Observations on spawning of coral reef invertebrates on the Great Barrier Reef

Observations were made on spawning behaviour and timing for a diverse group of marine invertebrates, over two summers (November to January) of 1990-1991 and 1991-1992 at Davies Reef on the Great Barrier Reef.Observations were made along a permanent belt transect (200m x 10m) divided into 10 equal quadrats (20m x 10m), located within the reef lagoon. A total of 214 scuba dives, which included 55 night dives, were made at this site over the study periods. Frequent observations were also made on snorkel. The species, date, time, phase of the moon and tide, number of individuals and sex of spawners were noted. Spawning behaviour was also recorded.Where possible samples of eggs from spawning females were taken to assess fertilisation success rates.Additional observations of spawnings dating between 1978 and 1991 on Davies, Broadhurst, Little Broadhurst, Lizard Island, John Brewer, Myrmidon and Orpheus Island are also available.
To better understand spawning behaviour and reproductive periodicity.