Carbon production and export from Biscayne Bay, Florida. I. Temporal patterns in primary production, seston and zooplankton

Abstract

Five stations along a transect from the western shore of Biscayne Bay, Florida to the Florida Current were sampled monthly for one year. The variability and amount of seston particulate organic carbon, adenosine triphosphate, chlorophyll a, primary production and zooplankton decreased along the seaward transect. The greater inshore biomass and variability of seston were the result of the allochthonous input of detritus and inorganic nutrients via terrestrial runoff. Annual primary production in this subtropical coastal lagoon ranged from 13 to 46 g C m −2 yr −1. Chlorophyll a in the bay ranged from 1 to 3 mg chlorophyll a m −2. In contrast, chlorophyll a in the surface centimetre of the sediment ranged from 50 to 300 mg chlorophyll a m −2. In this clear, shallow (2 to 3 m), oligotrophic lagoon, over 90% of total primary production is by submerged macrophytes and benthic algae. The high zooplankton biomass in the bay is most likely sustained by macrophyte detritus and the resuspension of benthic diatoms by the high winds associated with summer squalls and winter cold fronts.