Mark Swaby
Senior Member
About 2 weeks ago a total fish kill occurred on this 50 acre local lake due to oxygen levels being too low for life to survive.50 plus year old carp,massive numbers of pike,bream, tench,etc and lots of catfish all perished.Some things were seen prior to the kill. 1) About a month ago the sunny/warm days stopped and we had a dreary damp week,all the algae/weed starrted to dye off. 2)The lake water changed from clear to dark 3 weeks before the kill 3) The fry started to shimmer on the surface like it was raining, small fish were jumping around the edges. 4)The bigger fish were gasping on the surface the night the kill occurred shortly afterwards all the fish dyed.When the water oxygen levels were tested afterwards they were around 0.2ppm and you need above 2ppm for any survival.Local lakes were testing at levels like 7. The EA turned up after the kill but it was too late,so you need to do things yourself.Make sure your fishery lake managers have oxygen test kits and test daily if possible towards the end of the summer,the lowest levels are around 3 am but if you see levels around 3 then you need to start doing something.Get your club to buy pump/generator units or approach local clubs to share.Thunder storms and these conditions are very bad for dropping the oxygen levels.I was told all this by a friend who was involved and hope i have got all things correct, he had never seen anything like it and never wants to see it again.