Zooplankton Distribution in Surface Waters of Tampa Bay, Florida

Surface zooplankton was sampled at 42 locations in the Tampa Bay system on a quarterly basis (1969-1970) with 74 μm mesh nets. Thirty-seven holoplankton species were identified. The most abundant species were Oithona colcarva, Acartia tonsa, Paracalanus crassirostis and Oikopleura dioica. These four contributed 60% and 38% to zooplankton biomass and numbers, respectively. Copepod nauplii accounted for 29% and 6% of numbers and biomass. Meroplankton was a significant component of zooplankton contributing, respectively, 19% and 8% to total numbers and biomass. The most important types were pelecypod, cirriped, polychaete and gastropod larvae.

Holoplankton variety was greatest during the three warm season surveys and in the most saline regions of the bay. Zooplankton standing crop both in terms of biomass and numbers was highest in upper bay regions and the Manatee River, and during the three warm season surveys. Winter standing crop was approximately an order of magnitude less than during the three warm season surveys. Average biomass and numbers for surface zooplankton for the bay system over the four quarterly surveys were 40 mg/m³ and 80,782/m³. Distributions of individual species with respect to salinity are discussed and standing crop is compared to that in other Gulf of Mexico and U.S. east coast estuarics and to phytoplankton standing crop.