GYMNODINIUM BREVE RED TIDE BLOOMS - INITIATION, TRANSPORT, AND CONSEQUENCES OF SURFACE CIRCULATION

From its source waters in the Gulf of Mexico the led tide dinoflagella te, Gymnodinium breve is moved throughout its oceanic range by major c urrents and eddy systems. The continental shelf off the west coast of Florida experiences frequent G. breve blooms (in 21 of the last 22 yea rs) where the spatially explicit phases of G. breve blooms are closely coupled to physical processes. Bloom initiation occurs offshore and i n association with shoreward movements of the Loop Current or spinoff eddies. A midshelf front maintained by seasonal wind reversals along t he Florida west coast may serve as a growth and accumulation region fo r G. breve blooms and contribute to the reinoculation of nearshore wat ers. Local eddy circulation in the northeastern Gulf of Mexico and in the Dry Tortugas affects the retention and coastal distribution of blo oms while the Florida Current and Gulf Stream transport cells out of t he Gulf of Mexico and into the U.S. South Atlantic Eight. The causes o f bloom dissipation are not well known but mixing or disruption of the water mass supporting G. bp-eve cells, especially in combination with declining water temperatures, are important factors.