Hi,

I have not been fishing for long but am concerned for a local fishery.

I am yet to see someone catch there but the place is very well stocked.

You constantly see fish swimming very slowly around the edges of the water in the top 3 inches bumping into rocks.

The fish also have large `white` patches on their sides, which Im not sure is reflection or not but it looks a little like fin rot or something to me.

Also there are often fish swimming in circles on their sides slowly right near the surface.

Today I saw a pike sat about 6 inches down just bobbing there. Normally pike are quick to swim off but this guy just sat there. I (although I probably shouldnt have) put the tip of my rod in the water and gave him a little nudge in the tail and he just turned slowly from the impact. He was moving his fins to stay level but seemed in a trance or something.

Also, there is an overflow from another pond into this lake and where the overflow is there were about 10 - 15 fish all wallowing around in about 6 inches of water.

Every time I have been there have been at least 4 or 5 dead fish around the edges.

Can anyone offer any info on what this might be?

Someone has suggested that its just too muggy at the moment for the fish but its about 50ft deep so I wouldnt have thought that would be an issue.

It reminds me of when I used to keep fish and the water was not properly cycled.

Hi ChopsMcGee

You have described a lot of sick, possibly diseased, and dead fish in this fishery. It's difficult to say what is the cause. You are right in thinking something is radically wrong.I run a fishery but would not wish to guess at the cause or causes.

BK

What would you recommend I do?

Perhaps a report to the environment agency? I dont want to see the place shut down or a fine for the owner?

I do want to see healthy fish that I can catch though :-)

---------- Post added at 08:26 PM ---------- Previous post was at 08:25 PM ----------

Also where is your fishery :-)

Might bob down! :-)

The fish also have large `white` patches on their sides, which Im not sure is reflection or not but it looks a little like fin rot or something to me.

This sounds like saprolegnia.It is present in all freshwater and when fish have been bad handled,or have a lesion on them it gets into them and grows and eventually they die.Some can recover if it is minor,but when it gets hold ,they will do what you have described ,going toward the oxygenated water and wallow and bump and stay at the surface.These are typical of this disease.It eats away at the flesh,fins and body and head.

The other disease which can cause it is argulus.a parasite which attaches to the fish and they swim round in circles nad also on there sides.When they first get them they jump out of the water and slap down to try to rid themselves of it.Later they swim on the surface ,not interested in anything and as they cause a wound will get sapro on them eventually and show the signs described.

Now im not saying they have ,just saying what the symptoms are.If they have them you can see them on the skin of fish,like little jelly patches with 2 black spots (eyes)normally around the fin areas is best to see them.

Fish will always head toward more oxygenated water when they are ill like this, but if it is too far gone they will eventually die.Sadly.

__________________
Kevin

Also sounds like there is a very low oxygen content in the water, given the situation with the pike, and the fish wallowing around the inflow from another pond, which probably has low oxygen content too!
regards
bert

Temperature of the water could be a factor and without knowing the water,in flows and water feed system along with weed or algae situation, which can extract huge amounts of oxygen from the water.It would need a good look at to see and dispell each on what is there.

Argulus would effect coarse fish aswell.

The signs described ,even though a water can be perfect in oxygen,fish will show what is described aswell.

But oxygen depletion could not be ruled out but other info would be needed aswell.The white marks etc tell me something else.

__________________
Kevin

Agreed, the white or "cotton wool" fungus is probably Saprolegnia, but might not be, as it likes lower temperatures to thrive, and multiply, as secondary infection, through damage to fish, however can be primary infection too, if given right conditions.
Was just the lethargic pike, and many fish floundeing around in shallows which to me is indicator of depleted oxygen content.
Perhaps increasing the dissolved oxygen content with blowers/aereators would cure a lot of the problems?
regards
bert

Both rainbows and pike are highly susceptible to Argulus, the common fish louse. Pike because of their sedentary habit which makes them an easy target, and rainbows because they are non-native and therefore lack the natural defences present in our own species. This is information obtained from a guy in Cefas who is probably the best authority on Argulus at present.

The best way to be sure is to catch up one of the moribund fish in the margins and have a look at it. If it is Argulus they will be present in large numbers - 50+ is not unusual - and they are easy to see. They will be a pale green flattish beast about the size of a little fingernail.

Argulus are always present, and many fish can be found with one or two on them. They like shoal fish like bream, and sedentary fish like pike, perch or tench. It is when their numbers suddenly increase that problems arise. The best solution is for the fishery to close its doors to anglers - no loss this as no-one is going to catch fish under these conditions anyway. Reducing the numbers of fish present reduces the number of potential hosts and therefore speeds up the process of reducing Argulus numbers. The more fish the fishery owner sticks in there, the more he will lose. Apart from that there is little that can be done. The situation will return to normal in due course.

I agre Bert,often called "cold water disease"but will still develop even in warmish temps.By putting aeroators in would help to oxgenate water but would depend on how developed the disease has got to.

generally if this loch is 50ft deep,many fish would be heading for that,but as I say,not knowing the feeder of water or other things it would be hard to say.

Chemical use can rid sapro for some again depends on how developed it has got to.

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Kevin

Thankyou for all of your information.

Not sure if this is now relevant but there are a lot of other course fish visible, much smaller - perch, roach etc.

All are below 1lb and these fellows look to be ok. There have also been very large fry hatches recently and these too seem active.

It seems to be the larger fish that are effected. Would this be due to the lack of oxygen as well, I guess the smaller fish might not be as effected.

Also is there a way to make recommendations to the owner without offending him? I am no real expert by a long shot so I dont want to be seen as a trouble maker, but at the same time I feel for the fish, soft **** that I am! :-)