"After four days of intensive search and rescue, we have not been able to find the target finless porpoise, and we will switch to a routine search and rescue and continue to closely monitor its movements. At 11 o'clock in the morning of February 5, in the conference room of the wharf of the Nanjing Waterway Bureau of the Yangtze River near the mouth of the Sancha River in Nanjing, Liu Kai, a researcher at the Freshwater Fisheries Research Center of the Chinese Academy of Fishery Sciences, regretfully announced that it was difficult to hide his loss.
Injured finless porpoise found in the waters of Hongyun Bridge on January 30. Photo by Wu Jun.
On January 26, a diseased finless porpoise with yellow scars on its body was found in the Nanjing section of the Yangtze River, which immediately touched the hearts of many citizens. In the past few days, multiple departments, including the protected area, fishery administration, maritime affairs, marine police, and the Yangtze River Waterway Department, have conducted joint operations to try to search and rescue. This is the first time in the country to take the initiative to rescue wild finless porpoises, although it has not been successful for the time being, but it has accumulated valuable experience for the rescue of finless porpoises.
1% hope, 100% effort
On the afternoon of January 26, Chen Guanping, a photographer and monitor of the Nanjing Finless Porpoise Photography Team, photographed a "different" finless porpoise with many dark yellow patches on its head in the waters near Zhongshan Wharf and Power Plant Park. The next morning, he sent ** along with a 23-second short ** to the group of the photography team. At the same time, the Nanjing finless porpoise rescue team also found the finless porpoise during the patrol and reported it to the Nanjing Yangtze River Finless Porpoise Provincial Nature Reserve Management Station as soon as possible.
At 5:10 p.m. on February 2, a sick finless porpoise floating in the waters of the Nanjing Tidal Water Station. Photo by Wu Jun.
Urgent response! At 2:30 p.m. on the same day, a search team composed of 16 people, including members of the finless porpoise rescue team, fishery officers of the Nanjing Municipal Agricultural Comprehensive Administrative Law Enforcement Corps, and police officers of the Xiaguan Office of the Nanjing Branch of the Changhang Public Security Bureau, took two boats and traveled in the same direction along both sides of the Yangtze River to search the waters between the Nanjing Yangtze River Bridge and the Third Bridge in accordance with the method of visual observation of the national finless porpoise scientific expedition.
At 4:38 p.m., when the boat passed through the waters of Qianzhou Zhoutou, monitor Tang Lin captured two finless porpoises swimming together, one of which had obvious scars on its body. In the next two days, more and more ** was transmitted back from the front line, and after comparison, it was basically determined that this was the diseased finless porpoise that everyone was looking for.
On January 31, the Nanjing Yangtze River Finless Porpoise Provincial Nature Reserve Management Station held an emergency meeting, and more than a dozen experts, scholars and staff from different departments and scientific research and conservation units "consulted" online and offline.
On January 31, the Nanjing Yangtze River Finless Porpoise Provincial Nature Reserve Management Station held an emergency meeting to "consult" the finless porpoise. Photo by Wu Jun.
Hao Yujiang, a researcher at the Institute of Hydrobiology of the Chinese Academy of Sciences, who has many years of experience in raising and treating finless porpoises, judged from the images that the finless porpoise was suffering from systemic infection. "* Disease is a common disease in the finless porpoise population and generally recovers on its own. However, such a large area of infection must be manually intervened, otherwise the diseased finless porpoise can only passively wait for death. ”
According to the on-site observations, the finless porpoise came out of the water every 10 seconds, which was lower than the normal ventilation time, indicating shortness of breath and lack of physical strength. Chen Bingyao, vice president of the Nanjing Finless Porpoise Aquatic Life Conservation Association and a professor at Nanjing Normal University, said frankly that he had been dragging his sick body in the river for several days, and the success rate of treatment was not high, but he still suggested trying to fish and rescue him.
Sutai fishery department 00001, Wanguan fishery index 80001 ......Six fishing boats for scientific research purposes came from Anqing and Dangtu in Anhui Province, Zhenjiang and Taizhou in Jiangsu Province, and drove as far as two days. The Freshwater Fisheries Research Center of the Chinese Academy of Fishery Sciences also specially dispatched a group of fishermen who "washed their feet ashore" to participate in the rescue.
Zhang Chuncai, a Wuwei person from Anhui Province, came from upstream with 13 fishermen from the same village. The 67-year-old "boat boss" has walked all over the Yangtze River from Hubei to Jiangsu. After the "10-year fishing ban" on the Yangtze River was launched, he stayed at home, while the young people went to the factory assembly line. This time he "came out of the mountain again", he had mixed feelings. "I've been idle for so long, I really don't want to get on the boat again. But for the sake of this finless porpoise, I called out the old brothers again, and everyone fought again. ”
Even if there is only 1% hope, it is necessary to do 100% effort. An emergency rescue campaign around the finless porpoise ensued.
From active drive to waiting for an ambush
Call the boat and get it out of the way, it's going to startle the porpoise!" During a search on February 2, Jiang Meng, secretary general of the Nanjing Finless Porpoise Aquatic Life Conservation Association, shouted at the cab. Unfortunately, it was too late, and the finless porpoise, which had just been probing at the surface of the water, quickly disappeared into the waves behind the boat: they were lost again.
The adult finless porpoise is more timid and hides as soon as the boat approaches. The noise of the engine, the propeller, and the current of the boat will startle it. Jiang Meng was a little annoyed. To this end, they urgently called two unpowered dinghys, and on the windy and rough river, the two crew members used the most primitive oars to move forward in violent shaking.
Liu Kai told reporters that it is far more difficult to carry out rescue in the Yangtze River than in lakes and ex-situ reserves. "The Yangtze River is a completely open water, and the unstable winds, turbulent currents, and many passing boats can cause the finless porpoise to react to stress, and it can swim freely, so it is difficult to keep track of it. ”
On February 3, the unpowered boat searched the waters of Zhongshan Wharf. Photo by Wu Jun.
As a result, fishing regimens have changed. "It is not feasible to drive away actively, you can only crouch and ambush. Liu Kai introduced that on the basis of grasping the law of finless porpoise activity, send boats to wait in its active waters, and once it passes, it will be immediately contained. Rocky shorelines can easily cut fishing nets and injure finless porpoises, so it is best to raise water on the natural gentle shore beach dominated by mud.
Zhang Chuncai, who has been fishing for more than 40 years, is also bottomless. "In the past few days, the water depth has been at least 20 meters, and the fishing nets we brought are only 10 meters high, so it is not easy to trap. As he spoke, he shouted for the crew to open the deck and take out two 15-kilogram stones to sink to the bottom. He clearly remembers that when he was young, rare animals such as finless porpoises and baiji dolphins often appeared in nets, but after participating in many Yangtze River aquatic life expeditions and more than ten rescue efforts, he knew better than anyone that "this fish is not what we should hunt."
Since the 31st of last month, Nanjing has suddenly cooled down, and the rain and snow have fallen in the past few days, resulting in a "veil" on the river surface, and the visibility is low, which is not conducive to observation. The search and rescue on February 4 was also interrupted by the blizzard.
On February 3, the unpowered boat searched the waters of Zhongshan Wharf. Photo by Wu Jun.
The further you go, the greater the risk. Liu Kai's expression became more and more solemn day by day. The most recent sightings of the target finless porpoise were already difficult to swim in, and it even floated on the surface of the water at one point. Observations for several days show that it often haunts the waters between Hongyun Bridge and Zhongshan Wharf, indicating that this is its habitat.
But it is precisely this area of water that is the most frequented place for finless porpoises. Jiang Meng explained that it is located in the Jiajiang area, the water flow is slow, and the Qinhuai River carries a large amount of nutrients into the river, attracting fish to gather. "It still shows fatigue in such an environment, indicating that its physical strength is depleted and its predatory ability is also weak. Jiang Meng judged.
Experience worth accumulating
Near the shallows on the east coast of Qianzhou, three fishing boats lined up, laying their nets as they went, enclosing a water area about several hundred meters wide, and a model of a finless porpoise lying quietly in the middle of the water.
Although we could not find the target finless porpoise, considering that it was not easy to deploy ships and personnel, we decided to conduct an emergency drill to simulate the finless porpoise fishing scene. Liu Kai stared at every move not far away.
On the morning of February 5, the search and rescue personnel made a clear division of labor on the ship. Photo by Wu Jun.
After the encirclement was completed, the two non-powered boats approached and lowered the nets from both sides of the "finless porpoise" to complete the fishing. The crew picked up the "finless porpoise" in black cloth and carefully transferred it to the ship, and the researchers on the side immediately poured fresh water on the "finless porpoise" in order to adapt to the new environment.
After all, it is a finless porpoise model, and there are fewer uncontrollable factors, which is much easier than live fishing. For example, at high tide today, the finless porpoise will dive into deep water, but the model will remain on the surface of the water. Despite this, Liu Kai still recounted a number of experiences in the review: large boats should be netted on the periphery to fix the form of fishing nets, and then small boats with easy movement should enter the field to round up; In the past few days, the river water flow speed is relatively fast, and the mesh should not be too dense, which will hinder the flow of the river water and cause overturning; The line of the fishing net should not be too thick, as it is easy to scratch the ...... of the finless porpoise"Including the observation in the first 11 days, we have accumulated experience in adapting to the topography and water conditions of the Nanjing section of the Yangtze River, and further improved the practicability and scientificity of rescue. ”
12 drivers, 13 scientific researchers, 14 fishermen, as well as photography enthusiasts and finless porpoise conservation volunteers, an average of more than 50 people invested on site every day, for a finless porpoise, 11 days of wind and rain. In addition, Nanjing Underwater World, 11 kilometers away, is also "on standby". The California sea lions here will be ready to "move" if needed – the 64-tonne pool will be switched from seawater to fresh water as soon as possible, and the filtration circulation system will continue to operate. "We also add chlorine dioxide to the water to ensure that the microbial content is kept to a minimum. The three to four times a day of medicine and drying** plan has also been set a long time ago. Chen Dajun, director of the laboratory and veterinarian of the Nanjing Underwater World Freshwater Aquarium Department, said.
At 10 a.m. on February 5, a finless porpoise rescue drill was carried out in the waters of Nanjing Tidal Water Station. Photo by Wu Jun.
Although the search and rescue has not been successful for the time being, many discoveries in this rescue are worth gratifying.
Under the Yangtze River Bridge, the red buoy is 200 meters in front of the left and has two ends, and the surface of the body is smooth! "Eight finless porpoises were found 100 meters near the shore of Wentao Square, and there was no target finless porpoise!" "Six heads were found in the waters of the Yangtze River Smile Station, 50 meters from the shore! ”
Taking the search on January 27 as an example, the latest information was heard from time to time on the intercom, and in just one voyage, 18 to 20 individuals were witnessed and identified. Even on February 3, when the wind and rain were staggered, the photographer still captured more than 30 finless porpoises out of the water. Looking back nine years ago, there were only twenty or thirty finless porpoises in the Nanjing section of the Yangtze River. With the continuous restoration of the Yangtze River ecology, Nanjing has now become the only large city in China where wild Yangtze finless porpoises inhabit the central section of the city, and the number of finless porpoises living in the city has reached about 62.
What makes everyone even happier is that almost all finless porpoises are in a vigorous posture and powerful out of the water, zooming in, the surface of the body is also smooth, and there are even small finless porpoises that are not afraid of life appearing near the shore, and mother-child dolphin escorts have become the norm, and the finless porpoises living in Nanjing are healthy and energetic as a whole.
There is one thing to praise about Nanjing. Liu Kai said that the love and attention of ordinary citizens for the finless porpoise makes the diseased finless porpoise quickly locked, otherwise the probability of the wild finless porpoise being found after getting sick is very low.
*: Xinhua ** Junction.