Last month, China’s 40th Antarctic expedition completed its mission and returned to China. What scientific research progress has been achieved during this inspection? Let’s go to the Ocean University of China to see scientists’ biological research on Antarctic fish.
The survey of mesopelagic fish is an important part of the ocean survey of China’s 40th Antarctic expedition. At the Deep Sea and Polar Fisheries Research Center of the Ocean University of China, the reporter saw that researchers here were conducting preliminary identification and analysis of various species of mid-water fish collected during 40 Antarctic scientific expeditions.
Tian Hao, postdoctoral fellow at the Deep Sea and Polar Fisheries Research Center of the Ocean University of China: This station is sampling in the Amundsen Sea. The bottles are mainly Antarctic fish with side stripes. They are frozen on board and brought back to the laboratory, and then thawed. Species identification, classification and presentation, anatomy experiments and some biological determinations.
Mesopelagic fish are fish that live in the middle water bodies of the ocean. They live on plankton and shrimp, and are eaten by larger organisms. They play an integral role in the marine ecosystem and food chain, and are an indispensable link. Compared with the fish resources on the surface and bottom of the Southern Ocean, humans have limited understanding of the resources and species distribution of mid-pelagic fishes in the Southern Ocean. Therefore, investigation of mid-pelagic fishes in the Southern Ocean is very necessary.
reporter learned that researchers observed and analyzed the stomach contents and partial tissues of fish samples to explore the different roles that each fish plays in the ocean ecosystem.
Li Jianchao, associate professor at the Deep Sea and Polar Fisheries Research Center of Ocean University of China: mainly depends on what the fish eats. After zooming in, we can see that this is the remains of an Antarctic krill, and the one above is the remains of an amphipod zooplankton. Changes in the environment will also cause changes in the organisms it eats, which will have a certain impact on its own growth.
The researchers told reporters that during the investigation, they would also conduct research on very young larvae and juvenile fish. Although the larvae are small in size, they are very valuable samples for studying the early development of fish. By analyzing the age of otoliths of larval and juvenile fish, the hatching date and early growth status of each fish can be determined, and the distribution of spawning grounds and nursery grounds can be inferred.
The reporter learned that in order to timely track and grasp the dynamic changes of fish populations, the fish research team of Ocean University of China continues to study and introduce new methods.
During this expedition, researchers obtained more than 20 species and more than 800 rare Antarctic fish samples. Among them, bottom longline fishing was carried out for the first time in the Amundsen Sea, which enriched the fish survey system and played a key role in supporting research on Antarctic fish habitats.
Ye Zhenjiang, Professor of the Deep Sea and Polar Fisheries Research Center of Ocean University of China: Especially in the environment of scientific research ships, many survey devices are developed and designed by ourselves, and we have applied for relevant patents.
