Reproduction of 17 species of Halimeda from a range of sites on the Great Barrier were studied in situ and experimentally in the laboratory: 202 fertility events were monitored over a 6-year period.
Living plants were transported from the field and attached to racks in seawater tanks for the laboratory cascade experiments.
Variables recorded were: species; days of growth; number of fertility events; seasonality (month of gametangia formation); location (central, northern, and southern sections of the Great Barrier Reef); number of times gametangia found per month on species for which n>= 10; numbers of species with gametangia per month; lunar periodicity;
Gametangial characteristics: number gametangia measured; number gametangia per cluster; number papillae per cluster; number of gametangia per papillae; width and length (µm) of gametophore.
For the laboratory cascade experiments, comparison was made of spot measurements in the cascade to the environmental factors of light (day length, daily global irradiance, noon irradiance) and temperature (monthly means at Townsville breakwater, calculated temperatures for Cleveland Bay).
Data was collected between 1981-1987 at Davies, Keeper, John Brewer, and Myrmidon Reefs and at Cockle Bay, Magnetic Island; and 1985-1987 at Heron Island, and in the vicinity of Swains, Ribbon and Tijou reefs.