling across the shelf break and subsequent transport to the nearshore. Model simulations, when gauged against in situ observations, are useful for addressing such pathways and mechanisms of across shelf transport, and recent ecological applications include: 1) HAB occurrence, 2) gag larvae recruitment and 3) fish lesions found post DWH oil spill. Particle trajectories, either on fixed levels (surface and near bottom) or along isopycnal surfaces (for more general water parcel considerations) are useful for investigating connectivity and defining the origins (depths and locations) of anomalous water properties that are found near shore. These results also suggest design considerations for coastal ocean observing system implementation.