Characterization of Baker fjords region through its heavy metal content on sediments (Central Chilean Patagonia)

Abstract

ABSTRACT. The spatial distribution of heavy metals in marine surface sediment from the Baker Fjord, located in the Central Chilean Patagonian fjords (47°30’S to 48°40’S), is analyzed, with the objective of characterizing this zone from this point of view . The mouth of the Baker Fjord is connected to the sea, while its head is adjacent to the inner channels. This fjord represents an area of estuarine circulation that has little human activity and which has been scarcely studied in terms of metal composition. Its basin has a surface area of 41,486 km 2 , and it receives fresh water from the Baker and, Pascua Rivers, and oceanic water from the Gulf of Penas. Surface sediments´ metal pattern composition and distribution were characterized. Segregated abundances of Ba, Cd, CU, Pb, Sr, and Zn were observed, allowing us to propose a functional relationship between the studied analytes and spatial and sectorial differences in composition. A cluster analysis established patterns of horizontal distribution in association with areas of glacier influence, with transition or mixing zones, and with areas under marine influence. Finally, we inferred that metal concentrations corresponded to those of metamorphic rocks, therefore supporting that sediments are originated from these rocks and their high concentrations would be the product of natural enrichment. In turn, differences in abundance would be specific to each sector.