Intertidal macrobenthic community of bahía Chile (Greenwich island, Antarctic) and its relationship between physicochemical and granulometric parameters

Abstract

Human activity has been increasing in the Antarctic continent, which has meant an impact on coastal areas through waste, affecting intertidal benthic communities that have been little studied. The present study aims to determine the community parameters of benthic macroinvertebrates in the intertidal of Chile/Discovery Bay (Greenwich Island) and their relationship with physicochemical variables (organic matter, total petroleum hydrocarbons, free phosphorus and total nitrogen) in the vicinity of the Arturo Prat naval base outfall. For this purpose, sediment samples were taken in two transects parallel to the coastline, which were located on both sides of the outfall at 25, 50, 200 and 300 meters distance. A total of 10 taxa were identified of which Harpacticoidea and Oligochaeta were the most abundant.  Abundance values per sample ranged from 256 to 12,176 (Ind*m-2). While the average Shannon-Wiener index (H') ranged from 0.57 (± SD= 0.53) to 1.32 (± SD= 1.26) and the average evenness (J') ranged from 0.32 (± SD= 0.29) to 0.63 (± SD= 0.60). Principal component analysis showed a direct relationship between abundance and concentration of physicochemical variables. The composition of the intertidal sediment was mainly composed of very coarse sand and gravel at the stations sampled. On the other hand, the results obtained show that the physicochemical variables, taxonomic composition, equity and diversity values were similar to those obtained for other areas of King George Island.