Samples of water and barnacles Amphibalanus amphitrite were collected from Recife, Brazil, to assess if it accumulates total (TC) and thermotolerant coliforms (TTC) related with sewage pollution. The Most Probable Number (MPN) values and the standard procedures for examination of shellfish were used. Comparatively with the water samples, the highest coliform values came from the barnacles, with TC values ranging from < 3.0 × 10 3 to ≥ 2.4 × 10 6 MPN.g -1 , and TTC ranging from ≥ 2.4 × 10 3 to 2.9 × 10 5 MPN.g -1 . Barnacles accumulate the TC Ewingella americana, and the TTC Escherichia coli, Enterobacter gergoviae, Enterobacter aerogenes, and Enterobacter sakazakii. The results provided an indication of the level of organic contamination at the sampling locations and that this species could be a good organic pollution bioindicator.Keywords: barnacle, bioaccumulation, bioindicator, estuary, organic pollution. Acumulação de coliformes em

The speciation of As(III), As(V), MMA and DMA in marine sediments from La Coruña estuary is described. The arsenic species have been separated by ion-exchange chromatography and detected by hydride generation atomic absorption spectrometry (HGAAS). The redox potential has been determined in order to relate the concentration of arsenic species to this parameter.