Amazing! New discoveries on the seabed!

Seamounts are known as "undersea gardens". Due to their special geographical features and hydrological conditions, they have created unique biological communities and ecosystems. They are gathering places for colorful marine life and are also hot spots for deep-sea biodiversity research.

In recent years, with the support of the special project of basic scientific and technological resources survey and the strategic science and technology leading project of the Chinese Academy of Sciences, Researcher Xu Kuidong of the Institute of Oceanology, Chinese Academy of Sciences, has served as the chief scientist on the "Science" marine science comprehensive survey ship, China's large scientific facility, for five consecutive times. He has conducted multidisciplinary comprehensive surveys of seamount organizations in the western Pacific many times and obtained a series of new discoveries.

Coral forest on seamount

According to Xu Kuidong, using the "Science" and its equipped "Discovery" deep-sea robot, the survey system obtained first-hand data and samples on the environment and biodiversity of nine seamounts in the Western Pacific, and gained an understanding of the structure of the seamount ecosystem; established my country's largest seamount biological sample library with the richest species and data, discovered the high diversity, high specificity and low connectivity of Western Pacific seamount organisms, and published one new subfamily, four new genera and 56 new species of large organisms with the greatest conservation value on seamounts; discovered large tracts of colorful coral forests growing on seamounts, revealing the causes of high biomass on seamounts that support the oligotrophic waters of the Western Pacific.

The "Discovery" deep-sea robot is like an underwater sightseeing car. It is equipped with ultra-high-definition cameras, LED lights and various sensitive probes, which can "live broadcast" what it sees and hears along the way. The "Discovery" is also equipped with a variety of equipment for collecting water samples, sediments, rocks and biological samples. While collecting samples and data, it can carry out in-situ scientific experiments on the seabed, realizing the scientists' dream of "moving the laboratory to the seabed."

Venus flytrap anemone + sponge

Sponge + Sea Lily

Bamboo coral + sponge + crinoid

On the seamounts it has surveyed, the Discovery has seen representatives of almost all animal phyla, from the most primitive multicellular animals, sponges, to the most advanced mammals. Microorganisms such as bacteria and protozoa cannot be seen with the naked eye, but they often aggregate with tiny floating substances in the ocean to form "marine snow" visible to the naked eye, which becomes the main food source for seamount creatures.

"On the deep and dark seamounts, cnidarians such as sea anemones, gorgonians, black corals, columnar polyps, and glass sponges of various shapes, under the illumination of LED lights, some of these animals look like peach trees in full bloom, some like a flowing and unrestrained reed, and some like a large blooming sunflower, which looks amazing. " Xu Kuidong said.

Golden Gorgonian

Bamboo Gorgonian

Hydrocoral

Ugly Gorgonian

The "undersea garden" also has echinoderms such as starfish, brittle stars, sea cucumbers, sea urchins, and crinoids; mollusks such as bivalves, snails, and octopuses; and crustaceans such as deep-sea shrimps, crabs, hermit crabs, and armored shrimps. Common deep-sea fish active at the bottom of the seamount, such as sharks, deep-sea dogfish, sea lizards, and anglerfish, are also beautiful scenery on the seamount.

Although seamounts and land mountains are both "mountains", their formation causes are significantly different. Seamounts are mostly formed by dormant volcanoes, with hard bottoms such as rocks as the main body. In some areas, soft bottom sediments such as foraminifera sand or coral sand may form. On the other hand, land mountains are mostly formed by the compression and collision of continental plates.

Sponge + deep sea shrimp

Moray Eel

Cobalt-rich crust

Why can seamounts become beautiful and rich "gardens" thousands of meters deep in the dark seabed?

According to Xu Kuidong, this is because seamounts can cause upwelling and change the flow field above the seamounts, forming hydrological phenomena such as "Taylor columns", which directly or indirectly cause the accumulation of nutrients above the seamounts, increase primary productivity, and make the seamounts have higher biomass than the surrounding deep sea. "Taylor columns" refer to the circulation formed by stable ocean currents when they flow to the seamounts, which can retain organisms in the seamount area.

However, not all seamounts have "Taylor columns". The complex topography, water mass and flow field structure, and biological differences of seamounts lead to significant differences in material circulation and energy flow processes in different seamounts.

sea ​​anemone

Sponge

sea ​​lily

"There are more than 30,000 seamounts in the world with a height of more than 1,000 meters on the seabed. Humans have only conducted biological surveys on about 1% of them, which means that about 99% of seamounts are still little known. At present, my country is fully implementing the 'three depths' exploration strategy of deep earth exploration, deep sea observation and deep space earth observation. Seamount research has also ushered in new development opportunities, and more and more mysteries of seamounts will be unveiled." Xu Kuidong said.

Source: Xinhua News Agency