Vertical distribution of zooplankton in the frontal zone of the Gulf Stream and Labrador Current

Abstract

Zooplankton data collected during September 1995 in the North West Atlantic at 41°39'N, 49°58'W (the location of the site of the 'Titanic' wreck) were analysed. The region investigated was characterized by a very sharp frontal zone between the Gulf Stream and the main stream of the Labrador Current. The total plankton biomass in the water column was very high. The macroplankton biomass values below the 600 m layer were significantly higher as compared with the similar values measured before in other productive boreal regions of the Atlantic and Pacific oceans. A lot of dead mesoplankton animals occurred in the deep layers. The reason was that the cold-water mesoplankton advected by the Labrador Current died off intensively within the deep layers of the frontal zone and were used as a food resource by the macroplankton carnivores and scavengers that were very abundant there.