Preventing blue-green algae – a revolutionary method from Lake Nhill

Lake Nhill in Australia has been deliberately dyed blue to prevent blooms of dangerous plankton organisms. Will this innovative method really work and will it also be applied to other bodies of water around the world?

Fighting blue-green algae blooms is a global challenge

In the small Australian town of Nhill, in western Victoria, residents and experts have been grappling for years with the problem of blue-green algae blooms, which not only threaten public health but also spoil the aesthetics of local waters. One way to fight back has proven to be innovation, allowing Lake Nhill to become a model for others. In January this year. The waters, which are brown in color on a daily basis, were dyed blue using 20 liters of copper sulfate, which is an effective algicide. The aim of this action is to prevent the growth of poisonous blue-green algae, which in the past has repeatedly led to the closure of the lake to users.

Cyanobacteria, which are among the oldest organisms on Earth, are extremely resistant to environmental extremes such as drought and high temperatures. Their ability to survive makes them an essential part of aquatic ecosystems, but at the same time, their massive blooms are becoming a growing problem around the world. The direct cause of the proliferation of cyanobacteria is human activity, and their excessive numbers result in dead zones where aquatic life is sometimes impossible due to lack of oxygen and excessive fertilization of the waters.

Cyanobacteria prevention – cooling effect of blue

The dye used in tinting Nhill’s water, in addition to giving it an attractive color, serves a key function in protecting the lake’s ecosystem. By brightening the naturally brown water, it reduces the absorption of heat, and therefore the rate at which the tank heats up, and creates less favorable conditions for cyanobacteria growth. Stuart Bone, chairman of the Nhill Lake Committee, stresses that the choice of color was dictated not only by aesthetics, but also by functionality.

Prior to this method, Lake Nhill was prone to cyanobacterial blooms, which can cause gastroenteritis, nausea and vomiting and, by secreting toxins, increase the risk of Alzheimer’s disease. Thanks to the dye, visibility reaches a meter, indicating a significant improvement in water quality and a reduction in the occurrence of cyanobacteria.

An alternative to traditional methods

In the past, the prevention of cyanobacteria involved either completely draining the lake or using intensive chemicals that destroyed not only plankton organisms but also other forms of aquatic life. Blue dye is proving to be a solution that offers effective protection without negative side effects on the ecosystem. As Stuart Bone assures, the dye is safe for fish and humans, and does not leave marks on the skin or cause negative reactions.

The idea for the dye was taken from practices on golf courses, but in the case of Lake Nhill, it has much broader implications, as it allows the protection of aquatic life while maintaining recreational use of the waters.

Is copper sulfate safe?

Copper sulfate, which is a salt of sulfuric acid and copper, comes in the form of a crystalline, odorless powder that easily absorbs water. Its anhydrous form is white in color, but when it comes into contact with water molecules it takes on a characteristic blue hue. The corrosive and highly hygroscopic properties of the substance make it extremely dangerous, toxic and difficult to biodegrade. The use of this substance requires special precautions, as leaking the solution or spilling the powder in an uncontrolled manner can cause environmental contamination.

However, copper sulfate, like many other chemicals, can be used for a variety of purposes, and the safety of its use depends on how and how much it is applied. It is widely used in a variety of fields, including agriculture, the chemical industry and for drug production. Its use to stain the waters of Lake Nhill to prevent blue-green algae blooms may raise some safety concerns. Admittedly, it can be toxic to aquatic organisms and some plants, animals and humans, but only if used in excessive amounts or in the wrong way.

As Stuart Bone pointed out, the addition of dye to the lake was safe and has no negative impact on the aquatic ecosystem. Nevertheless, over time it will be possible to observe whether its use has actually harmed the environment. Monitoring and analysis of the effects of this innovative method will allow us to fully understand its impact on the lake ecosystem and evaluate its effectiveness in the long term.