Destruction of natural ecosystems. Destruction of natural ecosystems over vast areas of land

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Introduction

The Caspian Sea is an internal closed body of water. Like many other water bodies, it is subject to significant anthropogenic pressure; its ecological state is influenced by many factors, both natural and human activities. Because of this, the Caspian Sea has a number of environmental problems, many of which are common for seas of this type.

The Caspian Sea is a unique ecological natural object with its own ecosystem. Its approximate area is 372 thousand km2, volume is about 78,000 km3, average depth is 208 meters, maximum depth is 1025 meters, salinity is 12%. This transboundary facility surrounds several states: Russia, Kazakhstan, Turkmenistan, Iran, Azerbaijan. The safety of the Caspian ecosystem is an issue that should be relevant for all these countries. We cannot allow the Caspian Sea to suffer from the Aral Sea problem, which can safely be called a disaster. Nature knows many examples of human indifference, insufficient assessment of the situation, and incorrect measures of influence, as a result of which unique natural systems were lost and rare species of animals and plants were completely exterminated.

The conclusion can be the fact that any thoughtless intervention in natural systems can lead to a completely opposite result. An example is the destruction of the ecological integrity of the ecosystem of the Kara-Bogaz-Gol Bay, as a result of which a number of unforeseen environmental problems arose: desertification, salt storms, loss of natural mirabilite production, unfavorable sanitary, hygienic and environmental conditions. The environmental policy of the Caspian states should work as a single apparatus that will preserve the Caspian Sea and its unique natural ecosystem.

The consequences of environmental problems for society can be divided into two categories - direct and indirect. Direct consequences are expressed, for example, in the loss of biological resources (commercial species and their food items) and can be expressed in monetary terms. Thus, the losses of the countries of the Caspian region from the steady decline in sturgeon stocks, expressed in reduced sales, can be calculated. This should also include the costs of compensating for damage caused (for example, for the construction of fish breeding facilities).

Indirect consequences are an expression of ecosystems losing their ability to self-purify, losing their balance and gradually transitioning to a new state. For society, this manifests itself in the loss of aesthetic value of landscapes, the creation of less comfortable living conditions for the population, etc. In addition, a further chain of losses leads, as a rule, again to direct economic losses (tourism sector, etc.).

Behind journalistic arguments that the Caspian Sea has fallen into the “sphere of interests” of this or that country, the fact that these countries, in turn, fall into the sphere of influence of the Caspian Sea is usually lost. For example, against the background of 10-50 billion dollars of expected Western investment in Caspian oil, the economic consequences of the mass death of Caspian sprat are expressed in the amount of “only” 2 million dollars. However, in reality this damage is expressed at 200 thousand tons of cheap protein food. Instability and social risks generated by the shortage of available products in the Caspian region can create a real threat to Western oil markets, and under unfavorable circumstances, even provoke a large-scale fuel crisis.

A significant part of the damage caused to nature by human activity remains outside the scope of economic calculations. It is the lack of methods for economic assessment of biodiversity and environmental services that leads to the fact that planning authorities in the Caspian countries give preference to the development of extractive industries and the “agricultural industry” to the detriment of the sustainable use of biological resources, tourism and recreation.

All the problems described below are so closely interconnected that sometimes it is simply impossible to isolate them in their pure form. In fact, we are talking about one problem that can be described as “the destruction of the natural ecosystems of the Caspian Sea.”

Now, after a brief story about the Caspian Sea, we can consider the main environmental disasters of this water basin.

1. Marine pollution

The main pollutant of the sea, of course, is oil. Oil pollution suppresses the development of phytobenthos and phytoplankton in the Caspian Sea, represented by blue-green algae and diatoms, reduces oxygen production, and accumulates in bottom sediments. An increase in pollution also negatively affects heat, gas, and moisture exchange between the water surface and the atmosphere. Due to the spread of the oil film over large areas, the evaporation rate decreases several times.

The most obvious impact of oil pollution is on waterfowl. In contact with oil, feathers lose their water-repellent and heat-insulating properties, which quickly leads to the death of birds. Massive deaths of birds have been repeatedly noted in the Absheron region. Thus, according to the Azerbaijani press, in 1998, about 30 thousand birds died on the protected Gel Island (near the village of Alyat). The proximity of nature reserves and production wells poses a constant threat to Ramsar wetlands on both the western and eastern shores of the Caspian Sea.

The impact of oil spills on other aquatic animals is also significant, although less obvious. In particular, the beginning of production on the shelf coincides with a reduction in the number of sea pike perch and the loss of its resource value (spawning areas of this species coincide with oil production areas). It is even more dangerous when, as a result of pollution, not just one species, but entire habitats are lost.

Examples include Soymonov Bay in Turkmenistan and large sections of the western coast of the South Caspian Sea. Unfortunately, in the Southern Caspian Sea the feeding areas of juvenile fish largely coincide with oil and gas bearing areas, and the Marovsky lands are located in close proximity to them.

In the Northern Caspian, pollution from oil development was insignificant until recent years; This was facilitated by the weak degree of exploration and the special reserve regime of this part of the sea.

The situation changed with the start of work on the development of the Tengiz field, and then with the discovery of the second giant - Kashagan. Changes were made to the protected status of the Northern Caspian Sea, allowing oil exploration and production (Resolution of the Council of Ministers of the Republic of Kazakhstan No. 936 of September 23, 1993 and Resolution of the Government of the Russian Federation No. 317 of March 14, 1998). However, this is where the risk of contamination is greatest due to shallow water, high reservoir pressures, etc. Let us recall that only one accident in 1985 at Tengiz well 37 led to the release of 3 million tons of oil and the death of about 200 thousand birds.

The emerging quite obvious reduction in investment activity in the Southern Caspian gives reason for cautious optimism in this part of the sea. It is already clear that a massive increase in oil production is unlikely in both the Turkmen and Azerbaijani sectors. Few people remember the 1998 forecasts, according to which Azerbaijan alone was supposed to produce 45 million tons of oil per year by 2002 (in reality - about 15). In fact, the production available here is barely enough to supply 100% capacity to existing refineries. However, already explored deposits will inevitably be further developed, which will lead to an increased risk of accidents and major spills at sea. More dangerous is the development of the fields of the Northern Caspian, where annual production in the coming years will reach at least 50 million tons with projected resources of 5-7 billion tons. In recent years, the Northern Caspian has topped the list of emergency situations.

The history of oil development in the Caspian Sea is at the same time the history of its pollution, and each of the three “oil booms” made its contribution. Production technology has improved, but the positive effect in the form of a decrease in specific pollution was negated by an increase in the amount of oil produced. Apparently, pollution levels in oil-producing areas (Baku Bay, etc.) were approximately the same in the first (before 1917), second (40-50s of the 20th century) and third (70s) peaks oil production.

If it is appropriate to call the events of recent years the “fourth oil boom,” then we should expect at least the same scale of pollution. The expected reduction in emissions due to the introduction of modern technologies by Western transnational corporations has not yet been felt. So, in Russia from 1991 to 1998. emissions of harmful substances into the atmosphere per ton of oil produced amounted to 5.0 kg. Emissions from Tengizchevroil JV in 1993-2000. amounted to 7.28 kg per ton of oil produced. The press and official sources describe numerous cases of companies violating environmental requirements and emergency situations of varying severity. Almost all companies do not comply with the current ban on dumping drilling fluids into the sea. Satellite images clearly show a giant oil slick in the Southern Caspian Sea.

Even under the best of circumstances, without major accidents and with emissions reduced to international levels, the expected marine pollution will exceed anything we have previously experienced. According to generally accepted calculations, for every million tons of oil produced in the world, there is an average of 131.4 tons of losses. Based on the expected production of 70-100 million tons, in the Caspian as a whole we will have at least 13 thousand tons per year, with most of it falling in the Northern Caspian. According to Roshydromet estimates, the average annual content of petroleum hydrocarbons in North Caspian water will double or triple by 2020 and reach 200 µg/l (4 MAC) without taking into account emergency spills.

Only during the drilling of the Oil Rocks field from 1941 to 1958, artificial griffin formation (uncontrolled release of oil to the sea surface) took place in 37 wells. Moreover, these griffins operated from several days to two years, and the amount of oil released varied from 100 to 500 tons per day.

In Turkmenistan, noticeable technogenic pollution of coastal shallow waters in the Krasnovodsk Bay and Aladzha Bay was observed in the pre-war and war years (Great Patriotic War 1941-1945), after the evacuation of the Tuapse oil refinery here. This was accompanied by mass deaths of waterfowl. On the sandy-shell spits and islands of the Turkmenbashi Bay, “asphalt paths” hundreds of meters long, formed from spilled oil absorbed into the sand, are still periodically exposed after sections of the coast are washed away by storm waves. After the mid-70s, a powerful oil and gas production industry began to be created along almost 250 km of the coastal part of Western Turkmenistan. Already in 1979, the exploitation of the Dagadzhik and Aligul oil fields on the Cheleken, Barsa-Gelmes and Komsomolsky peninsula began.

Significant pollution in the Turkmenistan part of the Caspian Sea occurred during the period of active development of the fields of the LAM and Zhdanov banks: 6 open fountains with fires and oil spills, 2 open fountains with the release of gas and water, as well as many so-called. "emergency situations".

Even in 1982-1987, i.e. in the final period of “stagnation time”, when numerous legislative acts were in force: resolutions, decrees, instructions, circulars, decisions of local authorities, there was an extensive network of local inspections, laboratories of the State Hydrometeorological Service, the Committee for Nature Protection, the Ministry of Fisheries, the Ministry of Health, etc., The hydrochemical situation in all oil-producing areas remained extremely unfavorable.

During the perestroika period, when there was a widespread decline in production, the situation with oil pollution began to improve. So, in 1997-1998. the content of petroleum products in the waters of the south-eastern coast of the Caspian Sea decreased several times, although it still exceeded the maximum permissible concentration by 1.5 - 2.0 times. This was caused not only by the lack of drilling and a general decrease in activity in the water area, but also by the measures taken to reduce discharges during the reconstruction of the Turkmenbashi oil refinery. The reduction in pollution levels immediately affected the state of the biota. In recent years, thickets of charophyte algae have covered almost the entire Turkmenbashi Bay, which serves as an indicator of the purity of the water. The shrimp appeared even in the most polluted Soimonov Bay. In addition to oil itself, a significant risk factor for biota (this is a historically established set of species of living organisms, united by a common area of distribution at the present time or in past geological eras. The biota includes representatives of cellular organisms (plants, animals, fungi, bacteria, etc. ), and cell-free organisms (viruses).

Biota is an important component of the ecosystem and biosphere. Biota actively participates in biogeochemical processes. The study of biota is the subject of many sciences, including biology, ecology, hydrobiology, paleontology, biochemistry, etc.) are associated waters. As a rule, separation (separation of water and oil) occurs on land, after which the water is drained into the so-called “evaporation ponds”, which are used as natural relief depressions (takyrs and salt marshes, less often inter-barchan depressions). Since associated waters have high mineralization (100 or more g/l), contain residues of oil, surfactants and heavy metals, instead of evaporation, a spill occurs on the surface, slowly seeping into the ground, and then in the direction of groundwater movement - to the sea.

Against this background, the impact of associated solid waste is relatively small. This category includes the remains of oil production equipment and structures, drill cuttings, etc. In some cases, they contain hazardous materials, for example, transformer oils, heavy and radioactive metals, etc. The most famous are the accumulations of sulfur obtained during the purification of Tengiz oil (6.9 weight percent; about 5 million tons accumulated).

The main volume of pollution (90% of the total) enters the Caspian Sea with river runoff. This ratio can be traced for almost all indicators (petroleum hydrocarbons, phenols, surfactants, organic substances, metals, etc.). In recent years, there has been a slight decrease in pollution of inflowing rivers, with the exception of the Terek (400 or more maximum permissible concentrations for petroleum hydrocarbons), where oil and waste from the destroyed oil infrastructure of the Chechen Republic ends up.

It should be noted that the share of river pollution tends to decrease, to a lesser extent due to a reduction in production in river valleys, and to a greater extent due to the increase in offshore oil production. It is expected that in the future 2010-2020. the river-sea pollution ratio will reach 50:50.

Conclusion. An analysis of the situation with pollution shows that they are relatively little affected by the development of environmental legislation, the introduction of modern technologies, the availability of emergency equipment, the improvement of technology, the presence or absence of environmental authorities, etc. The only indicator with which the level of pollution in the Caspian Sea correlates is the volume of industrial production in its basin, primarily hydrocarbon production.

2. Diseases

Myopathy, or separation of muscle tissue in sturgeons.

In 1987-1989 In sexually mature sturgeons, a massive phenomenon of myopathy was observed, consisting in the separation of large sections of muscle fibers, up to their complete lysis. The disease, which received a complex scientific name - “cumulative polytoxicosis with multisystem damage”, was short-term and widespread (it is estimated that up to 90% of fish during the “river” period of their life; although the nature of this disease is not clear, a connection is assumed with pollution of the aquatic environment ( including volley discharges of mercury on the Volga, oil pollution, etc.) The very name “cumulative polytoxicosis...”, in our opinion, is a palliative intended to hide the true causes of the problem, as well as indications of “chronic sea pollution.” In any case , according to observations in Turkmenistan, according to information from Iranian and Azerbaijani colleagues, myopathy was practically not manifested in the South Caspian sturgeon population. In general, signs of myopathy were rarely recorded in the South Caspian, including the “chronically polluted” western coast. The newly invented name for the disease is a success among researchers Caspian Sea: it was later applied to all cases of mass death of animals (seal in the spring of 2000, sprat in the spring and summer of 2001).

A number of experts provide convincing information about the correlation of the proportion of the Nereis worm in the diet with the intensity of the disease in various sturgeon species. It is emphasized that Nereis accumulates toxic substances. Thus, the stellate sturgeon, which consumes the most nereis, is most susceptible to myopathy, and the least susceptible to this is the beluga, which feeds mainly on fish. Thus, there is every reason to assume that the problem of myopathy is directly related to the problem of river runoff pollution and indirectly to the problem of alien species.

For example:

1. Death of sprat in the spring and summer of 2001.

The amount of sprat that died during the spring-summer of 2001 is estimated at 250 thousand tons, or 40%. Taking into account the data on overestimation of the ichthyomass of sprat in previous years, it is difficult to believe in the objectivity of these figures. It is obvious that not 40%, but almost all sprat (at least 80% of the population) died in the Caspian Sea. It is now obvious that the cause of the mass death of sprat was not a disease, but a banal lack of nutrition. Nevertheless, the official conclusions include “reduced immunity as a result of “cumulative polytoxicosis.”

2. Distemper of carnivores in the Caspian seal.

As reported by the media, since April 2000, mass deaths of seals have been observed in the Northern Caspian Sea. Characteristic signs of dead and weakened animals are red eyes and a clogged nose. The first hypothesis about the causes of death was poisoning, which was partly confirmed by the finding of increased concentrations of heavy metals and persistent organic pollutants in the tissues of dead animals. However, these contents were not critical, and therefore the hypothesis of “cumulative polytoxicosis” was put forward. Microbiological analyzes carried out “hot on the heels” gave an unclear and ambiguous picture.

Canine distemper (canine distemper). Only a few months later it was possible to conduct a virological analysis and determine the immediate cause of death - morbillevirus

According to the official conclusion of CaspNIRKh, the impetus for the development of the disease could have been chronic “cumulative polytoxicosis” and extremely unfavorable winter conditions. An extremely mild winter with an average monthly temperature in February 7-9 degrees above normal affected ice formation. Weak ice cover existed for a limited time only in the eastern sector of the Northern Caspian Sea. The animals moulted not on ice haul-outs, but in conditions of greater crowding on the shalygas of the eastern shallow waters, the periodic flooding of which under the influence of surges aggravated the condition of the molting seals.

3. Death of seals

A similar epizootic (albeit on a smaller scale) with 6,000 seals washing ashore took place in 1997 on Absheron. Then one of the probable causes of the death of the seal was also called carnivorous plague. A feature of the 2000 tragedy was its manifestation throughout the sea (in particular, the death of seals on the Turkmen coast began 2-3 weeks before the events in the Northern Caspian Sea). It is advisable to consider the high degree of exhaustion of a significant part of the dead animals as an independent fact, separately from the diagnosis.

Most of the seal population feeds fat during warm periods, and during cold periods migrates to the north, where reproduction and molting occur on the ice. During this period, the seal goes into the water extremely reluctantly. There is sharp variability in feeding activity between seasons. Thus, during the period of reproduction and molting, more than half of the stomachs of the studied animals are empty, which is explained not only by the physiological state of the body, but also by the poverty of the under-ice food supply (the main objects are gobies and crabs).

During feeding, up to 50% of the total body weight lost during the winter is compensated. The annual food requirement of the seal population is 350-380 thousand tons, of which 89.4% is consumed during the summer feeding period (May-October). The main food in summer is sprat (80% of the diet).

Based on these figures, the seal consumed 280-300 thousand tons of sprat per year. Judging by the decrease in sprat catches, the lack of nutrition in 1999 can be estimated at approximately 100 thousand tons, or 35%. This amount can hardly be compensated by other food items.

It can be considered very likely that the epizootic among seals in the spring of 2000 was provoked by a lack of food (sprat), which, in turn, was a consequence of overfishing and, possibly, the introduction of the ctenophore Mnemiopsis. Due to the continuing decline in sprat stocks, we should expect a repeat of the mass death of seals in the coming years.

In this case, first of all, the population will lose all its offspring (animals that have not gained fat will either not begin breeding or will immediately lose their young). It is possible that a significant portion of females capable of reproduction will also die (pregnancy and lactation - exhaustion of the body, etc.). The population structure will change radically.

One should be wary of the abundance of “analytical data” in all of the above cases. There was almost no data on the sex and age composition of dead animals, or on the methodology for estimating the total number; data from samples taken from these animals were practically absent or not processed. Instead, chemical analyzes are provided for a wide range of components (including heavy metals and organics), usually without information about sampling methods, analytical work, standards, etc. As a result, the “conclusions” are replete with numerous absurdities. For example, the conclusion of the All-Russian Research Institute for Control, Standardization and Certification of Veterinary Drugs (disseminated by Greenpeace in many media) contains “372 mg/kg of polychlorinated biphenyls.” If you replace milligrams with micrograms, then this is a fairly high content, typical, for example, of human breast milk in people who eat fish. In addition, the available information about morbillevirus epizootics in related seal species (Baikal, White Sea, etc.) was not taken into account at all; The status of sprat populations as the main food item was also not analyzed.

3. Penetration of foreign organisms

The threat of alien species was not considered serious until the recent past. On the contrary, the Caspian Sea was used as a testing ground for the introduction of new species intended to increase the fish productivity of the basin. It should be noted that these works were mainly carried out on the basis of scientific forecasts; in a number of cases, the simultaneous introduction of fish and food was carried out (for example, mullet and the Nereis worm). The rationale for the introduction of a particular species was quite primitive and did not take into account long-term consequences (for example, the appearance of food dead ends, competition for food with more valuable native species, accumulation of toxic substances, etc.). Fish catches decreased every year; in the catch structure, valuable species (herring, pike perch, carp) were replaced by less valuable ones (small fish, sprat). Of all the invaders, only mullet gave a small increase (about 700 tons, in the best years - up to 2000 tons) of fish production, which cannot compensate for the damage caused by the invasion.

Events took a dramatic turn when mass reproduction of the ctenophore Mnemiopsis leidyi began in the Caspian Sea. According to CaspNIRKH, mnemiopsis was officially first recorded in the Caspian Sea in the fall of 1999. However, the first unverified data date back to the mid-80s; in the mid-90s, the first warnings about the possibility of its occurrence and potential damage appeared, based on the Black Sea-Azov experience .

Judging by fragmentary information, the number of ctenophores in a given area is subject to sudden changes. Thus, Turkmen specialists observed large accumulations of Mnemiopsis in the Avaza region in June 2000, in August of the same year it was not recorded in this area, and in August 2001 the concentration of Mnemiopsis ranged from 62 to 550 org/m3.

It is paradoxical that official science, represented by CaspNIRKH, until the very last moment denied the influence of Mnemiopsis on fish stocks. At the beginning of 2001, the thesis about “the departure of schools to other depths” was put forward as the reason for the 3-4-fold drop in sprat catches, and only in the spring of that year, after the mass death of sprat, it was recognized that Mnemiopsis played a role in this phenomenon.

The comb jelly first appeared in the Sea of Azov about ten years ago, and during 1985-1990. literally devastated the Azov and Black Seas. It was most likely brought along with ballast water on ships from the coast of North America; further penetration into the Caspian Sea was not difficult. It feeds mainly on zooplankton, consuming approximately 40% of its own weight in food every day, thus destroying the food base of Caspian fish. Rapid reproduction and the absence of natural enemies put it out of competition with other plankton consumers. By also eating planktonic forms of benthic organisms, the ctenophore also poses a threat to the most valuable benthophagous fish (sturgeon). The impact on economically valuable fish species is manifested not only indirectly, through a decrease in the food supply, but also in their direct destruction. Under the main pressure are sprat, brackish-water herring and mullet, whose eggs and larvae develop in the water column. The eggs of sea pike perch, silversides and gobies on the ground and plants may avoid being directly eaten by a predator, but during the transition to larval development they will also become vulnerable. Factors limiting the spread of ctenophores in the Caspian Sea include salinity (below 2 g/l) and water temperature (below +40C).

If the situation in the Caspian Sea develops in the same way as in the Azov and Black Seas, then the complete loss of the fishery value of the sea will occur between 2012-2015; the total damage will be about 6 billion dollars per year. There is reason to believe that due to the great differentiation of the conditions of the Caspian Sea, significant changes in salinity, water temperature and the content of nutrients across seasons and water areas, the impact of Mnemiopsis will not be as devastating as in the Black Sea.

The salvation of the economic importance of the sea may be the urgent introduction of its natural enemy, although this measure is not able to restore the destroyed ecosystems. So far, only one candidate for this role is being considered - the ctenophore beroe. Meanwhile, there are serious doubts about the effectiveness of Beroe in the Caspian Sea, because it is more sensitive to temperature and salinity of water than Mnemiopsis.

4. Overfishing and poaching

There is a widespread opinion among specialists in the fisheries industry that, as a result of economic turmoil in the Caspian states in the 90s, stocks of almost all types of economically valuable fish (except sturgeon) were underutilized. At the same time, an analysis of the age structure of the fish caught shows that even at this time there was significant overfishing (at least of anchovy sprat). Thus, in the sprat catches of 1974, more than 70% were fish aged 4-8 years. In 1997, the share of this age group decreased to 2%, and the bulk were fish aged 2-3 years. Catch quotas continued to increase until the end of 2001. The total allowable catch (TAC) for 1997 was determined at 210-230 thousand tons, 178.2 thousand tons were mastered, the difference was attributed to “economic difficulties.” In 2000, the TAC was determined at 272 thousand tons, the harvested amount was 144.2 thousand tons. In the last 2 months of 2000, sprat catches fell 4-5 times, but even this did not lead to an overestimation of the number of fish, and in 2001 The TAC was increased to 300 thousand tons. And even after the massive death of sprat by CaspNIRKH, the catch forecast for 2002 was reduced slightly (in particular, the Russian quota was reduced from 150 to 107 thousand tons). This forecast is completely unrealistic and only reflects the desire to continue exploiting the resource even in a clearly catastrophic situation.

This makes us cautious about the scientific justification of quotas issued by CaspNIRKh over the past years for all types of fish. This indicates the need to transfer the determination of limits on the exploitation of biological resources into the hands of environmental organizations.

Miscalculations of industry science have had the greatest impact on the condition of sturgeon. The crisis was obvious back in the 80s. From 1983 to 1992, catches of Caspian sturgeon decreased by 2.6 times (from 23.5 to 8.9 thousand tons), and over the next eight years - another 10 times (to 0.9 thousand tons in 1999 .).

For populations of this group of fish, there are a large number of depressing factors, among which three are considered the most significant: removal of natural spawning grounds, myopathy and poaching. An impartial analysis shows that none of these factors were critical until recently.

The last factor in the decline of sturgeon populations requires particularly careful analysis. Estimates of poaching catch have grown rapidly before our eyes: from 30-50% of the official catch in 1997 to 4-5 times (1998) and 10-11-14-15 times during 2000-2002. In 2001, the volume of illegal production by CaspNIRKH was estimated at 12-14 thousand tons of sturgeon and 1.2 thousand tons of caviar; the same figures appear in CITES assessments and in statements by the State Fisheries Committee of the Russian Federation. Considering the high price of black caviar (from 800 to 5,000 dollars per kg in Western countries), rumors about the “caviar mafia” allegedly controlling not only fishing, but also law enforcement agencies in the Caspian regions were widely spread through the media. Indeed, if the volume of shadow transactions amounts to hundreds of millions - several billion dollars, these figures are comparable to the budget of countries such as Kazakhstan, Turkmenistan and Azerbaijan.

It is difficult to imagine that the financial departments and security forces of these countries, as well as the Russian Federation, do not notice such flows of funds and goods. Meanwhile, the statistics of detected offenses look several orders of magnitude more modest. For example, in the Russian Federation, about 300 tons of fish and 12 tons of caviar are seized annually. During the entire period after the collapse of the USSR, only isolated attempts to illegally export black caviar abroad were recorded.

In addition, it is hardly possible to quietly process 12-14 thousand tons of sturgeon and 1.2 thousand tons of caviar. To process the same volumes in the USSR in the 80s, there was an entire industry; an army of business executives was involved in the supply of salt, dishes, packaging materials, etc.

Question about sea fishing for sturgeon. There is a prejudice that it was the ban on sea fishing for sturgeon in 1962 that allowed the populations of all species to recover. In fact, two fundamentally different prohibitions are confused here. A real role in the conservation of sturgeon was played by the ban on seiner and driftnet fishing for herring and small fish, which resulted in the mass destruction of juvenile sturgeon. The ban on sea fishing itself hardly played a significant role. From a biological point of view, this ban makes no sense, but it makes great commercial sense. Catching fish going to spawn is technically simple and allows you to get more caviar than anywhere else (10%). The ban on sea fishing allows production to be concentrated in the mouths of the Volga and Ural and makes it easier to control it, including the manipulation of quotas.

Analyzing the chronicle of the fight against poaching in the Caspian Sea, two important dates can be identified. In January 1993, it was decided to involve border troops, riot police and other security forces in this problem, which, however, had a slight effect on the volume of fish seized. In 1994, when the actions of these structures were coordinated to work in the Volga delta (Operation Putin), the amount of fish seized almost tripled.

Sea fishing is difficult and has never yielded more than 20% of the sturgeon catch. In particular, off the coast of Dagestan, which is now considered perhaps the main supplier of poached products, no more than 10% was caught during the period of permitted sea fishing. Sturgeon fishing in estuaries is many times more effective, especially when populations are low. In addition, the “elite” sturgeon stock is killed in the rivers, while fish with impaired homing accumulate in the seas.

It is noteworthy that Iran, which conducts mainly marine sturgeon fishing, has not only not reduced its catch in recent years, but is also gradually increasing its catch, becoming the main supplier of caviar to the world market, despite the fact that the South Caspian stock should be exterminated by poachers from Turkmenistan and Azerbaijan . To preserve juvenile sturgeon, Iran even went so far as to reduce the country's traditional kutum fishing.

It is obvious that sea fishing is not a determining factor in the decline in sturgeon populations. The main damage to fish is caused where its main catch is concentrated - at the mouths of the Volga and Ural.

5. Regulation of river flow. Changes in natural biogeochemical cycles

Massive hydraulic construction on the Volga (and then on the Kura and other rivers) starting in the 30s. The 20th century deprived the Caspian sturgeon of most of their natural spawning grounds (for beluga - 100%). To compensate for this damage, fish hatcheries were and are being built. The number of fry released (sometimes only on paper) is one of the main grounds for determining quotas for catching valuable fish. Meanwhile, the damage from the loss of sea products is distributed to all Caspian countries, and the benefits from hydropower and irrigation are distributed only to the countries in whose territory the flow regulation took place. This situation does not stimulate the Caspian countries to restore natural spawning grounds or preserve other natural habitats - feeding grounds, wintering grounds for sturgeon, etc.

Fish passage structures at dams suffer from many technical shortcomings; the system for counting fish going to spawn is also far from perfect. However, with the best systems, juveniles that migrate down the river will not return to the sea, but will form artificial populations in polluted and food-poor reservoirs. It was dams, and not water pollution, along with overfishing, that were the main reason for the decline in the sturgeon stock. It is noteworthy that after the destruction of the Kargaly hydroelectric complex, sturgeon were seen spawning in the highly polluted upper reaches of the Terek. Meanwhile, the construction of dams entailed even greater problems. The Northern Caspian was once the richest part of the sea. The Volga brought mineral phosphorus here (about 80% of the total supply), providing the bulk of the primary biological (photosynthetic) production. As a result, 70% of sturgeon stocks were formed in this part of the sea. Now most of the phosphates are consumed in the Volga reservoirs, and phosphorus enters the sea in the form of living and dead organic matter. As a result of this, the biological cycle has radically changed: shortening of trophic chains, predominance of the destructive part of the cycle, etc. The zones of maximum bioproductivity now are in the upwelling zones (this is a process in which deep ocean waters rise to the surface) along the Dagestan coast and on the slopes of the depths of the Southern Caspian Sea. The main feeding grounds for valuable fish have also shifted to these areas. The resulting “windows” in food chains and unbalanced ecosystems create favorable conditions for the penetration of alien species (comb jelly mnemiopsis, etc.).

In Turkmenistan, the degradation of the spawning grounds of the transboundary Atrek River is due to a complex of reasons, including a decrease in water availability, flow regulation in the territory of the Islamic Republic of Iran, and siltation of the riverbed. Spawning of semi-anadromous fish depends on the water content of the Atrek River, which leads to a tense state of commercial stocks of the Atrek herd of Caspian roach and carp. The effect of regulation of the Atrek on the degradation of spawning grounds is not necessarily expressed in a lack of water volumes. The Atrek is one of the most muddy rivers in the world, therefore, as a result of seasonal withdrawal of water, rapid siltation of the riverbed occurs. The Ural remains the only unregulated large river in the Caspian basin. However, the condition of the spawning grounds on this river is also very unfavorable. The main problem today is siltation of the riverbed. Once upon a time, the soils in the Ural valley were protected by forests; Later, these forests were cut down, and the floodplain was plowed almost to the water's edge. After navigation was stopped in the Urals “in order to preserve sturgeon,” work on cleaning the fairway stopped, which made most of the spawning grounds on this river inaccessible.

6. Eutrophication

Eutrophication is the saturation of water bodies with nutrients, accompanied by an increase in the biological productivity of water basins. Eutrophication can be the result of both natural aging of a reservoir and anthropogenic impacts. The main chemical elements contributing to eutrophication are phosphorus and nitrogen. In some cases, the term “hypertrophization” is used.

The high level of pollution of the sea and the rivers flowing into it has long raised concerns about the formation of oxygen-free zones in the Caspian Sea, especially for areas south of the Turkmen Gulf, although this problem was not considered a top priority. However, the latest reliable data on this issue dates back to the early 1980s. Meanwhile, a significant imbalance in the synthesis and decomposition of organic matter as a result of the introduction of the ctenophore Mnemiopsis can lead to serious and even catastrophic changes. Since Mnemiopsis does not pose a threat to the photosynthetic activity of unicellular algae, but affects the destructive part of the cycle (zooplankton - fish - benthos), dying organic matter will accumulate, causing hydrogen sulfide contamination of the bottom layers of water. Poisoning of the remaining benthos will lead to progressive growth of anaerobic areas. We can confidently predict the formation of vast anoxic zones wherever there are conditions for long-term stratification of waters, especially in places where fresh and salt water mix and mass production of unicellular algae occurs. These places coincide with areas of phosphorus influx - on the dumps of the depths of the Middle and Southern Caspian (upwelling zones) and on the border of the Northern and Middle Caspian. For the Northern Caspian, areas with low oxygen levels are also noted; the problem is exacerbated by the presence of ice cover during the winter months. This problem will further aggravate the situation of commercially valuable fish species (killings; obstacles on migration routes, etc.).

In addition, it is difficult to predict how the taxonomic composition of phytoplankton will evolve under new conditions. In some cases, with a high supply of nutrients, the formation of “red tides” cannot be ruled out, an example of which is the processes in Soimonov Bay (Turkmenistan).

7. Describe the process that ensures the constancy of the gas composition of water

The air always contains water vapor, both in gaseous and liquid (water) or solid (ice) states, depending on the temperature. The main source of steam entering the atmosphere is the ocean. Steam also enters the atmosphere from the Earth's vegetation.

At the surface of the sea, air constantly mixes with water: the air absorbs moisture, which is carried away by sea winds, atmospheric gases penetrate the water and dissolve in it. Sea winds, delivering new air currents to the surface of the water, facilitate the penetration of atmospheric air into ocean water.

The solubility of gases in water depends on three factors: the temperature of the water, the partial pressure of the gases that make up the atmospheric air, and their chemical composition. Gases dissolve better in cold water than in warm water. As water temperatures rise, dissolved gases are released from the sea surface in cold regions, and in the tropics they partially return them to the atmosphere. Convective mixing of water ensures the penetration of gases dissolved in water throughout the entire water column, right down to the ocean floor.

The three gases that make up the bulk of the atmosphere - nitrogen, oxygen and carbon dioxide - are also present in large quantities in ocean waters. The main source of saturation of ocean waters with gases is atmospheric air.

8. Explain the concept of “metabolism and energy”

The release of energy occurs as a result of the oxidation of complex organic substances that make up human cells, tissues and organs to the formation of simpler compounds. The consumption of these nutrients by the body is called dissimilation. Simple substances formed during the oxidation process (water, carbon dioxide, ammonia, urea) are excreted from the body through urine, feces, exhaled air, and through the skin. The process of dissimilation is directly dependent on energy consumption for physical labor and heat exchange.

The restoration and creation of complex organic substances of human cells, tissues, and organs occurs due to the simple substances of digested food. The process of storing these nutrients and energy in the body is called assimilation. The assimilation process, therefore, depends on the composition of the food, which provides the body with all the nutrients.

The processes of dissimilation and assimilation occur simultaneously, in close interaction and have a common name - the process of metabolism. It consists of the metabolism of proteins, fats, carbohydrates, minerals, vitamins and water metabolism.

Metabolism is directly dependent on energy consumption (for labor, heat exchange and the functioning of internal organs) and the composition of food.

Metabolism in the human body is regulated by the central nervous system directly and through hormones produced by the endocrine glands. Thus, protein metabolism is influenced by the thyroid hormone (thyroxine), carbohydrate metabolism by the pancreatic hormone (insulin), and fat metabolism by the hormones of the thyroid gland, pituitary gland, and adrenal glands.

Daily human energy expenditure. To provide a person with food that corresponds to his energy expenditure and plastic processes, it is necessary to determine the daily energy expenditure.

The unit of measurement for human energy is the kilocalorie. During the day, a person spends energy on the work of internal organs (heart, digestive system, lungs, liver, kidneys, etc.), heat exchange and performing socially useful activities (work, study, housework, walks, rest). The energy expended on the functioning of internal organs and heat exchange is called basal metabolism. At an air temperature of 20° C, complete rest, on an empty stomach, the main metabolism is 1 kcal per 1 hour per 1 kg of human body weight. Consequently, basal metabolism depends on body weight, as well as the sex and age of a person.

9. List the types of ecological pyramids

Ecological pyramid - graphic representations of the relationship between producers and consumers of all levels (herbivores, predators, species that feed on other predators) in the ecosystem.

The American zoologist Charles Elton suggested schematically depicting these relationships in 1927.

In a schematic representation, each level is shown as a rectangle, the length or area of which corresponds to the numerical values of a link in the food chain (Elton’s pyramid), their mass or energy. Rectangles arranged in a certain sequence create pyramids of various shapes.

The base of the pyramid is the first trophic level - the level of producers; subsequent floors of the pyramid are formed by the next levels of the food chain - consumers of various orders. The height of all blocks in the pyramid is the same, and the length is proportional to the number, biomass or energy at the corresponding level.

Ecological pyramids are distinguished depending on the indicators on the basis of which the pyramid is built. At the same time, the basic rule has been established for all pyramids, according to which in any ecosystem there are more plants than animals, herbivores than carnivores, insects than birds.

Based on the rule of the ecological pyramid, it is possible to determine or calculate the quantitative ratios of different species of plants and animals in natural and artificially created ecological systems. For example, 1 kg of mass of a sea animal (seal, dolphin) requires 10 kg of eaten fish, and these 10 kg already need 100 kg of their food - aquatic invertebrates, which, in turn, need to eat 1000 kg of algae and bacteria to form such a mass. In this case, the ecological pyramid will be sustainable.

However, as you know, there are exceptions to every rule, which will be considered in each type of ecological pyramid.

Types of ecological pyramids

1.Pyramid of numbers.

Rice. 1 Simplified ecological pyramid of numbers

Pyramids of numbers - at each level the number of individual organisms is plotted

The pyramid of numbers displays a clear pattern discovered by Elton: the number of individuals constituting a sequential series of links from producers to consumers is steadily decreasing (Fig. 1).

For example, to feed one wolf, he needs at least several hares for him to hunt; To feed these hares, you need a fairly large variety of plants. In this case, the pyramid will look like a triangle with a wide base tapering upward.

However, this form of a pyramid of numbers is not typical for all ecosystems. Sometimes they can be reversed, or upside down. This applies to forest food chains, where trees serve as producers and insects serve as primary consumers. In this case, the level of primary consumers is numerically richer than the level of producers (a large number of insects feed on one tree), therefore the pyramids of numbers are the least informative and least indicative, i.e. the number of organisms of the same trophic level largely depends on their size.

2. Pyramids of biomass

Rice. 2 Ecological pyramid of biomass

Biomass pyramids - characterizes the total dry or wet mass of organisms at a given trophic level, for example, in units of mass per unit area - g/m2, kg/ha, t/km2 or per volume - g/m3 (Fig. 2)

Usually in terrestrial biocenoses the total mass of producers is greater than each subsequent link. In turn, the total mass of first-order consumers is greater than that of second-order consumers, etc.

In this case (if the organisms do not differ too much in size) the pyramid will also have the appearance of a triangle with a wide base tapering upward. However, there are significant exceptions to this rule. For example, in the seas, the biomass of herbivorous zooplankton is significantly (sometimes 2-3 times) greater than the biomass of phytoplankton, represented mainly by unicellular algae. This is explained by the fact that algae are very quickly eaten by zooplankton, but they are protected from complete consumption by the very high rate of cell division.

In general, terrestrial biogeocenoses, where producers are large and live relatively long, are characterized by relatively stable pyramids with a wide base. In aquatic ecosystems, where producers are small in size and have short life cycles, the pyramid of biomass can be inverted or inverted (with the tip pointing down). Thus, in lakes and seas, the mass of plants exceeds the mass of consumers only during the flowering period (spring), and during the rest of the year the opposite situation can occur.

Pyramids of numbers and biomass reflect the statics of the system, that is, they characterize the number or biomass of organisms in a certain period of time. They do not provide complete information about the trophic structure of an ecosystem, although they allow solving a number of practical problems, especially related to maintaining the sustainability of ecosystems.

The pyramid of numbers allows, for example, to calculate the permissible amount of fish catch or shooting of animals during the hunting season without consequences for their normal reproduction.

3.Pyramids of energy

Rice. 2 Ecological pyramid of energy

Energy pyramids - shows the magnitude of energy flow or productivity at successive levels (Fig. 3).

In contrast to the pyramids of numbers and biomass, which reflect the statics of the system (the number of organisms at a given moment), the pyramid of energy, reflecting the picture of the speed of passage of food mass (amount of energy) through each trophic level of the food chain, gives the most complete picture of the functional organization of communities.

The shape of this pyramid is not affected by changes in the size and metabolic rate of individuals, and if all energy sources are taken into account, the pyramid will always have a typical appearance with a wide base and a tapering apex. When constructing a pyramid of energy, a rectangle is often added to its base to show the influx of solar energy.

In 1942, the American ecologist R. Lindeman formulated the law of the energy pyramid (the law of 10 percent), according to which, on average, about 10% of the energy received at the previous level of the ecological pyramid passes from one trophic level through food chains to another trophic level. The rest of the energy is lost in the form of thermal radiation, movement, etc. As a result of metabolic processes, organisms lose about 90% of all energy in each link of the food chain, which is spent on maintaining their vital functions.

If a hare ate 10 kg of plant matter, then its own weight may increase by 1 kg. A fox or wolf, eating 1 kg of hare meat, increases its mass by only 100 g. In woody plants, this proportion is much lower due to the fact that wood is poorly absorbed by organisms. For grasses and seaweeds, this value is much greater, since they do not have difficult-to-digest tissues. However, the general pattern of the process of energy transfer remains: much less energy passes through the upper trophic levels than through the lower ones.

Let's consider the transformation of energy in an ecosystem using the example of a simple pasture trophic chain, in which there are only three trophic levels.

level - herbaceous plants,

level - herbivorous mammals, for example, hares

level - predatory mammals, for example, foxes

Nutrients are created during the process of photosynthesis by plants, which form organic substances and oxygen, as well as ATP, from inorganic substances (water, carbon dioxide, mineral salts, etc.) using the energy of sunlight. Part of the electromagnetic energy of solar radiation is converted into the energy of chemical bonds of synthesized organic substances.

All organic matter created during photosynthesis is called gross primary production (GPP). Part of the energy of gross primary production is spent on respiration, resulting in the formation of net primary production (NPP), which is the very substance that enters the second trophic level and is used by hares.

...

Main parameters of the global environmental crisis

The most capacious and substantiated analysis of the question is “is there a global environmental crisis?” - cited by V.A. Zubakov. He cited 10 parameters of the global ecocrisis (Table 1).

Table 1 Busygin A.G. DESMOECOLOGY or theory of education for sustainable development. Book one. - 2nd ed., revised, additional. - Publishing house "Simbirsk Book", Ulyanovsk, 2003. P. 35. Main parameters (indices) of the State Energy Commission

To make the alarming pace of development of HES more tangible, it is enough to cite a few facts. One of the most threatening parameters of the environmental crisis is the exponential growth of the Earth's population, which American biologist Paul Ehrlich called the “population explosion.”

During the time of the Roman Empire - about 2 thousand years ago, the world population was a maximum of 200 million people. By the beginning of the 18th century, it did not exceed 700 million. According to V.G. Gorshkov, this figure corresponds to the “ecological limit of the population” of the Earth and the economic capacity of the biosphere.

So, in order to reach the first billion for humanity, and it reached this level during the time of A.S. Pashkin in 1830, it took 2 million years. Then, starting with the industrial revolution, the world's population grows exponentially, i.e. along a hyperbolic curve. So for the appearance of the second billion it took 100 years (1930), the third - 33 years (1963), the fourth - 14 years (1977), the fifth - 13 years (1990) and the sixth - only 10 years (2000).

Directly related to the topic raised is the inclusion of the parameter “increasing scale of military conflicts” in the GES index table. It is estimated that during the history of civilization, humanity has experienced 14,550 wars, that it was at peace for only 292 years, and that about 3.6 billion people died in wars.

V.A. writes significantly. Zubakov that material losses and costs associated with wars, and above all human losses, have recently been growing exponentially. Thus, in the First World War, 74 million people were mobilized, 14 times more than all those who fought in the 19th century. 9.5 million people were killed and 20 million people died from wounds and disease. During the Second World War, more than 110 million people were mobilized, and human losses amounted to 55 million people. If we leave aside the human pain associated with the loss of life of loved ones, and talk only about the “feeding territory,” then we get an ecological and social contradiction due to the fact that the lower the demographic pressure on the biosphere, the easier it is for it to cope with technogenic loads. And it is also necessary to take into account that there is a struggle for “feeding territory”, and in the biological sense, someone’s death is the life of another.

Modern weapons of mass destruction bring a completely different tone and harm to the biosphere. Here we are no longer talking about the usual “classical” military actions of the armies of the times of A.V. Suvorov, and forgiving peoples, civilians with the use of nuclear, chemical, bacteriological and environmental weapons. The last three types have already been tested.

Indices of technogenesis, under which A.E. Fersman understood “the set of chemical and technological processes produced by human activity and leading to the redistribution of the chemical masses of the earth’s crust” (reduced in table No. 1 to 4 main types). But to them it is necessary to add electromagnetic pollution, which, having entangled the globe with electrical, computer and other networks, has become a global magnitude.

The goal of technogenesis is the use of the so-called non-renewable resources of the large geological cycle, i.e. mineral.

One of the most important consequences of technogenesis is the production of waste. As an example, we can cite typical environmental monitoring data for the Samara region. In the state The 1996 report states that: 1) the absolute volume of emissions from motor vehicles is estimated at 4000 - 450 thousand tons, 2) enterprises in the region annually generate more than 450 thousand tons of toxic waste requiring special processing methods, 3) in general, no. industrial and household waste reaches 10 million tons annually.

The amount of toxic (“highly hazardous”) waste containing pesticides, carcinogenic, mutagenic and other substances is steadily increasing, reaching, for example, 10% of the total mass of municipal solid waste in Russia. On the territory of the Russian Federation there are so-called chemical “traps”, on which residential buildings were built over time, causing mass strange diseases of their inhabitants. In almost every country there are thousands and tens of thousands of such “traps”, the accounting and neutralization of which have not been established.

One of the main reasons for the current environmental crisis is that huge quantities of substances are extracted from the earth, converted into new compounds and dispersed into the environment without taking into account the fact that “everything goes somewhere”. As a result, harmfully large amounts of substances often accumulate in places where, by nature, they should not be. The biosphere functions on the basis of closed ecological cycles of matter and energy. And the production of waste is an exceptional (and, apparently, very negative) feature of civilization.

Geochemical pollution of biota and the environment, created mainly by five industries (thermal power engineering, ferrous and non-ferrous metallurgy, oil production, petrochemicals, production of building materials) consists of the saturation of living things with super-toxic heavy metals (mercury, lead, cadmium, arsenic, etc.) and pollution atmosphere, hydrosphere and pedosphere, the global consequences of which are:

global warming caused by the greenhouse effect of the atmosphere;

an increase since 1969 in the size of the ozone hole;

acid rain;

dusty air;

disruption of the ecology of the hydrosphere;

degradation of global soil functions;

deforestation.

The global consequences of soil degradation, deforestation and drought are 8. desertification and 9. loss of biodiversity.

It is impossible for modern inhabitants of the earth to hide from radiotoxication, noise pollution, or electromagnetic pollution. Radiation, elastic-mechanical and electromagnetic fields covered the entire globe. Therefore, these 3 types of pollution, which cause massive and varied diseases in people, can rightfully be considered a component of HES.

The environmental problem, in addition to the aspect of environmental pollution, has an equally important aspect of the exhaustibility of natural resources. It consists of 2 components:

Raw materials, the reasons for which are high rates of consumption of mineral resources, the non-integrated nature of their extraction and processing, focus on extensive nature-exploiting production, poor use of production waste and secondary raw materials.

Destruction of natural ecosystems over vast areas of land.

The global consequence of environmental degradation is the deterioration of the health of the world's population. The modern understanding of health includes not only the absence of disease and infirmity, but also “a state of complete physical, mental and social well-being,” as defined by the World Health Organization (WHO).

To summarize, the following are the main parameters of the global environmental crisis:

exponential population growth;

purity of the biosphere, namely: waste production, geochemical pollution of biota and the environment, radiotoxication, noise pollution and electromagnetic pollution;

energy;

exhaustibility of natural resources (raw materials and destruction of natural ecosystems over vast territories);

global deterioration in public health. Busygin A.G. DESMOECOLOGY or theory of education for sustainable development. Book one. - 2nd ed., revised, additional. - Publishing house "Simbirsk Book", Ulyanovsk, 2003, p. 35

The main causes of ecosystem destruction and resource depletion are as follows:

– Unlike nature, where the formation and consumption of food resources occur in a waste-free, almost closed cycle, waste is generated during the production of food and goods by humans. To satisfy all his needs, a person needs about 20 tons of natural raw materials per year, 90-95% of which goes to waste. Once upon a time, natural systems processed waste from human activity, as if protecting themselves from their harmful effects. In modern conditions, the biosphere’s capabilities for self-purification and self-regulation are almost exhausted.

– Capacity of the natural environment, i.e. The maximum population size of a certain species that an ecosystem can withstand for a long time without degrading does not allow the processing of all human waste, the accumulation of which poses a threat to global environmental pollution and degradation of natural ecosystems.

– Mineral reserves are limited by the physical and chemical conditions and size of our planet, which leads to their gradual depletion.

– The results of people’s destructive activities often have long-term consequences that cannot be traced over one generation. In addition, the impact on nature in one region can affect places remote from this region.

As a city grows, the costs of maintaining its functions increase and the quality of life decreases. The optimal capacity of the environment obviously corresponds to cities of moderate size, with a population of about 100 thousand people.

The industrial-urban system also strongly depends on the capacity of the environment at the input and output, i.e. the size of the rural environment. The larger the city, the more it needs suburban spaces. Often it is the quality of life, and not the lack of energy and other amenities, that becomes the factor limiting the development of a city. Some scientists believe that the Earth's carrying capacity has already been exceeded.

Current control issues

1. Definition of an ecosystem.

2. Describe the composition of the ecosystem.

3. The abiotic component is...

4. The biotic component is...

5. What functional groups do biotic components consist of?

6. What energy do photoautotrophs use?

7. What energy do chemoautotrophs use?

8. What process is carried out by consumers, or heterotrophic organisms?

9. What do phagotrophs and saprotrophs feed on?

10. What is the role of decomposers in the cycle of substances?

11. What ensures the functioning of the ecosystem?

12. The interaction of which processes is the most important function of any ecosystem?

13. How is self-regulation of systems ensured?

14. Define the following concepts: Homeostasis, Resistant stability, Elastic stability, Photosynthesis, Metabolism, Aerobic respiration, Anoxic respiration.

15. Ecological succession is...

16. How is autotrophic succession characterized?

17. How is heterotrophic succession characterized?

18. The evolution of ecosystems is...

19. Biome is...

20. Briefly list the main causes of ecosystem destruction and resource depletion.

Lecture No. 4.

1.Environmental factors.

2.Abiotic factors.

3. Biotic factors.

4. Anthropogenic factors.

Ecosystems and security of Russia. The modern concept of safety includes environmental risk. People's life expectancy is often determined by the state of nature more than by the country's defense system. The destruction of nature occurs before the eyes of one generation as quickly and unexpectedly as milk runs away on fire. Nature can “escape” from humans only once, and this has caused close attention to the living environment of humans, the diversity of nature, and especially biological diversity. Humanity has recently begun to realize that it is as mortal as the individual, and is now striving to ensure the indefinite existence of generations in an evolving biosphere. The world appears to a person differently than before. However, simply believing in nature is not enough; you need to know its laws and understand how to follow them.[...]

Ecosystems have the ability to recover after destruction. In cases where there is a possibility of penetration into an area that has been subjected to destructive effects (an extensive forest fire, a landslide that exposed lifeless rocks, the burial of large areas under volcanic ash, etc., all species capable of existing in a given climatic zone, a process occurs natural change of ecosystems. It begins with the simplest ecosystems, represented exclusively by “pioneer” eurybiont species, passes through intermediate, relatively stable states, stages, which regularly replace each other, to the final, climax stage. The species complex of this stage is the richest in stenobiont species and in principle, can exist (if we neglect the continuity of the evolutionary process) for an infinitely long time. Such a natural change of ecosystems is called succession (from the English succession - sequence). Under natural conditions, succession usually takes several hundred, and sometimes thousands of years.[...]

When a number of rocks, primarily apatite, which accumulated huge deposits of phosphorus in past geological epochs, are destroyed, this element enters terrestrial ecosystems or is leached by waters and ultimately ends up in the ocean. In both cases, it enters the food chain.[...]

Any ecosystem that exists in close proximity to the earth's surface is a biogeocenosis. Biogeocenosis is a really existing natural phenomenon, consisting of a biocenosis and an ecotype (environmental conditions) and characterized by the constant and continuous flow of two contradictory processes - the construction of organic matter with the conservation of solar energy and the destruction of organic matter with the release of energy. As a result of these processes, an exchange of matter and energy takes place between the individual components of the biogeocenosis, between them and the environment, and a redistribution of matter and energy occurs in space. A diagram of the relationships between the components of the biogeocenosis is shown in Fig. 1.[ ...]

The pace of ecosystem evolution changes dramatically under large-scale stress. Any factor that can bring an ecosystem out of a stabilized state initiates a faster pace of evolution. Such factors may include global climate change, geological processes, mass immigration when connecting continents, etc. Against the background of destroyed previous connections, an avalanche-like formation of new species occurs. New large taxa are formed, i.e. evolution takes on the character of macroevolution. Naturally, this process takes millions of years. Similar phenomena with which the history of the Earth is rich (Cretaceous crisis, etc.) are called environmental crises. An example of an environmental crisis is the dramatic changes in the biosphere that occurred in the mid-Cretaceous period, about 95-105 million years ago.[...]

According to another law, the ecosystem develops in such a way as to restore as much as possible what was destroyed. In other words, by reducing the harmful effects of humans on nature, the ecosystem, as it were, tries to return into the cycle all substances produced by humans. For example, 2 years after man destroys a forest, a steppe appears on a bare field, after 15...20 years - a bush, after 100 years it is replaced by pine, and after 150 years - oak.[...]

The greatest contribution to the destruction of the biosphere is made by the areas of “old” civilizations - Europe, Southeast and South Asia. The total area of destroyed ecosystems in Europe is 7 million sq. km, in South and Southeast Asia it is even more. There are almost no natural ecosystems left in these areas; the number of surviving natural ecosystems is measured in a few percent. The exception is China, where natural ecosystems have been preserved on 20% of the territory. However, this 20% falls on desert and high mountain areas.[...]

Young, productive ecosystems are very vulnerable due to the monotypic species composition, since as a result of some kind of environmental disaster, for example, drought, it can no longer be restored due to the destruction of the genotype. But they are necessary for the life of humanity. Therefore, our task is to maintain a balance between simplified anthropogenic and neighboring more complex, with a rich gene pool, natural ecosystems on which they depend.[...]

In terrestrial and soil ecosystems, fungi, along with bacteria, are decomposers, feeding on dead organic matter and decomposing it. The metabolic activity of fungi is very high; they are capable of quickly destroying rocks and releasing chemical elements from them, which are then included in the biogeochemical cycles of carbon, nitrogen and other components of soil and air.[...]

DESTRUCTION [lat. destructio) - destruction, disruption of the normal structure of something (ecosystem, soil, plants, etc.).[...]

Thus, in the process of destruction of aboriginal populations by pike perch in the isolated ecosystem of Lake. Balkhash, three most important stages can be distinguished: the first is a sharp decrease in the density of their populations, the second is a disruption of normal reproductive capacity, the third is the rupture of the range and isolation of individual local herds.[...]

In August 1999, as a result of the destruction of the Nyashevsky Prudok dam by a rain flood, it ceased to exist.[...]

As is known, natural ecosystems have everything necessary to maintain balance and will maintain it as long as the established connections and flows of substances, energy and information are maintained. Loss of biodiversity, air, water and soil pollution, and destruction of soil cover all reduce the ability to function normally and therefore pose a threat to the existence of equilibrium in systems. It is not known how long one can advance through a broken system, but it is clear that it is not infinite.[...]

Self-purification is the natural destruction of a pollutant in the environment as a result of processes occurring in the ecosystem.[...]

In addition to assessing the degree of disturbed ecosystem, the assessment of its affected area is of great importance. If the area of change is small, then with an equal depth of impact, a small-area disturbed system will recover faster than a large one. If the area of violation is more than the maximum permissible size, then the destruction of the environment is practically irreversible and belongs to the level of a catastrophe. For example, forest burning over an area of tens or hundreds of hectares is practically reversible, and forests are restored - this is not a disaster. However, if the area of forest burning or any form of technogenic destruction of vegetation reaches an area of tens or hundreds of thousands of hectares, the changes are practically irreversible and the incident is classified as a disaster. Thus, the size of a catastrophic environmental violation is quite large and exceeds, according to V.V. Vinogradov, area 10,000-100,000 hectares depending on the type of vegetation and geologist-geographical conditions.[...]

Landscape pollution leads to the destruction of habitats of organisms and disruption of the regenerative capacity of natural landscapes. As a result, ecosystems are degraded and destroyed. The state of the natural environment may be disrupted, which ensures self-regulation and reproduction of the main components of the biosphere (water, air, soil cover, flora and fauna) and healthy living conditions for humans (ecological balance).[...]

As it develops, the mind penetrates the metabolic processes in the ecosystem and transforms them. At the same time, the nature of the exchange changes, it becomes conditioned, given, intentional. Guided by a worldview, a person acts purposefully. As a result of human activity, natural ecosystems are transformed into socio-natural ecosystems, consisting of inanimate nature, living nature and non-nature - culture. Man uses the laws and properties of nature against itself, giving natural processes the direction, form and pace of flow that he requires. On the basis of the known laws of nature, man establishes his dominance over it and ensures it through labor. But work is not only a great benefit for man, freeing him from slavish dependence on nature. Labor, as a powerful means of influencing natural processes, also conceals another side. From a creative factor, under certain conditions, it can turn into its opposite - a destructive factor, especially in terms of the destruction of the OS.[...]

METHANE (M.) - gas (CH4) formed during the anaerobic process of destruction of organic substances, in particular cellulose (methane fermentation). M. is an important link in the carbon cycle. The bulk of M. is formed in waterlogged terrestrial ecosystems (therefore M. is called swamp gas). M. is the main component of natural fuels (up to 99%) and mine gases. The accumulation of metal in coal mines leads to accidents when it ignites.[...]

A significant and potentially dangerous impact on marine ecosystems is the burial of waste in the deep sea. Currently, at the bottom of the seas there are chemical weapons (ammunition) sunk at different times. Despite the fact that it is in metal containers, there is a real danger of destruction of the metal by sea water and depressurization of the containers. Some countries, such as the United States, plan to sink more than 100 old nuclear submarines in the Atlantic at great depths within 30 years, each of which has an estimated residual radioactive material of 2.3 × 1015 Bq. In Sweden there is a project to store radioactive waste under the seabed at a depth of 50 m below the seabed.[...]

ECOLOGICAL DISTURBANCE - 1. Deviation from the normal state (norm) of an ecosystem at any hierarchical level of organization (from biogeocenosis to biosphere). E. n. can occur in one of the ecological components or in the ecosystem as a whole, be causally external to the ecosystem in question or internal to it, have an anthropogenic or natural character, be local, regional or global. It is implied that if E. n. is not enough to lead to irreversible destruction of the ecosystem, then the latter is capable of self-recovery to a relatively previous state.[...]

Let's consider an example of restorative succession (demutation) in an area where the ecosystem of a coniferous (spruce) forest was destroyed during logging. During the logging process, the phytocenosis and zoocenosis are almost completely destroyed, but such an element of the ecotope as soil largely retains the properties that were inherent in it before logging. As for the climate control, it changes radically, primarily in terms of illumination, heating, albedo, and wind conditions. After felling, light-loving and fast-growing herbaceous plants and deciduous tree species will appear in the area cleared of forest. After some time (10-20 years), overgrown deciduous plants will gradually begin to inhibit herbaceous plants, and it will be possible for coniferous seedlings to take root and germinate. Then, as decades pass, deciduous trees will gradually give way to conifers (Fig. 2.21). In the future, the process of collapse of the coniferous population and its replacement by populations of deciduous species (aspen, birch, willow, etc.) may begin.[...]

APPLIED ECOLOGY - development of standards for the use of natural resources and the living environment, permissible loads on them, forms of management of ecosystems at various hierarchical levels, methods of “greening” the economy. In a more general interpretation - the study of the mechanisms of destruction of the biosphere by humans and ways to prevent this process, the development of principles for the rational use of natural resources without degradation of the living environment.[...]

Ecologically permissible load is human economic activity, as a result of which the threshold of ecosystem sustainability (the maximum economic capacity of the ecosystem) is not exceeded. Exceeding this threshold leads to disruption of stability and destruction of the ecosystem. This does not mean that in any given area this threshold cannot be exceeded. Only when the sum of all environmentally permissible loads on Earth exceeds the limit of the “economic capacity” of the biosphere, will a dangerous situation (ecological crisis) occur, which will lead to degradation of the entire biosphere, changes in the environment with serious consequences for human health and the sustainability of its economy. [... ]

During the cycle of matter, there is a continuous synthesis of living organic matter from simple inorganic compounds and the simultaneous destruction of the latter into the simplest inorganic compounds. These two parallel processes ensure the exchange of substances between the biotic and abiotic components of the ecosystem and maintain the constancy of nutrient resources in the environment with virtually no supply from the external environment. It is the closed circulation of matter that is the main core of the mechanism of biological regulation of environmental quality.[...]

In this work, an acceptable measure of deviations from the normal state of the ecosystem are considered to be those deviations that over time can be eliminated by the system itself. Reaching critical state values leads to the destruction or suppression of this system.[...]

The diversity of biological species is a necessary condition for the stability of the cycles of synthesis, transformation and destruction of organic matter in the biosphere. In natural ecosystems, biota maintains a balance between production and destruction of organic matter with high precision. Biota plays a critical role in the destruction of rocks and soil formation. In addition, the biota effectively controls the hydrological regime, the composition of the soil, atmosphere, and water. It has been established that biota fully retains this ability if humanity uses no more than 1% of the net primary production of biota. The rest of the production should go to maintaining the vital activity of species that stabilize the environment [Gorshkov V.G., 1980, 1995].[...]

However, over 10-20 years of using this territory, beavers eat up the plants that serve as food for them (primarily alder) and change their place of residence. There is a fairly rapid destruction of the “reclaimed” ecosystem and restoration of the old one. This cycle continues for approximately 100 years.[...]

E. tends to increase: under the influence of water and wind, crystals are destroyed, and water flows transfer substances from higher points on the surface to lower ones. E. increases with the destruction of organic substances to inorganic compounds. Living organisms, on the contrary, increase their orderliness, while E. decreases: simple substances are formed into complex ones, from one fertilized cell - a zygote - a complex multicellular organism grows, individuals form populations, populations unite into ecosystems, etc. Increased orderliness and decrease E. require a constant supply of energy (see Energy in the ecosystem). [...]

Connell and Sletir (1577), summing up various points of view, proposed three mechanisms of succession. Is the condition of any succession primary? or secondary is some kind of destruction of the existing ecosystem and (or) the appearance of free places that can be inhabited by organisms. [...]

Anthropogenic impact on nature disrupts nature’s remarkable ability to self-regulate, acquired in the process of evolution. Visible artificial changes in the natural environment often lead to fundamental changes in connections in ecosystems and the progressive destruction of the biosphere.[...]

The total global anthropogenic emissions of the two main air pollutants - the culprits of the oxidation of atmospheric moisture - SO2 and IPOx - amount annually to more than 255 million tons (1994). Over a vast area, the natural environment is becoming acidified, which has a very negative impact on the state of all ecosystems. Lakes and rivers devoid of fish, dying forests - these are the sad consequences of the industrialization of the planet” (X. French, 1992).[...]

The degree of maximum permissible water pollution in a water body, depending on its physical characteristics and ability to neutralize impurities, is considered as the maximum permissible load of PDN. But since the use of water is associated with its removal from a reservoir (or watercourse) and the threat of depletion of this object, destruction of the ecosystem, as well as use for swimming, fishing, recreation on the water, limiting the load only in terms of the entry of pollutants into the water turns out to be insufficient. Therefore, at present there is a problem of developing standards for the maximum permissible environmental load on aquatic ecosystems PDEN.[...]

V.F. Levchenko and Ya.I. Starobogatova (1990), according to which the classical succession process, in which species populations of organisms and types of functional connections between them naturally, periodically and reversibly replace each other. Such a sub-cyclic process can continue indefinitely if conditions external to the ecosystem are maintained and the environment has the property of self-healing. This process includes seasonal changes in the river ecosystem. The periods of destruction and restoration of the environment in this case are the same. At the macro level there is stability of the system, and at smaller temporal and spatial scales there is cyclicality and variability.[...]

In human ecology, an environmental violation is understood as any temporary or permanent deviation from environmental conditions favorable to humans. With a maximum permissible environmental disturbance, an intensity of environmental disturbance is allowed that is insufficient to lead to irreversible destruction of the ecosystem, and the ecosystem is capable of self-recovery to a relatively previous state.[...]

It is important to carry out assessments of the possible impact at intermediate and critical levels not only on the ecosystem in areas of direct impact, but also on the entire biosphere as a whole (for example, to restore or replace retired elements of the biosphere, it will be necessary to consume part of the reserves of ecosystems adjacent to the damaged areas); zones with a damaged or destroyed ecosystem can gradually negatively impact the ecosystems of neighboring areas (an example of such an impact is the onset of deserts, secondary pollution caused by pollution in neighboring areas, etc.).[...]

Protozoa perform various functions in the cleaning process. They regulate the number of bacteria in activated sludge and biofilm, maintaining it at an optimal level. By the end of biological treatment, the number of bacteria in the purified water decreases so much that the treated wastewater can be discharged into the reservoir without subjecting it to various additional treatments. Protozoa contribute to the sedimentation of sludge by absorbing suspended substances, create a mobile equilibrium of the activated sludge ecosystem, clarify purified wastewater, loosen the biofilm, promoting its rejection. Due to the absence of many enzyme systems, protozoa do not directly participate in the destruction of wastewater contaminants. But by consuming a large number of bacteria, they release a significant amount of “additional” bacterial exoenzymes. Due to the release of bacterial exoenzymes, protozoa participate in the oxidation of some toxic substances, turning them into non-toxic ones.[...]

Together with industrial and domestic wastewater, technogenic phosphorus compounds can enter soils and groundwater. Features of the migration and accumulation of phosphorus in the biosphere are the almost complete absence of gaseous compounds in the biological cycle, while gaseous compounds are obligatory elements of the biological cycle of carbon, nitrogen, and sulfur. The phosphorus cycle appears to be a simple, open cycle. Phosphorus is present in terrestrial ecosystems as an essential part of the cytoplasm; Organic phosphorus compounds are then mineralized into phosphates, which are again consumed by plant roots. During the destruction of rocks, phosphorus compounds enter terrestrial ecosystems; a significant part of phosphates is involved in the water cycle, leached and enters the waters of the seas and oceans. Here phosphorus compounds are included in the food chains of marine ecosystems.[...]

The task of preserving biodiversity in the city is the task of preserving natural communities that form the habitat and make it favorable for humans: regenerate air and water, soften the microclimate, provide psychological comfort, etc. However, it is impossible to fully solve this problem, since not all types of organisms are able to adapt to the urban environment. Indeed, at present there are such destructive processes for the city as biochemical corrosion of structures, weathering of walls and foundations of buildings, the formation of landslides and quicksand, and karst phenomena. And yet, research in recent years has revealed the dynamics and mechanisms of adaptation of many city inhabitants to new conditions and made it possible to formulate some principles for planning urban development taking into account environmental factors.[...]

Mention should be made of the large-scale environmental disaster in the Barents Sea in 1987-1988. Here in 1967-1975. Excessive fishing undermined the resources of herring and cod. Due to their absence, the fishing fleet switched to catching capelin, which completely undermined the food supply of not only cod, but also seals and seabirds. At sea markets along the shores of the Barents Sea several years ago, most of the hatched guillemots and gulls chicks died of starvation. Hungry harp seals by the tens of thousands have become entangled in nets off the coast of Norway, where they have rushed from their traditional habitats in the Barents Sea in a desperate attempt to escape hunger. Now the sea is empty: catches have decreased tenfold, and restoration of the destroyed ecosystem in the next decade is impossible.[...]

A natural analogue of a substance with a polycomponent composition, including different groups of light organic compounds, heavy hydrocarbons, associated natural gases, hydrogen sulfide and sulfur compounds, highly mineralized waters with a predominance of calcium and sodium chlorides, heavy metals, including mercury, nickel, vanadium, cobalt, lead, copper, molybdenum, arsenic, uranium, etc., is oil [Pikovsky, 1988]. The peculiarities of the action of individual oil fractions and the general patterns of soil transformation have been studied quite fully [Solntseva,. 1988]. The substances included in the light fraction are the most toxic in terms of sanitary and hygienic indicators. At the same time, due to volatility and high solubility, their effect is usually not long-term. On the soil surface, this fraction is primarily subject to physicochemical decomposition processes; the hydrocarbons included in its composition are most quickly processed by microorganisms, but remain for a long time in the lower parts of the soil profile in an anaerobic environment [Pikovsky, 1988]. The toxicity of higher molecular weight organic compounds is much less pronounced, but the intensity of their destruction is much lower. The harmful environmental impact of resinous-asphaltene components on soil ecosystems is not chemical toxicity, but a significant change in the water-physical properties of soils. If oil seeps from above, its resinous-asphaltene components and cyclic compounds are sorbed mainly in the upper, humus horizon, sometimes firmly cementing it. At the same time, the pore space of the soil decreases. These substances are inaccessible to microorganisms, the process of their metabolism is very slow, sometimes tens of years. A similar effect of the heavy fraction of oil is observed on the territory of the Ishimbay oil refinery. The composition of organic fractions of emissions from other enterprises is represented overwhelmingly by highly volatile compounds.

Destruction of natural ecosystems. Destruction of natural ecosystems over vast areas of land

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