Zooplankton Communities of the Argentine Continental Shelf (SW Atlantic, ca. 34°–55°S), An Overview

Abstract

A profuse literature related to the ecology of the Argentine continental shelf has been produced in the last four decades, documenting its biological richness and high productivity. Distinctive environmental characteristics define particular systems along and across the shelf, which in all cases are inhabited by mammal, bird, fish and cephalopod species in all life history stages, either as spawning, mating, nursery or juvenile grounds or just for adult feeding. At the productive base of these systems, zooplankton certainly plays a crucial role. This paper reviews the available information on zooplankton diversity and ecology for this huge region in the Southwest Atlantic Ocean, with the focus primarily upon copepods and secondarily on hyperiid amphipods and euphausiids. We describe general aspects of biogeographic zonation and diversity for the entire shelf, with emphasis on key zooplankton species. Then, we consider the structure and dynamics of the communities in relation to water masses, frontal areas and the overall circulation, specifically for (i) the northern shelf (34°–41°S), (ii) the Valdés frontal system over the northern Patagonian shelf (41°–45°S) and (iii) the southern Patagonian shelf (47°–55°S). We finally go over the open questions and prospects for the future work on zooplankton in the region.