Fish kills, contamination and water aeration

Wondering if anyone has been involved in any fish kill problems on club waters, and what the contaminants were/ what methods were used to remediate.

I have seen a few methods, some successful some not, in both pools and running water. Has anyone got feedback on impacted waters and how they were sorted out?

Most fish kills occur when there's a dissolved oxygen crash and fish suffocate.
This commonly happens after a thunderstorm when cold rain and hail cause rapid cooling of the water and the algae die. Same thing happens when raw sewage contaminates a river. Obviously aerators can help in these instances but otherwise best treated by the EA. My club has had this problem on a couple of lakes and the treatment is usually Hydrogen peroxide solution.

sbc_1974 said:

Wondering if anyone has been involved in any fish kill problems on club waters, and what the contaminants were/ what methods were used to remediate.

I have seen a few methods, some successful some not, in both pools and running water. Has anyone got feedback on impacted waters and how they were sorted out?

Click to expand...

I suspect the Angling Trust/Fish Legal website/newsletters are a gold mine of info.

peter crabtree said:

Most fish kills occur when there's a dissolved oxygen crash and fish suffocate.
This commonly happens after a thunderstorm when cold rain and hail cause rapid cooling of the water and the algae die. Same thing happens when raw sewage contaminates a river. Obviously aerators can help in these instances but otherwise best treated by the EA. My club has had this problem on a couple of lakes and the treatment is usually Hydrogen peroxide solution.

Click to expand...

interesting stuff, surprising what the aeration can do depending on the contaminant. Anyone have experience of slurry issues? Again, dissolved oxygen problems

If the problem is low oxygen levels then there's no other way to deal with it other than aeration. The quicker you bring them back up the less fish you're going to lose. We've used standard aeration methods floating sprays (tends to be slow) Water cannon quicker but expensive to run. Pumping direct pure oxygen into the water from cylinders. Very fast but needs a detailed knowledge of what the O levels are and a calculation as to how much you need to put in. Super saturation can be as harmful to fish as low levels.

On problem waters where it happens a lot, install a proper aeration system that runs the whole length of the lakebed and can be turned on when the weather gets hot. Such a system is not cheap about 10K but that's only the cost of losing 10 20+ fish. Since my club installed such a system about 4 years ago on a shallow problem water, we've had no low oxygen levels at all. You pays your money you get the returns....Simple!

Re slurry it's the ammonia content that’s causing the O depletion and it needs oxygenation quickly, no question. Slurry should not be entering any watercourse so get the EA out to stop the bar steward who is letting get in to stop it.
If it’s coming from an unknown seepage source that can’t be traced then a fragmites bed place in the inlet source will dramatically cut the problem down and may even stop it completely

I dunno about bar stewards Bad One. Most farmers I know would never deliberately pollute their waters or streams. Its not in thier interests; most are very concerned about their land and water. And its often accidental or neglect. Farmers are very busy and checking every bit of equipment or valve gets missed.
Could the EA or the Angling trust do more about this. prevention is better than cure. Could they set up a scheme were farmers could log their equipment onto a computer program and when it needs checking or replacing they could be sent a email reminding them that this valve or this bit of equipment etc , needs replacing, over hauling etc. This could all be done on automation. It would take a bit of setting up but, not much cost involved and I think a lot of farmers/land owners would welcome it. After all it could save them a lot of money from being prosecuted after a pollution event. And I think, would prevent a lot of these slurry pollution cases happening. Its often down to neglected valves, old equipment etc.

Sorry Mark the responsibility is theirs and theirs alone to make sure they don't pollute any watercourse because they’re busy people and to bone idle to make sure they have their own systems set up to make sure their equipment is up to scratch so it doesn't.
Farming is a business like any other business and subject to the same regulations as them. They are not and should not be treated any different because they are farmers.
If they are that incompetent that they can’t or won’t run that business so they don’t commit a criminal act they deserve everything coming their way. And/or they should get out of that business.
The two most prosecuted sections of businesses for polluting watercourses in the UK are the Water Industry and Farming in that order.
As to they wouldn't deliberately pollute, that’s not my experience and the order of prosecutions doesn’t support that either. One farmer local to me, between myself and the EA, we had him 4 times over a two year period for discharging pig **** direct by pipe from his slurry pit into the brook that ran across his land. At his last appearance in court the judge told him, if he appeared before the court again for polluting the brook he would be jailed.

His level of incompetence in trying to hide his crime was staggering. He’d discharge the **** into the brook when it was up. Not having the sense to realise that the corn he was feeding his pigs didn’t get fully digested by them and as the brook dropped it left a residue of tiny corn bits on the side of the brook.
Thankfully he’s no longer in the Farming business and the brook no longer gets polluted.

Thanks bad One for your reply-your more of a country man than me so, will know more. I will think on this a bit and come back if anything comes up.