Spatial and temporal variation in coral recruitment on the Great Barrier Reef : implications for dispersal hypotheses

• Published in: Marine biology 1990-10, Vol.107 (3), p.485-490
• Main Authors: FISK, D. A, HARRIOTT, V. J
• Format: Article
• Language: English
• Subjects: Acanthaster planci; Animal and plant ecology; Animal, plant and microbial ecology; Asteroidea; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Marine
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/bf01313433

Over 15,000 coral recruits were counted on settlement plates from three mid-shelf reefs and six fringing reefs in the northern section of the Great Barrier Reef during two summers (1986 and 1987) and one winter (1987). The density of coral recruits on some settlement plates from a fringing reef was up to 4.88 cm super(-2), the highest value ever reported. Mean density of recruits was greater on fringing reefs (81.1 recruits/settlement plate) than on mid-shelf reefs (15.6 recruits/settlement plate), but there was greater spatial variation in abundance of recruits between the fringing reef sites. Other differences between the mid-shelf reefs and the fringing reefs were that different taxa were dominant, and that settlement orientation differed, with mid-shelf recruits settling preferentially on horizontally oriented surfaces and fringing-reef recruits preferring vertical surfaces. Of the three mid-shelf reefs, Green Island reef recorded the highest recruitment rate for each of the two summers, despite having a depauperate adult coral population following predation by the asteroid Acanthaster planci . This suggests that coral larvae frequently travel between reefs.