Fish Farming ... When It Goes Belly Up

[David48]

Fish Farming ... when it goes belly up.

RedBullHorn spoke here about about some of the realities of Fish Farming.

When it goes well, like any farming practise ... the rewards are great.

Rewards, both financially and with contentment of a job well done.

But what happens it all goes 'belly up'?

The fish die in droves, each day the mortality rate increases.

Even the dogs won't touch the floaters.

Ma and Pa Farmer won't contact the local Fishery or Agricultural Board, any University or have the Fish tested. Just part of life on the Farm. They go instead to the Temple and pray.

Now, any of you lot who have lived in Thailand for some time well know that you don't try and teach Thais anything new ... so I wasn't about to break that time honoured tradition.

While it was interesting to see how the Thais dealt with this loss. Both financially and emotionally.

... it's the science of what happened interest me.

I'll but some media below and would like your opinion on what happened to them.

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[David48]

Oxygen levels, while not ideal were fine, I know what a Fish Kill looks like due to oxygen depletion looks like ... and it wasn't this.

The pond hasn't been disturbed, hence not a sudden rise in the waters acidity due to disturbance of Acid Sulphate Soils ... yes ... that's ASS for short!

They floated, bloated and the eyes bulged ... like Arnie Schwarzenegger in Total Recall

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[canuckamuck]

How many fish per cubic meter of water, how big are the fish, did you check nitrite levels, any signs of missing tails or whitish spots or slime on the fish? Are they being fed too much, what percentage died, did they all die at once?

How is the water circulated, is it circulated at all, does any fresh water ever get to them, did the water recently turn murky?

[jayci]

Possible that poor water quality has lead to bacterial infection. Might pay to check both the source water and pond water. If source water is okay, then frequent water changes might help. How are the prawns in the pond?

Certainly gut wrenching watching your fish die off like that.

[David48]

Questions from above ... canuckamuck thanks for asking.

1 of 2

How many fish per cubic meter of water?

I don't know the exact stocking rate. I know what you mean, but I am sure that it wasn't 'overstocked'

How big are the fish?

There was a variety of sizes, from smaller then the palm of your hand to larger the palm and fingers.

Did you check nitrite levels?

No ... but they never get checked ... is the Thai way.

Any signs of missing tails or whitish spots or slime on the fish?

No ... see below

and

Are they being fed too much?

Self feeding ... same as always. As the (alive) fish numbers dropped, the Farm Mother stopped feeding for a few days.

What percentage died?

Hard to say what percentage. I would have punted for maybe 10% but the Farm gf is scratching her chin and thinking closer to 30%.

Did they all die at once?

No, started with a small number and grew steadily each day for about a week and then the numbers dying declined for the next 3 or 4 days. So maybe a mortality period of 10 days.

[David48]

2 of 2

How is the water circulated ... is it circulated at all?

Yes ... traditional Thai Method ...

Does any fresh water ever get to them?

When the water level drops new water is pumped in.

Pond is between 4 - 5 feet in depth ... but the water has to only drop 6 inches and more is added as required.

Did the water recently turn murky?

No more then usual. You can see the water colour below.

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All advice is appreciated ...

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[cdmtdm]

i would suggest someone around the area sprayed pesticide/ herbicide on a crop , drifted onto the water surface ......are they growing any string beans in the rice fields at the moment? could have been a fair distance away .....how do u top your water up ? is it from a local stream or canal ? if so could have been the source ...only my opinion

[David48]

Possible that poor water quality has lead to bacterial infection. Might pay to check both the source water and pond water. If source water is okay, then frequent water changes might help. How are the prawns in the pond?

Certainly gut wrenching watching your fish die off like that.

Checking the water quality is the Farang way ... not the ordinary Thai Farmer method.

A great suggestion ... but not done round these parts.

The kill happened maybe 2 months ago ... it's passed and the fish now grow normally.

But I'm trying to expand my knowledge base so that, in the future, should I ever buy/manage a Farm, I more worldly wise.

I learnt and know a fair bit about the traditional Fish and Shrimp/Prawn Farming method ... but I'm also smart and humble enough to ask others when I encounter something I don't understand ... rather then prey at a Temple for the problem to go away.

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[David48]

i would suggest someone around the area sprayed pesticide/ herbicide on a crop , drifted onto the water surface ......are they growing any string beans in the rice fields at the moment? could have been a fair distance away .....how do u top your water up ? is it from a local stream or canal ? if so could have been the source ...only my opinion

No rice round these parts ... only Fish Farms as far as the eye can see.

All the surrounding Farms are owned by the Farm Fathers relatives.

There was some herbicide spraying, but conducted by the Farm Father well after this problem.

Water source could be the source of the problem ... but why did the fish die as fingerings when they are more susceptible?

Could have come in one of the water top-ups though ...

Warmly appreciating the answers being received.

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[cdmtdm]

yes check the water source ....and if the source is ok , try and dump what u can from the pond flush it out ... is it only one pond ? no one else ? do u all share the same supply?

[David48]

yes check the water source ....and if the source is ok , try and dump what u can from the pond flush it out ... is it only one pond ? no one else ? do u all share the same supply?

All the same supply ... though the pick-up points do vary.

Difficult to completely flush the pond as that would need emptying it ... thus losing both the Fish and Shrimp harvest.

Plus the pond is about 8 Rai in size.

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[jayci]

One of those fish looked like it had dropysy.

* DROPYSY *Description: Dropsy is a bacterial infection of your fish's internal organs. Being internal, it is difficult to diagnose and is often not treated early enough to save the host fish. It attacks fish that have been weakened due to excess stress resulting from poor water conditions, overcrowding or being moved. It causes excess body fluids to build up making the fish appear bloated or it's scales to stick out. Early stages of this infection may present themselves as popeye as excess fluid causes the eyes to bulge. Symptoms: The visible symptoms of drospy come from the excess body fluid buildup inside the fish. Bloating, as well as eyes or scales that protrude more than normal may be signs of dropsy. Avoidance of other fish and loss of appetite are also common. Treatment: Commercial treatments are available from your local fish store. Just ask as soon as possible. If possible, keep some on hand as you must treat this disease as soon as possible if your fish is to have any chance of survival. Usually by the time the scales of the fish are protruding, it is too late.

[canuckamuck]

I think Jayci might have it, Dropsy or some other bacterial issue. But because the dying was only in a 10 day period It makes me also suspect a change in water conditions or a toxin. Volumes of water do go through cycles, as there is a give and take between nitrates and nitrates and also the amount of plants and algae that inhabit it. Sometimes water can go toxic as either the nitrites spike or the oxygen drops too low due to an algae bloom or too much disturbance of the bottom.

If the fish aren't dying anymore, you will have a hard time working it out. And with an 8 rai pond, there ain't much you can do about it anyway.

[TommoPhysicist]

i would suggest someone around the area sprayed pesticide/ herbicide on a crop , drifted onto the water surface ......are they growing any string beans in the rice fields at the moment? could have been a fair distance away .....how do u top your water up ? is it from a local stream or canal ? if so could have been the source ...only my opinion

What he says ...... also consider chemicals washed off new building materials.

Run off from new metal roofing is particularly toxic to fish. Newly poured concrete, etc.

Not to rule out, deliberate poisoning from an enemy/rival/whatever.

[cdmtdm]

I think Jayci might have it, Dropsy or some other bacterial issue. But because the dying was only in a 10 day period It makes me also suspect a change in water conditions or a toxin. Volumes of water do go through cycles, as there is a give and take between nitrates and nitrates and also the amount of plants and algae that inhabit it. Sometimes water can go toxic as either the nitrites spike or the oxygen drops too low due to an algae bloom or too much disturbance of the bottom.

If the fish aren't dying anymore, you will have a hard time working it out. And with an 8 rai pond, there ain't much you can do about it anyway.

given the volume of water and relatively low stocking levels i doubt a Nitrite spike would be the issue ... fish can handle very high levels of Nitrates , but a nitrite spike is generally from a sudden increase in Ammonia .... if its a disease why then only your pond ? time to test the water IMO ...

[David48]

Thanks for all the advice above ... and I hope more opinions follow.

The flip side of this event is what happens to the Farm. Must be heart breaking to the Farm Mother as she is the one who has to deal with this.

First the dead fish are gathered up. For those with limited bandwidth ... some photos.

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[David48]

For those with better broadband ...

There is one more ... but can only post a limited number (2) of YouTubes at once.

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[David48]

^^

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[I Like Thai]

Possible that poor water quality has lead to bacterial infection. Might pay to check both the source water and pond water. If source water is okay, then frequent water changes might help. How are the prawns in the pond?

Certainly gut wrenching watching your fish die off like that.

Checking the water quality is the Farang way ... not the ordinary Thai Farmer method.

A great suggestion ... but not done round these parts.

The kill happened maybe 2 months ago ... it's passed and the fish now grow normally.

But I'm trying to expand my knowledge base so that, in the future, should I ever buy/manage a Farm, I more worldly wise.

I learnt and know a fair bit about the traditional Fish and Shrimp/Prawn Farming method ... but I'm also smart and humble enough to ask others when I encounter something I don't understand ... rather then prey at a Temple for the problem to go away.

.

Seems to have worked

Try and let the pond find it's own balance, don't interfere with bacterial levels or anything else. If the pond is in a suitable area, then it will survive. If not, then it will fail.

[DonaldBattles]

Some of my fish are dieing and I fear that I have too many. They don't seem to grow very fast. The pond is 11 years old and I feed the fish pellets every 3 days. Should I try to drain out the lake and destroy the small fish or just try to net them? The number that have died are small. How do you try to determine the correct population in order to get the Tilapia to grow faster.

[David48]

Donald ... almost don't know where to start with that one.

We would need to know ...

• Fish species

• Fish sex

• Feeding method. Natural - algae ... or ... Traditional - pelleted feed See the first post in the Thread fish-farms-201 for the a complete read on both methods.

• Aeration

• Pond depth

What other questions are there?

Everyone's 'Fry to Harvest' plans are different, but the gf's Parents Farm run about 9 months from introduction of the fry into the pond to their commercial harvest.

[RedBullHorn]

Eliminate nitrite = solution is Salt.

Neutralize bad bacteria = solution is EM.

Once every week, i salt my pond, 1 sack of salt per 800sqm pond size.

Once every month, i apply EM to all my pond, activated EM in 2 x 200 litre blue PVC barrel per pond.

Fight chemical with chemistry, fight bacteria with bacteria, fight fire with fire.

Some point of interest for rearing in tank

[DonaldBattles]

The fish are mostly Tilapia black with a few half breed orange. a few catfish and some snake heads. The ponds are about 1600 square meters and spring fed from the mountains. The upper is about 1 meter higher in elevation than the lower one. during the dry season they are about a meter deep. During the rainy season they can get up to 2 meters or a little less in spots. The ponds are about 11 years old.

They are really slow growing and I think that I have to many small ones.

[DonaldBattles]

How big is the sack of salt that you use weekly. Do you mix it with water and then put it in the lake or just distribute by hand?

[DonaldBattles]

Do they thin out the fry once per year? Please see specifications that I have posted. I forget to mention that I feed them CP 9332 pellets every 3 days about 6 kg per feeding for both ponds. Ponds about 1600 square meters each. Tilapia black and a few cat fish and snake heads. they just don't seem to grow. Not sure what I am doing wrong. The ponds are about 1 meter deep during the dry season and about 1.5 to 2 meters during the wet season.

[DonaldBattles]

I need to know where in Chiang Rai I might buy the professional aerator systems

[RedBullHorn]

How big is the sack of salt that you use weekly. Do you mix it with water and then put it in the lake or just distribute by hand?

The salt are pack and sold using commecial fish pellet feed sack. Tie the sack to a couple of bamboo pole in the pond near the inlet pipe, use an ice-pick or a screw driver and poke the entire sack with holes (as many holes as possible), submerge the sack just below the water surface. The inflow from the inlet pipe will dissolve the salt in the sack.

I do this once a week when i top up water for the ponds.

[canuckamuck]

Donald, How many fish do you have in each pond?

[DonaldBattles]

Donald, How many fish do you have in each pond?

There must be thousands as they reproduce good each year. Just way to many little ones and not very many big ones.

[ozzydom]

Donald, How many fish do you have in each pond?

There must be thousands as they reproduce good each year. Just way to many little ones and not very many big ones.

DB, this last post of yours answers your own question.

By having mixed sex Pla Nin they are breeding faster than the available food will sustain them so you end up with a pond full of runts.

Pla Nin will start reproducing at 4-5 inches which is still to small to market.

While breeding ,the male fish (which should be the biggest and fastest growing )tend the eggs in the nest ,fanning them to give water circulation,when predators (which you say you have plenty of)happen along ,the male takes the eggs into his mouth to protect them.

This behavior continues after they have hatched into fry.

The upshot of this behavior is that while breeding, the males do not feed or grow and actually lose weight and condition.

If your pond is just for fun then you should get a couple of fine mesh cast nets or lift nets and get the locals to thin your stocks out quite a bit, this will give the remainder a chance to grow.

If you are looking at commercial fish farming, I am afraid your only answer is to remove all fish and water,poison to clean up any straggling fry,then refill and restock with mono-sex fry or fingerlings and start again.

Stocking rate for your size pond without aeration should only be 1200-1500 per pond.

The feed you mention is inadequate ,once you fish progress past fingerling size and they are on full size pellet each pond would need at least 14kg per pond per dayin two feeds, so at current prices for 15.5 %protein you are looking at over 200 baht per day per pond.