Commercial divers harvest a number of different species, including short spined sea urchin, long spined sea urchin, periwinkles, and undaria (Japanese kelp).
Many commercial divers also participate in the wild harvest abalone fishery. Commercial dive species are harvested by divers using surface supply compressed air hookah gear operated mainly out of small trailerable boats.
The long spined sea urchin, Centrostephanus rodgersii, is considered by many to be an invasive species in Tasmania, and a threat to Tasmanian ecosystems. The urchin feeds on marine algae and if populations are left unchecked, can create large barren areas on the sea floor, depriving abalone, rock lobster and other species of their food and habitat.
In recent years, demand for long spined sea urchin in Asian markets has seen this species become a valuable commodity. Other potential markets for by products from urchin processing are being explored.
In 2018/19, divers removed 559.6 tonnes of long spined sea urchins, equivalent to roughly 1,665,000+ individual urchins. Demand for the urchin roe delicacy allows the commercial dive sector to be an effective and efficient control mechanism for long-spined urchin numbers.
TACs are set for short spined sea urchin and periwinkles in some zones / regions.
When the total allowable catch is reached in a zone, that zone is closed until the following licensing year.