BLUE-GREEN algae is still present in four places in Cumbria.

The Environment Agency said the potentially toxic micro-organism has been found in Windermere, Ullswater, Coniston Water and Killington Reservoir, posing a risk to the health of people and animals.

With sampling taking place on a weekly and monthly basis, a number of other locations have also been tested by the Enviornment Agency, but so far have come back negative.

As welcome as the dry weather is for some, it is obvious that with higher temperatures and prolonged low rainfall that some areas of the natural world are suffering and the increase in blue-green algae across the usually damp Lake District is just one consequence of this.

Jim Ratcliffe from the Environment Agency said: “Blue-green algae is a completely natural summertime occurrence, however it can be toxic and as such, users of these lakes must remain cautious.

"As well as having a negative effect on the appearance, quality and use of the water, it can also move around – you could see it one day, but it may have moved the next.

“We rely on members of the public to report suspected appearances of blue-green algae to our incident hotline on 0800 80 70 60.

"Once a report comes in we will send our samplers to test it and if confirmed, will contact landowners such as local authorities encouraging them to display warnings to notify the public of the health risks.

“We will then continue to take samples of affected lakes throughout the summer on a weekly or monthly basis.”

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 also cause foaming on the shoreline, which can sometimes be confused with sewage pollution. During a bloom, the water becomes less clear, blocking sunlight and stopping plants in the water from growing.

Blue-green algae naturally occurs in inland waters, estuaries and the sea.

Blooms can form when their numbers become excessive.

Once algal numbers are high, the bloom is likely to persist throughout the season, declining only on the onset of cooler conditions.

The dangers

Some types of algae, for example blue-green algae, form blooms and scum which can result in the production of toxins.

These toxin producing blooms are called Harmful Algal Blooms.

These toxins can be harmful to wild animals, farm livestock and domestic pets.

In humans, they have been known to cause rashes after skin contact and illnesses if swallowed.

Not all algal blooms and scums are toxic, but you can’t tell just by looking at them, so it’s best to assume they are.

From widespread moorland fires on parched ground, to fish in distress due to low water levels and algal blooms – these are all indications of the prolonged dry weather affecting our environment.

Hot and dry weather also brings a range of challenges at waste sites, mainly amenity issues like dust, odour and flies but also increased fire risk. For further information visit www.gov.uk/government/publications/algal-blooms-advice-for-the-public-and-landowners/algal-blooms-advice-for-the-public-and-landowners Advice on what to look out for, and the effects of blue-green algae, can be found here: http://www.lakedistrict.gov.uk/caringfor/policies/algae