A potentially toxic form of algae - which can be harmful to both humans and dogs - has been confirmed in parts of Wales, Natural Resources Wales has confirmed.
Blue-green algae, which is also called cyanobacteria, is a microscopic bacteria found in freshwater ponds, lakes, streams, and brackish water ecosystems.
Despite being a completely natural summertime occurrence, blooms in the algae can produce several toxins which can be dangerous to humans, as well as being potentially fatal to animals like cattle, horses and dogs.
Water bodies affected by blue-green algae or algal blooms may appear to be green, blue-green or greenish brown and can produce musty, earthy or grassy odours.
Blooms can form when the algae numbers become excessive and usually occur when the weather is very hot and there has not been a lot of rain, poor air circulation and lower water levels.
Cases of blue-green algae have recently been confirmed by the Environmental Agency in parts of the Lake District, but NRW has now confirmed that the algae has also been found in parts of Wales this year too.
NRW have been made aware of three confirmed cases of blue-green algae in Wales so far this year - although they say there may be more, and they are currently checking with teams across Wales.
Confirmed cases in Wales, include:
- Fagl Lane Quarry, Hope, Flintshire - NRW say this land is privately owned.
North Dock, Llanelli - NRW say this area is managed by Carmarthenshire Council. A NRW spokesman said: "The blue green algae bloom here was identified as being caused by a blue green algae that naturally occurs in the marine environment in large numbers and is not known to produce toxins. We do not routinely monitor this waterbody."
- Llyn Pencarreg near Llanybydder, Carmarthenshire - NRW said: "The land around the lake is in a number of private ownerships. Llyn Pencarreg still has blue green algae present."
What is blue-green algae?
Blue-green algae is a term used to describe a group of bacteria, called cyanobacteria.
They exists all over the world and are found naturally in many inland waters, estuaries and the sea.
They generally grow in non-flowing fresh water such as lakes, ponds, and slow-moving streams during hot weather when there is less rainfall - but can also occur at other times of the year.
The algae are very small and can’t be seen with the naked eye unless they are concentrated into clumps when they can look like green flakes, greenish bundles or brown dots in the water.
When the algae blooms, it can look like a blue-green scum has appeared on the surface of the water - almost like pea soup.
Blooms of the organisms often build up around the edges of ponds and lakes, which may look like foam.
According to Natural Resources Wales' information leaflet, bloom and scum-forming blue-green algae can produce harmful toxins.
What are the health risks to humans?
According to Public Health Wales these toxins can be potentially harmful to humans.
A statement on their website said: "People may be exposed to these toxins through contact with the skin (e.g. when swimming), through inhalation (e.g. when motor boating or water skiing), or by swallowing contaminated water.
"These toxins can cause skin rashes, nausea, vomiting, stomach pains, fever and headaches. Occasionally they can cause more serious illness such as liver and brain damage.
"Children are at greater risk than adults of developing problems because of their comparative lower body weight."
How can the health risks be minimised?
Not all blue-green algae blooms and scums are toxic but it is not possible to tell from appearance and so here are some precautions to take:
- Do not swim in the water
- Do not swallow the water
- Avoid contact with the algae
- Do not eat fish caught from the water
- Observe and abide by any warning notices positioned around the water
Public Health Wales encourage anyone who has come into contact with water containing blue-green algae to shower with fresh water immediately.
Anyone who comes into contact with affected water and becomes ill should obtain medical attention immediat