ABSTRACT: SESSILE INVERTEBRATE COLONIZATION AND COMMUNITY DEVELOPMENT ON HARD SUBSTRATA SIMILAR TO THE NATURAL HARD BOTTOM IN THE SOUTH ATLANTIC   Fioravanti-Score, A.M. Georgia Southern Univ., Statesboro. alex@ skio.peachnet.edu Quarried rocks were deployed by a natural occurring live bottom reef in Gray's Reef National Marine Sanctuary, Georgia. Colonization was measured over the course of one year. Two comparisons were made. First, rocks were placed in open or in caged enclosures to examine the effect of grazing on colonization patterns. Second, rocks were placed on sand bottom areas for comparison of community development. Bryozoans dominated all treatment types throughout the year. The highest diversity occurred in the caged enclosures and lowest on rocks on sand bottom areas. There was significant difference among different taxa in mean percent coverage between the open and caged enclosures, with open enclosures having higher coverage. Likewise, there was a significant difference among different taxa in mean percent coverage between rocks placed on sand bottom versus hard bottom, with sand bottom having higher coverage. Patterns of seasonal changes for selected taxa will be discussed.   Conference: Annual Meeting of the Society for Integrative and Comparative Biology, Boston, MA (USA), 3-7 Jan 1998. (World Meeting Number 981 5002)