Estimated 5,000 fish dead at Cavan lake

Mature bream, roach and perch found dead on lakeshore near Shercock

FISHKILL Heat claimed as factor in Barnagrow Lake incident

An estimated 5,000 fish have perished in a shocking kill at Barnagrow Lake.

Mature bream, roach and perch lay lifeless in the lapping waters right around the lakeshore this week. Investigations are underway into the cause of the fishkill with officers attached to Inland Fisheries Ireland (IFI) arriving on Wednesday to survey the watercourse, located between Maudabawn and Shercock.

Officials confirmed to the Celt they believe approximately 5,000 fish died from this incident.

Barnagrow Lake serves the Dernakesh Group Water Scheme which consists of around 360 households, including businesses and farms. The lake is also a popular with outdoor swimmers and anglers. It is often a focal point for the annual Cootehill Fishing Festival.

Locals reported seeing an green algae bloom on the lake during the heatwave. Experts have told the Celt that prolonged, extreme heat would have substantially reduced the water oxygen levels. There's speculation a build up of nutrients in the lake could be a factor.

Experienced angler Ronan Murray, who regularly fishes Barnagrow, was appalled by the scene.

“I went for a walk around the lake the other evening to check out the situation and there was easily a thousand fish dead on every shoreline of the lake,” he said.

He noted that bream can live between 40-50 years, and estimated that some of the larger bream he came across could have been up to 20 years old.

“This fish kill is a big loss to all the anglers in the area – it will take it a lot of time to recover from that.”

Ronan also runs a business as a guide for angling tourists and regularly brings them to Barnagrow, due to its reputation for coarse angling. “It is one of the better known lakes in the area,” he says.

He suspects the recent heatwave was a big contributor to the devastating incident.

“I was on Barnagrow Lake last week and the temperature of the water was 26 degrees,” recalls Ronan.

He suspects the problem is not limited to Barnagrow, having noted “hundreds of trout” found dead on the shores of the Annalee River in the Butlersbridge area in recent weeks.

“I was down at it at the weekend and I counted 15 trout lying dead along the bank,” he said.

“There is an algae bloom on all the lakes at the minute. That bit of rain has cleared off some of the lakes – there is no oxygen in the lakes – there is nothing you can do with that warm weather. Once water levels heat up, the oxygen levels become lower and lower.”

Cavan County Council says they have liaised IFI on the fishkill and are being updated as the investigation progresses.

Their spokesperson also outlined that they have issued general guidance to the public regarding algal blooms on its social media platforms.

The guidance warns that algal blooms, "which appear as a green scum" should be avoided as they "may cause skin irritation or be toxic if ingested".

It continues: "Please note that dogs are particularly sensitive to these blooms, and keep all dogs away from affected water and shorelines”.