BaselineAssessment of recent sediment influence in an urban polluted subantarctic coastal ecosystem. Beagle Channel (Southern Argentina)

In this study, baseline information about the environmental status of Ushuaia (UB) and Golondrina (GB) bays is presented. Surface and bottom seawater and freshwater discharged from land were evaluated. Multivariate analysis identified different water quality zones within the bays, two of them located next to the north and northwest coastlines of UB, where the majority of human activities are developed. Porosity, total organic matter, biochemical components, ammonium, and phytopigments were determined in sediment samples from each quality zone. Benthic fluxes of nutrients and dissolved oxygen were assessed in situ using opaque chambers. In northwest zone of UB, carbon equivalents of proteins and carbohydrates in surficial sediments were the same order as in hypertrophic ecosystems, whereas ammonium and phosphate released from sediment greatly exceeded the allochthonous sources. Management of municipal wastewater is required to remediate this chronic pollution.

Research highlights► Environmental status of Ushuaia and Golondrina Bays is presented. ► Carbon equivalents in sediments were the same order as in hypertrophic ecosystems. ► Ammonium and phosphate released from sediment exceeded the allochthonous sources. ► Management of municipal wastewater is required to remediate this chronic pollution. ► Sediment-water interaction may be the main factor controlling organic enrichment.