Green beach slurry just harmless algae
Holidaymakers are being reassured that a runny green substance appearing on Welsh beaches is algae and not sewage or slurry.
Natural Resources Wales said beaches are clean and healthy, despite some appearances of the phytoplankton, that thrive in warm summer weather.
Rough seas whip up the organic matter or waste from the plankton in the water into a foam that is brought onto the beach by wind and waves.
Steve Morgans, senior environment officer for Natural Resources Wales, said there had been recent reports by people concerned about the look of the algae at beaches, including Aberystwyth and Pendine as well as West Angle in Pembrokeshire.
"People often mistake the algae as sewage or other pollution because of its appearance," he said. "The natural foam has a slight seaweedy smell and is slightly oily.
"Rather than being a problem, the foam is a sign of productive and healthy Welsh seas. Phytoplankton forms the bottom of the food chain supporting a wealth of fantastic marine wildlife, like fish, birds and mammals like dolphins, much of which is protected in sites of European importance.
"Around this time of year we do get some reports of what appears to be sewage slicks on the coast. We treat each one seriously and whenever possible carry out tests to find out what it is.
"But almost always, despite its unpleasant appearance, the 'sewage' turns out to be this common algae which isn't harmful."
Phytoplankton, also known as microalgae, are similar to terrestrial plants in that they contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean, where sunlight penetrates the water.
Phytoplankton also require inorganic nutrients such as nitrates, phosphates and sulphur which they convert into proteins, fats and carbohydrates. Some marine algae can cause a slight irritation on the skin so is best avoided if possible.
People can report any unusual sightings on the incident number 0800 807060.
To find out more about the water quality in any of Wales's beaches visit the Natural Resources Wales website and search for 'bathing waters' or follow the link here.
