Dataset: Sponge species distribution and biomass surveys across the northern and central Great Barrier Reef and in the Coral Sea


Surveys were conducted on the fore-reef slopes (proximal to the major wind and wave inputs) of 2 inner shelf reefs (Pandora Reef and Philips Reef), 4 middle shelf reefs (Rib Reef, John Brewer Reef, Lodestone Reef and Davies Reef), 2 outer shelf reefs (Dip Reef and Bowl Reef) and one Coral Sea reef (Flinders South Reef). Three reefs were surveyed at other locations due to unfavourable weather (Myrmidon Reef [outer shelf], north-east slope, Flinders Cay [Coral Sea], south-west slope), or because no south-east side existed (Flinders West [Coral Sea], a near vertical south-west slope). At Davies Reef, surveys were also conducted in back reef and lagoon habitats. The fore-reef slopes of three reefs across Princess Charlotte Bay in the northern Great Barrier Reef were also surveyed (Rodda Reef, Corbett Reef and Clack Reef).Surveys were conducted along triplicate 20 m transect lines laid along depth contours (1.3, 2.5, 5, 7.5, 10, 15, 20 m) with transects separated by at least 10 m. At Davies Reef duplicate surveys were also conducted at 30 m and 40 m on the fore-reef and visual surveys were conducted at these depths on the back reef slope. All obvious sponges (cryptic, boring and very thin encrusting species excluded) were collected, sorted and wet weights recorded.All sponges were given unique species codes. Sponge species abundance was recorded. Sponges were divided into the following categories: phototrophic (Ph) with large populations of cyanobacterial symbionts (Pg/R>1.5 for at least 8 hrs/day); mixed (Mi) with fewer photosynthetic symbionts usually as a thin layer on the outside (Pg/R<1.5); and heterotrophic (He) with no photosynthetic symbionts (Pg = gross photosynthetic oxygen production, R= respiration).

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