Liu Xudong: Take a "photo" of the undersea creatures of Jiaozhou Bay

Liu Xudong is identifying marine benthic organisms in Jiaozhou Bay.

◆ Ge Jingjing Wang Yuan Han Xiaowei

A laboratory, a stereoscope, this is the working environment of Liu Xudong, an engineer of the Marine and Ecological Monitoring Department of Qingdao Ecological Environment Monitoring Center in Shandong Province. In five years, Liu Xudong monitored more than 200 species of benthic animals in the waters of Jiaozhou Bay and photographed nearly 500 high-definition "photos". From a microscopic perspective, the life forms at the bottom of Jiaozhou Bay are like fantasy blockbusters, which is breathtaking.

Benthic animals refer to groups of animals that live on the seabed or inhabit the sediment. Dealing with benthic animals is an important part of Liu Xudong's work.

"The ability of benthic animals to thrive well and be diverse is a direct reflection of the health of the marine environment." Born in 1985, Liu Xudong graduated from ocean university of China and walked into the monitoring laboratory of the Department of Oceanography and Ecology in 2013.

Not long after coming to the laboratory, Liu Xudong was fascinated by the fact that he was looking at a book called "Chinese Seafood Bivalve Atlas", which showed the animal entities in color photos, and before that, all the books and materials he had come into contact with were all hand-drawn in black and white. Liu Xudong suddenly had a bold idea, "I can also take pictures of benthic animals!" ”

In the past five years, Liu Xudong has monitored more than 230 species of benthic animals in Jiaozhou Bay and the coastal waters of Qingdao, and taken nearly 500 high-definition "photos". In 2018, he co-edited the "Atlas of Common Benthic Animals in the Yellow Bohai Sea", which was published, and more than 100 high-definition images from 93 to 124 pages in the book were written by him. ”

Taking a "photo" of an benthic animal is no easier than taking a picture of someone. Following in the footsteps of Liu Xudong, the author actually felt this process.

The first step is to go out to sea to sample. Qingdao has three collection missions a year, and Jiaozhou Bay has 14 benthic monitoring points, and animals need to be sieved for bottling when sampling. After arriving at the sampling point, Liu Xudong skillfully used roller skating equipment to sample benthic organisms. It is not very easy for the mud collector to control the opening and closing of the "big mouth" through a winch; when the mud miner "bites" the bottom mud and pulls it up, it often "grunts" into the wooden boat because of the weight and the rocking of the boat. Liu Xudong said that only wooden boats can be used to do this work, and if it crashes into the hull of a glass fiber reinforced plastic, the mud miner will be damaged. To get enough 0.2 square meters of sediment, the sludge collector needs to take it 4 times. "The mud collected 4 times is very heavy and cannot be brought back to the laboratory, so it can only be processed on site." Liu Xudong said while holding a water pipe, and washed away the sediment piled up in the iron sieve little by little. Long rinses have made Liu Xudong's hands white with bubbles, but Liu Xudong said that the monitoring work this season is already comfortable compared to the biting sea breeze in winter.

The second step is laboratory sorting. This is a very test of eyesight and endurance. The various samples are poured in a tray on a white background, illuminated by a high-gloss lamp, and carefully sorted with forceps. "Some very small individual animals, only 1 mm in size, generally sort for 40 minutes and the eyes can't stand it, and they have to stop to relieve their visual fatigue." Liu Xudong said that samples of a voyage need to be sorted for 2-3 hours.

The third step, after counting, weighing, and identifying, is to take a picture. After counting, weighing, and identifying the sample, it's time to take a picture. Liu Xudong used not a camera to take "photos" of benthic animals, but a special stereoscopic mirror for the laboratory. Under stereo microscopy, animal entities can be magnified up to 1000 times and present a 3D stereoscopic effect. A 5 mm hook shrimp can be seen clearly in the bodypiece microscope with its antennae, foot, tail segment and even compound eye.

In fact, a perfect benthic "photo" can be encountered but not sought. In Liu Xudong's eyes, "perfect" has two definitions, one is that the animal's limbs are complete, the posture is stretched, the characteristics are obvious, and the scientific value and appreciation value are both; the other is the discovery of animal species with good ecological health indicators.

"The middle Amanji worm, whose name has a strong Egyptian pharaonic style, belongs to the species of sea pupae, and the black eyes are very handsome"; "Photographed the short-horned double-eyed hook shrimp, a creature that claims to exist at 10,000 meters under the seabed, is powerful"; "The bell-clawed tiger fish, which is fierce at first hearing, comes from the intertidal zone of the mouth of the sand"; "The ripple insect the size of the needle tip has always felt to be the most beautiful"; "The head looks like a clown, a big flower face, and a strong scale insect of the tin scale family"... This is Liu Xudong's circle of friends, whenever he shoots a "perfect" benthic animal "photo", he can't help but share it with everyone.

Liu Xudong's teacher once warned him that biodiversity research requires full patience and can sit on the "cold bench". Liu Xudong remembered it in his heart and sat in the chair in the laboratory until today. "I'm very lucky that studying marine animals is my hobby, and now my hobby has become a job, and I'm addicted to it, and I have a lot of fun. Under the encouragement and drive of the older generation of marine people, I will continue to do a good job in monitoring marine life and continue to contribute to qingdao's marine environmental protection work with my own modest efforts. ”