Artificial reefs: Community asset or underwater junkyard?

Veronica Buck ABC Net 15 Dec 10;

Within just two years big concrete structures could be submerged off Western Australia's pristine coastline in a bid to enhance the local recreational fishing experience.

That is, if the state's peak fishing lobby group can convince the community that creating artificial reefs would be an environmental brainwave and not an underwater garbage site.

Recfish West's Cane Moyle says new technology and improved designs mean artificial reefs are now something to be embraced.

"Artificial reefs have evolved from previously just a mentality of dumping any sort of surplus material, be it boats or even tyres, in the marine environment to create extra habitat," he said.

Mr Moyle is joining scientists from the Fisheries Department in examining whether artificial reefs can be designed to successfully promote biodiversity and sustainability in WA.

The department's Stuart Smith says a delegation has just returned from a research trip to Asia where artificial reefs have been around for four decades and are largely used in the commercial sector.

"At the moment we would be looking at deploying reefs on a relatively small scale in Western Australia and conducting substantial research on the impacts of those reefs for recreational fishers," he said.

"And then looking at any potential applications for the commercial sector; at the moment the focus is very much in recreational fishers here."

It's music to the ears of Mr Moyle.

"One of the key questions we were looking at was were artificial reefs production devices or aggregation devices, meaning do they simply just aggregate fish and make them easier to catch or do they produce extra fish and productivity?

"The body of evidence that we saw, particularly in South Korea and China, was that these devices produce fish and are maintaining a number of fisheries over there.

"It's not something we see being required to recover fish stocks, it's about making the fishing experience even better for recreational fishers."

Authorities will also investigate whether fish stocking could be used for the benefit of recreational fishers.

Aesthetics

Mr Smith says there are two types of purpose built artificial reefs.

The first are large steel structures designed for deeper water and the second are concrete creations which have already been introduced on the east coast of Australia.

"Typically recreational fishers want them relatively close to the shore where the smaller boats can access them," he said.

"Because it's in shallower water the most suitable designs are usually the concrete structures which can be designed for specific fish species or different purposes, including shellfish and molluscs or for fin fish.

"They are around about two metres by two metres by three metres and a number of them are deployed in an area over 800 square metres normally."

Mr Smith says resource sector companies in the north of the state have registered interest in funding artificial reefs, to counter their impact on local marine environments.

"Because often they will go into a regional town centre and they'll have a large workforce during the construction phase of their projects and that construction workforce will spend some of their spare time fishing and so there can be pressure on the local community's fish stocks.

"We are finding local fishing communities in areas where new boat ramps are going in are also interested in artificial reefs because when you put in a boat ramp the increased accessibility of those locations means there's additional pressure on the fishing stocks and artificial reefs can help in that regard."

Mr Moyle suggests artificial reefs could be placed in areas near Broome, Karratha, Carnarvon and even the metro area.

He says if you look at some of the marine habitat in those areas, it's quite devoid of structure and fish require structure in terms of growth and production.

"Off the west coast, the metro coast it could be quite useful in areas like Cockburn Sound which has suffered a lot from developments and habitat destruction; Geographe Bay."

Money well spent?

An artificial reef would costs hundreds of thousands of dollars.

Recfish West suggests that could be funded from revenue generated by fishing boat licences and the mining sector.

The Conservation Council's Tim Nicol says whoever funds it is irrelevant.

"It sounds like an excessive waste of money considering how much reef we have out there and there's no fish on it," he said.

Mr Nicol says marine sanctuaries are the way forward.

"By creating marine sanctuaries you end up with spillover of fish into surrounding waters and you actually repopulate the reefs we have before we try to build new ones," he said.

The Fisheries Department says no trial would commence without extensive community consultation and environmental assessments of any potential impacts.

But if a suitable site is identified, WA could have its own purpose-built reef within two years.