PCB concentrations in intertidal sipunculan (Phylum Sipuncula) marine worms from the Pacific coast of Costa Rica
Specimens of the sipunculans Phascolosoma perlucens, Antillesoma antillarum, and Sipunculus nudus, were collected for PCB analysis in three coastal embayments on the Pacific coast of Costa Rica in October 2005. After collection the worms were kept in cool sea water and transferred to the laboratory for freeze drying. Half of the specimens of S. nudus were depurated in filtered sea water for 72 h before freeze drying. The whole worm sample was ground, using a mortar and pestle prior to being extracted with dichloromethane solvent. The extract was cleaned using a florisil column and analyzed using a 6890 Hewlett-Packard gas chromatograph equipped with a mass selective detector. Recovery efficiencies averaged between 72 and 80 %. Data are not corrected for blank or recovery efficiencies. Concentration data were calculated based on comparison with standards for Arochlor 1221, 1242, 1248 and 1254 (Supelco, Inc. ®). No worm samples were identified with six or more chlorine atoms. However, the higher chlorinated congeners were identified in the standards. Therefore, the lack of chlorination in the worms was not an analytical artifact. The sum of identifiable PCBs ranged from a barely discernable 0.01 ng/g dry wt in an A. antillarum sample from Culebra Bay to 67.71 ng/g dry wt in a P. perlucens sample obtained near the Rincón river in the inner Golfo Dulce. S. nudus worm samples from the Cocorocas sand flat in the Gulf of Nicoya had relatively high concentrations of PCBs whether they were depurated or not. The samples from Costa Rica are low in PCBs, especially compared to the marine sediment samples measured previously in Costa Rica. This was the first attempt to identify and quantify the presence of PCBs in any marine organisms from the Pacific coast of Costa Rica. Rev. Biol. Trop. 54 (Suppl. 1): 27-33. Epub 2006 Sept. 30.
Keywords: PCB, sipunculans, Costa Rica, Gulf of Nicoya, Phascolosoma perlucens, Antillesoma antillarum, Sipunculus nudus, marine pollution, estuaries