FOULING ORGANISMS OF HARBOUR AND NATURAL AREAS FROM THE SOUTH WESTERN ATLANTIC COAST (ARGENTINA): BIOLOGICAL AND ECOLOGICAL STUDIES OF POLYDORA LIGNI.
Bastida, R. 1,2,3; Martin, J. P. 1,2,3 & Ieno, E. 1,2,3
1CONICET
2Fundación Mundo Marino
3Universidad Nacional de Mar del Plata. Dean Funes 3350 7600- Mar del Plata, Argentina
The aim of this paper is to contribute to the knowledge of the biology and ecology of Polydora ligni raised on artificial non-toxic panels placed in natural estuarine areas and different harbours of the Argentine coast. Polydora ligni is a common member of fouling communities of the Southwestern Atlantic Ocean (Southern Brazil, Uruguay and Argentina) that causes serious damage to submerged structures. Field work and aquarium experiments were carried out both in natural and harbour areas. Settlement and reproductive cycles were studied using plankton and benthic samples. Tube-building activities and feeding strategies were monitored under lab conditions. Results of this research indicate the importance of the species in the pattern of settlement and in the process of ecological succession. The evolution of the fouling community during the study period is clearly marked by the dominance of P. ligni. Aquarium experiments revealed the presence of diatoms and detritus in diet of P. ligni, suggesting that palps are essential for feeding and production of burrows. As a result of spatial competition, numerous cases of epibiosis were recorded in the present study. Abundance of this species has increased in harbour areas since the late '60s and P. ligni has been proven to be highly resistant to toxics used in antifouling paints. The abundant presence of Polydora seems to be a good biological indicator of pollution phenomena.