What is that unsightly foam washing up on beaches along the Fylde coast?
The foam is a regular sight when the weather gets rough, and is often presumed to be dirt or scum swept up from the seabed.
But is it really?
Wildlife Trust marine community engagement officer Emily Parr said: “The foam that washes in, particularly when the weather gets stormy, is completely natural.
“It is all to do with the natural materials in the water.
“The sea water has lots of different parts in it and part of that can be algae.
“When the algae starts decaying you get something called ‘algal bloom’. That’s a normal thing. The consistency of the matter increases and that’s what is washing up.”
The sight of the white foam is a regular one on Fylde coast beaches. The Gazette frequently receives photos from readers who encounter the stuff on their morning stroll after a bout of stormy weather.
And earlier this week, Lancashire Police shared an image of Cleveleys Promenade covered in a layer of foam following a particularly blustery spell.
Now, following an amber weather warning as 75mph winds were expected to batter the Fylde coast overnight, it would be no surprise to see it make a return.
But it’s nothing to worry about, experts say.
“Nothing has changed in the composition of the water,” Emily said.
“It’s just the stormy weather that results in it all being churned up to the surface and it’s blowing ashore.
“It happens everywhere, not just in the Irish Sea.
“It’s not at all harmful to animals, marine life or humans.
“It just doesn’t look very nice.”
Emma Whitlock, of Fylde LOVEmyBEACH, said: “I have heard about it being an issue in the Cleveleys area.
“As a group we focus on pollution on our beaches. If it’s something natural then we’re not worried about it.
“It does bother people when it gets on their cars and houses and it’s a bit of a pain, but it’s something that comes along with living near the sea.”
Residents in the North West were warned to prepare for strong winds and heavy rain ahead of Storm Aileen, which hit the region overnight.
The Met Office issued an amber weather warning as forecasters predicted winds of up to 75mph in parts of the region.
A yellow weather warning for rain was also put in place for the county, warning of 30-40mm of rain falling within 6-9 hours.
Met office deputy meteorologist Chris Tubbs said: “There are no links between the very strong winds we expect to see here in the UK and the hurricanes affecting the United States and the Caribbean at present. This system originated well north in the Atlantic Ocean, independent of the current Caribbean hurricanes”.
As Storm Aileen clears, the UK will be left with cool showery conditions through the end of the week. There will be some periods of brightness although it will still feel cool, with top temperatures reaching 18-19°C.
Wyre Council closed the storm gates at Cleveleys and put the boards in at Rossall Promenade.
Members of the public were being advised to stay off the promenade and beach for own safety during high tides.
Phil Durnell, head of highways for Lancashire County Council, said: “We’re well prepared for whatever the weather holds for us with the arrival of Storm Aileen.
“We’re ensuring that our highway teams and external contractors are ready to deal with incidents such as roads being blocked by trees, as well as any other maintenance that may be needed.”