Oil spill effects on macrofaunal communities and bioturbation of pristine marine sediments (Caleta Valdés, Patagonia, Argentina): experimental evidence of low resistance capacities of benthic systems without history of pollution

FERRANDO A.; GONZALES E. ; FRANCO M.A.; COMMENDATORE M.G.; NIEVAS M.L.; MILITON C.; STORA G.; GILBERT F; ESTEVES J.L.; CUNY P.

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2015 vol. 22 p. 15294 - 15306

0944-1344

Abstract The Patagonian coast is characterized by the existence of pristineecosystems which may be particularly sensitive to oil contamination. In thisstudy, a simulated oil spill at acute and chronic input levels was carried outto assess the effects of contamination on the macrobenthic community structureand the bioturbation activity of sediments sampled in Caleta Valdés creek.Superficial sediments were either noncontaminated or contaminated by Escalantecrude oil and incubated in the laboratory for 30 days. Oil contamination inducedadverse effects on macrobenthic community at both concentrations with, for thehighest concentration, a marked decrease of approximately 40 and 55%of densityand specific richness, respectively. Besides the disappearance of sensitive species,some other species like Oligochaeta sp. 1, Paranebalia sp., and Ostracoda sp. 2 species have a higher resistanceto oil contamination. Sediment reworking activity was also affected by oiladdition. At the highest level of contamination, nearly no activity wasobserved due to the high mortality of macroorganisms. The results stronglysuggest that an oil spill in this protected marine area with no previous historyof contamination would have a deep impact on the non-adapted macrobenthiccommunity.