Fish species richness and abundances were quantified by snorkeling along the NW (seaward) side of the Uva Island patch reef. During each survey, 3 permanent 20x40 m transects were sampled with the longest axis oriented in the NW-SE direction, i.e. along the depth gradient and perpendicular to the zonation of forereef corals. The mean transect width estimate for visual measurement was ~10 m.  Substrate type and depth (relative to MLLW tidal datum) in each transect were mapped in situ at the beginning and end of the study. The shallow ends of the transects were located in abundant pocilloporid stands (with scattered reef frame blocks) of relatively high relief; the central sections were dominated by live stands of Pocillopora spp. of low relief; the deep ends contained mostly coral rubble with a few isolated patches of massive corals. In the 1980s, 3 of the permanent transects were surveyed; this was increased to 9 (over a period of 2-3 days the same 3 transects were re-sampled) in the 1990s and early 2000s.

Fish counts were made from the surface by snorkeling slowly, avoiding quick movements or splashing, down the long axis of each transect. Species and abundance of all visible (non-cryptic) individuals at least 15 cm total body length present within the transects were recorded. Whitetip and bull sharks were infrequently observed on the reef but did not enter the transects during the survey periods. Sampling time was standardized at 8 min per transect (per 800 m2). The sides of adjacent transects were separated by 3 m, and the time interval be tween successive visual sampling was ~5 min. Fishes were not observed to be attracted to or repelled by the observer.