The Ecology of Inshore Plankton Populations in Bermuda. Part II. Seasonal Abundance and Composition of the Zooplankton

Seasonal changes in the numerical abundance and taxonomic composition of the populations of zooplankton at two locations with contrasting hydrologic characteristics on the Bermuda platform were studied over a period of two years. Station A in Harrington Sound was in an area having restricted exchange with oceanic waters surrounding the islands, whereas station C was in the North Lagoon, an open region in contact with the Sargasso Sea.

The average standing stock of zooplankton/m³ over the period of observations was similar at the two sites—2300/m³ and 1900/m³ at stations A and C, respectively. Copepods comprised an average of 77 per cent and 95 per cent of the zooplankton populations at the respective sites and were the dominant group of plankton at each time of sampling at station C. Meroplanktonic molluscan larvae and cladocerans were sometimes predominant during the spring and summer at station A.

Of the copepods, Calanopia americana was the most abundant form at station A, whereas Paracalanus parvus was dominant in the North Lagoon.