[ASC-media] Subject: ASC-media Media Alert

Wendy Ellery w.ellery at aims.gov.au
Fri Mar 26 09:25:49 EST 2004

26 March 2004


New study indicates shark numbers under threat

A new study conducted by the Australian Institute of Marine Science, 
using a unique underwater survey technique, has revealed that fishing 
pressure could be taking its toll on parts of northern Australia's 
dwindling shark population.

Fisheries authorities have been concerned for some time the 
spiralling number of foreign boats targeting sharks in sections off 
Australia's north coast has seriously depleted stocks.  Fishermen are 
lured by the prized shark fin, a delicacy in Asian cuisine, and in 
high demand fetching more than $100 per kilo.

The Australian Government Department of Agriculture, Fisheries and 
Forestry enlisted AIMS to test its non-destructive techniques to 
survey shark abundance and provide a census of sharks in and around 
the MOU 1974 box, a region Australia has allowed traditional 
Indonesian fishermen in unmotorised boats to work.

The area under survey was Mermaid Reef in the Rowley Shoals, a 
Commonwealth Marine Protected Area closed to all fishing, and Scott 
Reef in the MOU 1974 box. Scientists were able to gauge the impact of 
fishing by comparing the numbers found inside the MOU box with 
numbers outside.

Using a fleet of Baited Remote Underwater Video Stations (BRUVS), 
designed by AIMS researcher Mike Cappo, the scientists were able to 
attract, count, and measure the sharks.

Compared with data from an expedition to the same region in 1999 the 
survey revealed a rapid decline in shark numbers at Scott Reef Mr 
Cappo said.

"The number of sharks observed inside the box is far less than those 
outside," he said.

Analysis of the BRUVS tapes showed that it took twice as long for 
sharks to appear at Scott's reef than at Mermaid reef further 
suggesting that they were much less abundant.

Project Leader, AIMS researcher Dr Mark Meekan said the sharks more 
valuable for the trade in fins were not sighted at Scott Reef but 
were abundant at Mermaid Reef.

"A range of evidence suggests that over-harvesting is the most 
plausible explanation for these differences in abundance of sharks 
between Mermaid and Scott Reef," he said.

"The shark stocks in the MOU box are extremely low and it is 
essential we take a closer look at the situation.  There are 
certainly indications that foreign fishing pressure may be impacting 
shark numbers," Dr Meekan said.

Mike Cappo said remedial measures must include an alternative source 
of income for the poor artisanal fishermen who rely on the fishery.

The team also tested an acoustic survey method based on centuries old 
technology where rattles were once used to attract sharks in a bid to 
kill them. 

"We used sound to attract the sharks into the field of the cameras 
and counted them using the video system. We were also able to measure 
the size of the sharks and assess bio-mass as well," said Dr Meekan.

The scientists said there needs to be a wider application of the 
surveys in the north in the immediate future to provide the 
authorities with the evidence needed to remedy the disturbing 
findings of the report.  

Footage of BRUV vision and Indonesian fishing boats working the MOU 
box (courtesy of Customs) is available on request.

Media Contacts:
The report is available at: 
Dr Mark Meekan, AIMS biologist, Mob,0429 101 812, Email: m.meekan at aims.gov.au
Mike Cappo, AIMS Experimental Scientist, Ph 07 4753 4262, Email: 
m.cappo at aims.gov.au
Wendy Ellery, AIMS Media Liaison, Ph 07 4753 4409, Email: w.ellery at aims.gov.au
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