Plankton Ecology and Productivity in Jamaican Waters with New and Unique Applications

Unique applications of plankton ecology and productivity in Jamaican waters are presented. While traditional indices were inadequate descriptors of mangrove lagoon water quality, planktonic indices (total Chlorophyll a , zooplankton groups and species) were more reliable. Phytoplankton biomass was used to indicate a longitudinal gradient along the Hellshire Coastline, identifying non-point sources of enrichment, and movement of water masses in the absence of expensive Eulerian current meters. Along that same coast, mean primary production, determined by 14 C techniques, confirmed a gradient from the eutrophic Kingston Harbour (21.1 g C m −2 year −1 ) to the oligotrophic control site (0.52 g C m −2 year −1 ). Maximum inshore station values (36.75–18.39 g C m −2 year −1 ) were more than 20 times greater than offshore and exceeded Harbour values, confirming non-point sources and localized mecha - nisms as important inshore sources of eutrophication. The novel use of Ecopath with Ecosim (EwE) software to model trophic flows within planktonic communities was done in two bays. For Discovery Bay, on Jamaica’s north coast, the model indicated a developing ecosystem with open mineral cycles and poor nutrient conservation while in Foul and Folly Bays on the southeastern coast the model indicated greater resilience and ability to recover from perturbations. These applications have facilitated informed management decisions for sustainable use in Jamaican coastal ecosystems.