Fish, shark, ray and benthos biodiversity surveys around remote Timor Sea Shoals

Cappo, Heyward, Speare GOALS: To map the benthic habitats, and record the associated fish, shark and ray faunas, of the major clusters of Timor Sea shoals at 3 depth zones : 20-30m, 40-60m and 90-110m. APPROACH: Towed camera footage and real-time seabed classifications [substratum,major benthic groups present (eg seagrass,sponge gardens, gorgonians, hard corals, occurrence of individual benthic animal (eg crabs, starfish, clams)] has been obtained from 3 shoals near Evans Shoal, 6 Karmt shoals and 6 Sahul shoals ; as well as 4 adjacent sites in 96-100m on the continental shelf. BRUVS have been deployed at these same 3 depth zones: 20-30m, 40-60m and 90-110m at 3 shoals near Evans Shoal, 6 Karmt shoals and 6 Sahul shoals; as well as 4 adjacent sites in 96-100m on the shelf. 6 BRUVS were set in a line and towed camera footage was obtained during 3 replicate tows amongst this set of BRUVS. Multivariate statistics will be used to explore associations amongst fish and the benthic habitats they are found in. HIGHLIGHTS TO DATE: · Shallows dominated by extraordinarily rich benthos down to >70m · Shallows have moderately diverse fish faunas, lacking large economically-important sharks, serranids, lutjanids and lethrinids · Deepest zones have most abundant fauna of larger fish in these 3 families · Sharks notably absent c.f. other similar regions (eg Rowley Shoals), and most seen were pups · Several species of lutjanid and serranid recorded for first time in Aust. waters · New photographs obtained of species never filmed underwater before (eg Wattsia, Epinephelus morrhua) · Juvenile lethrinids abunadnt in dense seagrass beds at depth · Seagrass detritus visible down to 100m