The East Strand and West Bay beaches in Portrush have been red-flagged
By Louise Cullen & Alan Haslam
BBC News NI
Red flags have been put in place at East Strand and West Beach in Portrush amid concerns about blue-green algae.
Causeway Coast and Glens Council said inspection of the water in the last 24 hours suggested “there may be the presence” of the potentially toxic bacteria.
People are advised not to swim and keep pets away from the tide line.
A local trader has told BBC News NI they fear the potential impact on trade from the warning.
Officials from the Northern Ireland Environment Agency are due to take samples for analysis to check levels.
It follows problems earlier in July at Portstewart, Castlerock and Benone, where bathing was also banned for several days.
Image source, Centre for Ecology & Hydrology
Algal blooms may be green, blue-green or greenish brown and can produce musty, earthy or grassy odours
Sightings were also in County Londonderry on Thursday.
The algae had washed down the Lower Bann River from Lough Neagh, where it is present in levels not seen since the 1970s.
Natural tidal movement will disperse it along the coastline.
It cannot survive in saltwater but there is a concern that clumps of it may wash up on the shore.
‘So frustrating’
Andy Hill, owner of Troggs Surf Shop, near East Strand beach, said the warning has had a serious impact on trade.
Mr Hill, who also operates a surf school and equipment rental service, said both were forced to close.
Image source, Andy Hill
Troggs Surf School was forced to close as a result of the red flags
“The surf has been terrible for months but today was the best it’s been all summer,” he told BBC News NI on Friday.
“It’s just so frustrating.”
Algal blooms are caused by water pollution and certain weather conditions.
Invasive species like zebra mussels also contribute to the problem by cleaning the water, allowing sunlight to penetrate more deeply and stimulate algal growth.
‘Keep people safe’
George Nelson, owner of Babushka cafe, which overlooks Portrush harbour, said he was glad to see a response to the potential health threat.
“We’re trying to stay positive and are hoping it’s only a matter of a day or two,” he said.
Mr Nelson praised the Department of Agriculture, Environment and Rural Affairs’ (DAERA) response to the situation.
“They’ve been very good at monitoring the situation and updating us,” he said.
“Better to keep people safe and get back to it when the time is right.”
Anyone seeing anything they suspect might be blue-green algae is urged to report it using the Bloomin’ Algae reporting app.
A DAERA spokesperson said: “The presence of blue green algae is being investigated at Portrush Harbour and Portstewart Harbour.
“To date, no evidence of blue green algae has been reported at the adjacent identified bathing water sites to Portrush Harbour and Portstewart Harbour.
“Please follow advice provided by the landowner or operator of the river, lake or beach.”
