Photosynthetic parameters of phytoplankton in the California Current System

We analyzed photosynthesis-irradiance (P-E) and phytoplankton absorption da ta from the coastal waters of the Southern California Eight (SCB) as well a s data in the literature for other coastal and oceanic regions of the Calif ornia Current system (CCS). Since there is substantial variability within d ata sets, we conclude that it is not possible at this time to predict fine time-and-space-scale variations in photosynthetic parameters. For simple pr imary production models, we recommend working averages for the CCS between northern California and Bahia de San Quintin (300 km south of San Diego) ba sed on data we summarized from coastal and oceanic waters. For the upper ha lf of the euphotic zone we propose to use the following averages: alpha(B) = 0.047 +/- 0.004 mg C (mg chl)(-1) h(-1) (mu mol quanta m(-2) s(-1))(-1) ( the initial slope of the photosynthesis-irradiance curve); and P-max(B) = 8 .60 +/- 0.060 mg C (mg chl)(-1) h(-1) (assimilation number). A linear inter polation for the gradient of alpha(B) and P-max(B) is recommended for the l ower half of the euphotic zone (10%-1% Eo depths), with values for the 1% E -o depth equal to 25% of the values of the upper euphotic zone: alpha(B) - 0.012, and P-max(B) 2.15.