When we talk about life on Earth, we tend to think of the animals and plants that are visible to the naked eye and that make up the biosphere we are familiar with. In this colorful world of life, there are also some seemingly insignificant little creatures, although they are small in size, they have amazing abilities and important roles, they are diatoms.
Diatoms are single-celled algae with pigments, and their cell walls are composed of siliceous and pectinous shapes and patterns, which are very beautiful under the microscope.
Diatoms are extremely widely distributed and can be found in almost all aquatic environments, and they grow in colonies, making up aquatic grasslands. Diatoms are primary producers of the ocean, providing food for fish and other aquatic animals, as well as being a provider of oxygen, providing nearly 20% of the earth's oxygen, more than tropical rainforests, and absorbing large amounts of carbon dioxide from the environment and storing it in the depths of the ocean. Diatoms also help in the formation of diatomaceous earth, a material with many excellent properties that is widely used in many industries, as well as preserving the remains of plants and animals.
Diatoms are very wonderful creatures that belong neither to the kingdom of animals nor to the kingdom of plants, but to the unequal flagellates of the protists. They have unique physiological characteristics, such as the ability to synthesize organic matter from light energy, the ability to breathe like animals, and the combination of hard cell walls and flexible flagella. The cell wall of a diatom is made up of two petals, the material of which is silicate, the same as that of a gemstone called opal, so the cell wall of the diatom will shine like a jewel. There are also various exquisite patterns and textures on the petal shells, some like snowflakes, some like stars, some like flowers, and some like spirals, and their shapes and structures all show the magic and beauty of nature.
The petal shells of diatoms can be divided into two types according to the characteristics of their morphology and ornamentation, one is centrium, their petal shells are circular or polygonal, the pattern on the shell surface radiates outward from the center, there is no longitudinal groove, this diatom mostly lives in seawater and exists in a planktonic way. The other is pinnachia, their petal shells are elongated or scaphoid, the patterns on the shell surface are symmetrical, there are longitudinal grooves, this diatom mostly lives in freshwater and exists in a benthic way.
Diatoms are an important part of the marine ecosystem, providing food and energy for other organisms in the ocean, while also playing a moderating role in the planet's climate change.
Diatoms convert the sun's light energy into organic matter through photosynthesis, providing nutrients for fish and invertebrates in the ocean, while also releasing a large amount of oxygen into the air, accounting for nearly 20% of the total oxygen on Earth, more than tropical rainforests. In the process of photosynthesis, diatoms also absorb carbon dioxide from the atmosphere and carry it into the depths of the ocean, thereby reducing greenhouse gases in the atmosphere and mitigating the rate of global warming. Diatoms are also capable of forming a substance called diatomaceous earth, which is a material with multiple uses that can be used to make products such as toothpaste, filters, insulation, **, and can also be used to build nanotechnology diatoms.
In addition, diatomaceous earth is able to preserve fossils of plants and animals, providing valuable information for the study of paleontology and paleoclimatology.
The increasing levels of carbon dioxide in the atmosphere due to human activities have led to the acidification of seawater, which is almost catastrophic to marine organisms with carbonate shells, mainly calcium carbonate: in acidified seawater, the process of building calcium carbonate shells consumes more energy; And if the acidification of the sea intensifies and the carbonate concentration drops too low, their carbonate shells may even be dissolved by the seawater. The valve shells of diatoms are formed from silicates, and unlike carbonates, they are more stable in an acidic environment and cannot be dissolved by seawater. This does not mean that diatoms are spared, as acidification can also affect the growth and reproduction of diatoms.
Diatoms need sufficient silicate for survival and reproduction, and the content of silicate is restricted by a variety of marine environmental factors. The two most important factors are sea temperature and acidity, both of which change in response to climate change, adversely affecting diatoms.
On the one hand, rising sea temperatures can lead to increased stratification of seawater, making it difficult for the upper and lower layers to mix, thus reducing the transport of silicates from the deep sea to the surface. As a result, the concentration of silicates on the surface layer is reduced, which is not sufficient to meet the needs of diatoms. At the same time, the increase in the temperature of the sea also promotes the metabolic rate of diatoms, so that they consume silicates at an increased rate. As a result, diatoms suffer from a lack of silicate and are unable to form and maintain valve shells properly, affecting their growth and reproduction.
On the other hand, seawater acidification refers to a decrease in the pH of seawater, mainly due to the absorption of large amounts of anthropogenic carbon dioxide by seawater. Seawater acidification affects the photosynthesis of diatoms because it reduces the activity of an enzyme called carbonic anhydrase. Carbonic anhydrase is an enzyme involved in maintaining the balance of carbonates in seawater, and it is able to convert carbon dioxide into bicarbonate, which provides diatoms with carbon**. If carbonic anhydrase activity decreases, diatoms will have difficulty accessing carbon, affecting their photosynthesis and reducing their productivity and resilience. The decline of diatoms can trigger a major shift in the ocean's food web, and even change the ocean's ability to absorb carbon dioxide, causing ecological imbalances and climate degradation that have a huge impact on humans and other organisms.
Diatoms are the basis of the marine food chain, providing food for fish and other aquatic animals, and if the number of diatoms is drastically reduced, then their predators will also be affected, leading to a decline in marine biodiversity. At the same time, diatoms are also an important part of the ocean's carbon sink, and they are able to absorb large amounts of carbon dioxide and store it in the depths of the ocean, thereby slowing down the trend of global warming.
If the number of diatoms decreases dramatically, the ocean's ability to absorb carbon dioxide will also decrease, accelerating the process of global warming. In addition, diatoms are also able to influence the formation and reflection of clouds, which in turn affects the energy balance of the planet. The valve shells of diatoms act as nuclei of cloud condensation, facilitating the formation of clouds, which reflect sunlight and thus reduce the temperature of the earth's surface. If the number of diatoms decreases drastically, then the formation and reflection of clouds will also be affected, changing the energy balance of the planet.
We should really pay attention to the research of diatoms, take decisive measures to combat climate change, protect these seemingly insignificant elves, and maintain the source of life on the earth. Fortunately, researchers are already exploring the establishment of nanotechnology for diatoms. Diatoms are one of the most beautiful life forms on earth, and they have made a great contribution to our survival and development, which we should cherish and protect.