Ecotoxicological quality in sediments of Reloncaví and Corcovado gulfs, Chile

A study of the ecotoxicological quality of surface sediment was carried out on samples collected in the main fjords and interior channels between Reloncaví and Corcovado gulfs. The surface sediment samples were taken with a box corer and analyzed for organic matter content and grain size. Dissolved oxygen was measured in water samples taken 10 m off the bottom. The ecotoxicological evaluation of the sediments was performed using fertilization assays with gametes of Arbacia spatuligera (EPA/600/4-91/003). A fertilization rate of 95%, similar to that of the controls, was achieved. Therefore, the sediments at the sampled stations located in the middle of the channels were classified as nontoxic. Only the sediment at Station 26 (i.e., sector Dalcahue) was classified as “slightly toxic” (90 ± 4.1%). The samples were taken from the central zones of the studied channels and fjords. Since toxicologically these central areas are not polluted, any possible effects of aquaculture activities are expected to be more local in scope.