Submarine outfall effect on subtidal macrobenthic communities in a southwestern Atlantic coastal city

CUELLO, GRACIELA V.; SARACHO BOTTERO, MARÍA ANDREA; LLANOS ELIZABETH NOEMI; GARAFFO GRISELDA VALERIA; HINES, EMILIANO; RODOLFO ELIAS; JAUBET MARÍA LOURDES

Heliyon

Elsevier Ltd

Año: 2023 vol. 9

Submarine outfalls are an effective alternative for the final discharge of wastewater. The aim wasto evaluate the subtidal macrobenthic community’s responses and the changes in bottom sedimentarydynamics due to submarine outfall (SO) location. Sampling stages were: before SO (BSO),after SO (ASO) and after treatment plant (AEDAR). Sampling sites were determined at differentdistances from the coastline (coastal, oceanic, and reference) on both sides of the pipe (North andSouth). Species shifts (from tolerant to sensitive) were observed along with a decrease in organicmatter in the AEDAR Stage. There were changes in the sedimentary dynamic with sedimentaccumulation on the South side of the SO (finest sediments) and erosion on the North side(coarsest sediments) in the ASO and AEDAR Stages. Species turnover was higher than nesting in allstages. Functional trait analysis allowed the identification of temporal variations in benthiccommunities. The body size, development mode, feeding mode, habit, adult mobility and toleranceto pollution were useful functional traits to detect changes through Stages (BSO, ASO, andAEDAR). Biotic indices classified the sites as slightly disturbed, indicating a slight improvement inthe AEDAR Stage.