Transoceanic fluxes in southern Patagonia

BRUN A.A; ACHA, MARCELO E.; PIOLA, ALBERTO R.

Santos

Simposio; 3rd International Symposium - Effects of Climate Change on the World?s Oceans; 2015

PICES-IOC-ICES

The Patagonian continental shelf hosts a diverse community of fish, mollusks, birds and mammals of commercial importance and conservation. The development of these species critically depends on the physical and chemical conditions of the marine environment. The most conspicuous oceanographic characteristic over the southern portions of the shelf is its low salinity presumably originated in oceanic and coastal areas of SE Pacific. The objective of this study is to determine the physical and chemical characteristics of the inflows to the Patagonian continental shelf and their seasonal variability, and the associated planktonic groups. Analysis in temperature-salinity space and historical hydrographic data SE Pacific and SW Atlantic indicate a marked seasonal variability in the physical properties of the surface layers in the western Magellan Strait. These changes are due to the increased continental runoff as a result of melting of continental ice in the warm season. This continental runoff generates 2.5° C temperature inversions in the upper 117 m, which are compensated by a sharp salinity increase. Published results indicate that copepods and amphipods in the region are also distributed in two layers with distinct composition and abundance. Because these zooplankton species serve as food of several species, their distribution might have a significant influence higher trophic levels.