SEPTIC tanks, algae-produced toxins and low rainfall have turned the water brown at east Cork beauty spot Loughaderra Lake.
Councillor Noel Collins (IND) said he is concerned at the muddy-coloured water in the lake — which is 2km outside of Castlemartyr on the N25 — and the effect it could have on fish and bird life; Mr Collins added the lake has been contaminated in the past.
“When investigated the lake was found to be a danger to fish and bird life. I fear the worst. This is a beautiful area. Many tourists stop here. I’d like to see it investigated further and I’d like to know why they are not restocking the lake with fish,” he said.
County Hall officials said it’s a decision for Inland Fisheries Ireland to restock fish but this has been discontinued because rainbow trout which were being introduced were not suited to the ecology of the lake. It is believed coarse fish such as pike, beam and rudd would be more suitable.
Public notices have been erected at the lake to ask the public to desist from feeding the birdlife that frequent it — such as swans — as this may pose a disease risk.
County Hall senior executive scientist Frank O’Flynn said the main contributing factor to the colour of the water is caused by septic tanks.
“The main impact on water quality in the lake is from diffuse loss of nutrients (particularly phosphorus) from agriculture and from septic tanks servicing individual dwellings, to groundwater in the catchment area,” said Mr O’Flynn. “The very low rainfall levels since May may have had a further negative effect on water quality in the lake with reduced freshwater inflows to the lake during this period.”