Algae blooms significantly threaten freshwater bodies, marine animals, and humans. While they initially cannot be visible, where the toxicity of the blooms has already spread throughout the water body, a green-like scrum can be seen atop the surface. This also means not all algae blooms are toxic. When the algae die, however, they are consumed by bacteria which leaves a strong bad odour, generally making it unsuitable for human use as oxygen is reduced.
The cause behind algae blooms is the high rate of nutrients, specifically the high phosphorous levels that algae predominantly feed on. Phosphorous is a nutrient created naturally, and although it is not inherently bad, too much of it could lead to algae blooms. This process of an overabundance of nutrients is known as eutrophication, which results from human pollution in water bodies through waterways. At the same time, however, algae blooms can occur due to increased nutrients naturally formed by accumulating nutrients, sediments, silt and organic matter from the watershed.
Many kinds of algae blooms could infect a freshwater body. The most common type found in Australia is blue-green algae, also known as cyanobacteria. It is generally experienced in warmer seasons, as temperature and light play a central role in the growth of the speed of algae blooms. One of Australia’s most famous cases of algae blooms includes the Murray River infection in 2016. Interestingly, the Australian bushfires that occurred during 2019-2020 have also triggered the growth of microscopic marine algae known as phytoplankton which have caused algae blooms to occur. With the drastic consequences algae blooms pose to the environment, humans and marine animals, there is a heightened need to prevent them from occurring. This article will look into the latest technologies incorporated into the water industry to detect harmful algae.
Innovative Ways Harmful Algae is Detected
The threat of toxic algae blooms is a problem many countries face worldwide. Here are some of the most popular innovative technologies adopted to curtail it.
Ultrasonic Sound Waves
Ultrasound refers to frequencies higher than the upper audible limit of human hearing which is 20 kHz. Companies in Australia that use this method to control algae growth call it ultrasonic sound waves. Through the use of sound waves, a layer is created on the top layer of the water. This affects the buoyancy regulation of the algae, leading it to sink to the bottom. When this happens, the algae receives very little light and cannot photosynthesise, which leads to them dying. Thus, in other words, ultrasonic waves block algae from receiving sunlight and nutrients to grow.
It should be noted that the death of algae does not necessarily mean that the freshwater body is intoxicated. Instead, the algae decompose naturally and do not harm any other animals. This technology can monitor algae growth in real-time and predict their growth.
Modified Local Soil (MLS) Technology
Research indicates that MLS is a cost-effective method of removing harmful algae blooms from the water bodies and putting them into the sediment. Accordingly, scientific evidence suggests that the capping treatment can reduce the algae flocs from being suspended again in the sediment. It can also help algae cells transform into fertilisers to restore submerged macrophytes in shallow water systems. Moreover, pollutants, nutrients and greenhouse gases can be significantly used using oxygen nanobubble-MLS materials. It has been successfully implemented in South and North China, whose results demonstrated that the condition of ponds was improved when this technology was incorporated than it has been for many years.
The United States of America was one of the first countries to adopt satellite technology to control algae blooms. This same technology is currently being used in Australia, noted by the University of Adelaide and the State Herbarium of South Australia in Coorong. As indicated by the term of the technology, high-resolution images are captured from out of space, allowing water managers to gauge whether there are algae in the water. It can pinpoint which area in the freshwater body there are algae and take action. The great thing about this technology is that it allows managers to detect growth from its initial stages rather than wait for it to progress to a certain level. As it also has predictive technology, managers can effectively take steps for prevention instead of focusing effort on simply curing. A famous example of this being implemented was seen in Utah, where in 2017, satellite imaging caught harmful algal bloom in Utah Lake. Having this information helped the government to take steps, thereby supposedly preventing the population from spending “$100,000 and $1 million in hospital fees, lost workdays, and other bills, thus, preventing the most vulnerable populations—pets, small children, and the elderly—from visiting the lake and potentially from getting sick or dying”.
Protect the Limited Fresh Water Bodies from Algae Blooms
Once algae blooms infect a specific water body, it is tough to disinfect it. Since algae generally are micro in nature. Hence, unless you examine it under a microscope or there is a spike in algae blooms, you will not know it has been infected. This is due to the external physical appearance that occurs. Once, however, the harmful cyanobacteria discolour water, release toxins and directly affect the drinking water quality of water bodies, it is too late. The consequence is that livestock will be impacted, and consumers may suffer health problems. Typical examples include eye irritations, rashes, swollen lips, earaches, fever, skin tumours and more. All this heightens the need for water system managers to incorporate intelligent algae detection technology in their water system management.