Team Updates
Algae Bloom threat and ideas for its resolution ～For the maintenance of the global ecosystem and the health of mankind～
1. What is algal bloom
A phenomenon in which cyanobacteria grow in high density and mass, and the water surface turns green. Exceptional danger is the abnormal growth of cyanobacteria that produce toxic substances. Algae blooms caused by this are called harmful algal blooms (HABs), which cause serious damage to humans and aquatic organisms.
2. About "Harmful Algae Bloom (HABs)"
Cyanobacteria that grow abnormally all over the world have a variety of properties in each water area. Among them, cyanobacteria classified as genus Microcystis are known for producing toxins called microcystin. Algae blooms caused by the abnormal growth of cyanobacteria that produce toxins, such as the genus Microcystis, are called harmful algal blooms (HABs).
In addition to the genus Microcystis, there are cyanobacteria that produce toxins. Genetic analysis should be used to classify individual cyanobacteria.
3. Specific damage caused by algal bloom and its impact on the ecosystem
This summer, harmful algal blooms (HABs) were raging in the United States. In Wilmington, North Carolina, three dogs who died in a lake with an unusual breeding of cyanobacteria died within hours. It has also been reported that when it enters the human body, it causes rashes, stomach cramps, and vomiting under the dysentery. In any case, it is thought that microcystin, a toxin produced by toxic cyanobacteria, is taken into the body.
In addition, cyanobacteria that have abnormally grown regardless of whether they are toxic or non-toxic, do photosynthesis during the daytime and decompose a large amount of carbon dioxide. It has an adverse effect on the ecosystem, such as making it difficult for organisms to survive.
4. Causes of abnormal growth of cyanobacteria
Cyanobacteria spores drift in the air and begin to breed when they spill into a water area that meets growth factors. Factors that may vary depending on the type of cyanobacteria include water, nutrients, temperature, and light. This is the reason why algae grow in the aquarium tank.
And, various factors can be considered for abnormal growth of cyanobacteria, but typical ones are an increase in water temperature and eutrophication of water areas. Basically, cyanobacteria have the property of being activated at higher water temperatures and it likes nutrients such as phosphorus and nitrogen, and it is easy to breed in waters with high concentrations. In addition, it is easy to breed in places where it is exposed to a lot of light or where the flow of water is poor.
5. Water areas where cyanobacteria are prone to overgrowth
The two world maps shown in the presentation data are the chlorophyll concentration in the sea area in September 2019 and the chlorophyll concentration in February 2019, respectively. By looking at the chlorophyll concentration, you can see how much cyanobacteria are present. In these figures, more cyanobacteria are present in the lighter sea areas. Looking at the northern hemisphere, the lighter areas increase in September, when the temperature is high. On the other hand, since the water temperature will be lower in February, there are fewer light-colored waters.
From this perspective, cyanobacteria are more likely to be activated at higher water temperatures.
In addition, the presentation data shows the state of cyanobacteria overgrowth in the Holmes Strait and the state of cyanobacteria overgrowth in some coastal areas. These figures show that cyanobacteria are more bred along the coast. In this figure, cyanobacteria are growing in the green area. This shows that cyanobacteria are more likely to reproduce because the coastal areas have more nutrients flowing from rivers and land.
6. Prediction of abnormal cyanobacterial breeding and ideas of its offering
I understood the mechanism of abnormal growth of cyanobacteria. Cyanobacteria are easy to breed on warm water and nutrient-rich beaches. The water area where cyanobacteria grow abnormally is expected to increase by global warming and sediment disasters. It seems that the water area with high temperature will increase due to the influence of global warming. Deforestation causes nutrients that should have been used to grow trees to accumulate in the soil, which is expected to flow into the waterside due to landslide disasters. Although it is not a landslide disaster, the tsunami of the Great East Japan Earthquake that occurred in Japan in 2011 caused nutrients to flow into the sea, and a large amount of cyanobacteria grew offshore. Therefore, it is necessary to predict the water area where cyanobacteria will grow abnormally in the future using weather data, soil data, water disaster data, etc.
As a future task, first predict the water area where cyanobacteria are expected to grow abnormally in the area around us. The information is then transmitted using websites, SNS, and applications. In doing so, it is also important to convey the dangers of harmful algal blooms at the same time. After that, we predict the abnormal breeding of cyanobacteria in all water areas from weather, soil, and disaster data, and send it to the public. In that case, data such as flood damage is also helpful.
7. Algae bloom countermeasure ideas
Abnormal breeding of cyanobacteria is expected to spread in the future. Although it is possible to suppress damage to living organisms by disclosing data about appealing danger, it is impossible to solve the fundamental problem unless cyanobacteria that continue abnormal breeding are suppressed. If the number of cyanobacteria continues to increase, the ecosystem will be disrupted, and aquatic organisms may disappear, which can be a threat to human health. Therefore, I thought of a way to control the cyanobacteria that would breed in the future, and an idea to remove cyanobacteria that had already propagated on a large scale.
In the future, the following ideas can be considered as ideas for controlling cyanobacteria that continue to breed. For example, spraying chemicals to the specified water area, or introducing aquatic organisms that feed on nutrients that flow into the water area (shellfish, etc.). Drugs are also concerned about the effects on aquatic organisms, so it is necessary to develop ingredients and enzymes that act only on cyanobacteria. And furthermore, it must be low cost and low risk.
As an idea to remove cyanobacteria that have already propagated, we will develop a component that suppresses the activity of cyanobacteria and act on it to prevent further growth. At that time, if it is a large scale, it would be better to use a drone or an agricultural airplane. Another idea is to develop technology that can recover the propagated cyanobacteria. And use the recovered cyanobacteria as a fuel for bioenergy or improve it as a medicine.
I would like to think about various ideas about the effective use of algae and. It is interesting to develop ingredients that reduce the activity of cyanobacteria, but the idea of using already grown cyanobacteria as a resource is more exciting.
It was once said that the algae cyanobacteria produced oxygen for the first time on earth. And it should be called the origin of any plant that performs photosynthesis. Cyanobacteria are now found everywhere on the planet. Taking advantage of its breeding ability and being able to control mankind may bring the atmosphere to the moon, Mars and other planets. From there, new life forms may be born and unique ecosystems may be built.
8. References
•https://neo.sci.gsfc.nasa.gov/view.php?datasetId=M...
•https://earthdata.nasa.gov/eosdis/daacs/obdaac
•https://oceancolor.gsfc.nasa.gov/
•https://www.huffingtonpost.jp/entry/toxic-algae-bl...
•https://www.kahaku.go.jp/research/db/botany/aoko/a...