and negatively related to salinity. Water around most of the WT reefs had higher nutrient, sediment and chlorophyll concentrations than around PC reefs. While mean concentrations around the PC reefs were fairly homogeneous, water quality around the WT reefs varied more widely. Overall, the water quality index (WQI) was strongly associated with reefs of the WT, however Fitzroy Island and the Barnard Reefs in WT had a WQI that was similar to that of Wilkie Reef in PC (Fig. 2). Some WT reefs (Alexandra Reef and Double Island) were strongly associated with particulate matter (suspended solids, particulate nitrogen and phosphorus, chlorophyll and phaeopigments). Two other WT reefs (Normanby and High Islands) were strongly associated with high concentrations of dissolved nutrients (nitrate, total dissolved nitrogen and phosphorus, and silicate) and reduced salinity
Fig. 2. Water quality around inshore reefs in PC and WT, displayed by a principal components analysis biplot. The water quality vectors point towards the location with highest concentrations (abbreviations are listed in Section 2). The vector of the water quality index (WQI, dashed line) is strongly associated with reefs of the WT. The WT and PC reefs are represented by black and grey thermometer symbols, respectively, with the fill of each symbol representing the water quality index of each reef. Concentrations of all particulate matter (suspended solids, particulate phosphorus and nitrogen, chlorophyll and phaeopigments) were highest at Alexandra Reef and lowest at Hannah Reef, whereas concentrations of silicate and lowest salinity were highest at Normanby Reef and High Island.
The taxonomic richness of some of the inshore reefs was high (Table 1). A total of 88 genera of fleshy macroalgae, 318 species of hard corals, 56 genera of octocorals, and 148 species of fish were distinguished in the surveys. Hard coral