Yonge Reef

Yonge Reef lies about 50km offshore and is an outer ‘ribbon’ reef. The ribbon reefs occur in the northern section of the GBR at the edge of the continental shelf, and as their name suggests are long, thin reefs. Channels between the reefs are narrow and this creates strong tidal currents in the area.

From March through to December, Yonge Reef is exposed to the prevailing south-east trade winds (average 20-25 knots). This reef is thought to be recovering from the effects of Cyclone Ivor in 1990. No bleaching has been recorded at the sites and crown-of thorns starfish have only been observed on one occasion (1994) and at extremely low density (LTMP).

There are 8 sites ranging in depth from 2m to 38m. Yonge 3 and 6 are no longer photographed. Yonge 1 and 2 are located at the back of the reef, where conditions are generally choppy with strong cross currents. Yonge 1 is located on a wall and Yonge 2 lies above this on the reef flat, in 2m of water. About 250m away, Yonge 8 is set-up on the lower ledge of a lagoon bommie (about 12m depth) in relatively calm conditions.

On the reef front conditions are characterised by high wave energy and tidal currents. Coral cover is good and typical of an outer reef exposed habitat. Yonge 4, 5 and 7 are at various depths down the front of the reef wall (4m, 12m and 20m).