Structure and activity of polychaete assemblages in oil-polluted sediment (Patagonia, Argentina)

ROMANUT, O.; STURLA LOMPRÉ, J.; COMMENDATORE, M.; FERRANDO, A.

ECOLOGÍA AUSTRAL

ASOCIACIÓN ARGENTINA DE ECOLOGÍA

Lugar: Buenos Aires; Año: 2023

0327-5477

One of the applied tools to determine the pollution and stress status of an environment is through macrobenthic bioindicators. This study aimed (1) To validate ex situ experimental conditions comparing different physical-chemical and biological variables between in situ and ex situ treatments after 13 days; (2) to analyze, through an ex situ experiment, the effect produced by two concentrations of crude oil (1 g/kg and 20 g/kg) on the Caleta Sara polychaete assemblages at different depths of the sedimentary column (0–8 cm and 8–16 cm) and (3) to compare the results at the family and genera taxonomic levels to evaluate if the concept of “taxonomic sufficiency” could be apply to these assemblages. The abundance, richness, diversity and bioturbation showed a significant decrease in oil-polluted sediment only in the upper level. Capitella (Capitellidae) and Boccardia (Spionidae) were the most abundant at the highest oil concentration. The concept of “taxonomic sufficiency” could not be applied because the proportion of families and genera was 1: 1 in all the cases except for Spionidae. Nevertheless, detecting the oil effect at the family level indicated that this level could be sufficient in Patagonian ecotoxicological studies. This study represents the first evaluation of the Caleta Sara assemblages under conditions altered by crude oil in the laboratory, simulating natural conditions and avoiding a negative impact on the studied site.