Algae

[smackinnon]

[attachimg=3]
I have fished a reservoir just outside Edinburgh for over 15 years and this year we have experienced a massive algal bloom for the first time. The algae reaches from the bottom of the loch right up to the surface and covers everything in its path. I know these images are not the best but any advice on cause or prevention.

[Wildfisher]

Does it stink? It looks like some kind of sewage pollution.

[arawa]

Had it last year in a hill loch I fish. No sewage or any form of human intervention there. I assumed, perhaps wrongly, very low water and hot weather had caused it. It has not reappeared this year.

[smackinnon]

No i don't recall it being smelly, We are high up in the Pentland hills so not sure where a source of sewage would come from. The algae is much greener that it looks in the photos.

[Wildfisher]

It was the colour that worried me, it may turn brown as it dies off as the water cools down.

[roberth]

I've noticed this on a few lochs this year. I assumed it was down to the extended dry period we've had.

[Wildfisher]

Extended dry weather can often reduce algae as there is less nutrient run off from surrounding fields. It depends on the loch I guess.

[Fishtales]

It is Filamentous Algae.

http://www.newtechbio.com/wiki/index.php?title=Filamentous_Algae

[smackinnon]

its odd that "arawa" mentioned low water as the reservoir was manually drawn down several feet at the start of year for some work to be carried out.
This reduction in water level has happened before but never resulted in the bloom we seem to have just now.

[Wildfisher]

It is Filamentous Algae.

http://www.newtechbio.com/wiki/index.php?title=Filamentous_Algae

Good find Sandy.