Avery, W. E. and W. D. Liddell. 1997. Sessile community recruitment patterns on Bahamanian shallow and deep-reef hard substrata. 8th International Coral Reef Symposium, Panama.



Settlement experiments were deployed over a range of 10- 250m off Lee Stocking Island, the Bahamas during two time intervals (Sept. 94 - Jan. 95; Jan. 95 - Sept. 95). The experiments enabled the analysis of the effects of five treatments which differed in orientation, depth and degree of exposure. During both time periods recruitment declined sharply with increasing depth. Peak recruitment for most taxa occurred between 20-50m. Sites located above 50m exhibited high cover on exposed surfaces and were dominated by filamentous and macroalgae, while deeper sites were characterized by serpulid and spirorbid polychaetes. Shallow sites yielded the greatest disparities between exposed and cryptic settlement surfaces. Filamentous and, to a lesser degree, macroalgae dominated the exposed surfaces. Tunicates, bryozoans, sponges and scleractinians occupied the cryptic surfaces. Greater recruitment occurred on horizontal cryptic than on vertical cryptic surfaces. For depths less than 100m, fish grazing may be a significant ecological determinant as grazing scars were observed on exposed vertical surfaces.

Avery (home page)