Australian Institute of Marine Science – Surveys of Octocorals communities, benthic cover and environmental factors on coral reefs of Palau

All surveys were carried out by the principal researcher using Rapid Ecological Assessment.
On each reef 1-3 sites were surveyed with up to 5 transects (usually 200-300m long, 1-3m wide for 10-15 minutes) per site at pre-defined depths (1-3m, 3-8m, 8-13m, 13-18m and reef flat).

Species recorded: octocorals (soft corals, gorgonians, sea fans, sea whips, sea pens, leather corals, arborescent octocorals, blue coral, stoloniferans), black and wire coral. Note that species are mostly at generic level. Octocoral genera (in some cases species) were given a taxon abundance ranking (0=absent, 1=rare, 2=uncommon, 3=common, 4=abundant, 5=dominant).

Site locations: Big Dropoff, German Channel, Heliofungia Lake, Ngerdmau, Niko Bay, Peliliu-West, PICRC House reef, Soft coral arc, Taoch Reef, Toachel Mlengui. Purpose To survey the cover of the main benthic groups, richness and abundance of octocorals in the reefs of Palau and related spatial and water quality gradients.

Additional information was collected during the surveys recording - site variables, visual estimates of abundance for other groups besides octocorlas, zooxanthellate richness. This data is not included in the dataset served to OBIS.
Comparable data are held for the Great Barrier Reef, Hong Kong, Papua New Guinea, Torres Strait, and Rowley Shoals (WA).

Purpose
To determine spatial patterns and abiotic controls of soft coral biodiversity: allowing examination of relationships of reef location (in-shore, mid-shelf and off-shore), environmental conditions and depth to taxonomic composition and richness.

Because roughly half Octocorals have photosynthetic symbionts they are ideal to assess how biodiversity is related to spatial and environmental factors, and photosynthetic symbionts and energy supply.

To examine principal drivers of biodiversity, community composition, and ranges of coral reef benthos.

Total Distribution Records: 376

Total Number of Taxa: 14 families, 32 genera, 6 species