A bathing ban is in place at a popular north coast beach over the August bank holiday weekend due to the presence of blue-green algae.

High levels of the potentially toxic algae was found at Benone Strand on Thursday.

No other beaches on the north coast are affected at this time, the Department of Agriculture, Environment and Rural Affairs (Daera) said.

It comes amid a number of reports of blue-green algae in loughs and waterways in Northern Ireland over the last few months, namely at Lough Neagh.

In a statement on Friday, Daera said blue-green algae was detected during a regular sample of bathing waters at the beach, where later analysis confirmed “high levels” of the bacteria in the water.

“The Department has issued the bathing water operator, Causeway Coast and Glens Borough Council, an ‘Advice against Bathing’ notification,” it added.

“No other north coast beaches are affected at this time.

“The department will continue to monitor these beaches for blue-green algae and provide advice to bathing water operators when required.”

On Benone Strand, a dozen or more cars are parked, but children and dogs remain safely on the sand.

Some adults have entered the water, despite loudspeaker announcements from the RNLI lifeguard hut warning that a red flag is in place and swimming is prohibited.

Lough Neagh drains into the Lower Bann, which flows to the north coast, so it’s no surprise that blue-green algae from upstream has reached the beach.

For those hoping for a last-hurrah summer swim on a sunny bank holiday weekend, however, it’s a disappointing blow.

Blue-green algae, technically known as cyanobacteria, is a collection of microscopic organisms that are naturally present in lakes and streams.

Under certain conditions, blue-green algae can become abundant in warm, shallow, undisturbed, nutrient-rich surface waters that receive a lot of sunlight.

When this occurs, blue-green algae can form blooms that discolour the water, or produce floating mats or scums on the water’s surface.

It can spread rapidly, with blooms beginning to double every seven to 14 days.

While some blue-green algae can produce toxins, it is not possible to tell by sight alone. For pets, livestock and wildlife, the blooms can be extremely dangerous.

If people are exposed to high levels of blue-green algae, either through contact with water blooms, swallowing the water or inhaling airborne droplets, may cause health effects.

These can include diarrhoea, nausea or vomiting, skin, eye or throat irritation; and allergic reactions or breathing difficulties.

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