[Polychaetes as bioindicators of organic pollution on the beaches of São Paulo]. / Poliquetas bioindicadores de poluição orgânica em praias paulistas.

This study consisted of an analysis of the occurrence of bioindicator polychaete species of organic pollution along beaches of the north coast of São Paulo State, southeastern Brazil, taking into account the importance of benthic species as indicators of organically enriched environments. A comparison was established between the frequence and abundance of these species in areas qualified as impacted and improper for bathing. The study area comprehends 17 beaches of the Caraguatatuba Bay and the Channel of São Sebastião. The data about the macrobenthos were collected from March, 1988 to March, 1991 and the data on bathing conditions came from reports published by CETESB. The biological samples were obtained with an iron core of 0.025 m2 surface area. The results show markedly the presence of species considered as indicators of organically enriched places, such as Capitella capitata, Heteromastus filiformis, Laeonereis acuta, and Scolelepis squamata. The high density of Capitella and Heteromastus in beaches considered improper for bathing consist in a strong indication of the degree of damage to these areas.