Blue-green algae found at Portrush for first time in 2024 - number of cases across Northern Ireland up by 40% on 2023; DAERA says no risk to swimmers
Blue-green algae has now been confirmed in Portrush harbour.
It comes about a fortnight after cases were discovered at the mouth of the River Bann, about two-and-a-half miles to the south-west.
Last year along the north coast, there were cases discovered in Portstewart harbour, Portrush harbour, and Castlerock beach.
The discoveries are logged onto a system called Bloomin' Algae, run by The UK Centre for Ecology and Hydrology, and are then checked to see if they are “confirmed cases”, “probable cases”, or false alarms.
The recent confirmed case in Portrush harbour was logged on Friday.
The appearance of blue-green algae is cyclical; it drops off during winter, and rises again from spring.
So far in 2024 there have been 149 confirmed cases in Northern Ireland. Over the same period in 2023, there were 104 (an increase of roughly 40%).
The Department of Agriculture, the Environment and Rural Affairs (DAERA) said: “DAERA is aware that blue green algae has reached the North Coast and has been monitoring the situation closely, along with Causeway Coast and Glens Borough Council and the National Trust, who are the bathing water operators.
"Surveys carried out at the end of last week showed that the level of blue green algae in the water at the north coast is low and would not present a risk to water users.
"The department continues to monitor the situation and provide bathing water operators with the necessary information to inform the public, including local signage at beaches.”
Martin Kelly runs Portrush Surf School near the harbour, and last year had to cancel an extremely busy weekend of bookings after blue-green algae was discovered.
Asked if visitor numbers had been depressed by the furore over blue-green algae, he said “without a doubt”.
“I know by my bookings and by people talking in the street,” he said.
“It's a memory I try to forget to be honest, but looking back [to 2023] we had loads of phone calls saying 'we are booked for next weekend – is it safe to go ahead?'
“It definitely put people off the water.”
Is he concerned about a drop in bookings again now?
“Yes, you have to be,” he said.
“It'll hit the news again and people will then think the Portrush beaches are closed. Without a doubt, it hits the news again, bookings will be going down.”
Rob Skelly ran The Edge watersports centre on the River Bann, near Coleraine.
He was forced to shut last year because of the algae, and expected it would be permanent. He hasn't changed his mind.
He said the algae is just a “symptom” of decades of pollution, and that a “carrot and stick approach” should be taken: help for farmers to cut pollutants, plus fines for rules-breakers.
Mr Skelly said it is “no surprise” that it has turned up in Portrush again, given that the River Bann discharges just a few miles away.
“To be honest I'm surprised it wasn't seen earlier,” he said.
The main focus of blue-green algae is in Lough Neagh.
A governmental briefing paper written last September about the problem found that essentially its likely causes were runoff from farms, sewage, and possibly climate change.
The algae (which, despite its name, is actually a bacteria) thrives in warmer water, and the briefing paper found that surface temperature at the lough has increased from under 10C in the early 1970s to between 12C and 13C today.
The spread of the invasive zebra mussel species is also understood to have played a role, as they have made the water clearer, stimulating more algal photosynthesis.