The ocean is an objective pool of natural resources, but it doesn't mean that we can develop and pollute endlessly. The amount of pollutants that can be contained in a certain range of sea areas is limited, and the environmental capacity is a comprehensive index for us to make full use of the self-purification ability of the ocean. The marine environmental capacity is closely related to the size, location, hydrometeorology, aquatic organisms, self-purification ability, population characteristics of organisms, physical and chemical characteristics of pollutants and environmental standards implemented.
From the perspective of environmental space, the larger the space, the greater the ability of the environment to purify pollutants, and the greater the environmental capacity.
For marine pollutants, the more unstable their physical and chemical properties are, the greater the environmental capacity is.
Marine desertification and its harm refers to the decline of marine (and coastal) productivity under the action of human beings, that is, the marine environment develops in a direction that is not conducive to human survival. The main cause of marine desertification is the decline of environmental carrying capacity in the sea area, which is manifested in the reduction of productivity in the sea area, the deterioration of seawater quality, the destruction of mangroves and coral reefs, overfishing, frequent outbreaks of biological disasters such as red tides. Due to the fluidity of seawater and organisms, the "source" sea area is often destroyed, which affects the ecological environment of adjacent or even the whole sea area.
The total area of China sea area is about 4.277× 106 square kilometers. Due to the rapid development of coastal economy and the unreasonable use of the ocean by human beings, some sea areas are experiencing serious desertification, especially in the coastal waters of Bohai Sea. In recent 20 years, with the rapid economic development around Bohai Sea, Bohai Sea has suffered unprecedented pollution. The area of polluted sea area increased from less than 26% in 1992 to 4 1.3% in 2002, and the content of heavy metal elements in some coastal seabed sludge even exceeded the national standard by 2000 times. After a large amount of nitrogen and phosphorus nutrients are discharged into the coastal waters, the eutrophication degree of seawater increases, resulting in frequent occurrence of red tides. There was no red tide record in Bohai Sea before 1960s, only three times in 1970s, 0/9 times in 1980s, 27 times in 1990s and 88 times in 2000-2008. The largest red tide covered an area of over 6,543,800 square kilometers, and accumulated economic losses amounted to several billion yuan. At the same time, overfishing has caused a serious decline in fishery resources, which shows that the species of fishery organisms in the Bohai Sea have decreased significantly, and the traditional economic fish resources have dropped sharply, showing a trend of younger age and miniaturization, with juvenile fish accounting for more than 60% of the total fishing.
Ocean dumping refers to the disposal of wastes and other substances into the sea by ships, planes, platforms and other means of transport; The process of dumping ships, planes, platforms and other artificial structures into the sea, and disposing of wastes and other substances generated from the exploration and development of seabed mineral resources and related offshore processing into the sea, but excluding the discharge of wastes generated from the normal operation of ships, planes and other vehicles and facilities.
The first country in the world to implement ocean dumping was the United States. As early as 1875, the United States began to dump acid mud into the sea in Charleston harbor, South Carolina, which was the first time to dump waste into the sea. Britain began dumping garbage at the mouth of the Thames from 1887. Since then, Japan, France, Ireland, New Zealand and other countries have also dumped wastes at sea. Unreasonable dumping of wastes has polluted the marine environment and caused serious marine ecological damage. For example, in the 1930s, more than 7,000 tons of arsenic were dumped in the Baltic Sea due to damaged cement packaging, resulting in a large number of fish deaths.
In order to protect the marine environment, the Intergovernmental Conference on the Convention on the Dumping of Wastes at Sea held in London from 65438 to 0972 adopted the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, namely the London Convention on Dumping of Wastes. Protocol 1996 of the Convention stipulates that parties "shall prohibit the dumping of any wastes or other substances, except those listed in the list". The dischargeable list includes hydrophobic substances, sewage sludge, fish wastes or substances produced by industrial fish processing operations, offshore ships, platforms or other man-made structures, inert and inorganic geological substances, and huge articles originally composed of iron, steel, concrete and similar harmless substances. China also clearly stipulates in the Regulations on the Administration of Ocean Dumping that "the dumping of wastes into the ocean is strictly controlled", and defines the substances that are prohibited from dumping and those that need special permission to dump.
Marine ecological compensation of marine ecological resources is the basis of sustainable development of human society and environment. However, in the process of developing and utilizing marine resources, due to people's lack of understanding and ineffective macro-control of production scale, the number of marine living resources has dropped sharply and the marine ecosystem has been destroyed to varying degrees. In order to ensure the sustainable utilization and development of marine ecological resources, it is necessary to manage marine ecological resources by economic means. Because marine ecological resources are public goods, there is insufficient or zero output according to the market mechanism. As a manager, the government should compensate the victims of marine ecological environment damage and the contributors who have contributed to environmental governance.
Marine ecological compensation means that users or beneficiaries of sea areas pay corresponding fees to the owners of marine resources or those who pay the price for the protection of marine ecological environment in the process of legally utilizing marine resources, and its purpose is to support and encourage the protection of marine ecological environment.
To carry out marine ecological compensation, we must first determine the stakeholders of a certain marine development or protection activity, that is, the people, groups or organizations affected by the activity and its results. The main basis is as follows: ① to determine the economic value of marine ecological resources; (two) the main compensation objects that have contributed to the protection of marine ecological resources; ③ Fully consider the indirect stakeholders related to the development and protection of marine ecological resources; ④ When carrying out ecological compensation to protect the value of marine ecological resources, don't ignore the service value of marine ecosystem. Economic compensation or economic compensation is one aspect of marine ecological compensation, and the compensation intensity can be determined according to the value of marine resources and the local economic development level.
In addition to economic compensation, marine ecological compensation should also include marine habitat compensation and marine resources compensation. In terms of resource compensation, China has done a lot of practice, such as the productive proliferation of China shrimp in the Yellow Sea and Bohai Sea in 1980s.
Marine ecological destruction marine environmental problems include marine environmental pollution and marine ecological destruction. Marine environmental pollution refers to pollutants entering the ocean, which exceeds the self-purification ability of the ocean; However, marine ecological damage is damage caused by extraction or development, also known as non-pollution damage, that is, improper extraction or development of certain substances and energy from the marine environment (non-pollution activities) has adverse effects and damage to the marine environment.
Typical marine ecological damage caused by unreasonable human production activities includes: ① coastal engineering construction, reclamation of land, cutting down mangroves, digging ponds to raise shrimp, etc. Destroy the coastal environment and coastal ecosystem; (2) Over-fishing of some traditional economic fish by human beings leads to a sharp decline in the quantity and quality of fish and shrimp resources in the offshore waters, which in turn leads to a large number of non-economic organisms breeding due to the sharp decline of natural enemies, which makes the marine ecology unbalanced and destroys the marine ecological environment; (3) Red tides endanger the marine environment such as aquaculture and fishing. Estuaries and harbors are mostly adjacent to large and medium-sized cities and densely populated, which are the main areas where marine ecological damage occurs. In the heavily polluted sea area, the ecosystem becomes very fragile and more vulnerable to ecological damage. Reducing the discharge of pollutants and controlling the over-exploitation of marine resources are the main measures to prevent the marine ecology from being destroyed.
The service function of marine ecosystem refers to the products and services provided by a specific marine ecosystem and its components for human survival and development in a certain period of time. The service functions of marine ecosystem generally include 14 basic functions, such as food production, raw material production, oxygen production, gene resource provision, climate regulation, waste treatment, biological control, disturbance regulation, recreation, cultural value, scientific research value, primary production, nutrient circulation, biodiversity maintenance and so on.
According to the similar functions and nature of marine ecosystem services, these functions can be divided into four categories: supply, regulation, culture and support.
Supply function refers to the function of marine ecosystem to provide food, raw materials, genetic resources and other products for human beings to meet and maintain human material needs.
Regulation function refers to the service function and benefits that human beings get from the regulation process of marine ecosystem.
Cultural function refers to the intangible benefits that people get from the marine ecosystem through spiritual feeling, knowledge acquisition, subjective impression, entertainment and aesthetic experience.
Support function is the function of maintaining species diversity and ensuring primary production for the material function, regulation function and support function of marine ecosystem.
These marine ecosystem service functions are the overall expression of marine ecosystem and its biodiversity, the result of the interaction between biology, biology and environment, and the contribution of marine ecosystem to human beings.
Enclosure experiment of marine ecosystem The experiment of studying the structure, function and changes of marine ecosystem in a relatively closed ecosystem surrounded by natural seawater by artificial methods is called enclosure experiment of marine ecosystem. The water depth of this fence is between 1 and 10 meters. Seawater can't be exchanged with the surrounding seawater and won't be affected by tidal current and horizontal disturbance, but it is very similar to the surrounding natural environment, which can solve the problem of great difference in test conditions in natural sea areas and make the experimental results more objective. According to the amount of water, the paddock can be divided into three categories, namely, small paddock (1 ~ 10 m3), medium paddock (10 ~ 100 m3) and large paddock (>: 100 m3); According to ecosystem types, it can be divided into plankton ecosystem enclosure, plankton-benthic ecosystem enclosure and benthic ecosystem enclosure; According to the matrix, it can be divided into soft bottom enclosure, rock foundation enclosure and suspended enclosure.
At present, the research contents of isolation experiments abroad in China generally include four aspects: ① Study on the natural ecology of marine life. This paper mainly studies the relationship between plankton population structure, composition and environment, as well as the material and energy transfer between organisms of different trophic levels in the food chain, and establishes a mathematical model on this basis. ② Study on pollution ecology. For example, the migration and transformation of pollutants such as nutrients, heavy metals, petroleum and pesticides in the ecosystem and their effects on the structure and function of the ecosystem. (3) the study of fishery resources, especially the study of supplementary biological resources and factors affecting biological resources. ④ Study on the relationship between air-sea interface flux and water-sediment interface flux. During the period of 1984- 1987, the Third Institute of Oceanography of the State Oceanic Administration, Shandong Ocean College and Xiamen University cooperated with Canadian scientists to carry out enclosed ecosystem experiments in Xiamen, and conducted experiments on the effects of oil and heavy metals on marine ecosystems in a land-based pond of 20 m×10 m× 5 m.