Marine plants are autotrophic organisms in the ocean that use chlorophyll for photosynthesis to produce organic matter. Marine plants are primary producers. There are many types of marine plants, from lower algae without true nuclei (i.e. prokaryotic cells of cyanobacteria and prochlorophytes), to red algae, brown algae and green algae with true nuclei (i.e. eukaryotic cells), to higher seed plants, etc., 13 phyla, a total of more than 10,000 species.
Overview of Marine Plants Marine plants refer to autotrophic organisms in the ocean that use chlorophyll for photosynthesis to produce organic matter. From lower algae without true nuclei to higher seed plants, there are a wide range of categories, including 13 phyla and more than 10,000 species. Among them, the diatom phylum is the largest, reaching 6,000 species; the Prochlorophyta phylum is the least, with only 1 species. Marine plants are mainly algae. Marine algae are simple photosynthetic nutrient organisms with complex morphological structures, life styles and evolutionary processes, between photosynthetic bacteria and vascular plants, and occupy a very important position in the origin and evolution of organisms. There are not many types of marine seed plants, only 130 species are known, all of which belong to angiosperms. They can be divided into two categories: mangrove plants and seaweeds. They and other organisms living in them form the biological community along the coast of the ocean. In addition, marine plants also include marine lichens, which are algae-fungus symbionts. There are not many types of marine lichens, which are found in tidal zones, especially supratidal zones.
Features
Marine plants have complex shapes, ranging from single-cell golden algae of 2 to 3 microns in size to multicellular giant brown algae of more than 60 meters in length; there are simple colonies and filaments, as well as trees with complex body structures such as vascular bundles and embryos. Plants in the ocean are called seaweeds. Some seaweeds are very small and can only be seen by magnifying them dozens or hundreds of times with a microscope. They are composed of a single cell or a string of cells, with branches and leaves of different colors, and float in the water relying on the branches and leaves. Single-cell seaweed grows and reproduces very quickly, increasing many times a day. Although they are constantly eaten by various fish and shrimps, their number is still huge.
Seaweed, like land plants, cannot survive without sunlight. In its life process, marine green plants absorb nutrients from seawater, and synthesize organic substances (sugar, starch, etc.) through photosynthesis under the irradiation of sunlight to meet the needs of marine plant life. Photosynthesis must have sunlight. Sunlight can only penetrate the surface of the seawater, which means that seaweed can only live in shallow seas or the surface of the ocean. Large seaweed can only live on the beach and on the seabed within a few dozen meters of water depth. Large seaweed is tens or even hundreds of meters long. Their soft bodies cling to the seabed and are swayed back and forth by the impact of waves, but they are not easily broken. The economic value of seaweed is very high. Seaweed, such as kelp, laver and agar in China’s shallow seas, are all very good food. Some can also be used to extract industrial and pharmaceutical raw materials such as iodine, bromine and potassium chloride. Seaweed is food for marine animals. Some marine animals are herbivorous, while others rely on eating “herbivorous” animals to survive. Therefore, animals in the ocean rely on seaweed for survival.
Classification
Algae: Algae are low-level autotrophic plants containing chlorophyll and other auxiliary pigments. The plant body is single-celled, single-celled, or multi-celled. Algae do not have true roots, stems, or leaves. The entire plant is a simple thallus. Each part of the algae has the function of producing organic matter, so algae are also called thallus plants. Seaweed is the main body of marine plants and a great natural treasure of mankind. There are more than 100 species of marine algae that can be used as food. Scientists divide seaweed into two types: floating algae and benthic algae based on their living habits.
Mangroves: Undersea forests are rare species of mangroves in the world. The height of this kind of mangroves growing on the seabed is uneven, and the highest can reach 5 meters. They are exposed from the beach at low tide and swallowed by the sea water at high tide. Only the taller ones slightly reveal their tops and sway with the waves. Various birds rest on the treetops. Egrets, herons, and black-tailed gulls are frequent visitors here. Turtle doves and bitterlings also build nests and settle down on higher trees all year round. There are five families and six species of trees in the underwater forest. Their roots are particularly developed, intertwined, entangled, and in various shapes, which are very ornamental. In the coastal area of Zhangzhou, Fujian, which has a coastline of 680 kilometers, mangrove resources are extremely rich. There are thousands of acres of mangroves at the mouth of Zhangjiang River in Yunxiao County, Zhangzhou City-undersea forest.
Mangroves are forests growing in seawater. They are unique forest vegetation growing in tropical and subtropical coasts and intertidal zones of estuaries. Their root system is very developed, intertwined and standing on the beach. They have leathery green leaves and are shiny. Like lotus, they are not stained by mud. When the tide is high, they are submerged by the sea, or only the green crown is exposed, as if they are holding up a green umbrella on the sea. When the tide recedes, they become a lush forest. Mangrove coasts are mainly distributed in tropical areas. The east and west coasts of South America, the West Indies, and the west coast of Africa are the main areas where mangroves grow in the Western Hemisphere. In the East, the distribution center is Sumatra in Indonesia and the west coast of the Malay Peninsula. Along the Bay of Bengal, India, Sri Lanka, the Arabian Peninsula and the eastern coast of Africa, there are all places where mangroves grow. Mangroves are also widely distributed along the coast of Australia. They are also distributed in Indonesia, the Philippines, the Indochina Peninsula, and the coastal areas of Guangdong, Hainan, Taiwan, and Fujian in my country. Due to the influence of the Kuroshio warm current, mangrove coasts are distributed all the way to Kyushu, Japan. [2]
Eating
There are also records in history that the Irish people relied on red algae and green algae to survive famine years. The habit of eating seaweed in Western countries is not as common as in Eastern countries. There are fewer species of marine seed plants, which mainly grow in low-tidal rock marshes or on subtidal rocks. Common ones include giant kelp, red root shrimp-shaped algae and salt marsh vegetables, all of which are important economic species, mainly used in the papermaking and building materials industries.
The people of Eastern countries such as China and Japan have a very long history of eating seaweed and using seaweed as medicine. There are records of British sailors using red algae to prevent and treat scurvy in history; there are also records of the Irish people relying on red algae and green algae to survive famine years. The habit of eating seaweed in Western countries is not as common as in Eastern countries. A Western oceanographer once lamented that the Chinese and Japanese eat seaweed as commonly as Americans and British eat tomatoes. He hopes that one day, Westerners will develop the habit of eating seaweed like Easterners.
Function
Marine plants are the “fertile grassland” of the ocean world. Marine plants are not only the natural “pastures” of marine fish, shrimps, crabs, shellfish, sea beasts and other animals, but also green food for humans, and also the providers of industrial raw materials and agricultural fertilizers with a wide range of uses. They are also important raw materials for making marine medicines. Some seaweeds, such as giant kelp, can also be used as energy substitutes. Light is the energy source of marine plants, temperature is the growth factor of marine plants, and mineral nutrients are the nutrients of marine plants. Algae are ancient and primitive low-value objects, widely distributed in rivers, lakes and oceans. They have many species and various forms. They are a large group of plants.
Seaweed is a large family of marine organisms. From single-cell diatoms and dinoflagellates that can only be seen under a microscope to giant kelp that is hundreds of meters high, there are more than 8,000 species. Brown algae is a unique algae in the ocean, and its characteristic is its huge size. Giant kelp, Fucus, cystis, kelp, and Sargassum are famous brown algae. Kelp is a seafood that the Chinese people like to eat. It not only has a strong seafood flavor, but is also rich in nutrition. It contains iodine and other minerals and vitamins, which can prevent and treat thyroid disease (commonly known as big neck). Other seaweeds with edible and medicinal value include Chinese laver, kelp, agar, etc.
