In Reply to: Re: WILDLIFE AROUND LOUGH LANNAGH posted by MayoCoCo on June 30, 2005 at 17:01:42:

It supports precisely what I said - quote:

"Full kill will occur in 3 to 5 weeks. Once dead, weeds sink to the bottom and decompose. "

Sinking to the BOTTOM and decomposing means that the bacteria breaking the vegetation down - what I referred to as rotting away - but they suck huge amounts of oxygen from the water in so doing. The consequent deoxygenation of the water will kill every last remaining trout in the lake if not pike, roach, and sticklebacks too. It could be even worse if it causes the sediments on the bottom to go anoxic they will start to release phosphorus into the water which could trigger a new phase and turn the lake pea green. You must remember that plants growing in shallow lakes like Lough Lannagh provide habitat for large zooplankton species like Daphnia. Thse feed on algae. Kill the plants and you remove the habitat for these big zooplankton species. Add nutrients from rotting sediments and you stimulate cyanobacteria - the kind that killed those dogs in L. Derg the other day. Now you have no zooplankton to graze down the phytoplankton such as these nasty cyanobacteria. Hey presto a green-green peas soup and notices saying "do not let your animals into the water" - they will die!