Solving the problem of algae in a pond. Algae, types of algae, all about algae, about algae, algae description What is seaweed and how are they useful for humans
Everyone knows that the water in natural reservoirs near city limits is not crystal clear. Few people would think to taste it. Even the places for swimming are chosen by the sanitary and epidemiological station with special care. And not just because of pollution wastewater and dangerous bottom topography. Today I will tell you why you shouldn’t swim in unfamiliar bodies of water.
Have you ever seen a picture like this?
From mid-summer to late autumn, many stagnant bodies of water begin to “bloom.”“Blooming” occurs due to mass development microscopic algae. The water becomes cloudy and turns yellowish-brown or blue. green color, acquires an unpleasant smell of mud. At "hyperbloom" The pond is completely covered with a viscous greenish film. On a moderate scale, “blooming” increases the biological productivity of water bodies, and “hyperblooming,” on the contrary, is accompanied by a deterioration in the organoleptic properties of water, causing death of fish and other aquatic life, poses a serious threat to the health and life of people and animals.
Dangerous Blue-Greens.
The fact is that among the algae that cause “blooming” many toxic species. These are mainly representatives of the department Cyanoprokaryota (Cyanophyta, Cyanobacteria) – blue-green algae. Found in fresh water bodies of Bashkiria about 10 species of microalgae, capable of producing hepato- and neurotoxins, dangerous not only for aquatic habitats, wild and domestic animals, but also for humans.Thus, hepatotoxins secreted by some types of algae Microcystis (Microcystis aeruginosa, M. viridis and M. wesenbergii) harmful to fish and livestock. Some strains Anabenes(Anabaena lemmermannii) also release neuro- and hepatotoxins. Individual populations Athanizomenon(Aphanizomenon flos-aquae) synthesize aphantoxins, the toxic effects of which have also been established in animals.
Microcystis colonies.
Filamentous blue-green algae Anabena.
Mass reproduction of Aphanizomenon.
What are the risks of swimming in flowering ponds?
Swimming in “blooming” ponds can cause dermatitis and other skin diseases. Eating fish caught from them leads to poisoning and intestinal disorders. Scientists believe that with constant consumption of water from flowering reservoirs, the development of cancer and gastrointestinal diseases, Haffa disease, congenital malformations, etc. is possible.
Security measures.
Flowering is usually occurs more often in closed bodies of water(still lakes, ponds, oxbow lakes, quarries). The accumulation of algae is especially abundant in the surf strip, where they are carried by the current and wind. Therefore, a blooming pond can be identified immediately. If you have installed pool, then the quality of the water in it also needs to be monitored: use by special means against flowering or change the water more often. The intensity of the bloom also depends on how anthropogenically eutrophicated the water body is: the more polluted it is by household and industrial waste, the more abundant the bloom. Although, moderate blooms are often recorded by scientists in the waters of Specially Protected Natural Areas (reserves, sanctuaries, national parks). That's why, Be careful and do not swim in unfamiliar bodies of water. And even more so, do not drink water from them, even boiled water.
Microalgae bloom.
Blooming duckweed.
NOTE: Do not confuse algae blooms with massive growth of duckweed! A small duckweed plant can be seen with the naked eye. Algae can only be detected with a microscope. Duckweed is safe to bloom; this plant is happily eaten by ducks, chickens, geese and pet turtles.
What is algae?
Algae is a problem for all reservoirs, ponds, lakes, rivers and other water bodies. But the concept of algae is often combined different plants. But not all aquatic plants are algae. And not all aquatic plants are the same: there are desirable and undesirable plants for your pond.
Even experts disagree on what to call or classify algae. It is very difficult to define what algae are, but generally speaking, algae are simple organisms that can even consist of one or several cells, grouped into colonies and living in aquatic environment. There are three main types of algae: blue-green algae, filamentous (mossy) and slimy (attaching).
Blue-green algae– single-celled (planktonic), microscopic plants that take root in any body of water. They can bloom in different colors: bright green, pea soup or even blood red. They are the base of the food chain, and a healthy pond should contain this type of algae as a food source for other living organisms. But their excessive growth can turn your pond into a swamp. Blue-green algae have recently been reclassified from the algae group to the Monera group, which includes bacteria, because blue-green algae are more closely related to bacteria than other types of algae. Blue-green algae come in a variety of colors, such as red, brown, or yellow. Blue-green algae are nitrogen-fixing organisms and require nitrogen to survive, as does carbon dioxide, a substance very common in most ponds. When blooming, blue-green algae form dense masses on the surface of the pond water and can cover the entire surface. It is believed that the Red Sea got its name from the bloom of red-colored blue-green algae.
Filamentous algae called mud or moss-type plants, they usually grow in water or cover the surfaces of objects and stones in the water in the form of greenish “moss” formations. These colonies of united cells have a slimy, mossy texture; the algae attached to the surface do not have roots, but have a dense structure. Filamentous algae grow in water with high levels of calcium and phosphorus. Typically, this type of algae is revitalized after lime is added to ponds to increase fish production. They usually appear in warm places reservoir and can grow so much that they cover the entire surface of the water.
Slimy algae - usually have a slimy, hard or bristly texture, often causing the most damage when they develop into a "mud" problem.
Benefits of algae
Oddly enough, algae to some extent fulfill the task of improving the health of the water in the pond, because... for their life activity they use harmful nitrogen and its compounds. Blue-green algae is the first link in most food chains found in your pond, so your pond ecosystem needs it. Zooplankton feed on blue-green algae, and baby fish (baitfish), in turn, feed on zooplankton. Without a food source, fish will compete rather than thrive in your pond. Often, pond owners who use their ponds to raise bass and koi will fertilize the water to maintain a high population of blue-green algae. This is done to provide more food for zooplankton and baby fish (baitfish), as well as to block sunlight and shade the water in the pond, which in turn leads to a reduction in the growth of filamentous algae and other unwanted aquatic plants. Fry can hide in thickets of aquatic plants, and their absence allows perches to get food much easier.
Problems caused by algae
Typically, the most common complaint about algae is that it harms the aesthetics of the pond. A green pond covered with algae is not pleasing to the eye. When algae covers the surface of a pond, it is not a pleasant sight.
Algae creates a problem for the health of your pond when there is too much of it and when it blooms. During photosynthesis, plants absorb sunlight and carbon dioxide and release oxygen. Photosynthesis is a beneficial process for every pond. Oxygen is necessary for the process of decomposition of organic substances, as well as for fish and other inhabitants of the pond for their vital functions. However, the process of photosynthesis occurs only in sunlight. As soon as the sun sets, plants stop producing oxygen and begin to consume it.
Therefore, the more aquatic plants and algae in your pond, the more oxygen they will produce during the day and the more they will absorb at night. During the night, the oxygen concentration in the water decreases significantly. The lowest concentration of oxygen in water occurs just before sunrise.
Water bloom is a process of very rapid growth and spread of unicellular algae under favorable conditions. Typically, water blooms occur during the hottest, sunniest part of summer. When algae blooms, the water in the pond can become covered with them very quickly. But the main problem When algae bloom, they die during and after the bloom. The death of algae during bloom can be caused by cloudy weather (lack of sunlight), the arrival of a cold air front, strong wind, etc.
When the algae in your pond dies, a large amount of organic matter appears, which settles to the bottom of the pond, where it is decomposed by microorganisms. With increased organic matter loads in your pond, the decomposition process intensifies, increasing oxygen consumption and carbon dioxide production.
This creates two problems. The first is oxygen deficiency. When the oxygen in the pond is consumed by the decomposition of dead algae, there is not enough oxygen for fish and other aquatic life. The algae die-off can be so extensive that most of the dissolved oxygen in the water is used up in the decomposition process, and your fish and other aquatic life may die. Nature is designed in such a way that the larger the organism, the more oxygen it consumes. Therefore, large fish that have been living in your pond for several years may be the first to die if the oxygen concentration in the water decreases significantly.
The second problem associated with large-scale death of algae and increased amounts of organic matter is the emergence of new biogenic (nutrient) substances. When algae die and decompose, carbon dioxide and nutrients are available to the next generation of plants. Carbon dioxide and nutrients trigger the algae growth cycle over and over again.
Interestingly, in salty or hard water, a phenomenon called “Red Tide” can occur - a bloom of water caused by the presence of harmful algae that has this generic name. These algae produce toxins that can be ingested by shellfish that feed on the algae. Shellfish such as mussels and oysters are not safe to eat if they are caught in waters affected by Red Stream. Through the process of bioaccumulation, fish and animal organisms can accumulate toxins, especially in bones and fatty tissues. When an organism containing toxins is consumed by other animals or humans, the bioaccumulated toxins are transferred into their bodies. Crustaceans such as crabs, lobsters, and shrimp, as well as minke whale meat, are safe to eat because they do not accumulate toxins.
Another problem that occurs with excessive algae growth is the problem with the equipment and pumps used to operate the pond and to water it. It's no secret that many pond owners use pond water for irrigation. If algae grows excessively, it can clog the water pump and its filters, which will require many hours of work to clean. The algae that passes through the pump will be scattered throughout the irrigated area and will have an unsightly appearance when it dies.
Ways to combat algae
There are many products available to control and prevent algae growth. These are herbicides, bio-additives based on beneficial bacteria, chemicals, ultraviolet sterilizers, herbal additives, for example, barley straw. Each product affects algae in its own way, and in different conditions with varying effectiveness. Some products only work during one algal bloom cycle; others may work for a longer period of time. Consider these cleaning methods below, all their pros and cons.
Paints
Using the water tint method is an old technology, but it continues to be used and works. Special blue or black powder or liquid paints are used to darken the water and reduce the penetration of sunlight necessary for algae growth. For this purpose, “BioBlack enzymes & Pond colorant” TM Microbe-lift preparations are produced. An additional benefit that coloring water blue or black provides is that it prevents birds of prey catch fish in a pond, because in this case it is more difficult to see them there.
But purchasing special paints is not always easy, in addition, this treatment method does not work well in ponds that are intended for irrigation or connected to other bodies of water, because the paints are removed when the water moves. It is not always acceptable to tint the water in decorative ponds.
Bacteria and enzymes
Barley straw
We often hear about the “miraculous” effect of this remedy on the state of water in a reservoir. Barley straw has been used as a natural algaecide for centuries in England and Scotland. Research has shown that barley straw helps balance quality, lower pH and water hardness, which can affect the growth rate of certain unwanted plants and algae. Straw decomposes under the influence of water and sunlight, and a byproduct of its decomposition - peroxide (peroxide) - prevents the development of both filamentous and blue-green algae. But the rates of straw application and the success of its use are different for different ponds. Typically the recommended dose for private ponds is 25 kg of barley straw per 1000 m2 of water surface in relatively shallow ponds 1.2 - 1.5 m deep.
There are other ways to purify water using natural means - adding spruce needles and birch leaves (brooms) to the reservoir. At the same time, the acidity level of the water changes and algae growth slows down. However, it is better to use herbal remedies to control algae growth than to kill it once algae has become a problem.
Skimmers
Copper-based preparations
Copper is usually the first answer most people get when they bring up algae reduction. The most common copper-based preparation is granulated copper sulfate. Its low cost and effectiveness against blue-green and filamentous algae explain its widespread use. But you need to keep in mind that copper is poisonous to certain types of fish (for example, gudgeons, as well as salmon), snails and other cold-blooded animals. Consistent use of copper-based products can lead to a buildup of copper in pond sediment, which is extremely harmful to both aquatic life and humans. The use of specific biological agents, rather than copper-based drugs, is probably the most reasonable approach.
Fish
Can fish clear algae from water? You can often hear the popular belief that fish clean the water of algae, well... or some of it. Carp and grass carp do indeed feed on aquatic plants, but they do not feed on algae. They are mentioned here only because fish are precisely the reason for changing the balance of aquatic plants and algae in the pond. After all, fish eat plants and produce waste, which, when decomposed, saturates the water with organic matter and promotes the growth of algae. The question is, do you want to grow plants or algae in your pond?
By the way, yes, telapia eats blue-green and filamentous algae in ponds, but this is tropical fish, which becomes stressful when the water temperature drops to 10°C.
Herbicide-based preparations
Herbicide-based preparations are sometimes used in natural ponds on agricultural land.. These preparations must be used strictly in accordance with the manufacturer’s recommendations regarding the elimination of algae, and not all plants in general. Herbicides have significant restrictions on their use in fish farming.
Physical algae removal
This very labor-intensive method is used to remove filamentous and non-motile (attaching) algae. For removal, nets, rakes, and water vacuum cleaners are used; algae can be removed from stones with scrapers and brushes. The method is labor-intensive and ineffective. Once you remove all the algae, new plantations will appear in the organic-rich waters.
The True Cause of Excessive Algae Growth
With all that said, algae or aquatic plants are not a pond water problem, they are just external manifestation Problems. Nutrients (nutrients) are the main problem in most ponds. The main reason for the growth of algae and unwanted aquatic plants is the excess of available nutrients in the water, which allows them to thrive. Grass clippings, leaves, runoff from fertilized meadows and farm fields or pastures, animal waste (geese, ducks, fish, etc.) and organic materials (dead aquatic plants) are some of the most common sources of nutrients in ponds. All of them supply huge amounts of nitrogen and phosphorus to the water, which promotes the growth and prosperity of aquatic plants. The key to controlling the growth of algae and aquatic plants is to limit the amount of nutrients (nutrients) in the pond water.
Limiting nutrients is easier said than done. More detailed information is provided in the article, but first step- physical blocking of nutrients (biogenic) substances entering the water. Second- removal of nutrients (biogenic) substances that are already in the pond. This process may consist of physically removing aquatic plants by trimming and raking them out of the water. All plants and algae in a pond contain nutrients and when they die, the nutrients are released and made available to the next generation of vegetation. The death of plants does not completely solve the problem - dead plants must be removed.
Third step- this is aeration. Additional oxygen, as stated above, speeds up the decomposition process and reduces the amount of nutrients available. In addition, aeration helps remove carbon dioxide and other gases that are released during the decomposition process and which provide food for aquatic plants.
Algae can be used as indicators of the condition of a reservoir. They are bioindicators. They are the initial link in the trophic chain of the reservoir ecosystem.
This is a large and heterogeneous group of primitive, plant-like organisms. With few exceptions, they contain the green pigment chlorophyll, which is necessary for nutrition through photosynthesis, i.e. synthesis of glucose from carbon dioxide and water. Colorless algae are very rare, but in many cases the green chlorophyll is masked by pigments of a different color. In fact, among the thousands of species included in this group, you can find forms colored in any of the tones of the solar spectrum. Although algae are sometimes considered to be among the most primitive organisms, this opinion can only be accepted with significant reservations. Indeed, many of them lack complex tissues and organs comparable to those well known in seed plants, ferns and even mosses and liverworts, but all the processes necessary for the growth, nutrition and reproduction of their cells are very, if not completely, similar to occurring in plants. Thus, physiologically, algae are quite complex.
Algae are the most numerous, most important to the planet, and most widely distributed photosynthetic organisms. There are many of them everywhere - in fresh waters, on land and in the seas, which cannot be said, for example, about liverworts, mosses, ferns or seed plants. To the naked eye, algae can often be observed as small or large patches of green or otherwise colored foam ("mud") on the surface of the water. On soil or tree trunks they usually appear as a green or blue-green slime. In the sea, thalli of large algae (macrophytes) resemble red, brown and yellow shiny leaves of various shapes.
Morphology and anatomy
The sizes of algae vary widely - from microscopic forms with a diameter or length of thousandths of a centimeter to sea giants more than 60 m long. Many algae are unicellular or consist of several cells forming loose aggregates. Some are strictly organized colonies of cells, but there are also true multicellular organisms. Cells can be connected at their ends, forming chains and threads - both branched and unbranched. The whole structure sometimes looks like a small disk, a tube, a club and even a tree, and sometimes it resembles a ribbon, a star, a boat, a ball, a leaf or a tuft of hair. The surface of the cells can be smooth, or covered with a complex pattern of spines, papillae, pits and ridges.
Most algae have cells general structure similar to the green cells of plants such as corn or tomato. A rigid cell wall, consisting mainly of cellulose and pectin substances, surrounds the protoplast, in which a nucleus and cytoplasm are distinguished with special organelles included in it - plastids. The most important of them are chloroplasts, which contain chlorophyll. The cell also contains fluid-filled cavities - vacuoles, which contain dissolved nutrients, mineral salts and gases. However, this cell structure is not characteristic of all algae. In diatoms, one of the most important components of the cell wall is silica, which creates a kind of glass shell. The green color of chloroplasts is often masked by other substances, usually pigments. A small number of algae do not have a rigid cell wall at all.
Locomotion
Many aquatic vegetative cells and algal colonies, as well as some types of their reproductive cells, move quite quickly. They are equipped with one or more whip-like appendages - flagella, the beating of which pushes them through the water column. Some algae lacking a cell wall are able to stretch parts of their body forward, pull the rest towards them, and thereby “crawl” along solid surfaces. This movement is called amoeboid, since well-known amoebas move in approximately the same way. The rectilinear or zigzag locomotion of diatoms - owners of a solid cell wall - is probably due to water currents created by various stream movements of their cytoplasm. Sliding, crawling, and wave-like movement of algae more or less rigidly attached to the substrate is usually accompanied by the formation and liquefaction of mucus.
Reproduction
Almost all unicellular algae are capable of reproducing by simple division. The cell divides in two, and so do both daughter cells, and this process, in principle, can go on ad infinitum. Since the cell dies only as a result of an “accident,” we can talk about a kind of immortality. A special case is cell division in diatoms. Their shell consists of two halves (flaps) that fit into each other, like two parts of a soap dish. Each daughter cell receives one parent valve, and completes the second itself. As a result, in a diatom, one valve may be new, and the second may be inherited from a distant ancestor. The protoplast of some vegetative cells is capable of dividing to form motile or immobile spores. Of these, after a long or short period At rest, a mature algae develops. This is a form of asexual reproduction. During sexual reproduction in algae, male and female reproductive cells (gametes) are formed. The male gamete merges with the female one, i.e. Fertilization occurs and a zygote is formed. The latter, usually after a dormant period lasting, depending on the type of algae, from several weeks to several years, begins to grow and ultimately produces an adult individual. Gametes vary greatly in size, shape and mobility. In some algae, male and female gametes are structurally similar, while in others they are clearly different, i.e. are sperm and eggs. Thus, the sexual reproduction of algae has many forms and levels of complexity.
Distribution and ecology
aquatic algae
It is difficult to find a place on the planet where there are no algae. They are usually considered aquatic organisms, and, indeed, the vast majority of algae live in puddles and ponds, rivers and lakes, seas and oceans, and in certain seasons they can become very abundant there. Algae attach to rocks, stones, pieces of wood, aquatic plants, or float freely, forming part of plankton. At times, this suspension, which includes billions of microscopic forms, reaches the consistency of pea soup, filling vast spaces of lakes and seas. This phenomenon is called “algal bloom” of water. The depth at which algae can be found depends on the transparency of the water, i.e. its ability to transmit the light necessary for photosynthesis. Most algae are concentrated in a surface layer several decimeters thick, but some green and red algae are found at much greater depths. Some species are capable of growing in the ocean at a depth of 60-90 m. Some algae, even frozen into ice, can remain viable in a state of suspended animation for many months.
Soil algae
Despite its name, algae is not only found in water. For example, there are a lot of them in the soil. In 1 g of well-manured soil you can find approx. 1 million of their individual copies. Those concentrated on the soil surface and directly below it feed themselves through photosynthesis. Others live in the dark, are colorless and absorb dissolved food from environment, i.e. are saprophytes. The main group of soil algae are diatoms, although green, yellow-green and golden algae are also abundant in places in this habitat.
Snow algae are often found in large quantities in the ice and snow of the Arctic and Antarctic deserts, as well as alpine highlands. They grow just as well in the cold polar seas as in hot springs. The so-called “red snow” is the result of the presence of microscopic algae in it. Snow algae are colored red, green, yellow and brown.
Other types of algae
Algae live in many other habitats, sometimes quite unusual. They are found, for example, on the surface or inside of aquatic and terrestrial plants. Settling in the tissues of many tropical and subtropical species, they grow here so actively that they can damage their leaves: in the tea bush this disease is called “rust”. IN temperate climate algae often cover the bark of trees with a green coating, usually on the shaded side. Some green algae form symbiotic associations with certain fungi; such associations are special, completely independent organisms called lichens. A number of small forms grow on the surface and inside larger algae, and one genus of green algae grows only on the shell of turtles. Green and red algae are found in hair follicles three-toed sloths, inhabiting rain rainforests Central and South America. Algae also grow on the bodies of fish and crustaceans. It is possible that some flatworms and coelenterates may not swallow food at all, since they get it from green algae that live in their bodies.
Limiting environmental factors
Although algae are found almost everywhere, each species requires a certain combination of light, humidity and temperature, as well as the presence of necessary gases and mineral salts, to live. Photosynthesis requires light, water and carbon dioxide. Some algae tolerate significant periods of almost complete drying out, but they still require water to grow, which serves as the only habitat for the vast majority of forms. The oxygen and CO 2 content in water bodies varies greatly, but algae usually have enough of them. Large amounts of algae in shallow bodies of water sometimes consume so much oxygen overnight that they cause massive fish kills: they can no longer breathe. For algae to grow, nitrogen compounds and many other chemical elements dissolved in water are required. The concentration of these mineral salts in the water column is much lower than in many soils, but for a number of species, as a rule, it is sufficient for mass development. Sometimes algae growth is severely limited due to the lack of a single element: diatoms, for example, are rare in water containing little silicate.
Attempts have been made to divide algae into ecological groups: aquatic, soil, snow or crust forms, epibionts, etc. Some algae grow and reproduce only at certain times of the year, i.e. can be considered annuals; others are perennials, in which only reproduction is confined to a certain time. A number of unicellular and colonial forms complete the vegetative and reproductive phases of their life cycle in just a few days. All these phenomena are, of course, associated not only with the heredity of organisms, but also with various environmental factors, but clarifying the exact relationships within the emerging environmental groups algae is a thing of the future.
Algae in the past
It is likely that some forms of algae existed already in the most ancient geological eras. Many of them, judging by modern species, could not leave fossils due to the peculiarities of their structure (lack of solid parts), so it is impossible to say exactly what they were like. Fossil forms of the main current groups of algae, except for diatoms and several others, have been known since the Paleozoic (570-245 million years ago). The most abundant algae in that era were probably green, brown, red and chara algae that lived in the seas and oceans. Indirect evidence of the early appearance of algae on our planet is the scientifically proven existence in the Paleozoic of many marine animals that were supposed to feed on organic matter. Their primary source was most likely photosynthetic algae, which consume only minerals.
Fossil diatoms
Fossil diatoms (diatoms) in the form of a special rock - the so-called. Diatomite - found in many regions. Diatomite can be of both marine and freshwater origin. In California, for example, there is a deposit with an area of approximately 30 km 2 and a thickness of almost 400 m. It consists almost exclusively of diatom shells. There are up to 650 thousand of them in 1 cm 3 of diatomite.
Evolution of algae
Many groups of algae appear to have changed little since their origins. However, certain species of them, once very abundant, are now extinct. Major fluctuations in species diversity and the total number of algae throughout the history of the Earth, as far as is known, did not exist. Aquatic habitats have changed little over many millions of years, and modern forms of algae have certainly existed for a very long time. It is unlikely that any large group of algae appeared later than the Paleozoic or early Mesozoic (240 million years ago).
Economic aspects
Harm caused
Some algae are economically damaging or at least a major nuisance. They contaminate water sources, often giving it an unpleasant taste and odor. Some massively multiplied species can be identified by their specific “aroma.” Fortunately, there are now so-called algaecides are substances that effectively kill algae without impairing the quality of drinking water. To combat algae in fish ponds, measures such as increasing the “flow” of the system, shading it, and stirring it up are also used. Crayfish, for example, maintain water turbidity sufficient to greatly inhibit algae growth. Some algae, especially during periods of their “blooming”, spoil areas designated for swimming. During storms, many marine macrophytes are torn from the substrate and thrown onto the beach by waves and wind, literally covering it with their rotting mass. In their dense accumulations, fish fry can become entangled. Several types of algae, when ingested by animals, cause poisoning, sometimes fatal. Others turn out to be a disaster in greenhouses or damage plant leaves.
The benefits of algae
Seaweed has many beneficial properties.
Food for aquatic animals. Algae can be considered the primary food source for all aquatic animals. Thanks to the presence of chlorophyll, they synthesize organic substances from inorganic substances. Fish and other aquatic animals consume this organic matter directly (by eating algae) or indirectly (by eating other animals), so algae can be considered the first link in almost all food chains in water bodies.
Food for humans. In many countries, especially in the East, people use several types of large algae for food. Their nutritional value is low, but the content of vitamins and minerals in such “greens” can be quite high.
Agar source. Some seaweed produces agar, a gelatinous substance used to make jelly, ice cream, shaving cream, salads, emulsions, laxatives, and for growing microorganisms in laboratories.
Diatomite Diatomite is used in abrasive powders and filters, and also serves as a thermal insulation material replacing asbestos.
Fertilizer. Algae are a valuable fertilizer, and marine macrophytes have been used to feed plants since ancient times. Soil algae can largely determine the fertility of a site, and the development of lichens on bare stones is considered the first stage of the soil-forming process.
Algal crops. Biologists have been growing algae in laboratories for a long time. At first they were grown in small transparent cups with pond water on sunlight, and in Lately For this purpose, special culture media with a certain amount of mineral salts and special growth substances, as well as controlled sources of artificial light, are used. It has been discovered that some algae require very specific conditions for optimal development. The study of such laboratory cultures has enormously expanded our knowledge of the growth, nutrition and reproduction of these organisms, as well as their chemical composition. Nowadays, pilot installations have already been built in different countries, which are a kind of huge aquariums. Experiments are carried out on them under strictly controlled conditions using sophisticated equipment to determine the prospects for using algal cultures. As a result, it has been proven that the dry matter production of algae per unit area can be much higher than that of current agricultural plants. Some of the species used, such as the single-celled green alga Chlorella, produce a “harvest” containing up to 50% edible protein. It is possible that future generations of people, especially in densely populated countries, will use artificially grown algae.
Classification of algae
In the past, algae were considered primitive plants (without specialized conducting, or vascular, tissues); they were allocated to the subdivision of algae (Algae), which, together with the subdivision of fungi (Fungi), constituted the department of thalli (layers), or lower plants (Thallophyta), - one of the four divisions of the plant kingdom (some authors, instead of the term “division,” use the zoological term “ type"). Next, the algae were divided by color - green, red, brown, etc. Color is a fairly strong, but not the only basis for the general classification of these organisms. More important for identifying different groups of algae are the types of formation of their colonies, methods of reproduction, characteristics of chloroplasts, cell walls, reserve substances, etc. Old systems usually recognized about ten such groups, considered classes. One of modern systems refers to “algae” (this term has lost its classification meaning) eight types (divisions) of the kingdom of protista (Protista); however, this approach is not recognized by all scientists.
Green algae division (phylum) Chlorophyta of the kingdom protists
They are usually the color of grass green (although the color can vary from pale yellow to almost black), and their photosynthetic pigments are the same as those of ordinary plants.
Most are microscopic freshwater forms. Many species grow on the soil, forming felt-like coatings on its damp surface. They can be single- or multicellular, form filaments, spherical colonies, leaf-like structures, etc.
Cells are motile (with two flagella) or immobile. Sexual reproduction - different levels complexity depending on the type. Several thousand species have been described. The cells contain a nucleus and several clearly defined chloroplasts.
One well-known genera is Pleurococcus, a single-celled algae that produces green growths often seen on tree bark.
The genus Spirogyra is widespread - filamentous algae that form long fibers of mud in streams and cold rivers. In the spring they float in sticky yellowish-green clumps on the surface of ponds.
Cladophora grows as soft, highly branched "bushes" attached to rocks near river banks.
Basiocladia forms a green coating on the back of freshwater turtles.
The water mesh (Hydrodictyon), consisting of many cells, living in stagnant waters, really resembles a “string bag” in structure.
Desmidiaceae are single-celled green algae that prefer soft swamp water; their cells are distinguished by their bizarre shape and beautifully ornamented surface.
In some species, cells are connected into filamentous colonies. In the free-swimming colonial alga Scenedesmus, sickle-shaped or oblong cells are combined into short chains. This genus is common in aquariums, where its mass reproduction results in a green "fog" appearing in the water.
The largest green algae is sea lettuce (Ulva), a leaf-shaped macrophyte.
Red algae (purple algae) constitute the department (phylum) Rhodophyta of the kingdom of protists
Most are marine leafy, bushy or encrusting macrophytes that live below the low tide line. Their color is predominantly red due to the presence of the pigment phycoerythrin, but can be purple or bluish. Some scarlet fish are found in fresh water, mainly in streams and clear, fast rivers. Batrachospermum is a gelatinous, highly branched algae consisting of brownish or reddish bead-like cells. Lemanea is a brush-like form that often grows in fast-flowing rivers and waterfalls, where its thalli are attached to rocks. Audouinella is a filamentous algae found in small rivers. Irish moss (Chondrus cripus) is a common marine macrophyte. Purple plants do not form motile cells. Their sexual process is very complex, and one life cycle includes several phases.
Brown algae constitute the division (phylum) Phaeophyta of the kingdom of protists
Almost all of them are inhabitants of the sea. Only a few species are microscopic, and among macrophytes the largest algae in the world are found. The last group includes kelp, macrocystis, fucus, sargassum and lessonia (“sea palms”), which are most abundant along the coasts of cold seas. All brown algae are multicellular. Their color varies from greenish-yellow to dark brown and is caused by the pigment fucoxanthin. Sexual reproduction is associated with the formation of motile gametes with two lateral flagella. The specimens that form gametes are often completely different from organisms of the same species that reproduce only by spores.
Diatoms (diatoms)
They are united in the class Bacillariophyceae, which in the classification used here is included, together with golden and yellow-green algae, in the department (phylum) Chrysophyta of the protist kingdom. Diatoms are a very large group of unicellular marine and freshwater species. Their color ranges from yellow to brown due to the presence of the pigment fucoxanthin. The protoplast of diatoms is protected by a box-shaped silica (glass) shell - a shell consisting of two valves. The hard surface of the valves is often covered with a complex pattern of strokes, tubercles, pits and ridges characteristic of the species. These shells are among the most beautiful microscopic objects, and the clarity of their pattern is sometimes used to test the resolving power of the microscope. Typically, the valves are permeated with pores or have a gap called a suture. The cell contains a nucleus. In addition to cell division in two, sexual reproduction is also known. Many diatoms are free-swimming forms, but some are attached to underwater objects by slimy legs. Sometimes cells are united into threads, chains or colonies. There are two types of diatoms: pinnate with elongated, bilaterally symmetrical cells (they are most abundant in fresh waters) and centric, whose cells, when viewed from the valve, look round or polygonal (they are most abundant in the seas).
As already mentioned, the shells of these algae are preserved after cell death and settle to the bottom of reservoirs. Over time, their powerful accumulations are compacted into a porous rock- diatomite.
Flagellates
These organisms, due to their ability for “animal” nutrition and a number of other important characteristics, are now often classified as the subkingdom of protozoa (Protozoa) of the kingdom of protists, but they can also be considered as a department (type) of Euglenophyta of the same kingdom that is not included in Protozoa. All flagellates are unicellular and motile. Cells are green, red or colorless. Some species are capable of photosynthesis, while others (saprophytes) absorb dissolved organic matter or even ingest solid particles. Sexual reproduction is known only in some species. A common inhabitant of ponds is Euglena, a green algae with a red “eye”. It swims with the help of a single flagellum and is capable of both photosynthesis and feeding on ready-made organic matter. In late summer, Euglena sanguinea can turn pond water red.
Dinoflagellates
These unicellular flagellated organisms are also often classified as protozoa, but they can also be classified as an independent department (phylum) Pyrrophyta of the protist kingdom. They are mostly yellow-brown, but can also be colorless. Their cells are usually motile; The cell wall in some species is absent, and sometimes it has a very bizarre shape. Sexual reproduction is known in only a few species. The marine genus Gonyaulax is one of the causes of “red tides”: near the coasts it can be so abundant that the water takes on an unusual color. This algae produces toxic substances, sometimes leading to the death of fish and shellfish. Some dinoflagellates cause phosphorescence in tropical seas.
golden algae
They are included, along with others, in the department (phylum) Chrysophyta of the kingdom of protists. Their color is yellow-brown, and the cells are motile (flagellate) or immobile. Reproduction is asexual, producing silica-impregnated cysts.
Yellow-green algae
Nowadays it is customary to combine them with goldens into the division (phylum) Chrysophyta, but they can also be considered an independent division (phylum) Xanthophyta of the protist kingdom. They are similar in shape to green algae, but differ in the predominance of specific yellow pigments. Their cell walls sometimes consist of two halves that fit into each other, and in filamentous species these valves are H-shaped in longitudinal section. Sexual reproduction is known only in a few forms.
Charovaya (rays)
These are multicellular algae that make up the division (phylum) Charophyta of the kingdom of protists. Their color varies from grayish-green to gray. Cell walls are often encrusted with calcium carbonate, so dead characeae are involved in the formation of marl deposits. These algae have a cylindrical, stem-like main axis, from which lateral processes, similar to plant leaves, extend in whorls. Characeae grow vertically in shallow water, reaching a height of 2.5-10 cm. Reproduction is sexual. Characeae are unlikely to be closely related to any of the above groups, although some botanists believe that they originated from green algae.
Literature
Encyclopedia "The World Around Us""Encyclopedia for children. Biology." publishing house Avanta+
Gorlenko "Course of lower plants"
Seaweed has been part of the diet of many peoples since prehistoric times. The Japanese are best known for their love of algae, but there is also information about the active use of algae among the Vikings and Celts (red algae is described, among other things, in the Nordic sagas). Polynesians and Hawaiians have long grown kelp on special sea farms. The ancient Greeks also ate algae, which is reflected in one of the famous sayings Plato: “The sea cures all ailments!”
Among the known 10,000 species of algae, 300-400 species are considered edible and suitable for other commercial uses (cosmetics, fertilizers, etc.). The nutritional value and therapeutic properties of algae are explained by the characteristics of the environment in which they grow.
The ocean is a giant mineral bath containing all 56 minerals we need for health in a bioavailable form. Algae absorb these minerals, and that is why they are one of the richest, sometimes unique sources of them, in particular, iodine, magnesium, calcium, iron, potassium, manganese and others.
Nutritional and therapeutic properties of algae
- Algae is the only plant source of Omega-3 fatty acids in the form that humans need to absorb. It is the consumption of algae that explains the high content of Omega-3 in wild fish. It is appropriate to recall here that Omega-3 is a macronutrient necessary for humans for brain health, immunity and regulation of inflammatory processes.
- Algae are practically the only significant source of iodine in places with low levels of this mineral in the soil. Iodine is essential for normal thyroid function, regulating our metabolism. This complex mineral should preferably be consumed exclusively in whole food format, like seaweed, where it is contained along with the antioxidant selenium, without which iodine can further disrupt thyroid function.
- Algae are known for their protective effect against radiation and environmental pollution due to the effect on iodine receptors and preventing radioactive iodine molecules from entering them (receptors).
- Seaweed help strengthen bones due to the calcium they contain in a certain proportion with magnesium and vitamin K, which together are necessary for the proper absorption of calcium.
- Due to the high content of chlorophyll in combination with magnesium, the use of seaweed Supports healthy blood circulation, detoxification function- this is why algae is often recommended to be added to smoothies and used in beauty clinics for body wraps.
Common sea edible algae
Most algae used for food are seaweed. Seaweed is classified into 3 main categories based on color: red, green and brown. True, the color of the algae themselves does not always coincide with their classification. Among the most common types of edible algae are:
Arame
Known locally as seaweed, a type of Japanese kelp (brown seaweed) is usually dried and cut into thin strips, soaked before use and added to soups and salads. Arame is an excellent source of iodine, which can contain 100-500 times more iodine than seafood, vitamin A in the form of beta-carotene and calcium.
Wakame
Another type of brown seaweed, kelp, is used in the very popular chukka salad. It is distinguished by its high content of calcium, iron, vitamins A, E and K. The phytochemical fucoxanthin, which is contained in wakame, helps normalize lipid and carbohydrate metabolism, in other words, it can be effective as part of weight loss therapy for type 2 diabetes.
Nori
A type of red algae (despite its green color), it is especially known as the material in which rolls are wrapped. Recently it has also been popular in the form of snacks - fried pieces of nori with salt and spices. Not a very significant source of iodine. It is better known for its high protein content - 30-50% of dry weight, rich in calcium, iron, potassium, vitamins E and K, beta-carotene. Nori chips are easy to make at home and serve as a nutritious snack!
Kombu
A type of brown algae (dark green in color). It is especially known for its high content of free glutamine, a substance to which we owe our rich protein taste. Kombu contains enzymes that help digest polysaccharides (substances, particularly in legumes, that cause increased gas formation). For these properties, kombu is most often used in the preparation of Japanese rich broth - dashi, and is also added to dishes with legumes and rice for easier digestion. Kombu releases its minerals during cooking and is usually removed from dishes when cooked. Kombu sheets can also be used as a kind of crackers - they are toasted in the oven for about 10 minutes at 180C, broken into small pieces and topped with topping. In Finland, at a biohackers' dinner, pieces of toasted kombu were served with pollock roe and dried black chanterelles and were a big hit.
Dulce
Brown algae, which has a fairly neutral and pleasant mild taste, is often sold in the form of small flakes that can be added to salt in many dishes when cooking. Dulse, according to some studies, is the champion among algae in terms of the content of beneficial phytochemicals, including those that suppress uncontrolled cell growth. These algae are rich in iodine, calcium and iron.
A number of seaweeds are also widely used in cooking for their gelling properties. Among them are agar-agar, carrageenan from Irish moss.
River algae
The most famous river algae are spirulina and chlorella, which are a type of blue river algae.
Blue-green river algae. Due to its high nutritional density, in particular its protein content in the form of bioavailable amino acids, the UN has named spirulina possible solution problems of malnutrition in poor developing countries.
In addition to being high in protein, spirulina is very rich in B vitamins, vitamin K, beta-carotene, iron, manganese, chromium, and antioxidant phytochemicals—all in a bioavailable form, in a whole food context. The fiber and phytochemicals in spirulina help normalize intestinal microflora - the growth and reproduction of friendly bacteria and inhibit the growth of pathogens.
Due to its high nutritional value, spirulina is a phenomenal nutritional supplement that helps produce energy at the cellular level, strengthen the immune system, reduce inflammation, and normalize limit metabolism.
Due to its very specific taste, it is often swallowed in tablet form and also added to smoothies. Dosages may vary as this is a whole product and negative consequences no large-volume consumption was detected.
Single-celled green algae is also highly nutritious, but is especially known for its chelating properties, that is, the ability to bind toxic substances and remove them from the body, including heavy metals.
Due to the high content of antioxidant substances, regular consumption of chlorella helps reduce the level of oxidative stress, which underlies premature aging.
A special substance in chlorella called “chlorella growth factor” is known, part of which are nucleic acids, which are necessary to prevent DNA mutations and regenerate tissues, the volume of which decreases with age. The cell walls of chlorella are very strong, and in order to absorb the nutrients it contains, you need to buy chlorella with broken walls.
It is important to know!
When choosing algae, it is important to know their place of origin. Just as algae absorb minerals from the environment, they absorb toxic substances - in places where the ocean is particularly polluted, in particular radioactive, like off the coast of Japan. That is why in developed countries everyone buys organic algae, whose origin is controlled by a certifying organization.
“Stronger than cobra venom” is what they sometimes say about cyanotoxins released by blue-green algae. But in water this poison is usually in a very dilute state. So only in stagnant bodies of water, densely covered with accumulations of these algae, can swimming for people be truly dangerous. And lead to severe poisoning, gastrointestinal disorders, skin and eye irritations. For fish, since they do not swim in water but live constantly, cyanotoxins pose a much greater threat. The dominance of blue-green algae in the Volgograd and Tsimlyansk reservoirs is already leading to the death of fish and waterfowl. This week, at a meeting of the Basin Council of the Lower Volga Basin District in Volgograd, experts decided what to do with blue-green algae, which became a real problem in this hot summer of 2016.
Why have dangerous algae proliferated so much?
“The Mediterranean Sea is turquoise, and ours, the Volgograd Sea, is malachite!” — a friend from Volgograd posted on social networks a photo of an unusual shade of water in a reservoir, reminiscent in color and stains of the casket of the owner of the Copper Mountain. Little did she know that she had photographed exactly those same dangerous blue-green algae.
Now these algae fill the bays of the Volgograd and Tsimlyansk reservoirs, eriks in the Volga-Akhtuba floodplain, and many small lakes. The rapid proliferation of blue-green algae has led to clogging of water intakes, and it is necessary to invest in their cleaning. On the Volga and the warm Akhtuba River flowing from it, there are also blue-green algae, but not in such quantities. Still running water carries them down to Astrakhan. But near Astrakhan itself, fish are now also dying from them.
“There are two reasons why blue-green algae have proliferated so much this year,” said the chief ichthyologist of the Federal State Budgetary Institution “Nizhnevolzhrybvod” Sergey Yakovlev. — One of the factors is water temperature: in the Volgograd region, in most reservoirs, the water temperature in reservoirs exceeded 25 degrees this summer and even reached 29 degrees Celsius on some days. The second reason: the presence of nutrients - nutrients for algae. Algae especially love nitrogen and phosphorus, which are part of fertilizers for fields. This summer was not only hot, but also rainy. Plus more high level water in the Volga led to erosion of the banks. Thus, rains and the Volga contributed to the penetration of fertilizers and fertile soil into water bodies and the growth of blue-green algae. This can be dangerous not only for fish. Cases have been recorded around the world of pets drinking from water bodies contaminated with blue-green algae and then dying from poisoning. In addition, cyanotoxins can cause mass various diseases from a simple allergic reaction to poisoning and liver disease. Try not to swallow water when swimming in rivers and ponds.
Will chlorella or silver carp help?
This year, according to Yakovlev, it is no longer possible to control blue-green algae. Late. Such a mass of algae cannot be removed by mechanical means. Adding hydrogen peroxide to reservoirs so that blue-green algae settles to the bottom is also unrealistic, given the enormous size of the Volgograd and Tsimlyansk reservoirs. But some preventive measures can be taken to prevent this from happening again next year. So far, at a meeting of the Basin Council of the Lower Volga Basin District in Volgograd, it was decided to go to Moscow and ask for funding to fight this blue-green muck.
“Biological methods are the most effective and cheapest in the fight against blue-green algae,” says Sergei Yakovlev, chief ichthyologist of the Nizhnevolzhrybvod Federal State Budgetary Institution. “For example, you can kill two birds with one stone by populating our reservoirs with such valuable commercial fish like silver carp. He just eats these algae. But, unfortunately, now there are so many blue-green algae that even the annual release of up to 20 million units of juvenile silver carp into the reservoirs of the Volgograd region does not solve the problem. The silver carp can no longer cope. This means you need to add chlorella. These are green algae, a natural competitor of blue-green algae. It can displace blue-greens by simply depriving them of nutrients and territory. Unlike blue-green algae, chlorella is not dangerous and is eaten by many people. river fish, and not just one silver carp. So we are not threatened with the prospect of turning reservoirs into swamps due to chlorella.
Meanwhile, specialists from Togliatti have been proposing to make a profit from blue-green algae for several years. Methods have already been developed for processing blue-green algae into biofuels and fertilizers. So maybe it's time to start? Raw materials in bulk!