Tempisque River runoff affect abundance and taxonomic composition of microplankton.
Five microplankton assemblages associated with a seasonal and river–marine gradient.
146 microplanktonic taxa were identified, 52 of which were new citations in the area.
Phytoplankton were mainly limited by light rather than nutrients.
From ecotone model at the estuary head to ecocline model for the rest of the estuary.