Global distribution of tropical and subtropical copepods

Abstract

Here we show the main distribution characteristics of marine copepods across the subtropical-tropical latitudes and to bathypelagic depths in the Atlantic, Indian and Pacific Oceans (35°N-40°S). The copepod samples were collected from December 2010 to June 2011 during the Malaspina Circumnavigation Expedition. Epipelagic (0-200 m), mesopelagic (200-1,000 m) and bathypelagic strata (1,000-3,000 m depth) were sampled using an opening and closing Hydro-Bios Multinet at the following depths: 0-200, 200- 500, 500-1,000, 1,000-2,000 and 2,000-3,000 m. As expected, copepods were the most abundant contributors to the zooplankton community (84%), with more than 290 taxonomic categories identified. Other marine organisms observed were chaetognaths (5%), siphonophores (3%), ostracods (2%) and euphausiids (1%). The general distribution patterns observed included low abundances, irregular spatial distributions across the three oceans, and a large decrease of abundance as the depth of the water increased. The lowest abundance was found in the southern and western regions of the Pacific Ocean, while the highest abundances were found close to the upwelling systems of the northeastern Pacific Ocean, off the Cape Vert Islands and in the Benguela current. Large differences were not observed among oceans where depth played the most important role in the structure of the copepod communities.