| New
opportunities will become available to aquaculture around the world
with the release of an innovative product from Australia's own
OneSteel.
After considerable research and
development, OneSteel has released MarineMesh, which sees a unique
ultra heavily galvanised steel wire, known as MarineWire, woven into
fish nets. These nets are attached to floating cages for salt and
fresh water fish farming. OneSteel's new product development
manager, Matt Condon, explained that its patented galvanising
technology allows it to significantly increase the amount of coating
on its wire. The additional coating adds to the life of the wire in
marine environments making steel nets a viable option for fish
farming. |
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OneSteel started investigating the
potential for steel nets in Australia in 1998 and since then has carried
out numerous trials at sites around the country. These trials have
ranged from square nets for barramundi farming in tropical North
Australia, through to circular nets for atlantic salmon in the cold
waters of Tasmania. OneSteel is also investigating opportunities
internationally with further trials in Asia and the Mediterranean.
"MarineMesh steel nets offers fish
farmers an alternative to traditional synthetic nets which do not offer
high levels of security from predators and require frequent net changing
due to bio-fouling. In all our trials to date, MarineMesh wire nets have
prevented losses from predators beneath the water," Mr Condon said.
"Sharks, seals, sea lions and crocodiles - they all love an easy feed
and with aquaculture we have been providing it to them on a platter.
Predators not only cause problems by killing or wounding fish, they tear
holes in traditional nets leading to stock loss. MarineMesh minimises
the need to use divers for costly repairs - a big bonus especially in
shark or crocodile infested waters."
Fouling of nets has long been one of the
greatest and most expensive problems faced by fish farmers, particularly
in warmer waters. From trials international marine biology consultant
Professor Carmelo Agius has witnessed, MarineMesh has significantly
reduced fouling. Based in Malta, Prof. Agius has worked with OneSteel as
a consultant on the MarineMesh project. "Fouling reduces water flow
through the net and therefore water exchange, resulting in reduced
oxygen replenishment and increased waste accumulation. This leads to
stress and disease," he said. "Fouling can also support potential
disease organisms." As net changing and cleaning along with repairing,
accounts for as much as 60 per cent of labour costs, the MarineMesh
system offers significant savings.
The structural strength of steel means
MarineMesh nets maintain their shape better in most situations without
the need for additional weights. "As for environmental concerns there
are many positive aspects to using MarineMesh in a natural environment,
such as the ocean. There is minimal chance of other species, such as
dolphins, turtles or seals, becoming tangled in the nets and there is
little stress on the fish stock contained within the pen." Professor
Agius explained. The development of MarineMesh will help boost investor
and management confidence in the fish farming sector, according to Prof.
Agius. "Because it will increase stock safety and reduce production
costs, it should make the industry feel more confident," he said. "I see
MarineMesh having huge potential in certain environments where fish
farming has previously been out of the question. As I already mentioned
it will suit predator infested areas and those in biologically rich
waters which can cause heavy fouling, but it may also suit high energy
environments where strong tides and currents cause stress on the nets
and typhoon prone areas which have to resort to submersible cages."
He also sees it offering opportunities to
fish farming of species which had previously provided challenges such as
sea bream which have a tendency to chew nets, and groupers which like a
stable, quiet environment.
MarineMesh is currently being used in one
of Australia's newest aquaculture ventures, Skretting's barramundi farm
at Bathurst Island, 100 kilometres north of Darwin. This farm is on
target to export around 1000 tonnes of barramundi per annum by the end
of 2002.
"OneSteel has recently commissioned a new
steel net making machine which means MarineMesh nets will now be
commercially available. By working closely with fish farmers, OneSteel
aims to design nets to suit most operations and conditions in which they
farm fish in floating cages."
More about:
E-mail:
onesteeldirect@onesteel.com
Source:
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