Recently, a research team from the National Geographic Society of the United States visited the waters of Argentina’s Tierra del Fuego, the southernmost tip of South America, and found that the underwater seaweed forest ecosystem has hardly changed after half a century. This discovery has attracted widespread attention from marine biologists around the world. .
What is seaweed forest? Seaweed forest is a submarine forest composed of a variety of large brown algae such as Laminaria. Most of the seaweed forests in the world grow in sea areas with seasonal changes. They are mainly distributed on the west coast of North America, the coast of South America, the coast of Antarctica, the coast of South Africa, the coast of Australia, and the coast of New Zealand.
The world’s largest seaweed forest covers an area of more than 8,000 square kilometers, and this “forest” is located in the Pacific Ocean in North America. Under the nourishment of the rich nutrients in the upwelling current, the macroalgae in the seaweed forest can grow to more than 60 meters. The air sacs at the base of the leaves enable the seaweed to extend to the sea surface, forming a huge undersea forest landscape.
Seaweed forest is known as the “Marine Treasure”. It can not only purify seawater and maintain ecological stability, but also provide oxygen, food and living space for fish. It is considered to be the most colorful and vibrant ecology on earth. One of the systems provides a safe refuge for hundreds of creatures (including molluscs, crustaceans, echinoderms, fish and marine mammals, etc.), as well as a productive fishing ground for humans.
The seaweed forest is like a forest on land. It can be divided into several layers: the upper layer is called the canopy, which refers to the top part of the seaweed forest. The largest seaweed species can extend from the canopy down to 30 meters or even deeper under the sea; The second layer is the middle layer. Rockfish, sardines and other fish swim among the giant seaweed leaves; the third layer is the bottom layer, where crabs and octopuses live on the seabed and the false roots of the seaweed on the rocks. , Sea urchin and abalone etc.
In the seaweed forest ecosystem, marine organisms check and balance each other, rely on each other, and use each other to form a complete ecological food chain. For example, seaweed releases a large amount of oxygen through photosynthesis to supply shellfish, while the carbon dioxide emitted by shellfish will be absorbed by algae, and its excrement will be eaten by sea cucumbers, sea snails and other organisms; excess nitrogen and phosphorus in the seawater and other organic matter will be used by algae Absorption, the luxuriant algae provide abundant bait for the growth of abalone, lobster and other organisms. Because the seaweed forest is in a natural buffer zone that avoids rapid ocean currents and has a wealth of biological species, it is also a place where seals, sea lions, sea otters and other mammals, as well as various seabirds often forage. In addition to creating a peaceful place for the vast number of marine life, seaweed can also convert inorganic salts into organic matter during growth and development, and play a role in purifying seawater.
Over the years, due to climate change and human fishing activities, seaweed forests have been destroyed. According to the Commonwealth Scientific and Industrial Research Organization of Australia, the east coast of Tasmania, Australia, was once a paradise for macroalgae. There is a huge deep-sea macroalgae that was born 1.3 billion years ago. However, with climate changes, winter The minimum water temperature has risen by 20% in two decades, resulting in a shrinkage of the kelp forest coverage by more than 95%. In addition to climate warming, a large amount of pesticides, herbicides and other chemical fertilizers have flowed into the ocean, causing marine pollution and leading to the rapid disappearance of kelp forests.
However, just as the seaweed forests on the east coast of Tasmania, Australia, and other areas were severely damaged, in 1973, a scientific research team went to the seaweed forests of the Tierra del Fuego, Argentina to investigate and found that the pure land was not polluted or disturbed. . Half a century later, the seaweed forest here has been well preserved, like a time capsule in the ocean. Why can this seaweed forest remain intact?
It turns out that the Argentine government attaches great importance to the protection of the marine environment, especially the protection of seaweed forests and marine life. Prior to 2013, the only protected ocean in the country was Namkula-Borwood Beach No. 1 Reserve, and the protected area of the ocean was less than 3% of its territorial waters. In December 2018, the country’s Senate passed a bill establishing two new protected areas, Namkula-Borwood Beach No. 2 Reserve and Yaganes Reserve. The area of the protected areas has increased to account for them. 9.5% of the territorial sea area, thus doubling the protected marine area. It is precisely because of such strong marine conservation measures that the seaweed forests in the waters of Argentina’s Tierra del Fuego have remained so intact.
The seaweed forest is the cornucopia of the ocean. It is not easy to protect it from pollution, intrusion and destruction, but it is not difficult to protect it. Argentina is a model of marine environment and marine life conservation. As long as we can be like them, then a vibrant and energetic marine environment and marine life will definitely be presented to the world.