SEED-GERMINATION AND RECOLONIZATION OF ZOSTERA-CAPRICORNI AFTER GRAZING BY DUGONGS

A seagrass meadow dominated by Zostera capricorni Aschers. was intensi vely grazed by dugongs (Dugong dugon Muller) between November 1992 and January 1993, leaving a bare sand surface. In less than a year densit ies had returned to pre-grazing levels with shoot densities of around 11,000 m(-2) by August 1993. Recovery of the seagrass appears to have been augmented by a high incidence of sexual reproduction. The floweri ng season was between August and March, with a peak in December (1219 +/- 338.8 flowering shoots m(-2); 11.8% of all shoots). Seeds were fou nd in the sediment throughout the year with least in late winter and e arly spring (August to November). Germinating seeds were found in the sediment throughout the year with the highest number and proportion in May (86 +/- 30.5 m(-2) and 22%). Seed production was considerably hig her at this site than has been found in previous studies of Z. caprico rni. (C) 1997 Elsevier Science B.V.