Barrens / coralline flats

Barrens/coralline flats are rocky reefs often dominated by encrusting pink coralline algae, with minimal fleshy algae due to sea urchin grazing.

A lot of boulder habitat within the aquatic reserve are barrens.

Marine life

Blue groper hunt sea urchins in the barrens, while large schools of luderick rest here. Living amongst the boulders are many smaller fish species, shrimp, and larger predators like Eastern red scorpionfish, moray eels, wirrah, and the threatened black rockcod.

Female Port Jackson sharks lay their eggs deep in crevices, and one-spot pullers form mating aggregations, covering boulders with their eggs.

Eastern red scorpionfish waiting in the barrens to ambush prey. (Photo: John Turnbull)