Have you had to cancel events or shut your centre due to water quality issues? Have blue green algae blooms been reported in your location? Do customers complain of odours or discoloured water? Blue green algae can have a detrimental impact on watersport businesses. Learn more about this algae and how to avoid exposure and associated health risks for your customers.
What is Blue Green Algae?
Blue-green algae, also known as cyanobacteria, is a form of bacteria that thrive in slow-moving or still water. It is highly adaptable, survives in a wide range of conditions and tolerates extreme environmental stresses.
Algae will reproduce in what is known as a “bloom” when conditions are right – such as warm temperatures and sunlight. The presence of additional nutrients, such as phosphorus and nitrogen, can further accelerate the reproduction process. This usually occurs late summer or early autumn. However, under certain conditions, blooms can occur earlier in the year, potentially impacting recreational activities and water sports.
Algal blooms can have a significant impact on water quality, and some species produce toxins that are hazardous to humans. Even if the bloom is not visible to the naked eye, it can still be present in the water column. Or, it can form a smelly, thick scum on the water surface. All algal blooms are treated as toxic until the water is tested, for the safety of the public. Blooms typically occur each year. They can have varying levels of severity, and can persist for weeks, months, or even the entire season if the conditions are right.
What causes blue green algae?
Contributing factors include high temperatures, fluctuating water levels, and nutrient loading from fertilisers, sewage, and other sources. Blue-green algae blooms will increase if these factors are left unchecked. These blooms tend to be more concentrated in freshwater systems, where human presence and pollutants are more likely to be found.
Cyanobacteria, the bacteria responsible for producing blue-green algae, can also produce a variety of toxins. These are known as cyanotoxins, which can be dangerous to humans and other organisms. To reduce the presence of blue-green algae blooms, it is necessary to reduce nutrient loading, regulate water levels, and minimise human interaction with the water. However, minimising human interaction with waterbodies is not achievable for water sports locations.
What are the health risks of blue-green algae?
Consuming, breathing in, and touching water contaminated with blue-green algae toxins can cause a range of health problems. Drinking such water may result in gastrointestinal issues such as vomiting, diarrhoea, fever and headaches. Inhaling it can induce respiratory issues. While coming into contact with it may cause irritation, rashes and flu-like symptoms. Eating fish and other food caught in algae-infested water may also be hazardous, with children being more vulnerable. Boiling such water does not make it safe to drink as it does not get rid of the toxins.
Water sports locations should take extra precautions to prevent blue-green algae blooms. It can be dangerous to customers participating in activities such as outdoor swimming, kayaking, and stand up paddle boarding. If algae-tainted water is swallowed, it can cause a number of side effects mentioned above, including headaches, diarrhoea, vomiting, fever and abdominal pain. Children participating in recreational activities can be even more adversely affected by the toxins. These health risks can be damaging to your business, its reputation, and your customer relationships. To ensure customer safety, it is essential to monitor water conditions closely and take any necessary steps to prevent blue green algae growth.
When evaluating the risk that people and animals may face from contact with blue-green algae, it is essential to consider how the water is being used. To reduce the possibility of exposure, it is important to implement preventative measures such as controlling discharges, informing your users of potential hazards, displaying warning signs, and limiting access. Once the risk has been sufficiently reduced, the restrictions can be removed.
How does aeration prevent blue-green algae?
Aeration helps to safeguard against stratification and encourages oxygenation in the water column. The mechanical circulation of the water mixes it with the atmosphere, providing a steady influx of oxygen, while exchange with rising bubbles further oxygenates the water. This increase in oxygen levels makes it less hospitable to cyanobacteria, as they prefer low oxygen environments.
Aeration of a pond or lake can be beneficial by creating surface agitation, which helps to reduce the occurrence of algae blooms. Moving water is less conducive to algae growth than still, stagnant water, so the agitation created by aeration helps to limit the areas in the pond that are suitable for their growth. Additionally, this agitation mimics the effect of natural wind, providing further protection against algae build-up.
Surface agitation is beneficial for keeping current algae populations in check, as it helps to mix up the algae already present in the water column. By disrupting the stratification of the water, the agitation lowers the temperature, creating a less hospitable environment for the algae. Additionally, the mixing of the water helps to ensure that the algae is not able to sit at the surface and soak up all the necessary sunlight for photosynthesis, which is essential for its survival.
How to identify blue-green algae
There are many tools with which to identify blue-green algae in a waterbody. The UK Centre for Ecology and Hydrology have a ‘Bloomin’ Algae‘ app to assist with identification. Alternatively, if you suspect a case of blue-green algae, report incidents on The Environment Agency’s Incident Hotline.
If your pond, lake or reservoir is impacted be blue-green algae, ISS Flowthrough can create an aeration system that is completely customised to your site. Our systems cause no interference with recreational activities and ensure that you maintain a safe, enjoyable environment for your customers. View our report on Basin 2 Water Quality Issues in our Projects section. Or, contact us for additional information or quotes.