Mapping plankton distribution in the Bay of Biscay during three consecutive spring surveys

Nano-microplankton biomass, mesozooplankton biomass and hydrographic features were measured with mesoscale spatial resolution during 3 surveys in the Bay of Biscay between March and June 2004. Regions of high plankton biomass were associated with mesoscale physical structures. Generalized additive models (GAMs) based upon surface salinity, surface temperature and stratification of the water column explained 83 % of the variability in nano-microplankton biomass distributions, 67 % for small mesozooplankton, and 41 % for large mesozooplankton. The results show that when biological and physical data are collected at the relevant spatial scales, nanomicroplankton and small mesozooplankton biomass distributions can be largely explained using simple hydrographic variables and non-parametric regression models.