Breeding the southern bluefin tuna in captivity has long been considered the holy grail for the Australian tuna industry.
The tuna has almost been wiped out by overfishing, and a sustainable fishery seemed little more than an ambitious dream. But this week at a South Australian hatchery, a young fish of 25 centimetres reached a milestone birthday: 100 days, more than five times what captive breeders have been able to achieve previously.
Clean Seas chairman Hagen Stehr said: "Young tuna has never been held that long before onshore."
The project, involving the Australian Seafood Co-operative Research Centre, the Fisheries Research Development Corporation and the South Australian Research and Development Institute, aims to produce 250,000 bluefin at the hatchery outside Arno Bay on the Eyre Peninsula by 2015. "There's a commercial industry in the making of immense proportion," Mr Stehr said. "In years to come, it will be a billion-dollar industry."
Worldwide demand for the southern bluefin tuna is rising. Japan takes about 80 per cent of the catch. The young fish were spawned in April after adult females were given hormone injections. They will be kept in a temperature-controlled hatchery over winter.
http://www.theage.com.au/environment/tuna-breeding-shows-billiondollar-promise-20090708-ddex.html
barneyboy
Posts: 1392
Date Joined: 08/01/09
thats awesome news
theres hope for them yet
FEEEISH ONNN!!!
saltatrix
Posts: 1081
Date Joined: 30/03/08
Im going to church next
Im going to church next Sunday and I dont go to church. If its achieved then there is hope. It may allow a glint of possibility in the reduction in pressure on a species that has been hammered.
Angling tourism is worth $10 billion to the Australian economy - 90000 jobs; more than any sport; spread the word
Ewan
Posts: 271
Date Joined: 15/05/06
Aquaculture - What will they eat?
Pretty huge and interesting development - but what do/will they feed them?
It's the main problem with aquaculture...they need to feed a fish for several years before it reaches market size/value. So what can you feed a fish for a couple of years that doesnt cost more than the fish is 'worth'?
It is an extremely inefficient transfer of energy - I can't remember some figures I was once told, but depending on the species, you might need 10kgs of food for 1kg of growth, etc, etc...Actually i think it was substantially more than that. Obviously some fish grow faster than others...
Particularly to get the right taste/colour in the flesh, the fish need to be fed with other fish - so now we are talking about netting tonnes and tonnes of wild mulies/sardines to feed the captive fish. Or maybe krill or something. Which then removes this food from the wild system and where one environmental problem might be in some part addressed (overfishing of the tuna), another has been created/exacerbated (overfishing of pilchards/etc).
Cant forget the mass mulie kill of a couple of years ago, caused by a virus from imported pilchards for - the captive tuna feedlots...
An analogy might be...think of how much land is required to grow pasture for sheep, which are herbivores, only one step up from primary production of the grass. If instead you wanted to farm/eat lions in the same commercial quatities, then you might say one lion requires 20 sheep to eat over its commercial lifespan. So multiply the amount of pasture required for the sheep, by 20, to get the same number of carcasses for the abattoir. Obviously the numbers etc here are wrong, but you can see how farming of a carnivore takes much more energy than farming of herbivores.
Aquaculture of the future - to address food/protein shortages, etc, will be in farming algae and shrimp and krill and the like, as it is the only way to do it efficiently. In the meantime, farming of fish is a commercial venture only, to make money. It rarely if ever results in environmental benefits, usually instead causing problems such as localised nutrient enhancement, escapees, viruses and increased demand for food...
There's alot more to aquaculture than first meets the eye!! Still - it is good that research is progressing...
Cheers,
Ewan