which is too small to be ingested by most of the organisms of the mesozooplankton. We follow the assumption that the microzooplankton follow the phytoplankton biomass very closely (being its prey), which implies similar growth rates for both. Such a condition is satisfied in the open ocean where protists are an important component of the nano- and microzooplankton populations ( Le Borgne and Landry, 2003) and is likely valid in the SW lagoon.