Quantitative and qualitative aspects of inshore phytoplankton off Barbados

Abstract

The report is a 2-year time-series study of qualitative and quantitative aspects of inshore phytoplankton off Barbados with special emphasis on diatoms. Cell counts during a 2-year period averaged 22 536 per litre, of which 94% were diatoms. Amazon River water appeared not to have any consistent measurable effect on the abundance of the phytoplankton over the 24-month period. Chaetoceros and Nitzschia species were the major numerical contributors to the diatoms. A high ratio (17:3) of neritic to oceanic species of the most common diatoms was considered indicative of the existence of a system of retention for the inshore phytoplankters. Species composition of the total phytoplankton community was also considered. A total of 147 taxa included the following: diatoms, 103; blue-greens, 3; dinoflagellates, 35; silicoflagellates, 1; coccolithophores, 2; greens, 3. The latter three were present in consistently low concentrations.