Blue green algae

[flyman]

Our club trout lake have had abrown scum over the surface latley so i
asked the enviroment agency tocome and test the water,to befare they was up there the same day.they phoned me up to say there was blue green algae
present but it was dying of,so carry on stockingfor the comp we had that weekend.they had contacted the council who came up that morning and
shut the pond to any water sports including fishing.
We are now hoping the council will get to the root of the problem not just
open and shut the pond when conditions are right we lease the pond of the council i have noticed acouple of scabby fish of late,do it afect the fish
or have any of you had any dealings with blue green algae,any information

flyman

[geejayy]

ok, i dont know it all by any means,
but our lake at bossington used to suffer this problem occasionally,
the blooms seem to develop in mid to late summer as the water temp peaks
it starts to establish itsself on the bed of the lake then as gasses form in the silt it bubbles up to leave a 'orrible scum on the surface .
this stuff produces toxins that when become concentrated by low flows and large blooms can be harmful(irritant) to animals and humans in contact with it(not sure about fish).
i used to take care not to ingest any of the affected water and skin contact would give me a minor rash.

detailed info here, (sounds a bit frightening but the authoritys concentrate more on takeing steps to prevent letting affected water enter the tap water system and warning the public not to swim etc)

http://www.scotland.gov.uk/Publicati.../05/14852/5345

if i remember right the main problem with regards to fish health is the fact that it depleats availiable oxygen from the water , that is already short due to high water temp.

controls;- as far as i know once conditions are right for the spores to start a bloom and the bloom is in progress there is little that can be done practically to stop it.
the measures we employed were to (if possible) increase flow through the lake by opening hatches and allowing more water in/out this had the effect of slightly dropping the temp but mainly drew the floating scum off the surface and away giving areas where you could at least cast a fly into a clear patch of water without getting the flyline and all your gear covered in snot.
also as our hatches tumbled water into the lake it helped to oxygenate it a little.

I dunno if it works on greenblue algae but in low flow years the test valley gets affected by a filimentous algae bloom( blanket weed)
there is little we could do about it in the river but keepers who attended lakes reported a little success with;-

in the springtime suspend a Bale of barley straw ,in the lakes inlet , and repeat about june,
as this decomposes over the summer it releases a natural chemical which inhibits the growth of blanket weed, not 100% effective but it did seem to help on some waters.

i'm not sure if these inhibitors work against bluegreen algaes though.

[flyman]

thanks for the information we are waiting for the council at the moment,
Ive looked up that Web sight the other day thank,s a lot .

Flyman

[Greenheart]

It's been a problem for a few years now. I believe it's down to the use of nitrate fertilizers on farm land which wash into the watercourses. Add to that the low flow rates caused by over abstraction from boreholes & you have a problem. I know there were stories of dogs dying after swimming in or drinking affected water.