Ocean outlook

Some readers may think, if the ocean can't grow food, how can it become a granary in the future?

Yes, rice and wheat can't grow in the ocean, but the fish and shellfish in the ocean can provide delicious and nutritious protein food for human beings.

As we all know, protein is the most important substance that constitutes an organism and the foundation of life. At present, only 5% ~ 10% of protein ingested by human beings is provided by the ocean. Worryingly, since 1970s, the marine catch has been stagnant and many species have been exhausted. According to a folk saying, humans almost ate all the grandchildren of yellow croaker. To make the ocean a veritable granary, the output of fresh fish should be at least ten times higher than it is now. The experiment of a marine farm in the United States shows that it is entirely possible to greatly increase fish production.

In nature, there are countless food chains. In the ocean, if there are algae, there are shellfish, and if there are shellfish, there are small fish or even big fish ... The total area of the ocean is more than twice that of the land, and most of the few fishing grounds in the world are offshore. This is because algae growth needs sunlight and compounds such as silicon and phosphorus, and these conditions are only available in the offshore near the land. Marine survey shows that in the deep-sea water below 1000 meters, the contents of silicon and phosphorus are very rich, but they cannot float to the warm surface. Therefore, only a few small sea areas, due to the action of natural forces, the deep sea water automatically rises to the surface, thus making these sea areas full of algae and dense fish, becoming a rare fishing ground.

Inspired by these sea areas, oceanographers use the principle of updraft to artificially pump deep seawater to the surface in those sunny sea areas, then cultivate algae there, feed shellfish with algae, and feed lobsters with processed shellfish. Surprisingly, this series of experiments have been successful.

Experts optimistically pointed out that the ocean granary has great potential. The annual output per hectare of land crops with the highest yield in 20 14 is only 0.75438+0 tons in protein. However, scientific experiments show that the maximum output of mariculture in the same area can reach 27.8 tons, and the commercially competitive output is 16.7 tons.

Of course, there will be many difficulties from scientific experiments to actual production. Most importantly, pumping water from the deep sea below 1000 meters requires considerable electricity. Where does such a huge amount of electricity come from? Obviously, under today's conditions, these energy needs cannot be met.

However, scientists have found the trick: they intend to use the temperature difference between the tropical and subtropical ocean surface and the deep sea to generate electricity. This is the so-called seawater temperature difference power generation. In other words, the designed marine farm will be combined with the seawater temperature difference power station.

According to the calculation of relevant scientists, due to the strong light in tropical and subtropical waters, there are as many as 6,250 trillion cubic meters of warm water available for power generation in this sea area. If people use 1% warm water to generate electricity every time, and then pump the same amount of deep seawater to cool down, they can get 750 million tons of various seafood every year by using this electricity for aquaculture. It is equivalent to four times the total amount of fish and meat consumed by human beings in the mid-1970s.

Through these simple calculations, it is not difficult to see that it is completely feasible for the ocean to become the granary of mankind in the future. The development and utilization of marine energy and resources, the study of ocean and global change, marine environment and ecology are the most practical ways for human beings to maintain their own survival and development, expand their living space and make full use of this last resource-rich treasure land on earth.

Marine development needs to obtain large-scale and accurate marine environmental data, and needs seabed exploration, sampling and underwater construction. To accomplish the above tasks, a series of ocean development support technologies are needed, including deep-sea exploration, deep diving, ocean remote sensing and ocean navigation.

It has become a fixed trend to ask for fresh water from the ocean. In the Middle East where fresh water resources are scarce, seawater desalination was regarded as an effective way to obtain fresh water resources decades ago. The United States is actively building desalination plants to meet people's current and future demand for fresh water. There are nearly 8,000 desalination plants in the world, which produce more than 6 billion cubic meters of fresh water every day. Russian oceanographers have found that there are also abundant fresh water resources at the bottom of the world's oceans, accounting for about 20% of the total seawater. This shows a bright future for mankind to solve the freshwater crisis.

Deep sea refers to the sea area with a depth of more than 6000 meters. There are more than 30 trenches in the world with a depth of more than 6000 meters, of which more than 20 are located at the bottom of the Pacific Ocean. The depth of Mariana Trench is 1 1000m, which is the deepest sea area discovered so far. Deep-sea exploration is of great significance to the research and utilization of deep-sea ecology, the exploitation of deep-sea minerals and the study of deep-sea geological structures. The United States is the first country in the world to conduct deep-sea research and development. The submersible Alvin once discovered marine communities at 4000 meters underwater, and the robot Jason dived 6000 meters underwater. 1960 65438+ 10, the American submersible "Diryat" first dived into the Mariana Trench, the deepest trench in the world, with the maximum dive depth of10916m. For the first time, scientists took the "Trieste" deep-sea submersible to conduct a scientific investigation on successfully diving to the deepest part of the Mariana Trench. Surprisingly, scientists actually saw a fish and a little red shrimp swimming on such a seabed! In September 2008, the submarine "Mariana" jointly developed by the United States and Japan dived into the top of the Mariana Trench, the deepest trench in the world, with a maximum dive depth of 10034 meters. 20 12 in March, James Cameron, a famous American Hollywood director, took the submarine Deep Sea Challenger alone and dived nearly 1 1 km to the bottom of the Mariana Trench in the western Pacific Ocean. At 7: 52 local time in Guam on the 26th, that is, at 5: 52 Beijing time, Cameron successfully dived to the bottom of the challenger Haiyuan in the Mariana Trench, the deepest part of the world's ocean, and returned to the water on the morning of the 26th local time. This is the second time that human beings have dived into the Mariana Trench, and Cameron is the first person to dive into this "deepest part of the earth" alone. According to the National Geographic Society, Cameron dived to a depth of10898m in about two hours and reached the bottom of the Mariana Trench. The bottom of the trench is eternal darkness, the temperature is only a few degrees Celsius, and the water pressure is equivalent to 1000 atmospheric pressure. Cameron explored the seabed for more than three hours, collected biological and geological samples, and took photos and videos.

During the period of 1997, our country made a scientific experiment with a cableless underwater vehicle robot, which was successful, marking that China's deep-sea development was on the right track.

Marine remote sensing technology mainly includes two kinds of remote sensing technologies, which take light, electricity and other information carriers and sound waves as information carriers.

Marine acoustic remote sensing technology is a very effective means to detect the ocean. Using acoustic remote sensing technology, we can detect seabed topography, observe ocean dynamic phenomena and detect seabed stratigraphic profile, which provides information for submersible navigation, collision avoidance and seabed contour tracking.

Marine remote sensing technology is an important means of marine environmental monitoring. The rapid development of satellite remote sensing technology makes it possible for human beings to observe large-scale ocean phenomena from space. The United States, Japan, Russia and other countries have launched more than 10 dedicated ocean satellites, providing a solid support platform for ocean remote sensing technology. China Ocean Development Report (20 13) of the Bureau of Oceanic Administration analyzes the domestic and international environment of China's marine economic development, and puts forward the forecast data of China's marine economic related indicators in the next 20 years, including the total output value of marine economy, major marine industries and coastal economy.

The report shows that by 2030, China's marine economy will account for more than 15% of GDP, and China's marine economy will enter a mature stage.

During the 11th Five-Year Plan period, China's marine economy grew at an average annual rate of 13.5%. In 20 12, the marine economy grew by 7.9%, slightly higher than the GDP growth rate of 7.8%, and the marine GDP exceeded 5 trillion yuan, accounting for 9.6% of GDP. Liu, a researcher at the Institute of Marine Development Strategy of the State Oceanic Administration, believes that in the future, the marine economy will still maintain a growth rate higher than or slightly higher than GDP growth.

The report predicts that from 20 15 to 2030, China's marine economy will gradually mature from immaturity, the growth mode will change from extensive to intensive, and the utilization efficiency of marine resources will be greatly improved. The contribution rate of marine economy to the national economy will continue to rise gradually. By 2020, the proportion of marine GDP to GDP will exceed 12%, and by 2030, this proportion will exceed 15%.

In recent years, marine emerging industries have grown rapidly. The average annual growth rate of marine emerging industries as a whole is over 28%, among which the average annual growth rate of marine biomedical industry is 39%, seawater utilization industry is 33%, and marine power industry is 24%.

Wu, an associate researcher at the Institute of Marine Development Strategy of the State Oceanic Administration, said that with the strong promotion of many emerging marine industries and the steady growth of most major marine industries, the total marine production in China has maintained a high growth rate, and the regional marine economic characteristics have become more prominent.

China attaches great importance to the development of marine emerging industries. The Twelfth Five-Year Plan for the Development of National Strategic Emerging Industries officially issued by the State Council in September 20 12 deployed emerging industries that will develop in the marine field during the Twelfth Five-Year Plan period.

The report predicts that the growth rate of emerging marine industries will still be higher than the overall growth rate of the marine economy in the future. During the "Twelfth Five-Year Plan" period, China will cultivate and expand three to five marine emerging industries, form a marine emerging industrial system characterized by marine high technology, and support and lead the development of marine economy.

Developing marine high-tech industry is an important way to realize the sustainable development of marine economy. According to the report, Tianjin, Guangdong, Qingdao, Wuxi and other places are expected to become marine high-tech industrial bases supported by the state in the future according to the industrial base, technological advantages and talent status. Through the construction and development of marine high-tech industrial base, the overall development of marine high-tech and its industrialization in China will be promoted.

According to the report, due to the influence of reclamation projects and the development of coastal industries, China's marine resources and environment will remain an important factor restricting the development of China's marine economy in the future. Land reclamation in coastal areas will not only alleviate the shortage of land resources and create favorable conditions for regional economic development, but also have a series of far-reaching effects on marine resources and ecological environment. The report predicts that how to effectively cope with the challenges of marine resources degradation and marine ecological environment problems and realize the green growth of marine economy will become a major issue for China to develop its marine economy in the future.