Zooplankton Population Dynamics in Relation to the Red Tide Dinoflagellate Karenia brevis on the West Florida Shelf of the Gulf of Mexico

Abstract

Blooms of the toxin producing dinoflagellate <italic>Karenia brevis</italic> are common in the Gulf of Mexico, and while several studies have investigated nutrient sources and bloom processes, there has been less research in regards to zooplankton population dynamics within these blooms. Zooplankton community structure and copepod species composition were analyzed from samples collected on the West Florida Shelf during October 2007-2010. Copepods constituted the most important zooplankton group, averaging 60% of total abundance. In 2009 there was a significant difference between the abundance of zooplankton at stations within a <italic>K. brevis</italic> bloom. As the <italic>K. brevis</italic> bloom progressed, total zooplankton abundance decreased. Additionally, the role of zooplankton within <italic>Karenia brevis</italic> blooms was investigated as both grazers of primary productivity and potential sources of regenerated nutrients.