The density of juvenile scleratinian corals was quantified in shallow-water (4-18 m) sites representing three common reef types of the Florida Reef Tract: high-relief spur and groove, relict reef flat, and relict spur and groove. Reef types were chosen to encompass differences in depth, physical relief, and coral abundance. The purpose of this study was to 1) determine the density of juveniles in relation to non-juvenile corals and depth; and 2) evaluate correlations between juveniles and non-juvenile density in relation to larval dispersal strategies. Juvenile corals were identified and enumerated in random 1-m2 quadrat surveys and compared to density and cover of non-juveniles. Juveniles of 16 species were identified among the study sites. The number of species observed as juveniles was significantly greater in deeper (>10 m), relict spur and groove sites. Juvenile density differed significantly among sites and reef types, ranging from 1.18 to 3.74 colonies m-2. Juvenile density was greatest in relict spur and groove sites and was weakly correlated (r = 0.581) with depth. Juveniles comprised from 20.6 to 51.5% of the total coral assemblage in study sites. The majority of juveniles in high-relief spur and groove and relict reef flat communities were Agaricia agaricites, Porites astreoides, and P. porites. The majority of juveniles in relict spur and groove sites were P. astreoides, P. porites, and Montastraea cavernosa. Non-juvenile density and cover were significantly different among the study sites. Non-juvenile density (r = 0.577) was weakly correlated with depth. Coral cover ranged from 0.4 to 13 percent throughout the study area and was greatest in high-relief spur and groove communities. Life history strategies of juveniles in high-relief spur and groove and relict reef flat communities were generally characterized by species that brood larvae and attain a small colony size. Juveniles of three dominant brooding species (A. agaricites, P. astreoides, and P. porites) were significantly correlated to parental abundance across sites, suggesting that either self-seeding may occur for some species or that some recruits have been able to grow and survive. Density of juvenile A. agaricites was inversely related to depth (r = -0.326). Juveniles of three broadcasting species (M. annularis, M. cavernosa, Siderastrea siderea) were significantly correlated to parental abundance and increased in abundance with depth (r > 0.450). In contrast to some previous studies of juvenile coral assemblages in Caribbean reefs, the results suggest that parental abundance and composition may be a direct function of juvenile abundance in reef communities of the Florida Keys.
|Original language||English (US)|
|Number of pages||15|
|Journal||Bulletin of Marine Science|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Aquatic Science