The Ecology of Inshore Plankton Populations in Bermuda. Part I. Seasonal Variation in the Hydrography and Nutrient Chemistry

Variations in the hydrography, the levels of inorganic nutrients and chlorophyll a, and the total nitrogen and phosphorus content of particulate matter were observed approximately biweekly from March, 1964, through March, 1966, at several locations on the Bermuda platform.

A thermocline developed in Harrington Sound (station A) during the summer of each year. Oxygen levels below the thermocline decreased with a concurrent marked increase in phosphate-P and “ammonia-N” concentrations. Completely anaerobic conditions were found late in the summer. The levels of chlorophyll a at station A showed an approximately fourfold increase shortly after the breakdown of the seasonal thermocline.

In general, at the North Lagoon site (station C), nutrient levels and chlorophyll a were low and the seasonal changes small relative to Harrington Sound.