Did you know? It’s algal bloom season | Latest news

Algal blooms can appear as green, blue-green, or brownish-green discoloration on water surfaces, sometimes with foamy or slimy textures. They may be found on lakes, ponds, or slow-moving rivers, which encourage the bloom formation.

Algal blooms in the UK are usually seen between May and September, coinciding with warmer, sunnier weather and increased nutrient levels in the water. While blooms can theoretically occur year-round, the conditions required for them to develop and become visible are most prevalent during these summer months. 

Warm, sunny, and calm weather conditions, along with sufficient nutrient levels (like nitrogen and phosphorus), contribute to algal bloom formation. These nutrients can come from various sources, including agricultural runoff, sewage effluent, and even storm water runoff. 

While not all algal blooms are toxic, it's always best to assume they are and avoid contact with the water or algae, especially if you are concerned about potential health effects. Exposure to toxins via drinking water or recreation can cause skin rashes, respiratory issues, or liver damage.

Keep your dog away from effected areas too.

They can also produce toxins that are harmful to ecosystems, aquatic life as they reduce oxygen levels, block sunlight, and can cause unpleasant odours.

An increase in temperature because of climate change and altered precipitation patterns may intensify blooms.

How to report

If you suspect a bloom might be toxic or is associated with pollution, you can report it to the Environment Agency's hotline on 0800 807060.