High flow (Vaal) = Fish KILLS ??? (LM Yellows?)

[troutmaster]

I was told by a colleague this morning that his dad went to check out the Vaal yesterday; private stretch more or less opposite Eastco...

Apparently there are plenty of HUGE carp and yellows dying and being washed out

The guy didn't have pics nor is he able to confirm LM or SM, but from the size he indicated I would guess LM...

Is this true? Anybody had similar experiences? What would cause this (lack of oxygen?)?

If they are indeed LM then it is VERY VERY sad news indeed.

[gkieser]

I have heard in the past that when the vaal experiences such huge flows, that all the crap that has settled is washed up into the upper layers releasing unwanted chemicals from decomposition of the muck and that is not good for the fish. The last time, a few years back (not as high as now) caused major fish kills, yet the yellows still remain - they are a resilient bunch for sure!

[Herman Jooste]

Barend, I can't believe lack of oxygen, virtually every metre of water below the Barrage is being tumbled around and around.
If they are all large fish, then my theory is that the rule of nature is at play.
If you are old and fat from inaction in the normal flows, this flood is going to tax you to the extereme, the extreme being death through exhaustion.

Before evreyone jumps down my throat I must stress, this is my theory, with no scientific backup whatsoever. In nature it's only the fittest that survive in extreme conditions, and the whole Vaal River is experiencing extreme conditions at the moment.

Who knows , maybe the next 7 years till the next floods will produce extremely strong fish?????.

[Scythe]

It happens with every major flood, the muck on the bottom gets turned up when the water goes ballistic.

You have to remember that it's not just pure water that's rushing around, it's now masses of water with lots of particulates and suspended solids in addition to poisons which were rotting on the bottom stirred up for good measure ... not to mention the fact that the sewage systems would basically be flushing straight into the river due to the massive influx of water, as we all know most sewage plants these days operate into their WET capacity outside of flood conditions, let alone inside their DRY capacity.

[geoffrey]

Did check out the river from Vaal dam to Parys Yesterday. There were a lot of dead fish in backwaters and against fences etc. Most of the fish were washed up some were still alive. The majority were Moggle I saw only one yellowfish which was about 4 kg but was injured. The rest were Muddies but they were all big fish. Only saw a few dead carp around 3 to 5 kg.

Interesting find was a Koi of around 3 kg swimming against the side very healthy but staying out of the silted water. At Klipbaai in Vanderbijlpark a lot of bass were holding behind reed banks obviously battling to breath as they were nosing the surface.

The water in Loch Vaal has all but drained out leaving only the raging torrent of the river ripping through the silted bottom, the water is liquid mud and I think this is what is choking the fish.

Below the Vaal dam there are thousands of fish hugging the banks, they were feeding and even spawning in the shallow currents, mostly Moggle and Muddies with the odd catfish thrown in.

The water below Parys is very dirty with zero vis and a lot of suspended solids

[FlyFanatic]

ahh well, they survived the previous times so im sure they will do again.

[E.T.]

Nature has a way of sorting itself out....

[E.T.]

After the big flood with Noah on the Ark, did all the fish die? Did someone re-stock all the waterways? Or did they survive? Why is it then that in about 6000 years we are still not able to catch all the fish?

Sure fish die in a flood, but thats just nature's way of getting rid of the weak ones. Every year Salmon swim upstream from the ocean to spawn and they die after spawning. They dont die because of old age, they die because they are exhausted, drained, starving,etc and the mere thought of getting to the final destination over rules all other instincts,desires.

A Kudu gets up in the morning and think, I must outrun the Lion in order to survive. The Lion gets up thinking that he needs to outrun the Kudu in order to survive. Moral of the story.....You need to run to survive.

Same with fish.....They must swim. The Vaal fish are lazy because they are only used to 30-70 cummecs on average and when 1500 plus cummecs hit them.....they start crapping bricks. If you are going to swim in the main current you need fins that can out perform a dolphin. Fish die in the ocean too if they end up in the wrong place.....If not.... We would never see whales beach!

[FlyFanatic]

lol ET, dont think this is the problem, if we take you and put you outside in -50degC with a short ur gonna k@k also. its not the fins or the flow rate that is the problem, its the shit that gets stirred up because of the flood, silt in the water etc. So no matter how healthy a fish is, if it gets caught in an area where the water has been churned pretty badly its gonna die.

but hey, thats the way it goes, the okes in haiti also got a raw deal, thats the way life goes, no matter if ur a fish or whatever.

[Scythe]

I agree, in a normal flood situation the weak would be taken to keep the genepool strong, with all the additional, crap and raw sewage going into the rivers because of US, this hardly qualifies as a normal flood.

This is not simply a case of "Oh well they survived for millions of years so they should survive this" as the dirty, polluting, expertly breeding animal we homo sapiens are, our impact on our environs during the last 100 years has brought about such a monumental change to the environment, species are struggling to adapt.

MY ZAR 0.02, YMMV.