Rock Lobster (Southern Zone) Fishery

The South Australian Southern Rock Lobster Fishery is one of several state- managed fisheries operating in southern Australian waters. The species supports important commercial and recreational fisheries in South Australia, Tasmania, Victoria, Western Australia and New Zealand.

The most productive fishing grounds are in waters adjacent to South Australia, which have historically supported the largest fishery for the species. The total commercial catch of Jasus edwardsii from South Australian waters is on average 2500 tonnes/ year, which represents about 30% of the total annual commercial catch for the species. The total South Australian recreational catch is estimated to be between 87 and 118 tonnes /year.

The Rock Lobster Fishery is South Australia’s most valuable commercial fishery. In 2004–05, the gross landed value of production across both fishing zones was A$66 million. In 2004–05, catches were 446 and 1900 t in the northern and southern zones, respectively. More than 95% of the annual catch is exported to a number of destinations, the most significant of which is currently Hong Kong. The total annual export revenue generated by both fisheries is in the order of A$110 million/year.

The Rock Lobster Fishery was separated into two management zones in 1968.

The northern zone encompasses a stretch of coastline in excess of 3700 km, including all waters adjacent to South Australia west of the River Murray mouth to the Western Australian border, from the low water mark out to 200 nautical miles. The southern zone encompasses all remaining state waters along a much smaller, yet more productive stretch of coastline of about 425 km.

Annual production in the northern zone is generally less than half that of the southern zone.  The spatial separation into two zones recognises key differences in the geological and ecological character between the eastern and western borders of South Australia.

The northern zone is characterised by patchy and discrete, predominantly granite reef formations that are separated by large expanses of flat sandy bottom. These reef structures generally afford less habitat for rock lobster shelter than the more continuous and interconnected bryozoal limestone reefs that characterise the southern zone. Because of these characteristics, the northern zone holds lower densities of lobsters than the neighbouring southern zone.  In the northern zone, the lower density of lobsters, environmental characteristics and other factors such as its close proximity to the western extension of the geographic distribution of J. edwardsii, generally results in higher inter-annual recruitment variation than the southern zone.

Growth rates and size at sexual maturity for J. edwardsii are highly variable throughout the waters of South Australia, with growth rates generally faster in the northern zone due to higher water temperature and lower lobster densities.

Lobsters are commonly landed at more than 40 locations in the northern zone, but only seven locations in the southern zone.  Northern zone vessels fish for 1–10 days per trip, generally fishing for longer periods on the West Coast. The southern zone fishery is a day fishery with vessels fishing close to their home port. The costs of fishing in the northern zone are higher than those in the southern zone due to the larger distances travelled, particularly with the rise in fuel prices.