French Turbot Farmer

[anniefish]

Hi all,
did anyone watch Thalassa on SBS last night? I only caught the last half, but it was about a French fisherman who developed a system to spawn and grow Turbot. He has a huge system, they take, I think 18 months to reach saleable size.
The interesting thing he developed was a way to transport the fish live without water. He had caught some Turbot wild and put them in the fridge overnight, he found one was still alive. This got him thinking, and he developed a system where the fish are caught, put into smaller tanks of water, the water temperature is slowly lowered and oxegenated. The fish are then transported to the airport in these containers. The water is let out and the fish packed into boxes, (not polystyrene as this kills the fish), there are four in a box with noses to the four corners and tails to the center. These are then stacked into a special container and the fish flown to Hong Kong. When they get there, they are put into water again, which is highly oxegenated. The fish just swim to the bottom of the tank. I think the death rate was about 5%. Just amazing what can happen when you think out side the square.
It made me think about our problem of fish transport - maybe we need to lower the water temp. Maybe the fish will transport better? What do you think?
By the way, it took him 11 years to make a profit.

[GaryD]

Hi,

Hatchery operators often chill fish to enable them to be handled safely.

Gary

[inzane]

Thats really interesting. One of the fish I am trailing is the giant gourami. Its farmed in asia and its majour plus point is it has a labrinth oragn that allows it to breath air. They transport it to market wrapped in wet leaves and they live for hrs and hrs. Not much help with other species though! Any of you lot heard of the aussie outfit who reakon they have cracked the aquaculture of blue fin tuna? Most of them will be off to japan so they'll want to know more!

[Hamish]

Hi,

Hatchery operators often chill fish to enable them to be handled safely.

Gary
That is interesting Gary - seems to contradict this quote from the DPI web site regarding Jade Perch:

''Handling fish below 17oC may cause mortalities. Large-scale mortalities have occurred at temperatures in ponds below 13oC''

http://www2.dpi.qld.gov.au/fishweb/14076.html

[GaryD]

Hamish,

I think DPI are probably referring to the temperature of the water in which the fish are living rather than the use of lower temperatures to slow the fish' metabolism to enable it to be handled. As it happens, anaesthesia by hypothermia works more effectively on fish that normally live in water which is above 10 degrees C.

Gary

[nick]

if you are talking wild caught young tuna that are grown on and air transported to japan then Pt lincoln in south Australia is the place you need to visit. basically a medium sized rural town with a select handful of multimillionaires who own the tuna farming.

The fish are caught at see off the perth coast and moved slowly across the bite to pt lincoln where they are fed up and shipped fresh to japan. They also have to deal with great white sharks down in that region of the world so the cages are well engineered.

Now on the other hand if you are actually talking about the group of people who have claimed to be able to breed and rear tuna fry in captivity, i have heard of them but that is all. Also if they are successful than the australian tuna industry is likely to collpase and the whole operation will be moved to south america where labour is cheap and feed fish are plentiful.

any way there is your early morning ramble, enjoy

[inzane]

There was an article in scientific american with a company claiming to have spawned bluefin tuna in captivity and have raised the fish past the laval stage...apparently still be a couple of years till they are old enough for market...Had like 200,000 gallon tanks or something!

[Hamish]

I think it is brilliant that people are working on this - but I dont fully understand why all the interest in salt water AP. There does not seem to be a really useful vegetable product that makes it worth while.

Why not grow fresh water fish and a selection of vegetables? There is very little water used after the initial set up - and what is used is able to be topped up easily with rain (which is falling heavily here at the moment!) or RO.

I just dont get it.

[inzane]

The interest is because seafish and shellfish taste good. As for vegetables their are lots of really nice seaweeds... With fisheries collapsing left right and center if you live near the sea and have the space, its as logical as freshwater AP. Here in the UK they are breeding lobsters in aquaculture setups, growing them in trays like were suggested for the yabbies, the releasing them at 2", to try and maintain some wild stock!

[Hamish]

Ok - I guess if you had a very close supply of sea water it would be ok. But then again why not just cage farm them in the sea - or pipe the water directly into the tank and back out again - so it is recirculating and constantly refreshed - thus avoiding the need for the seaweed. Perhaps I am not placing enough value on the seeweed as a product.

[echidna]

Ok - I guess if you had a very close supply of sea water it would be ok. But then again why not just cage farm them in the sea - or pipe the water directly into the tank and back out again - so it is recirculating and constantly refreshed - thus avoiding the need for the seaweed. Perhaps I am not placing enough value on the seeweed as a product.

That's how prawn farming is done at the moment and the nutrient enriched waters are creating environmental disasters. If plants can be grown to strip that nutrient and clean the water before release, then the environment and the farmers both benefit.

Some quick reading on halophytes -

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WH9-4KFMMC4-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=d093e6177544e544f06e8ece99034888

http://www.halophyte.org/htmls/projects.htm

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080001445_2007039195.pdf

http://www.dailystaregypt.com/article.aspx?ArticleID=6918

[djs-sa]

in regards to the tuna hatchery it is in cowell 45km out of lincoln, from my understanding is they can breed fry up to fingerling size then released into the sea pens and raised the same from this point as wild caught and caged tuna

[GaryD]

Hamish......
I just dont get it. It's the purple-hatted vegetarian thing.

The whole tuna farms idea has been the subject of controversy. Several years ago, a number of the tuna cages were moored in Boston Bay (at Port Lincoln) during a freak tide situation which saw all of the silty fish poop on the harbour bottom get stirred up choking the fish. This resulted in the death of hundreds of tonnes of prime tuna. Since that episode, the tuna farms have to be moored outside of the bay.

These "farms" (actually large circular floating cages) are towed by large tuna boats out to where the other tuna boats are catching the tuna well south of Port Lincoln. As the boats catch the tuna it is off-loaded into the cages. When they're loaded up they are towed (at about 1 knot) back to where they will be moored along the coast.

Most of the tuna will be harvested for the Japanese sashimi trade....it will be killed (according to strict standards) and packed carefully in ice ready for shipment to Japan. It will be in the Tokyo fish market the following morning.....and on the plate later that day.

The ability to breed and grow out tuna in captivity has been the holy grail of aquaculture for many years.

GaryD

[Hamish]

Thanks for the explaination Gary.

[inzane]

The thing with fish farming in cages is it really messes with the environment, with all the nitrogenous wastes they through out, can lead to algal blooms ect. They also spread diseases to wild populations, and as you know lot animals in a small space ='s lots of disease! Another thing is the fish that are trawled off the bottom of the sea to be ground up for food.

Recirculating the water forces us to deal with the waste and can create a sweet little system. The idea is you grow fish, the produce waste that grows algae and seaweed which feeds humans and little bugs which are grazed by something like mullet that are harvested to feed the fish. This takes a lot of strain off the natural environment, and is ace if you have desert by the sea, ie cheap land with loadsa sun!!!!

[redleg]

Port Lincoln tuna outfit is on the share market as ' Cleanseas' run by haagen stehr. He is known as a very determined man..
they grow tonnes of kingfish in the spencer gulf as well as tuna fattening and the experimental stuff.
i think the current tuna farming is also to help marketing. they used to catch fish , chill them and send them to japan. sometimes they took a while to get there and were not worth much , other times they were straight on a plane , and arrived in top condition in time for a peak demand , top price.
now they catch them when the freight is sorted and there is a market waiting , thus consistant good prices . my guess anyway.

[DaveOponic]

"but I dont fully understand why all the interest in salt water AP. There does not seem to be a really useful vegetable product that makes it worth while."

Here in Asia seaweed is a popular food .... mainly Japanese style Nori for Sushi and snacks - Thailand produces a popular snack food made from Nori - flavoured with Wasabi/Chilli/Tom Yum (my kids love it and very healthy - no msg variety!) Wakame seaweed and other varieties are available in supermarkets, very nutritious and delicious food.

Brunei is doing a lot of aqauculture. Mainly prawns from what I can gather but also local fish varieties and Barramundi is the latest addition. As the Sultan owns a huge beef property in the Northern Territory I am sure that he has tasted it a few times and influenced the industry here to grow it.

Not sure about the pollution caused by fish farming here. The sea is pretty stagnant in places not much tidal movement or swell. Up near Seria there's a lot of oil in the water, that's probably more of a problem.

When I lived in Java I saw lots of prawn farming, all along the North Coast of Java... quite amazing how they manage to feed about 100 million people on the island.

Dave