NOAA Technical Memorandum NMFS-SEFSC-xxx

of LD versus thicket and reserve vs. reference sites with any sort of power, these groupmeans were plotted for inspection.Coralliophila abbreviataThe lengths of snails infesting different hosts (LD A. palmata, thicket A. palmataand Montastraea spp.), were compared between years (1998 through 2001) and betweenno-take reserve and reference sites. Length data were transformed (X’=X 1/2 ) and analysisof variance (ANOVA) using general linear model (GLM, Statsoft Inc., 1995) wasperformed to evaluate the effects of host, year and reserve status on the mean length ofsnails on A. palmata. Pair-wise contrasts were considered significantly different whenthe least squares mean " 95% confidence interval did not overlap.In this ‘reserve’ model both the reserve and host effects are potentiallyconfounded by a ‘site effect’ caused by unbalanced design. Thus a ‘site specific’ modelwas also run to isolate site differences (sites: SC, LG, HS, ML, FR, PI), and included yearand host factors to identify any significant interactions. Size frequency distributions wereconstructed using 1mm size intervals to visually compare the size-structure of thepopulations between hosts, years, and sites.RESULTS:Acropora palmataAcropora palmata suffered dramatic losses between the May 1998 and the May1999 survey, coinciding with a severe bleaching incident associated with the 1997-98ENSO event and the passage of Hurricane Georges along the Florida reef tract (25 Sept1998). In the initial survey of May 1998, a total of nine isolated patches were sampled atthe six sites. Two of these nine patches (22%) had undergone complete mortality by theMay 1999 survey and are excluded from the data presented here. An additional reservesite (Grecian Rocks) where ~100 colonies were lost from additional between 1998 and1999 is also excluded from the following presentation. These disappearing patches (oneat French and one at Little Grecian, and the Grecian Rocks site) represents a loss of ~220A. palmata colonies between 1998 and 1999.5