Vertical relationships between chlorophyll, production and copepods in the eastern tropical Pacific

Data consisting of high resolution profiles of in situ chlorophyll,copepods and primary production have been measured with a towedBatfish and profiling pumping system at two sites named ‘BIOSTAT’(9°45'N, 93°45'W) and ‘DOME’ (7°19'N,83°25'W) sites during March 1981. Primary production profileswere generated from Batfish profiles using a chlorophyll/lightmodel and incubated pump samples, the latter with high verticalresolution of 3–5 m. The BIOSTAT site had a subsurfacechlorophyll maximum situated at {small tilde}50 m, and a productionmaximum at a depth of 40 m Copepods had a mean depth centroidcorresponding to the production maximum although their distributionwas more uniformly dispersed from 0 to 40 m. The latter observationindicated that copepods occurred at depths of high productionpotential and low biomass rather than high total productionand high biomass as found at 40 m depth. The DOME site had amixed surface layer of chlorophyll (0–20 m) while copepodswere located at the base of the chlorophyll layer and primaryproduction maximum located at the surface (0–10 m). Theareal daily production measured at the BIOSTAT and DOME siteswere 0.27 and 0.80 mg C m^–2day^–1 respectively.