People walking around Ullswater are warned that blue-green algae blooms may be present in the water.
The algae produces toxins that can kill pets and people are advised to take precautions against the naturally occurring environmental phenomenon, by Eden council.
The algae is more likely to appear during periods of warm, dry weather. Its growth is made worse by nutrient pollution, which contributes to the formation of blooms.
Algae is found naturally in inland waters such as rivers, streams and lakes.
During a bloom, the water becomes less clear and may look green, blue-green or greenish-brown.
Scums can form during calm weather when several bloom-forming species rise to the surface. This can look like paint, mousse or small clumps.
Cyanobacteria or blue-green algae, can produce toxins.
These toxins can kill wild animals, livestock and pets such as dogs who may swim in, or drink affected water.
They can also harm people, producing rashes after skin contact and illnesses if swallowed.
You cannot tell if an algal bloom is toxic just by looking at it, so it is safest to assume it is.
Keep children and pets away from the water and avoid skin contact with the water, or algae. Carry a bottle of water for your dog to drink and to wash off any scum.
If you or your pet become unwell after contact with water that may be contaminated with blue-green algae, you should seek immediate medical or veterinary advice.
You can report blooms to the Environment Agency by calling 0800 80 70 60 (24-hour service).
