"Food is the most important thing for people", and human beings must survive and develop. Food is the foundation and eternal theme of human survival and development.
China, the oriental giant, held his head high and supported a big family of 65.438+0.2 billion children with sweat and wisdom, accounting for 7% of the world's cultivated land and feeding 22% of the world's population. However, with the exhaustion of land resources, the deterioration of environment and the rapid growth of population, the pressure of survival is increasing. Where is the way out? China, when she looked up from the yellow land, turned her eyes to the vast ocean and blew the horn of marching into the ocean.
The ocean is an important support for human survival and development, and it is the largest treasure house of resources. Marine life is one of the richest and most important marine resources in this blue treasure house. There are many kinds of marine life, large resources, diverse chemical components and effective biological utilization, which have great potential to provide food, medicine and energy for human beings. According to statistics, there are about 500,000 species of animals living in the ocean and coastal zone, accounting for 4/5 of the total number of animals on earth. In addition, there are 1.35 million kinds of plants growing in the ocean. Scientific research shows that there are 2.6 trillion tons of biological resources in the world's oceans, but the development and utilization of marine life is still in the primary stage, providing only 2% of human food. It is predicted that the ocean will become the "second granary" of human beings in 2 1 century, and the arable land area is about 15 times that of land. For example, as long as the seaweed naturally growing in the offshore waters is processed into human food, the annual output is equivalent to 15 times of the current world wheat output. If algae and plankton are included in the food range, the ocean can feed 30 billion people. Now when it comes to marine food, people will think of delicious fish, shrimp, crabs, shellfish and other animals. In fact, the focus of "marine food agriculture" is seaweed plants. For example, one hectare of aquatic algae can extract 20 tons of protein after processing, which is equivalent to the protein content of soybeans in 40 hectares of cultivated land for one year. What an attractive development prospect!
The ocean is not only the cradle of life, but also feeds all kinds of marine animals and plants. In the vast sea, there are sparkling night insects, jellyfish with crystal clear bodies, beautiful corals, colorful shellfish, armored shrimps and crabs, puffed squid and various precious sea cucumbers, as well as grotesque fish, ancient and tenacious turtles and graceful seals, sea lions, walruses and dolphins, and huge whales.
Coral has left a good impression on people of all ages. Its branches are slender and flexible, and it is a valuable ornament after processing. In the past, people used to regard coral as a kind of plant and called it "coral tree" because it was too much like a plant. Living corals die and new corals are born again. Over the years, the calcareous bones of dead corals have formed various barrier reefs. Many islands in Xisha and Nansha Islands in China are such coral reefs.
Marine fish, there are about 30,000 species of marine fish in the world, and there are 2,000 species in China waters. Fish are colorful, colorful and strange, which is beyond the reach of any other marine life. So, what is a real fish? The so-called true fish must meet three conditions: first, vertebrates who live in water all their lives; The second is to breathe with the gills and exercise with the fins; Third, there are real maxilla and maxilla. The cuttlefish, abalone and whale mentioned in our daily life are not real fish although they all have the word "fish" in their names. Squid and abalone are mollusks among invertebrates, while whales are marine mammals that breathe with their lungs. Among the marine fish, the butterfly fish is the most vivid and beautiful, and the swordfish is the fastest. The swimming speed can reach 130 km per hour, which is faster than the train. The fiercest fish are sharks ... these strange marine fish have a very close relationship with humans. They are an important source of human intake of protein. protein is not only delicious on the table, but also a raw material for medicine and industry.
Marine animals are mammals that live in the sea. As we all know, mammals are the tallest animals in the biological world. From the evolutionary history, there were no mammals in the ocean, but later they returned to the ocean from land. It is not clear when and why they will return to their hometown. The characteristics of this kind of animals are viviparous, young ones grow up on breast milk, breathe with lungs, have constant body temperature and developed nervous system. There are 130 kinds of mammals in the ocean, such as whales, dolphins, dugong, seals and sea lions. At present, the largest blue whale caught by people is 33.5 meters long and weighs 1950 tons, which is equivalent to the weight of 35 elephants. It can eat one ton of krill in one meal and 4-5 tons of krill in one day.
Dugong, commonly known as "mermaid" or "manatee". People often say that it is the ugliest animal, and its appearance is far from "beauty". But people gave it the nickname "Mermaid", which was probably just a beautiful imagination added to the legend by scholars who had never met before, so the ugly animal became a "beauty". Dugong is ugly, but very docile.
As early as the 1960s, it was predicted that marine animals would be widely used in the military and could collect intelligence for the navy. In recent years, countries around the world have made great progress in the study of marine animals and achieved remarkable results.
Seaweed is the main body of marine plants, with about 20 thousand species. At present, there are about 65,438+000 kinds of algae that can be used as food. There are microscopic algae that are almost invisible to the naked eye. Some are bait for fish and shrimp, and some are microalgae food for development and utilization. Microalgae are rich in protein, fat, sugar and other nutrients and minerals. For example, the protein content of Chlorella is as high as 88.2%, and the protein content of Spirulina is as high as 7 1%.
Marine macroalgae such as kelp, Undaria pinnatifida, Ulva and laver are popular marine vegetables with rich nutrition and bright colors. Giant algae is the largest algae in the ocean, which is more than 300 meters long and can grow more than 60 centimeters every day. These large brown algae constitute the so-called "undersea forest" and become the "fertile grassland" of the marine world. They are not only the natural "pasture" and breeding ground for fish, shrimp, shellfish, crabs and marine animals in the ocean, but also the natural treasure house of human green food and medicine.
To sum up, in the face of the grim situation of population explosion and food shortage in the future, people have to look to the ocean for food and resource development for the needs of human survival and development.
I hope I can help you. You can ask questions ~ ~ ~
I wish you progress in your studies and go up a storey still higher! (*^__^*)