Effects induced on the bryozoan Pentapora fascialis by a severe sea-storm which occurred in December 1993 at Tino Island (Ligurian Sea, NW Mediterranean) are described. Mortality, recruitment and growth of P. fascialis colonies have been measured directly by photographic monitoring for three and a half years. Near total mortality of the erect P. fascialis colonies in the photostation (11 m depth) was observed, while other benthic encrusting species seemed not to be affected. Many recruits were observed six months after the storm, but a clear relationship between recruitment and ovicells presence was not found. The percent cover increased and the number of colonies decreased with time following the storm: this was partly due to fusion between colonies. After three and a half years the cover of P. fascialis reached the pre-storm cover.

32nd European Marine Biology Symposium, KRISTINEBERG MARINE RES STN, LYSEKIL, SWEDEN, AUG 16-22, 1997