20-Hour Rescue Stranded Sperm Whale Returns to Sea
Experts interpret the classic operations in the rescue process, calling for reducing pollution to the marine environment and noise pollution, and avoiding excessive fishing activities
On the morning of April 19, a male sperm whale ran aground in the waters of Shipu Town, Xiangshan County, Ningbo City.
At about 5:20 on April 20, after a 20-hour relay rescue, the sperm whale successfully arrived at the destination sea area and was released into the sea under the tow and escort of the fishery administration boat.
"It's really a miracle."
Hao Yujiang, an associate researcher at the Institute of Hydrobiology, Chinese Academy of Sciences, said that many experts judged that the sperm whale's situation was not optimistic. Although they were "slapped in the face" later, everyone was still very happy. This is a rare large-scale cetacean successfully rescued at home and abroad. case.
What are the classic operations of this rescue?
How to avoid beaching of cetaceans in the future?
In this regard, a reporter from the Beijing News interviewed Hao Yujiang.
Interpretation 1
Are there many sperm whale strandings?
Cetaceans are a collective term for all small dolphins and medium and large cetaceans. There are about 90 species in the world, and they are indicators of the health of the marine environment.
According to Hao Yujiang, the sperm whale is the largest toothed whale and is a second-class national protected animal.
The living habits of sperm whales are also very unique. They are cetaceans that live in the deep sea. The general prey water depth is three to five hundred meters, and the deepest can dive to more than 1,000 meters.
The distribution range of sperm whales is relatively wide, and the community structure is close to the matrilineal clan society.
Female sperm whales live in temperate, tropical waters with their babies and other females.
Male individuals like to be alone, and will seek out female groups during the breeding season. After the breeding season, they will go to colder high latitudes to hunt for food.
"Sperm whales are very social. I once saw a video of a female sperm whale giving birth and after giving birth, other sperm whales in the group stopped and formed a circle to protect the newborn sperm whales. The scene was very warm." He It is said that animals that are usually very social have higher IQs.
The marine mammal research team of the Institute of Deep Sea Research of the Chinese Academy of Sciences has studied and analyzed the data of cetacean strandings along the coast of my country for nearly 70 years.
The study collected a total of 1,763 cetacean stranding records from 1950 to 2018.
The stranding data recorded a total of 36 species of cetaceans, including nine baleen whales and 27 toothed whales, the findings showed.
As typical nearshore species, coastal finless porpoise and Chinese white dolphin (43%) were the dominant species in stranding records.
In terms of the number of animal strandings, 92% of the strandings were single individuals, almost all baleen whales were single, and some groups of dolphins in toothed whales were stranded.
Over time, the number of whale strandings each year has continued to increase, and in the past 30 years, there have been significantly more than before 1990.
Hao Yujiang said that from 2007 to 2019, my country recorded a total of 12 strandings of 17 sperm whales, 3 of which were collective strandings (usually, the stranding of more than two adults is collective stranding).
But none of these sperm whales were rescued successfully in the end, and some died again after returning to the sea.
This is the first sperm whale stranding event recorded in my country after 2019. Fortunately, the male sperm whale returned to the sea and survived.
Interpretation 2
What are the reasons for the success of this rescue?
Hao Yujiang introduced that when rescuing the animal, it is necessary to straighten the animal, keep the breathing hole facing upwards, and keep the breathing hole open.
Small instruments can be used to dig holes around the perimeter of the animal's body to collect water and keep its body moist.
He reminded that for small and medium-sized cetaceans, do not forcefully pull the flippers of the whales during rescue to avoid fractures.
Also, keep your surroundings quiet, too noisy environments can make wildlife nervous.
"This time is a rare successful case, and such examples are rare at home and abroad." Hao Yujiang said that in his group of experts, most experts thought that sperm whales could not be rescued because it was too difficult to rescue. , Especially after the tide receded, the sperm whale's breathing was very weak, the body could not move, and all the genitals were exposed, which showed that its vital signs had reached a state of serious weakness.
Unexpectedly, after the tide rose, the sperm whales breathed normally and became more and more powerful.
The reason for this, he believes, is that this male may be in his prime and his physical condition should be good. "If its basic physical conditions are poor, it will definitely not survive such a long period of dehydration."
In addition, the local fishery, fire, public security and other relevant departments rescued very appropriately.
He said that the stranded sperm whale was 19.5 meters long and weighed 30 to 40 tons.
For such a large, heavy animal, injecting the drug basically doesn't do much.
The ambulance crew kept pouring water on the sperm whale's body to keep it moist. Although much of it was mud, it also relieved the animal's dry and cracked skin and also played a role in cooling the animal.
When the tide rises, let the sperm whales return to the deep sea by dragging, driving, etc.
Hao Yujiang believes that yesterday's rescue operation was very classic.
Because cetaceans are very heavy, usually after stranding, their own weight will compress the internal organs of the body, causing damage to internal organs, especially after the lungs are compressed, breathing will gradually weaken.
However, Hao Yujiang analyzed that sperm whales are deep-diving cetaceans, which can dive to 1,000 meters, which is equivalent to a pressure of 100 atmospheres. Because of their adaptation to deep diving, their bodies may have a strong ability to withstand pressure. Morphology is also very strong, and its internal organs may not have caused extremely serious compression damage during the stranding.
Interpretation 3
How to carry out follow-up monitoring?
This time, the local fishery administration arranged for personnel to track and monitor the sperm whales. Judging from the current monitoring status, the sperm whales can swim, breathe and dive normally, exceeding expectations.
In the case of being stranded for such a long time, it is still worried that there will be some damage to its internal organs, so it remains to be seen whether it will be stranded again.
Hao Yujiang pointed out that if sperm whales recover well, long-term monitoring through visual observation is difficult. Another method is to install tracking beacons for cetaceans to automatically emit signals.
"The dorsal fin of dolphins is very strong connective tissue, and the tracking beacons are generally mounted on the dorsal fin. But large cetaceans have very thick skin, so the tracking beacons are usually anchored directly on the animal's skin."
In early July 2021, more than 10 melon-headed whales were stranded in Taizhou, Zhejiang.
Soon after, two rough-toothed dolphins ran aground in Ninghai County, Zhejiang Province.
The sperm whale was stranded in the waters of Shipu Town, Xiangshan County, Ningbo City.
Why have cetacean strandings occurred many times along the coast of Zhejiang in recent years?
Hao Yujiang analyzed that this may be related to the topographic environment of the offshore waters of Ningbo, Zhejiang. From the map, there are a large number of small islands along the coast, like a maze, and the transition between shallow water and deep water is relatively sudden.
For sperm whales, which live in the deep sea, the flat underwater terrain may interfere with their echo detection capabilities. Coupled with the small islands scattered around, once they enter such waters, it is difficult to swim out by their own echo detection capabilities. this waters.
Hao Yujiang said that there are more than a dozen hypotheses about the reasons for the stranding of cetaceans.
The more common ones include animals with diseases, entering shallow waters in the process of chasing food, and beaching at low tide.
It is generally believed that individual strandings may be related to their own physical condition, such as disease.
However, the reason for the stranding of the male sperm whale this time cannot be judged.
Interpretation 4
How to prevent beaching of cetaceans?
Hao Yujiang pointed out that natural causes such as personal injury and illness are inevitable, but it is necessary to reduce the pollution of the marine environment caused by humans, reduce pollutant emissions and noise pollution, avoid excessive fishing activities, and create a healthy marine ecosystem.
Cetaceans are at the top of the food chain in the ecosystem, and their presence is an important indicator of ecosystem diversity and an indicator of marine ecological function and health.
"If the structure of an ecosystem is damaged, or its function declines, it is difficult to support the survival of the top creatures like cetaceans."
Large cetaceans also play an important role in cycling energy and matter throughout the ocean, he said.
After the natural death of cetaceans, they will sink to the bottom of the sea, that is, the so-called "whale fall". Their bodies will be enjoyed by other fish, crustaceans and other marine organisms, and the nutrients in the bones will be heavy during the long degradation process. Returning to the sea plays an important role in the energy and material circulation of the ocean, especially the deep sea.
Therefore, it is very meaningful to protect and rescue cetaceans.
Beijing News reporter Zhang Lu