The oceans are an important component of the biosphere. Among the inhabitants, the opinion was entrenched that the main role in the processes of photosynthesis is played by trees on land. 70% of oxygen is produced by underwater plankton. Therefore, pollution of the world's oceans is detrimental to the planet. There are other reasons why people should take good care of the aquatic ecosystem. About ocean pollution, consequences and prevention measures later in the article.
The largest pollution began after the development of coastal areas. 60% of cities are located near the seas and oceans. As a result, the aquatic environment is polluted with household waste. The "weak zone" of coastal settlements is the ports. Uncontrolled mass fishing destroys ecosystems in the ocean. This leads to the deterioration of the state of the coast. Fishermen, ship captains, workers of other maritime professions contribute to the pollution of the world's oceans.
The main part of oil products is transported by water. Although accidents on cargo ships and devices for pumping black gold are rare, they are massive. One malfunction of an oil rig can result in the spilling of millions of tons of raw materials. As a result, stains form on the surface, which are extremely difficult to remove.
The Atlantic is considered the most polluted ocean, while the Mediterranean Sea suffers the most. This water area is renewed every 70 years. Every year, 400 billion tons of garbage enters the water.
The greatest pollution of the Atlantic Ocean is observed off the coast of Spain, Italy and France.
The vast majority of debris enters directly. People themselves throw packaging, bottles, food into the sea. Part of the waste enters the water area through sewers and rivers. To a greater extent, water pollution is caused by such substances:
The entry of these types of raw materials is most detrimental to water, plants and animals. In the future, people suffer from this.
Pouring black gold into the ocean is a problem of our time. About 16 million tons enter the water area every year. This is a quarter of the amount of raw materials received. Most of it spills out during shipping. There are paths made of oil products along the sea routes. The transport of pollutants with river runoff is another factor in the entry of raw materials into the ocean. 2 million tons of oil per year is poured into the waters in this way. 12% of waste comes from spills. This phenomenon is typical for offshore oil production sites.
In the United States of America, thousands of disasters occur every year, resulting in oil slicks in the ocean. 36% of raw materials come through rivers and wastewater as industrial waste.
There is a major oil pollution of the world's oceans in the Gulf of Mexico. The accident happened on the Deepwater Horizon platform. As a result, millions of barrels of the substance spilled into the ocean. 5% of the surface was covered with oil products. The negative influence of raw materials was eliminated by a chemical dispersant. But this substance in itself is a powerful pollutant.
According to statistics, every year 8 million tons of plastic waste enters the ocean. These wastes are the vast majority of debris in the aquatic environment. Without proper processing and disposal, balloons, plastic containers, packaging, toys cause the gradual destruction of the ocean. The most dangerous products from this raw material for underwater inhabitants.
Animals swallow waste, confusing it with food, plastic gets into their respiratory tract, interferes with normal movement. Plastic pollution is a global environmental problem. This type of garbage practically does not decompose. It lies unchanged for 1 thousand years. Therefore, it is much more dangerous than organic waste. Most raw materials enter the ocean from coastal zones.
In many countries, wastewater is discharged into the ocean without being filtered first. 80% of this type of liquid is drained into the Mediterranean Sea without any treatment. For this reason, entire beaches are closed, as sewage poisons the body.
As a result of agricultural activities, large amounts of pesticides are released into the waters. Beneficial to plants, they are detrimental to the animal world. Fertilizers "feed" the algae, causing them to bloom. They consume more oxygen dissolved in the liquid medium. This disrupts the life of underwater inhabitants. As a result of biological contamination, the overall quality deteriorates.
The growth of algae is called eutrophication. The problem of ocean pollution with fertilizers is acute in the Gulf of Mexico, in the Baltic Sea. Dead zones formed there as a result of eutrophication.
The problem of pollution by pesticides and other chemicals contained in food products is becoming more and more urgent.
There are the following groups of pesticides:
Some of them end up in the ocean on purpose. Throwing any waste into the water, including pesticides, has become a common practice in recent decades. In 1972, a decree was issued prohibiting the dumping of the most poisonous garbage into the ocean. And in 1996, an amendment appeared that further limited the disposal of waste in water. But they still note the problem with pesticides dumped before the decrees were issued.
Pollution of the seas with toxic raw materials occurs at the expense of industry. Toxins enter the water during their production, as a result of leaks, during the combustion of raw materials containing poisons.
The danger of chemicals lies in their small molecular weight, which is why they are carried with water and air over great distances.
The whole world around us suffers from burning fuel. The atmosphere and the ocean are the most affected. 25% of combustion products end up in the seas. As a result, the concentration of hydrogen ions in surface waters changes.
The acid-base balance is disturbed, which is also called oxidation. The problem is getting worse every year. Scientists have determined that in the ocean, if we continue at this rate, pH will drop by 150% by the end of the century. Changes are detrimental to mollusks. They need calcium carbonate to build their skeleton. Salt is also found in limestone, chalk. Due to acidification, the amount of the mineral in the ocean is reduced, as a result of which the life of animals is threatened.
It may seem that the death of molluscs is an insignificant loss for ocean fauna. But these animals are the beginning of the food chain. Their death leads to a sharp decrease in the number of fish and birds. As a result, mammals also suffer. Oxidized water bleaches coral reefs. As a result, it is harder for larger fish to hunt prey, and smaller ones cannot recognize a predator.
The negative effect of water oxidation on mollusks has already been discussed above. But not only changes in pH negatively affect mammals. They actively accumulate toxins in the body, since they are not destroyed immediately. During the food chain, larger fish absorb harmful impurities. The concentration of toxic substances is constantly increasing. Large marine animals, like seals, can have much more toxins in the body than in the environment due to accumulation. And polar bears that feed on seals are 3 billion times more polluted.
Everyone is concerned about the pollution of the seas. Developed countries are actively developing ocean protection measures. In some states, the water quality standard is enshrined at the legislative level. The company is forced to pay a fine if the discharges do not meet the norm. Other countries have a pollution tax. Enterprises must pay interest on profits in proportion to their contribution to water damage. This works in theory, but in practice the laws do not justify themselves. People refuse to obey, there is no necessary tool to determine the quality of water - all these factors prevent the introduction of fines.
Oil products and plastic waste are considered the most serious pollutants of the world's oceans. The main resources are directed to combat them.
The whole world is actively looking for ways to purify water from garbage. Since plastic is the biggest pollutant in the world's oceans, a lot of efforts and resources are aimed at combating this substance. The organization "The Ocean Clenup" was created in the Netherlands. It is developing technologies to remove plastic waste from ocean waters.
The organization was founded in 2012. During this time, many developments and discoveries have been made. To combat pollution, the company has created a special U-shaped trap. The Ocean Clenup estimates that the device is capable of removing more than 50 million tons of waste per year. The founder of the organization noted that in tests, the speed of the trap is sufficient to overtake plastic. The machine is able to independently change direction and pace depending on the wind and current. But it is impossible to talk about the effectiveness of the device with full confidence until it is placed in a garbage patch.
During the last test, the machine lost the entire two-week “catch”. The testers decided not to return it for emergency repairs and are now investigating why the breakdown occurred. Although the problem of plastic pollution in the ocean is still not solved, the Dutch are also moving in this direction.
Another way to deal with the global problem of mankind is the accumulation of plastic waste. It consists in minimizing the consumption of this raw material. In the European Union, a decision has been made to ban the use of plastic products by 2021. Such radical change in the West is the right direction for what the rest of us should strive for.
But fundamentally, this will not improve the state of the aquatic environment, since almost all plastic enters the ocean from reservoirs, rivers and lakes in Asian countries.
In the 1950s, a conference was held in Great Britain, at which the goal was to develop methods for protecting the seas from oil products. Later, a convention was adopted in Geneva, expanding the rules established earlier in London. They forced every country in the world to legalize a number of regulations, according to which it is forbidden to pollute the water environment with oil. In the 1970s, shipping came under the watchful eye of the London Conference. It was decided that all ships entering the port should be checked for a certificate. It indicates that the body and all mechanisms are fully functional, there are no damages. A separate inspectorate was created to check.
The role of Russia in the pollution of the world's oceans is determined by active oil refining on its territory. Therefore, the country is looking for ways to improve the condition of the water system. The Russian Academy of Sciences has developed a method for cleaning tankers. The bottom line is that a special substance is added to the water. It adsorbs liquid directly on the vessel.
And the remaining oil is available for further use. To prevent leakage of black gold from tankers, their hull is being improved. Due to the double bottom, if it is damaged, the raw material will not leak out, as it will be contained by the second shell. If an accidental discharge does occur, floating mechanisms exist to collect the oil.
Japan has developed a unique device for collecting raw materials spilled into the ocean. The essence of pollution of the water area with oil products is the formation of a dense film on the water. The invention of the Japanese was created in order to adsorb it and turn it into a thick mixture that is easy to remove. An interesting fact: the main component of the reagent is ordinary rice husk. A new method for eliminating oil products was demonstrated using the example of the Atlantic Ocean. The researchers lowered the ceramic plate to a depth and attached an acoustic one to it.
Vibration is turned on, which causes the oil to collect in a thick layer above the plate. The device is energized. After it is turned on, the oil fountain is set on fire and the harmful raw materials burn out.
Water pollution is a serious problem of mankind. Scientists around the globe have been tormenting themselves for years with the question of how to save the world's oceans. Science does not stand still.
Invent new ways to reduce the ingress of waste into the water and their catch. In the disposal of the most harmful pollutants - oil and plastic - have made significant strides. But the problem still exists. It is in our power to reduce the consumption of goods. This will result in reduced waste generation. Only as a result of the complex work of the government, scientists and ordinary people can the ocean be protected.
If you look at a photograph of our planet taken from space, it becomes incomprehensible why it was called "Earth". More than 70% of its entire surface is covered with water, which is 2.5 times the total land area. At first glance, it seems incredible that the pollution of the world's oceans could be so significant that this problem would require the attention of all mankind. However, the figures and facts make us think seriously and start taking measures not only to save and support the Earth's ecology, but also to ensure the survival of mankind.
The problem of pollution of the world's oceans is becoming more and more alarming every year. Harmful substances enter it mainly from rivers, the waters of which each year bring to the cradle of mankind more than 320 million tons of various iron salts, more than 6 million tons of phosphorus, not to mention thousands of other chemical compounds. In addition, it also comes from the atmosphere: 5 thousand tons of mercury, 1 million tons of hydrocarbons, 200 thousand tons of lead. About a third of all mineral fertilizers used in agriculture fall into their waters, about 62 million tons of phosphorus and nitrogen alone enter annually. As a result, some huge "blankets" forming places on the surface of the ocean, with an area of whole square kilometers and a thickness of more than 1.5 meters, are rapidly developing.
Acting like a press, they slowly stifle all living things in the seas. Their decay absorbs oxygen from the water, which contributes to the death of bottom organisms. And of course, the oceans are directly related to the use of oil and petroleum products by mankind. When they are extracted from offshore fields, as well as as a result of coastal runoff and tanker accidents, from 5 to 10 million tons are poured annually. The oil film that forms on the surface of the water blocks the vital activity of phytoplankton, which is one of the main producers of atmospheric oxygen, disrupts moisture and heat exchange between the atmosphere and the ocean, and kills fish fry and other marine organisms. More than 20 million tons of solid domestic and industrial waste and a huge amount of radioactive substances (1.5-109 Ci) fell into the bottomless depths of the cradle of mankind. The greatest pollution of the world's oceans occurs in the coastal shallow zone, i.e. in the shelf. It is here that the vital activity of most marine organisms takes place.
At present, the problem of protecting the world's oceans has become so urgent that it concerns even those states that do not have direct access to its border. Thanks to the UN, a number of important agreements are now in force related to the regulation of fishing, shipping, from the depths of the sea, etc. The most famous among them is the "Charter of the Seas", signed in 1982 by most countries around the world. In developed countries, a system of prohibitive and permissive economic measures is in place to help prevent pollution. Numerous "green" societies monitor the state of the earth's atmosphere. Enlightenment is of great importance and the result of which is perfectly visible on the example of Switzerland, where children perceive their country with mother's milk! It is not surprising that after they grow up, the very idea of encroaching on the purity and beauty of this beautiful country looks like blasphemy. There are other technological and organizational means of control aimed at preventing further pollution of the world's oceans. The main task for each of us is not to be indifferent and to strive in every possible way to make our planet look like a real paradise, which it originally was.
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Experts say that the environmental problems of the world's oceans must be addressed in the 21st century, otherwise serious consequences can be expected. What threatens the oceans? What is the reason for the increased concern of environmentalists? What resources does the planet lose due to water pollution?
The pollution of world waters has been talked about for a long time. And not only talk - just look at the number of major environmental studies - since the beginning of the 21st century alone, more than a thousand of them have been carried out. By pollution, environmentalists mean the entry into the waters of the World Ocean of such substances that can disrupt the natural biological and inorganic balance of matter and lead to serious changes in the composition or dynamics of the ocean waters.
At the moment, pollution of the oceans has already led to the following consequences:
All of these consequences of pollution of the World Ocean are detrimental not only for the inhabitants of the sea, but also for civilization. The seas are a serious source of resources, ranging from oil to fresh water reserves. Therefore, the rational use of water resources is a priority environmental task.
Despite the ability of the world's waters to self-purify, it is not able to cope with the current levels of pollution.
The most dangerous and significant pollution factors:
The last two points are external sources of pollution, which, although dependent on natural factors, are also associated with human activities.
In the last century, pollution was localized. Most of the pollutants were observed in coastal zones, on the coasts of the continents, near industrial centers, and also near the largest shipping routes. In the last 20 years, the situation has changed - now pollutants are found even in the waters of high latitudes - near the poles. Thus, pollution is widespread and affects all the waters of the oceans.
The main causes of pollution:
At the moment, the most polluted oceans are considered to be the Pacific and Atlantic, and the most polluted seas are the North, Mediterranean, Baltic, as well as the internal waters of the Persian Gulf.
It is one of the main contributors to the pollution of the oceans. There are calculations that show that the average annual discharge of oil into the ocean is about 15 million tons. This number includes both unintentional leaks and tanker accidents, as well as deliberate runoff from refineries. The measures are now being tightened, but the impact of the time when there were no laws to protect the ocean from tanker washing and runoff from factories is still being felt.
The largest zones of oil pollution are located in coastal waters, as well as along the route of oil tankers. Ecologists note a sharp reduction in the species diversity of flora and fauna in these zones.
The environmental problems of the Pacific Ocean and the Atlantic are, first of all, an oil film, which, according to various sources, covers from 2 to 4% of the water surface. The waters of these two oceans annually receive 6 million tons of oil and waste from the oil industry - and this is only the waste that has been calculated. Half of the waste comes from the development of offshore fields. Pollution from continental mining enters the water through river runoff.
After oil enters the ocean, the following happens:
The result is a drop in biological productivity. This is especially important for areas whose economy is based on fishing and seafood. The long-term result is an unpredictable change in the biological content of the ocean.
The dumping or burial of toxic waste in the odes of the oceans is called dumping. This is a common practice in all industrial centers of the planet. Despite the current bans, the runoff from industrial enterprises is growing every year.
On average, dumping accounts for up to 10% of all pollutants entering the ocean.
Basically, pollution occurs in such situations:
Waste dissolves in water and accumulates in bottom sediments. After a reset, it is impossible to purify the waters and return them to their original state. Initially, dumping had an ecological justification - the possibility of the World Ocean, which is able to process a certain amount of toxic substances without damage.
Dumping has long been considered a temporary measure. Now it is clear - as long as there is industry, the same amount of waste is being buried in sea waters. The oceans cannot cope with the processing of such an amount of waste, the ecology of sea waters is under threat. At the moment, global waste disposal is one of the most important problems for the world community.
Consequences of irregular waste disposal:
As a result, the base for the extraction of food resources is shrinking.
Pollution can also be indirect. Thus, chemical industry enterprises located far from coastal areas also affect the state of waters. Pollutants are released into the atmosphere, from where harmful substances, together with precipitation, enter the sea water.
Radioactive contamination is a small fraction of the total contamination, but can be more dangerous than oil spills. The reason is the ability of radioactive compounds to retain destructive properties for a long time.
Radiation has a detrimental effect on both plants and animals. Radiation exposure is summed up over time, radiation exposure does not pass without a trace. Infection is transmitted through food chains - from one animal to another. As a result, harmful doses of radiation are concentrated in living organisms. So, there are areas where plankton is 1000 times more radioactive than water.
International treaties banning nuclear testing have stopped the massive contamination of the ocean with radioactive waste. But the former burials remained and still affect the life of marine life.
The main ways of accumulation of nuclear waste in the waters of the World Ocean:
Nuclear waste causes a whole range of problems - not only the ecology of the living suffers, the natural balance of inorganic substances is disturbed.
Pollution of the world's waters is one of the biggest environmental problems of our time. Despite all the measures taken to protect waters from the harmful effects of industry, no serious results have been achieved so far.
The rate at which pollutants enter the oceans has increased dramatically in recent years. Every year, up to 300 billion m 3 of wastewater is discharged into the ocean, 90% of which is not previously treated. Marine ecosystems are exposed to increasing anthropogenic impact through chemical toxicants, which, accumulating by hydrobionts along the trophic chain, lead to the death of consumers of even high orders, including terrestrial animals - seabirds, for example. Among chemical toxicants, petroleum hydrocarbons (especially benzo(a)pyrene), pesticides, and heavy metals (mercury, lead, cadmium, etc.) pose the greatest danger to marine biota and humans. In the Sea of Japan, “red tides” became a real disaster, a consequence of eutrophication, in which microscopic algae flourish, and then oxygen in the water disappears, aquatic animals die and a huge mass of rotting residues is formed that poisons not only the sea, but also the atmosphere.
According to Yu.A. Israel (1985), the environmental consequences of pollution of marine ecosystems are expressed in the following processes and phenomena (Fig. 7.3):
Rice. 7.3.
To a certain extent, marine ecosystems can withstand the harmful effects of chemical toxicants using the accumulative, oxidizing and mineralizing functions of aquatic organisms. For example, bivalve mollusks are able to accumulate one of the most toxic pesticides - DDT and, under favorable conditions, remove it from the body. (DDT is known to be banned in Russia, the United States and some other countries, however, it enters the World Ocean in significant quantities.) Scientists have also proved the existence in the waters of the World Ocean of intensive processes of biotransformation of a dangerous pollutant - benzo (a) pyrene, thanks to the presence of heterotrophic microflora in open and semi-enclosed water areas. It has also been established that the microorganisms of reservoirs and bottom sediments have a sufficiently developed mechanism of resistance to heavy metals, in particular, they are able to produce hydrogen sulfide, extracellular exopolymers and other substances that, interacting with heavy metals, convert them into less toxic forms.
At the same time, more and more toxic pollutants continue to enter the ocean. The problems of eutrophication and microbiological pollution of coastal zones of the ocean are becoming more and more acute. In this regard, it is important to determine the allowable anthropogenic pressure on marine ecosystems, to study their assimilation capacity as an integral characteristic of the ability of biogeocenosis to dynamically accumulate and remove pollutants.
Oil pollution of the oceans is undoubtedly the most widespread phenomenon. From 2 to 4% of the water surface of the Pacific and Atlantic oceans is constantly covered with an oil slick. Up to 6 million tons of oil hydrocarbons enter sea waters annually. Almost half of this amount is associated with the transportation and development of deposits on the shelf. Continental oil pollution enters the ocean through river runoff. The rivers of the world annually carry out into the sea and ocean waters more than 1.8 million tons of oil products.
At sea, oil pollution takes many forms. It can cover the surface of the water with a thin film, and in case of spills, the thickness of the oil coating can initially be several centimeters. Over time, an oil-in-water or water-in-oil emulsion is formed. Later, there are lumps of heavy fraction of oil, oil aggregates that are able to float on the surface of the sea for a long time. Various small animals are attached to floating lumps of fuel oil, which fish and baleen whales willingly feed on. Together with them, they swallow oil. Some fish die from this, others are soaked through with oil and become unsuitable for eating due to an unpleasant smell and taste.
All components are non-toxic to marine organisms. Oil affects the structure of the marine animal community. With oil pollution, the ratio of species changes and their diversity decreases. So, microorganisms that feed on petroleum hydrocarbons develop abundantly, and the biomass of these microorganisms is poisonous to many marine life. It has been proven that long-term chronic exposure to even small concentrations of oil is very dangerous. At the same time, the primary biological productivity of the sea is gradually decreasing. Oil has another unpleasant side property. Its hydrocarbons are capable of dissolving a number of other pollutants, such as pesticides, heavy metals, which, together with oil, are concentrated in the surface layer and poison it even more. The aromatic fraction of oil contains substances of a mutagenic and carcinogenic nature, such as benzo(a)pyrene. Much evidence has now been obtained for the mutagenic effects of polluted marine environments. Benz(a)pyrene circulates extensively in marine food chains and ends up in human food.
The largest amounts of oil are concentrated in a thin surface layer of sea water, which is of particular importance for various aspects of ocean life. Many organisms are concentrated in it, this layer plays the role of a "kindergarten" for many populations. Surface oil films disrupt gas exchange between the atmosphere and the ocean. The processes of dissolution and release of oxygen, carbon dioxide, heat transfer undergo changes, the reflectivity (albedo) of sea water changes.
Chlorinated hydrocarbons, which are widely used as a means of combating pests in agriculture and forestry, with carriers of infectious diseases, have been entering the World Ocean along with river runoff and through the atmosphere for many decades. DDT and its derivatives, polychlorinated biphenyls and other stable compounds of this class are now found throughout the world's oceans, including the Arctic and Antarctic.
They are easily soluble in fats and therefore accumulate in the organs of fish, mammals, seabirds. Being xenobiotics, i.e. substances of completely artificial origin, they do not have their “consumers” among microorganisms and therefore almost do not decompose under natural conditions, but only accumulate in the oceans. At the same time, they are acutely toxic, affect the hematopoietic system, inhibit enzymatic activity, and strongly affect heredity.
Along with river runoff, heavy metals also enter the ocean, many of which have toxic properties. The total value of the river runoff is 46 thousand km 3 of water per year. Together with it, up to 2 million tons of lead, up to 20 thousand tons of cadmium and up to 10 thousand tons of mercury enter the World Ocean. Coastal waters and inland seas have the highest pollution levels. significant role in pollution
The ocean plays and the atmosphere. For example, up to 30% of all mercury and 50% of lead entering the ocean annually is transported through the atmosphere.
Due to its toxic effect in the marine environment, mercury is of particular danger. Under the influence of microbiological processes, toxic inorganic mercury is converted into much more toxic organic forms. Methylmercury compounds accumulated through bioaccumulation in fish or shellfish pose a direct threat to human life and health. Let us recall at least the infamous Minamata disease, which got its name from the Gulf of Japan, where the poisoning of local residents with mercury was so sharply manifested. It claimed many lives and undermined the health of many people who ate seafood from this bay, at the bottom of which a lot of mercury accumulated from waste from a nearby plant.
Mercury, cadmium, lead, copper, zinc, chromium, arsenic and other heavy metals not only accumulate in marine organisms, thereby poisoning marine food, but also adversely affect marine life. Accumulation coefficients of toxic metals, i.e. their concentration per unit weight in marine organisms in relation to sea water varies widely - from hundreds to hundreds of thousands, depending on the nature of the metals and types of organisms. These coefficients show how harmful substances accumulate in fish, molluscs, crustaceans, plankton and other organisms.
The scale of pollution of products of the seas and oceans is so great that in many countries sanitary standards have been established for the content of certain harmful substances in them. It is interesting to note that at only 10 times the natural mercury concentration in the water, oyster contamination already exceeds the limits set in some countries. This shows how close the limit of sea pollution is, which cannot be crossed without harmful consequences for human life and health.
However, the consequences of pollution are dangerous, first of all, for all living inhabitants of the seas and oceans. These consequences are varied. Primary critical disturbances in the functioning of living organisms under the influence of pollutants occur at the level of biological effects: after a change in the chemical composition of cells, the processes of respiration, growth and reproduction of organisms are disturbed, mutations and carcinogenesis are possible; movement and orientation in the marine environment are disturbed. Morphological changes often manifest themselves in the form of various pathologies of internal organs: changes in size, development of ugly forms. Especially often these phenomena are recorded in chronic pollution.
All this is reflected in the state of individual populations, in their relationships. Thus, there are environmental consequences of pollution. An important indicator of the violation of the state of ecosystems is a change in the number of higher taxa - fish. The photosynthetic action as a whole changes significantly. The biomass of microorganisms, phytoplankton, zooplankton is growing. These are characteristic signs of eutrophication of marine water bodies, they are especially significant in inland seas, seas of a closed type. In the Caspian, Black, Baltic Seas over the past 10-20 years, the biomass of microorganisms has grown almost 10 times.
Pollution of the World Ocean leads to a gradual decrease in primary biological production. According to scientists, it has decreased by 10% by now. Accordingly, the annual growth of other inhabitants of the sea also decreases.
What will be the near future for the World Ocean, for the most important seas? In general, for the World Ocean, it is expected to increase its pollution by 1.5-3 times over the next 20-25 years. Accordingly, the environmental situation will also worsen. The concentrations of many toxic substances can reach a threshold level, and then the natural ecosystem will be degraded. It is expected that the primary biological production of the ocean may decrease in a number of large areas by 20-30% compared to the current one.
The path that will allow people to avoid the ecological impasse is now clear. These are non-waste and low-waste technologies, the transformation of waste into useful resources. But it will take decades to bring the idea to life.
Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.
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Introduction
1. Common pollutants of the oceans
2. Pesticides
3. Heavy metals
4. Synthetic surfactants
5. Oil and oil products
6. Water bloom
7. Waste water
8. Discharge of waste into the sea for the purpose of disposal (dumping)
9. Thermal pollution
10. Compounds with carcinogenic properties
11. Causes of ocean pollution
12. Consequences of pollution of the oceans
Conclusion
List of used resources
Introduction
Our planet could well be called Oceania, since the area occupied by water is 2.5 times the land area. Oceanic waters cover almost 3/4 of the surface of the globe with a layer about 4000 m thick, making up 97% of the hydrosphere, while land waters contain only 1%, and only 2% are bound in glaciers. The oceans, being the totality of all the seas and oceans of the Earth, have a huge impact on the life of the planet. A huge mass of ocean water forms the climate of the planet, serves as a source of precipitation. More than half of the oxygen comes from it, and it also regulates the content of carbon dioxide in the atmosphere, as it is able to absorb its excess. At the bottom of the World Ocean there is an accumulation and transformation of a huge mass of mineral and organic substances, therefore the geological and geochemical processes occurring in the oceans and seas have a very strong influence on the entire earth's crust. It was the Ocean that became the cradle of life on Earth; now it is home to about four-fifths of all living beings on the planet.
The role of the World Ocean in the functioning of the biosphere as a single system cannot be overestimated. The water surface of the oceans and seas covers most of the planet. When interacting with the atmosphere, ocean currents largely determine the formation of climate and weather on Earth. All oceans, including enclosed and semi-enclosed seas, are of permanent importance in the global life support of the world's population with food.
The ocean, especially its coastal zone, plays a leading role in maintaining life on Earth, since about 70% of the oxygen entering the planet's atmosphere is produced in the process of plankton photosynthesis.
The oceans cover 2/3 of the earth's surface and provide 1/6 of all animal proteins consumed by the population for food.
The oceans and seas are under increasing environmental stress due to pollution, predation on fish and shellfish, the destruction of historical fish spawning grounds, and the deterioration of coasts and coral reefs.
Of particular concern is the pollution of the oceans with harmful and toxic substances, including oil and oil products, and radioactive substances.
1. CommonpollutantsWorldoceanon the
Ecologists identify several types of ocean pollution. These are: physical; biological (contamination by bacteria and various microorganisms); chemical (pollution by chemicals and heavy metals); oil; thermal (pollution by heated waters discharged from thermal power plants and nuclear power plants); radioactive; transport (pollution by maritime modes of transport - tankers and ships, as well as submarines); household. There are also various sources of pollution of the World Ocean, which can be both natural (for example, sand, clay or mineral salts) and anthropogenic origin. Among the latter, the most dangerous are the following: oil and oil products; wastewater; chemicals; heavy metals; radioactive waste; plastic waste; Mercury. Let's take a closer look at these contaminants.
The following facts speak of the scale of pollution: 320 million tons of iron, 6.5 million tons of phosphorus, and 2.3 million tons of lead are annually replenished with coastal waters.
For example, in 1995 alone, 7.7 billion m 3 of polluted industrial and municipal wastewater was discharged into the waters of the Black and Azov Seas. The waters of the Persian and Aden Gulfs are the most polluted. The waters of the Baltic and North Seas are also fraught with danger. So, in 1945-1947. about 300,000 tons of captured and own ammunition with toxic substances (mustard gas, phosgene) were flooded in them by the British, American and Soviet commands. The flooding operations were carried out in great haste and with violations of environmental safety standards. Cases of chemical munitions by 2009 were badly destroyed, which is fraught with serious consequences.
The most common ocean pollutants are oil and petroleum products. An average of 13-14 million tons of oil products enter the World Ocean annually. Oil pollution is dangerous for two reasons: firstly, a film forms on the surface of the water, depriving the access of oxygen to marine flora and fauna; secondly, oil itself is a toxic compound. When the oil content in water is 10-15 mg/kg, plankton and fish fry die.
Real environmental disasters are large oil spills when pipelines break and supertankers crash. Only one ton of oil can cover 12 km 2 of the sea surface with a film.
Especially dangerous is radioactive contamination during the disposal of radioactive waste. Initially, the main way to dispose of radioactive waste was to bury it in the seas and oceans. These were, as a rule, low-level radioactive waste, which was packed in 200-liter metal containers, filled with concrete and dumped into the sea. The first such burial was made in the USA, 80 km from the coast of California.
Leaks from nuclear reactors and nuclear warheads that sank together with nuclear submarines pose a great threat to the penetration of radioactivity into the waters of the oceans. Thus, as a result of such accidents, by 2009, six nuclear power plants and several dozen nuclear warheads were in the ocean, rapidly corroded by sea water.
At some bases of the Russian Navy, radioactive materials are still often stored directly on open areas. And due to the lack of funds for disposal, in some cases, radioactive waste could fall directly into sea waters.
Consequently, despite the measures taken, the radioactive contamination of the oceans is of great concern.
2. Pesticides
Continuing to talk about pollutants, it is impossible not to mention pesticides. Because they, in turn, are one of the important pollutants. Pesticides are a group of man-made substances used to control pests and plant diseases. Pesticides are divided into the following groups:
- insecticidesforfightfromharmfulinsects
- fungicidesAndbactericides- forfightfrombacterialdiseasesplants,
- herbicidesagainstweedyplants.
It has been established that pesticides, destroying pests, harm many beneficial organisms and undermine the health of biocenoses. In agriculture, there has long been a problem of transition from chemical (polluting) to biological (environmentally friendly) methods of pest control. Currently, more than 5 million tons of pesticides enter the world market. About 1.5 million tons of these substances have already entered the terrestrial and marine ecosystems by ash and water. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater. In the aquatic environment, representatives of insecticides, fungicides and herbicides are more common than others. synthesizedinsecticides are divided into three main groups: organochlorine, organophosphorus and carbonates.
Organochlorine insecticides are obtained by chlorination of aromatic and heterocyclic liquid hydrocarbons. These include DDT and its derivatives, in the molecules of which the stability of aliphatic and aromatic groups increases in the joint presence, various chlorinated derivatives of chlorodiene (eldrin). These substances have a half-life of up to several tens of years and are very resistant to biodegradation. Common in the aquatic environment polychlorinated biphenyls- derivatives of DDT without an aliphatic part, numbering 210 homologues and isomers. Over the past 40 years, more than 1.2 million tons of polychlorinated biphenyls have been used in the production of plastics, dyes, transformers, capacitors. Polychlorinated biphenyls (PCBs) enter the environment as a result of industrial wastewater discharges and the incineration of solid waste in landfills. The latter source delivers PBCs to the atmosphere, from where they fall out with atmospheric precipitation in all regions of the globe. Thus, in snow samples taken in Antarctica, the content of PBC was 0.03 - 1.2 kg. / l.
3. heavymetals
Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic) are among the common and highly toxic pollutants. They are widely used in various industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is quite high. Large masses of these compounds enter the ocean through the atmosphere.
Mercury, lead and cadmium are the most dangerous for marine biocenoses. Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 121 thousand. tons of mercury, and a significant part is of anthropogenic origin. About half of the annual industrial production of this metal (910 thousand tons / year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. At the same time, some bacteria convert chlorides into highly toxic methyl mercury. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. By 1977, there were 2,800 victims of Minomata disease, which was caused by waste products from factories for the production of vinyl chloride and acetaldehyde, which used mercury chloride as a catalyst. Insufficiently treated wastewater from enterprises entered the Minamata Bay. Pigs are a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, pigs are actively dispersed into the environment during human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines. The migration flow of lead from the continent to the ocean goes not only with river runoff, but also through the atmosphere.
With continental dust, the ocean receives (20-30) * 10 ^ 3 tons of lead per year.
4. Syntheticsurface-activesubstances
Detergents (surfactants) belong to an extensive group of substances that lower the surface tension of water. They are part of synthetic detergents (SMC), widely used in everyday life and industry. Together with wastewater, surfactants enter the mainland waters and the marine environment. SMS contain sodium polyphosphates, in which detergents are dissolved, as well as a number of additional ingredients that are toxic to aquatic organisms: flavoring agents, bleaching agents (persulphates, perborates), soda ash, carboxymethylcellulose, sodium silicates. Depending on the nature and structure of the hydrophilic part of the surfactant molecules, they are divided into anionic, cationic, amphoteric, and nonionic. The latter do not form ions in water. The most common among the surfactants are anionic substances. They account for more than 50% of all surfactants produced in the world. The presence of surfactants in industrial wastewater is associated with their use in such processes as flotation beneficiation of ores, separation of chemical technology products, production of polymers, improvement of conditions for drilling oil and gas wells, and equipment corrosion control. In agriculture, surfactants are used as part of pesticides.
5. OilAndoil products
Oil is a viscous oily liquid that is dark brown in color and has low fluorescence. Oil consists mainly of saturated aliphatic and hydroaromatic hydrocarbons. The main components of oil - hydrocarbons (up to 98%) - are divided into 4 classes:
a). Paraffins (alkenes). (up to 90% of the total composition) - stable substances, the molecules of which are expressed by a straight and branched chain of carbon atoms. Light paraffins have maximum volatility and solubility in water. pollutant ocean pesticide oil product
b). Cycloparaffins. (30 - 60% of the total composition) saturated cyclic compounds with 5-6 carbon atoms in the ring. In addition to cyclopentane and cyclohexane, bicyclic and polycyclic compounds of this group are found in oil. These compounds are very stable and difficult to biodegrade.
c). Aromatic hydrocarbons. (20 - 40% of the total composition) - unsaturated cyclic compounds of the benzene series, containing 6 carbon atoms in the ring less than cycloparaffins. Oil contains volatile compounds with a molecule in the form of a single ring (benzene, toluene, xylene), then bicyclic (naphthalene), polycyclic (pyrone).
G). Olefins (alkenes). (up to 10% of the total composition) - unsaturated non-cyclic compounds with one or two hydrogen atoms at each carbon atom in a molecule that has a straight or branched chain.
Oil and oil products are the most common pollutants in the oceans. By the beginning of the 1980s, about 16 million tons of oil were annually entering the ocean, which accounted for 0.23% of world production. The greatest losses of oil are associated with its transportation from production areas. Emergencies, discharge of washing and ballast water overboard by tankers - all this leads to the presence of permanent pollution fields along sea routes. In the period 1962-79, about 2 million tons of oil entered the marine environment as a result of accidents. Over the past 30 years, since 1964, about 2,000 wells have been drilled in the World Ocean, of which 1,000 and 350 industrial wells have been equipped in the North Sea alone. Due to minor leaks, 0.1 million tons of oil are lost annually. Large masses of oil enter the seas along rivers, with domestic and storm drains. The volume of pollution from this source is 2.0 million tons / year. Every year, 0.5 million tons of oil enters with industrial effluents. Getting into the marine environment, oil first spreads in the form of a film, forming layers of various thicknesses.
The oil film changes the composition of the spectrum and the intensity of light penetration into the water. The light transmission of thin films of crude oil is 11-10% (280nm), 60-70% (400nm). A film with a thickness of 30-40 microns completely absorbs infrared radiation. When mixed with water, oil forms an emulsion of two types: direct oil in water and reverse water in oil. Direct emulsions, composed of oil droplets up to 0.5 µm in diameter, are less stable and are characteristic of oils containing surfactants. When volatile fractions are removed, oil forms viscous inverse emulsions, which can remain on the surface, be carried by the current, wash ashore and settle to the bottom.
6. Bloomwater
Another common type of ocean pollution is water blooms due to the massive development of algae or plankton. Algal blooms off the coast of Norway and Denmark have caused a wild bloom in the North Sea Chlorochromulina polylepis resulting in serious damage to the salmon fishery. In the waters of the temperate zone, such phenomena have been known for quite a long time, but in the subtropics and tropics, the "red tide" was first noticed near Hong Kong in 1971. Subsequently, such cases were often repeated. It is believed that this is due to industrial releases of a large number of trace elements, especially the washout of agricultural fertilizers into water bodies, which act as biostimulators of phytoplankton growth. With the explosive growth of phytoplankton biomass, first-order consumers cannot cope, as a result of which most of the food chains are not used and simply die off, sinking to the bottom. Decomposing the organic matter of dead phytoplankton, bottom bacteria often use all the oxygen dissolved in water, which can lead to the formation of a hypoxia zone (with an insufficient oxygen content for aerobic organisms). Such zones lead to reduction of biodiversity and biomass of aerobic forms of benthos.
Oysters, like other bivalves, play an important role in water filtration. Oysters used to filter the water in the Maryland part of the Chesapeake Bay in eight days. Today, they spend 480 days doing this due to flowering and water pollution. After blooming, the algae die and decompose, allowing bacteria to grow and take up vital oxygen.
All marine animals that obtain food by filtering water are very sensitive to pollutants that accumulate in their tissues. Corals do not tolerate pollution well, and coral reefs and atolls are under serious threat.
7. sewagewater
In addition to water blooms, sewage is one of the most harmful wastes. In small quantities, they enrich the water and promote the growth of plants and fish, and in large quantities they destroy ecosystems. Two of the world's largest waste disposal sites - Los Angeles (USA) and Marseille (France) - have been treating polluted water for more than two decades. Satellite imagery clearly shows the effluent discharged by the exhaust manifolds. Underwater footage shows the marine deaths they caused (underwater deserts littered with organic debris), but remedial measures taken in recent years have greatly improved the situation.
Efforts to liquefy sewage are aimed at reducing their hazard; while sunlight kills some bacteria. Such measures have proved effective in California, where household waste is dumped into the ocean - the result of the life of almost 20 million inhabitants of this state.
8. Resetwasteinseafrompurposeburial(dumping)
Many countries with access to the sea carry out marine burial of various materials and substances, in particular soil excavated during dredging, drill slag, industrial waste, construction waste, solid waste, explosives and chemicals, and radioactive waste. The volume of burials amounted to about 10% of the total mass of pollutants entering the World Ocean.
The basis for dumping in the sea is the ability of the marine environment to process a large amount of organic and inorganic substances without much damage to the water. However, this ability is not unlimited. Therefore, dumping is considered as a forced measure, a temporary tribute to the imperfection of technology by society.
Industrial slags contain a variety of organic substances and heavy metal compounds. Household waste contains on average (by weight of dry matter) 32-40% organic matter; 0.56% nitrogen; 0.44% phosphorus; 0.155% zinc; 0.085% lead; 0.001% mercury; 0.001% cadmium.
During the discharge, the passage of the material through the water column, part of the pollutants goes into solution, changing the quality of the water, the other is sorbed by suspended particles and goes into bottom sediments. At the same time, the turbidity of the water increases. The presence of organic substances often leads to the rapid consumption of oxygen in water and often to its complete disappearance, the dissolution of suspensions, the accumulation of metals in dissolved form, and the appearance of hydrogen sulfide. The presence of a large amount of organic matter creates a stable reducing environment in the soil, in which a special type of interstitial water appears, containing hydrogen sulfide, ammonia, and metal ions.
Benthic organisms and others are affected to varying degrees by the discharged materials. In the case of the formation of surface films containing petroleum hydrocarbons and surfactants, gas exchange at the air-water interface is disturbed. Pollutants entering the solution can accumulate in the tissues and organs of hydrobiants and have a toxic effect on them. The discharge of dumping materials to the bottom and prolonged increased turbidity of the bottom water lead to the death of inactive forms of benthos from suffocation. In surviving fish, mollusks and crustaceans, the growth rate is reduced due to the deterioration of feeding and breathing conditions. The species composition of a given community often changes.
When organizing a system of control over the discharge of waste into the sea, the definition of dumping areas, the determination of the dynamics of pollution of sea water and bottom sediments is of decisive importance. To identify possible volumes of discharge into the sea, it is necessary to carry out calculations of all pollutants in the composition of the material discharge.
9. Thermalpollution
Thermal pollution of the surface of reservoirs and coastal marine areas occurs as a result of the discharge of heated wastewater from power plants and some industrial production. The discharge of heated water in many cases causes an increase in water temperature in reservoirs by 6-8 degrees Celsius. The area of heated water spots in coastal areas can reach 30 square meters. km. A more stable temperature stratification prevents water exchange between the surface and bottom layers. The solubility of oxygen decreases, and its consumption increases, since the activity of aerobic bacteria that decompose organic matter increases with increasing temperature. The species diversity of phytoplankton and the entire flora of algae is increasing.
Based on the generalization of the material, it can be concluded that the effects of anthropogenic impact on the aquatic environment are manifested at the individual and population-biocenotic levels, and the long-term effect of pollutants leads to a simplification of the ecosystem.
10. Connectionsfromcarcinogenicproperties
Carcinogenic substances are chemically homogeneous compounds that exhibit transforming activity and the ability to cause carcinogenic, teratogenic (violation of embryonic development processes) or mutagenic changes in organisms. Depending on the conditions of exposure, they can lead to growth inhibition, accelerated aging, disruption of individual development, and changes in the gene pool of organisms. Substances with carcinogenic properties include chlorinated aliphatic hydrocarbons, vinyl chloride, and especially polycyclic aromatic hydrocarbons (PAHs). The maximum amount of PAHs in the current sediments of the World Ocean (more than 100 µg/km of dry matter mass) 0 was found in tectonically active zones subject to deep thermal effects. The main anthropogenic sources of PAHs in the environment are the pyrolysis of organic substances during the combustion of various materials, wood, and fuel.
11. CausespollutionWorldocean
Why is the ocean polluted? What are the reasons for these sad processes? They lie primarily in irrational, and in some places even aggressive, human behavior in the field of nature management. People do not understand (or do not want to realize) the possible consequences of their negative actions on nature. To date, it is known that the pollution of the waters of the World Ocean occurs in three main ways: through the runoff of river systems (with the most polluted areas of the shelf, as well as areas near the mouths of large rivers); through atmospheric precipitation (this is how lead and mercury enter the Ocean, first of all); due to unreasonable human economic activity directly in the oceans. Scientists have found that the main route of pollution is river runoff (up to 65% of pollutants enter the oceans through rivers). About 25% is accounted for by atmospheric precipitation, another 10% - by wastewater, less than 1% - by emissions from ships. It is for these reasons that pollution of the oceans occurs. Surprisingly, water, without which a person cannot live even a day, is actively polluted by it.
Maincausespollution:
1. Uncontrolled pollution of water areas is growing.
2. There is a dangerous excess of permissible objects of fishery species of ichthyofauna.
3. There is a need for a more intensive involvement in the economic circulation of the mineral energy resources of the ocean.
4. There is an escalation of international conflicts due to disagreements in the sphere of equatorial delimitation.
12. ConsequencespollutionWorldocean
The world ocean is of exceptional importance in the life support of the Earth. The ocean is the "lungs" of the Earth, the source of food for the population of the globe and the concentration of huge wealth of minerals. But scientific and technological progress had a negative impact on the viability of the ocean - intensive shipping, increased oil and gas production in the waters of the continental shelf, dumping of oil and radioactive waste into the seas led to serious consequences: pollution of marine spaces, disruption of the ecological balance in the oceans. At present, humanity is facing a global task - to urgently eliminate the damage caused to the ocean, restore the disturbed balance and create guarantees for its preservation in the future. An unviable ocean will have a detrimental effect on the life support of the entire Earth, on the fate of mankind.
The consequences, to which the wasteful, careless attitude of mankind towards the Ocean leads, are terrifying. The destruction of plankton, fish and other inhabitants of ocean waters is far from all. The damage could be much greater. Indeed, the World Ocean has general planetary functions: it is a powerful regulator of the moisture circulation and thermal regime of the Earth, as well as the circulation of its atmosphere. Pollution can cause very significant changes in all these characteristics, which are vital for the climate and weather regime on the entire planet. Symptoms of such changes are already observed today. Severe droughts and floods are repeated, destructive hurricanes appear, severe frosts come even to the tropics, where they never happened. Of course, it is not yet possible to even approximately estimate the dependence of such damage on the degree of pollution of the World Ocean, however, the relationship undoubtedly exists. Be that as it may, the protection of the ocean is one of the global problems of mankind.
Conclusion
The consequences, to which the wasteful, careless attitude of mankind towards the Ocean leads, are terrifying. The destruction of plankton, fish and other inhabitants of ocean waters is far from all. The damage could be much greater. Indeed, the World Ocean has general planetary functions: it is a powerful regulator of the moisture circulation and thermal regime of the Earth, as well as the circulation of its atmosphere. Pollution can cause very significant changes in all these characteristics, which are vital for the climate and weather regime on the entire planet. Symptoms of such changes are already observed today. Severe droughts and floods are repeated, destructive hurricanes appear, severe frosts come even to the tropics, where they never happened. Of course, it is not yet possible to even approximately estimate the dependence of such damage on the degree of pollution. Oceans, however, the relationship undoubtedly exists. Be that as it may, the protection of the ocean is one of the global problems of mankind. The Dead Ocean is a dead planet, and therefore all of humanity. Thus, it is obvious that the pollution of the oceans is the most important environmental problem of our century. And you have to fight it. Today, there are many dangerous ocean pollutants: these are oil, oil products, various chemicals, pesticides, heavy metals and radioactive waste, sewage, plastics and the like. The solution of this acute problem will require the consolidation of all the forces of the world community, as well as a clear and strict implementation of the accepted norms and existing regulations in the field of environmental protection.
Listusedresources
1. Internet resource: wikipedia.org
2. Internet resource: Syl.ru
3. Internet resource: 1os.ru
4. Internet resource: grandars.ru
5. Internet resource: ecosystema.ru
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