Coccolithophore export production in Guaymas Basin, Gulf of California: Response to climate forcing.

The flux and taxonomic composition of coccolithophores has been determined for sediment trap samples collected over a two-year period from Guaymas Basin, central Gulf of California. The Gulf of California is a subtropical marginal sea with exceptionally high rates of primary productivity. The annual biogenic sediment fluxes are largely dominated by silica, with diatoms as the major contributor to the opal flux. For the July 1990 through November 1992 study period, the total coccolithophore export production in Guaymas varied in response to the strength of El Nino/Southern Oscillation (ENSO). Coccolithophore production follows the general surface primary productivity pattern with relatively high fluxes from late fall to late winter, and low production in the summer when the water column is highly stratified and nutrient depleted. High fluxes of up to 10