Latitudinal changes of copepod egg production rates in Atlantic waters:: temperature and food availability as the main driving factors

Planktonic copepod abundance and egg production rates were determined in relation to temperature and chlorophyll concentration across a latitudinal transect in the Atlantic Ocean, ranging from 52 degrees S to 24 degrees N. Copepod distribution followed a pattern similar to that of chlorophyll a. with higher values at the southern latitudes. In contrast, egg production rates were significantly higher in the Atlantic intertropical zone, in the vicinity of the Equator. Copepod abundance was determined mainly by phytoplankton concentration, while rate processes (egg production rates) depended on chlorophyll a concentration and temperature. We propose multiple regression models including these 2 factors that explain up to 70% of the carbon specific egg production rates. The accuracy of these models versus previous ones including only temperature is also discussed.