Australian study tracks Sydney’s wobbegong sharks

by NSW Dept Primary Industries on 28 Sep 2008
The NSW Government is supporting an Australian first study to unlock the secret life of Sydney’s resident wobbegong sharks, with seven sharks born at the Sydney Aquarium released into the water off Manly.

Minister for Primary Industries Ian Macdonald and Minister for Environment and Climate Change Carmel Tebbutt said the sharks are being released at Cabbage Tree Bay Aquatic Reserve at Shelly Beach.

'This Australian first study will provide a fascinating insight and give our scientists more information to better understand these animals and the important role they play in our ecosystem,' Minister Macdonald said.

'This release is part of a research project looking into the design requirements and ability of ‘no take’ marine reserves to protect sedentary predators, such as wobbegong sharks.

'The research is also exploring the use of captive-bred sharks that can help replenish wild populations that may be depleted through fishing.'

Minister for Environment and Climate Change, Carmel Tebbutt, said wild wobbegong sharks at the aquatic reserve have been tagged with acoustic tags and their movements tracked over the past few months to understand their normal way of life.

'The captive-born wobbegong sharks have also been tagged, so fisheries scientists and volunteer supporters will be able to monitor how the introduced sharks interact with the local species,' Ms Tebbutt said.

'New underwater acoustic receivers placed around the reserve will pick up the movement of the wobbegongs and provide a greater insight into this species, where they go and how they live.

'This is a fantastic partnership between the Departments of Primary Industries, Environment and Climate Change, the Sydney Aquarium and the Sydney Institute for Marine Science.'

Wobbegong sharks are a bottom-dwelling shark and found in the oceans off Australia and can reach up to three metres in length.

This species forms part of the Ocean Trap and Line Fishery and is sold as boneless fillets or flakes.

'A good understanding of the underwater lifestyle of a species is important to effectively manage any fish population, this helps to determine any changes in localised abundance of a species,' Minister Macdonald said.

'Information on habitat use and residency patterns will provide us with a better understanding on the potential for protected marine areas to be reserved especially for exploited species.'

The research has been supported by the NSW Department of Primary Industries, NSW Department of Environment and Climate Change, Sydney Aquarium Conservation Fund, Sydney Institute of Marine Science, Australian Acoustic Tagging and Monitoring System (part of the Integrated Marine Observing System), Defence Maritime Services, and Macquarie University.

About the Wobbegong. Shark - Orectolobus ornatus

Wobbegong Distribution - Wobbegong sharks occur along the east coast from southern Queensland through to Western Australia, including Tasmania. They inhabit shallow, inshore waters (less than 100 metres deep) where rock and weed are prominent.

Size - Reaches a length of 3 metres and a weight of over 70kg.

Characteristics - The head & body are various shades of brown forming mottled patterns, and they have numerous skin flaps around the mouth. Wobbegong sharks can become aggressive if disturbed, and are able to reach back and bite a hand holding their tail.

Confusing species - There are two species of wobbegong shark commonly found in coastal waters of New South Wales: the banded (pictured) and the spotted wobbegong. Spotted wobbegongs have distinctive white rings in their patterning.

http://www.dpi.nsw.gov.au
http://www.dpi.nsw.gov.au/fisheries/recreational/saltwater-fishing/sw-species/banded-wobbegong-shark