*4.2. Image Analyses*

Photographs taken along each transect were assessed to determine the percentage of cover of benthic organisms and substrate. Each photograph contained approximately one square meter of the substrate. A grid was placed over each image to aid in the calculation of substrate proportions. In every photograph each component of the benthic substrate was recorded as a percentage of the total area and rounded to the nearest 5%. The categories that were used to determine benthic substrate included the 10 Reef Check International substrate categories, including hard coral, soft coral, recently dead coral, nutrient indicator algae, sponge, rock, rubble, sand, silt, and other [72].

Only data in the hard coral category were analysed for the purpose of this study. Insufficient numbers of some growth forms in the photographs limited the morphological categories to two: branching and massive, within the first of which corymbrose corals were grouped with branching and within the second of which sub-massive corals were grouped with massive (see Table 2).


**Table 2.** Categories used to characterize benthic substrate during image analysis.

Each of the hard coral categories were grouped by growth form and health status, including live branching hard coral (BC), massive hard coral (MC), and hard coral of other growth forms (HC). Those corals that were visibly bleached with translucent tissue covering their skeleton were classified as bleached branching corals (BBC), bleached massive corals (BBM), and bleached corals of other growth forms (BHC). Those corals that were recently dead were also classified into their respective growth forms, including recently dead branching corals (RDBC), recently dead massive corals (RDMC), and other recently dead corals (RDHC).

Each of the hard coral categories used in the analysis are illustrated in Figure 6. These photographs illustrate the specification of recently dead coral in both massive and branching colonies as opposed to coral that has been dead for an extended period that has since turned to rock or rubble (Figure 6). Examples are included from both shallow and deep transects across various reef sites (Figure 6).
