The ability to recognise blue-green algae and quickly confirm its presence using specialist algae testing can help owners, operators and managers of lakes, reservoirs and other watercourses, including recreational water sites, manage the potential health risks to people, pets and other animals. In this expert guide we consider what this algae is and how to recognise it, the risks to people and animals, how these risks can be managed, and the benefits of blue-green algae testing. We conclude by reviewing the recommended trigger levels from the World Health Organization, what these mean for the safe management of watercourses, and how best to treat unwanted algal blooms.
What is blue-green algae?
Blue-green algae is a type of bacteria called cyanobacteria. This type of bacteria is similar in many ways to other types of water plants. Cyanobacteria occurs naturally all over the world, and can be found growing in lakes, rivers, streams and oceans. Blue-green algae is however more common in ponds, lakes and slow moving rivers and other watercourses, especially during the summer months when water temperatures rise.
Blue-green algae is actually a type of bacteria called cyanobacteria
What does blue-green algae look like?
Single algae are too small to be visible to the naked eye. Blue-green algae only becomes obvious when they form larger clumps. These can look like flakes, bundles or little green or brown dots in the water. Given the right weather conditions, blue-green algae can multiply rapidly. Most types of algae float, and can appear as layers of foam or scum on the surface. This is sometimes referred to as algal bloom or algae bloom.
What are the dangers?
If blue-green algae is allowed to grow unchecked in ponds, lakes and slow moving rivers, it can have a significant impact on both the appearance and the water quality. The water might turn a shade of green, green-blue or brown. Additionally, some types of blue-green algae have a distinctive musty or earthy smell.
High levels of blue-green algae can result in unsightly foaming along river banks or shorelines. This is often mistaken for pollution from raw sewage. As the bacteria dies, it uses up oxygen in the water and this can cause huge problems for fish and other organisms living in the water.
Some types of blue-green algae can also be harmful to humans and animals as they produce toxins. These toxins can affect wildlife, pets and farm animals as well as being dangerous for humans.
Is this a common problem?
Blue-green algae is naturally occurring. It develops naturally in bodies of water across the UK every summer. In most ponds, rivers and lakes, the development of blue-green algae follows the same pattern every year. Once there is a problem with bloom or scum caused by blue-green algae in a pond or other body of water, there is no straightforward way of treating it.
What are the health risks from blue-green algae?
The algae can produce several different toxic substances that can cause a number of health issues, some of them serious. People and animals coming in to contact with the polluted water might get these toxins on their skin if they swim in the water, breathe them in when using boats on the water, or swallow them accidentally.
The toxins can cause skin rashes, high temperature, headache, nausea and vomiting. In some cases, toxins can also lead to serious health conditions such as brain or liver damage. Due to their smaller stature, children are typically more at risk from the toxic effects than adults.
Minimising the risks from cyanobacteria
Unfortunately you can’t tell by just looking at a bloom of blue-green algae whether it is toxic or not. The safest course of action is to assume the worst and take steps to minimise risks. If you do decide to have the water tested, carefully take samples using protective equipment so your skin is never in contact with the water.
Immediately put up notices advising people to stay out of the water, and keep their pets and other animals out of it too. Avoid direct contact with any affected water, and don’t eat any fish which have been caught in a lake or pond affected by blue green algae.
Blue green-algae testing and recommended trigger levels
If you have carried out blue-green algae testing, the action you take will depend on the levels of bacteria found and the extent of any contamination in the water. The World Health Organisation (WHO) has produced excellent guidance on what steps to take if it is identified.
Treating blue-green algae
The natural response to an issue with biological contamination is to look for a product to kill off the bacteria and clean up the water. There are commercially available herbicides and algaecides which will successfully kill off the blue-green algae bacteria. However, using these will mean that all of the toxins in the algae will be released immediately into the water when they are killed. By far a better course of action is to take suitable precautions to protect people, pets and other animals and then let nature take its course and wait for the algae to die off naturally as the weather turns cooler.
Specialist recreational water quality analysis including blue-green algae testing
Water Treatment Services offer a comprehensive range of water quality testing and laboratory analysis solutions including blue-green algae testing (cyanobacteria), to support owners, operators and managers of natural, open swimming and recreational water sites. Our experts can provide advice and support to help you identify the most appropriate strategies for the on-going management of your water quality.
Contact Water Treatment Services to find out more about our laboratory water analysis services including microbiological testing, chemical and in-field sampling services.
With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of specially trained technicians, in-field specialists and consultants we can offer professional, cost effective laboratory analysis solutions across the whole of the UK and internationally.
Contact us today to learn how our expert water management solutions can help keep your water safe.
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