Researchers track Australian sharks


Researchers are tracking over 50 vulnerable sharks on Australia s southern coast to assess the conservation value of restricted fishing zones.

The sharks, fitted with acoustic tags, were all caught within an area that has been closed to commercial fishing activity in South Australia. This is one in a network of three restricted fishing areas, with similar zones in Tasmania and New South Wales.

New methods of handling and tagging the fish were developed for the study to minimise stress, and monitoring will take place over the next three years from 24 acoustic listening stations.

To assess the optimum size and location of such areas, we need to know how much time the sharks spend there, what the seabed habitats are like, and what role they play in the ecology of the sharks.

"For example, the sharks may rely on shelter in rough habitats, and these are scarce, said Dr Alan Williams of CSIRO Wealth from Oceans National Research Flagship.

This large scale experiment, the deepest of its kind in the world, will be important to understand the balance between maintaining fisheries, and protecting the marine ecosystem.

Of notable interest in the study are Gulper sharks, which have already been put forward for protection under Australia s Environment Protection and Biodiversity Conservation Act 1999 due to severe depletion of the species. Swellsharks and Greeneye dogfish are also in the study.