RATES OF PHYTOPLANKTON PRODUCTION, BIOMAS AND BACTERIAL PRODUCTION IN THE GULF OF GUINEA, SOUTH EAST NIGERIA

Primary production, chlorophyll a concentration, bacterial abundance and production in 12 sampling station in the Gulf of Guinea were investigated between July 2007 and July 2008. Primary production measured using 14C uptake method varied from 14.87 to 162.12 μgCL-1d-1. Chlorophyll a concentrations were higher near the shore and ranged from 1.15 to 7.12 μg L-1. Bacterial abundance in the water surface varied from 0.23 to 6.04 x 109 cell L-1 and showed positive correlations with dissolved organic carbon (DOC) (r2= 0.644), chlorophyll a (r2= 0.547)primary production (r2=0.93). Bacterial production rates determined from tritiated thymidine incorporation ranged from 9.34 to 170.28 μgCL-1d-1. Estimate of bacterial carbon demand suggests that other sources of organic carbon will be needed to meet bacterial carbon requirements. A strong relationship between DOC and phytoplankton biomass was established suggesting that in the gulf of Guinea SE, Nigeria phytoplankton biomass is a major source of DOC.