Public Health Risk – Algae Warning For Bathers And Animals 

A PUBLIC health warning has been issued in Dumfries and Galloway over the threat to bathers and animals posed by blue-green algae. 


Amid forecasts of hot weather, bathers and pet owners are being advised of the danger posed by this bacteria found in some ponds and lochs which can prove potentially deadly.


Public Health Consultant Dr Andrew Rideout said: “The recent spate of warm weather may see people tempted to cool off in ponds and lochs, and for owners to allow dogs to take a dip or have a drink.
“There are dangers around swimming in natural waters at any time, but at this time of year a key concern is the presence of blue-green algae.
“Although it’s referred to as algae, it’s actually a group of bacteria called cyanobacteria. It usually can’t get a foothold in moving water, but in areas of warmer, still water it can start to form – and it really does pose a significant risk.
“Blue-green algae emits toxins. A human or pet swimming through it with their head just above the water can be at serious risk.
“For that reason, if people are wishing to swim to cool down in the hot weather we would advise using public swimming pools. Anyone who does venture into natural waters should be extremely vigilant for the presence of this algae, which may not always be immediately apparent.
“Walking past waters with blue green algae should not pose a risk, but anyone who does enter these waters and starts to feel unwell should seek medical advice immediately.”

The bacteria cannot be seen by the human eye unless they clump together. At this point, it can look like green flakes, greenish bundles or brown spots.


When it blooms, it can look like a blue-green scum has appeared on the surface of the water – described as looking a bit like pea soup.


Blooms of the organisms often build up around the edges of ponds and lakes, and may look like foam.


Blue-green algae is most common in non-flowing fresh water such as ponds and lochs during hot weather, but it can also occur at other times of the year.


Dead fish can sometimes be seen in areas of water with high concentration of the toxic bacteria. Pets should not be allowed to drink from these waters.


Harmful blue-green algae may not be visible on waters, to please be alert for any warning signs within the area.


Symptoms of blue-green algae poisoning are as follows:

  • Vomiting/being sick
  • Diarrhoea
  • Seizures/fitting
  • Weakness/collapse/unconsciousness
  • Disorientation/confusion
  • Drooling
  • Breathing difficulties


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