RELATIONSHIPS BETWEEN HABITAT AND RECRUITMENT OF 3 SPECIES OF DAMSELFISH (POMACENTRIDAE) AT HERON REEF, GREAT-BARRIER-REEF

Recruitment of coral-reef fish species varies widely on a range of spa tial scales, but the extent to which this variation is related to vari ability in habitat structure is unclear. We examined relationships bet ween the recruitment of three species of damselfish (Pomacentrus moluc censis Bleeker, P. wardi Whitley and P. amboinensis Bleeker) and micro habitat structure (composition of the substrata) across six broad habi tat zones at Heron Reef. Comparison of the distribution of recruits wi th the availability of substratum types along 10 x 2-m belt transects indicated that recruits of all three species utilised the substrata no n-randomly. However, despite the distinct patterns of microhabitat use exhibited by each species, relationships between the density of recru its and the availability of preferred substrata were poor. We suggest that spatial stochasticity in larval supply and/or post-settlement mor tality weakens relationships between recruitment and microhabitat avai lability. Univariate and multivariate analyses indicated significant d ifferences in the recruitment of each species and in overall recruitme nt among habitat zones, and these differences may reflect large-scale variation in larval supply and/or rates of post-settlement mortality. Based on combined recruitment data, there was little evidence to sugge st that areas of patchy coral reef received more or less recruitment t han comparable areas of contiguous reef. Furthermore, recruitment to l agoonal patch reefs did not differ from recruitment to nearby sections of the reef slope offering a similar habitat with respect to depth an d characteristics of the substratum. (C) 1998 Elsevier Science B.V.