A healthy ocean

On land, where there is land, grass can grow. Of course, in areas covered with snow and ice all the year round, grass will not grow, but its growth rate is not high. Even in places like the Arctic Circle, you can still see many flowers and plants in summer. Plants are the most common creatures on land, so there are many kinds and quantities of herbivores that eat plants. Most oceans are actually very barren. In the deep sea, there are no plants, because there is no sunshine. There are only plankton and animals that feed on it in the sea, and the number is usually small.

The truly rich areas are basically shallow sea and continental shelf areas near the coastline. Some of the largest fishing grounds in the world are located around the land. But in shallow water, some water flows fast, which is not conducive to the growth of plants. Although some areas are shallow, they are only tens of meters, which still blocks the absorption of sunlight and hinders the survival of plants. So there are few areas rich in plants in the ocean. Herbivores, such as manatees, are few in species and quantity. In the ocean, the most basic food for animals is plankton. Then a large number of small animals, such as krill, feed on plankton. There are also small fish that feed on small animals such as krill, and even huge blue whales.

Yes, there are about 6 families 13 genera and about 70 different species of marine algae, all of which belong to angiosperms. There are animals that eat seaweed, such as dugong (and more), and they are exposed to breastfeeding. This is a manatee mammal, and sailors mistakenly think it is a mermaid in the ocean. There are three subspecies of manatees, and of course they also eat seaweed. These species can hardly see any difference because they all have the same ancestor.

I believe you also found a * * * similarity-all the rural areas are surrounded by cities, and all the creatures in the sea come back from the land. Their ancestors, whether angiosperms or mammals, were born entirely on land, all of which were born nearly 65.438+0.5 billion years ago. They are all more complex and powerful evolutionary tree species. More interestingly, the ancestors of algae invaded the ocean about 70 million years ago, and the ancestors of manatees invaded the ocean about 60 million years ago. It can be seen that before this, nothing born on land could reach the ocean. Why?