On March 22, "World Water Day", the special interpretation of the "Yangtze River Vitality Report 2022" co-sponsored by WWF and The Paper was held in Shanghai.
Over the years, WWF has continued to work on the conservation research and practice of the freshwater ecosystem of the Yangtze River, protecting wetlands, and protecting the stable habitat of finless porpoises, fish and millions of waterbirds, so as to enhance the service value of the watershed ecosystem.
It is understood that WWF explored and researched and built the conceptual framework of the "Yangtze River Vitality Index" in 2018 to track the health of the freshwater ecosystem of the Yangtze River and help the protection of the Yangtze River, the construction of the Yangtze River Economic Belt and the high-quality development of the Yangtze River Basin. WWF released the first Yangtze River Vitality Report in 2020, which attracted widespread attention at home and abroad.
In 2022, on the basis of the first Yangtze River Vitality Report, WWF once again worked with relevant research institutions to optimize and improve the Yangtze River Vitality Index, and added relevant content such as the impact and assessment of climate change and extreme weather events on the Yangtze River Basin, and released the Yangtze River Vitality Report 2022.
The following is the full text of Hao Yujiang, leader of the 2022 finless porpoise scientific expedition and associate researcher of the Institute of Hydrobiology of the Chinese Academy of Sciences:
Thank you host! My name is Hao Yujiang, from the Institute of Biobiology of the Chinese Academy of Sciences, who has been engaged in the conservation of finless porpoises for a long time, and I have participated in three of the four scientific expeditions of the Yangtze finless porpoise in the past. The first time in 2006, the second time in 2012 because I was abroad, did not participate. In 2017, I had the honor of being the on-site commander of the expedition.
During the 2022 inspection, the Ministry of Agriculture and Rural Affairs Jiang Office organized four scientific expeditions in four sections, and I served as the leader of the first scientific expedition team, from Yichang to Chenglingji. It is a pleasure to share with you today and it is also a very good learning opportunity. In particular, I just listened to the reports of Director Ren and President Chen and learned about the system of assessing the vitality of the Yangtze River.
I also came up with a topic at the right time, the Yangtze finless porpoise: a barometer of the vitality of the Yangtze River.
After listening to the two reports just now, this sentence is really true, the Yangtze finless porpoise is the highest creature in the Yangtze River, aquatic mammals, cetaceans, intelligence level from the perspective of biological evolution is the highest creature, and has a very beautiful and very charming smiley face, loved by the general public, and even called its laughter "the smile of the Yangtze River". Because it is right at the top of the ecosystem, if the Yangtze River ecosystem is regarded as a pagoda, it is a pearl at the top of the Yangtze River aquatic biodiversity pagoda.
Therefore, it is indeed the flagship species of the Yangtze River ecosystem, and its population rise and fall also represents the health of the Yangtze River ecosystem, or the state of healthy vitality. Therefore, it is a barometer of the vitality of the Yangtze River.
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On February 28 this year, the Ministry of Agriculture and Rural Affairs officially released the results of the 2022 Yangtze River porpoise scientific expedition, which showed that the new population statistics of finless porpoises were 1249, which has received great attention from all walks of life after the release of this data. Today, I would like to take this opportunity to share with you how the scientific expedition was conducted, how this data was obtained, how to interpret this data, and how this result indicates our next protection work.
The finless porpoise population has increased to some extent
First of all, let's review the time, scope and content of this visit. This is the fourth scientific expedition, and this expedition is slightly different from the previous two in terms of the time frame of the inspection, the first few were basically carried out in November and December in autumn and winter, and this time it was brought forward to September. However, from the perspective of the water level of the Yangtze River, it is similar to the original, and last year it happened to face extreme drought in the Yangtze River, and the water level was relatively low. The inspection is generally arranged in the dry season, although the time is advanced to September, but the water environment of the Yangtze River is very similar to the dry season.
Courtesy of the Institute of Aquatic Sciences, Chinese Academy of Sciences
The scope is the same, mainly the main stream of the Yangtze River, the Yangtze finless porpoise is mainly distributed in the middle and lower reaches of the Yangtze River, and Poyang Lake, Dongting Lake, so the range of the main stream is from Yichang to Shanghai, two Tongjiang lakes, Poyang Lake and Dongting Lake, this time specifically increased the investigation of the Han River. The main task is to examine the number of finless porpoises, what kind of changes have occurred in the number, second, whether the distribution area has changed, and third, whether the living environment of the Yangtze finless porpoise has changed.
The inspection basically uses fishery administration boats from various places, and our team uses 020 fishery administration boats and Jingzhou fishery administration boats 025. Large platforms are used for mainstream investigation, and small fishing boats are generally used in the lake area, and fishing boats are also used in Poyang Lake. The investigation method is basically the same as the original, and the most important investigation is the truncated sampling method of investigation through eyes and telescopes. As a toothed cetacean, the finless porpoise has a very frequent vocalization, and its number is measured by recording its sound, which is called passive acoustic investigation.
In addition, the so-called image assistance system was added to the expedition, and a panoramic camera was installed in front of the research vessel, which recorded the human activities on the river, the coastal environment, and the possible scenes of finless porpoises during the expedition. In addition, we use environmental DNA methods to test water quality.
The original three expeditions were all two research ships, and the two-ship two-way investigation was carried out, starting from Wuhan to Yichang, Yichang to Shanghai, and Shanghai and back to Wuhan. This time, under the unified leadership of the Jiang Office of the Minister of Agriculture and Rural Affairs, Yichang, Chenglingji, Hukou, Nanjing, and Shanghai were divided into four sections, each of which was carried out by two research vessels. The time is much shorter than the original, the original expedition is about 38-40 days, this main stream expedition is basically in a week, basically about seven or eight days to end, different sections are slightly different.
The two lake area expeditions were originally completed by two boats, and this time the two lake area expeditions adopted a segmented method and were divided into four sections for two-way investigations. The tributaries are mainly single-boat two-way, and the Han River has done a single-boat one-way investigation. The inspection plan is different, but the basic inspection technical means are exactly the same as the previous three times.
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Many people are most interested in how the population of finless porpoises is counted, and whether they are counted? I said yes, it was counted, but it was not, it was actually the result of calculation, and this is the most original recorded data.
The first line is the number of miles of all the sailed miles of the main stream of the Yangtze River, Poyang Lake, Dongting Lake and Han River. The second line is the original data of the investigation, the number and first time the finless porpoise was seen in each section of the investigation, because there are groups, the first row is how many times it is seen, the second line is how many heads are seen, and the blue in parentheses below represents the first time the finless porpoise was seen in this section of the river in 2017. It is still obvious from the raw data.
In 2022, the results of the main stream of the Yangtze River, Poyang Lake and Dongting Lake showed that the population of finless porpoises increased significantly compared with 2017. But this is not the final result given, but the raw data of multiple repeated expeditions by multiple ships. There are also acoustic detection results below, and from the acoustic results, they are indeed higher than the 2017 data. Although the original data is not the final result, it gives everyone the initial impression that the results in 2022 are indeed significantly higher than in 2017.
Courtesy of the Institute of Aquatic Sciences, Chinese Academy of Sciences
How exactly is it calculated? The method idea is very simple, the original data you just saw, the finless porpoise is living in the water, more than 95% of the time is underwater, with the visual method to see the finless porpoise, see some finless porpoise, in fact, there are invisible finless porpoise. The main thing is to estimate the probability that we will see a finless porpoise, or how many finless porpoises have not been seen, which is the so-called observation probability G0 value. The probability of observation is related to distance, the lower the probability of seeing it at the farther away, and the higher the probability of seeing it closer. After estimating the observation probability, the size of the inspection area (effective bandwidth) is estimated, which is equivalent to the size of the inspection area.
With the amount of raw data and knowing the area, it is very simple to calculate the density of finless porpoises. The scope of investigation is not the entire living area of the finless porpoise, but the intercept sampling method is used. In estimating the area of habitat suitable for finless porpoises in the Yangtze River, knowing the density and knowing the area, multiply the number.
The final quantity is basically calculated in this way, which is a very simple idea, but the specific calculation process is very complicated, there are many parameters of calibration and correction, and there is indeed a range of changes. Finally, the number of each river section was given, 595 in the main stream, 492 in Poyang Lake, and 162 in Dongting Lake.
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Of course not, this is the result of calculations, the most likely to be close to its true representation of population numbers. Our results were examined using the same methodology and similar time periods for comparison of population dynamics monitoring. The final result was 1249 head. Compared with 1012 in 2017, this result has a significant increase in the data, and there is indeed a significant difference, representing a certain degree of growth in the finless porpoise population.
Why passive acoustic investigation? As a toothed whale, finless porpoise is their tool underwater sonar, its eyes play a small role, especially underwater, mainly relying on vocalization to detect the environment, including fishing, avoiding boats. Through the passive acoustic recorder for recording, the investigation process uses two methods, when the boat sails during the day, the mobile passive acoustic investigation is used, there is a long cable at the stern of the boat, two A-tags are hung on the cable, the sound recorder, the sound recorder records the sound of the finless porpoise, the distance between the two is fixed, the same finless porpoise will be recorded by these two A-tags after emitting sound, there is a certain time difference between them, you can judge the swimming direction of the finless porpoise, According to the smooth curve of the direction trajectory on the acoustic capture map, it can be judged that a finless porpoise appears, and the method of estimating the finless porpoise can be estimated by acoustic monitoring. At night, the boat will stop, and we will put an acoustic recorder SoundTrap on the side of the boat, which can only record the relative sound of finless porpoises, and can only relatively estimate whether there are finless porpoises in this area, or how many there are.
The finless porpoise in the main stream of the Yangtze River is more continuously distributed
Next, look at the results, from the situation of the main stream of the Yangtze River, the distribution of finless porpoises is more continuous than in 2017, the green position is to indicate the location where finless porpoises were found, from the overall result point of view, divided into three natural sections, the middle section, the lower section is the largest number, the upper section, especially the river section above Wuhan, the habitat is more discontinuous, but the habitat of the river section below Wuhan is more continuous and complete.
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In the course of the investigation, we found that the so-called high-density areas of finless porpoise distribution, including Hubei, Dongting Lake Estuary (Chenglingji), Huangshi Jingjiangmen, Anqing Reserve, Wuhu Black Sandbank, Nanjing Reserve, these areas have a relatively large distribution of finless porpoise. In the areas including Yichang Gezhouba, Jiayu Wanzhou Bay, Ehuang Bridge, Tongling Reserve, and Yangzhou Sanjiangying, the density of these river sections is relatively high.
Judging from the distribution of mother and child dolphins in the main stream of the Yangtze River, this expedition in 2022 is the highest proportion found among the four expeditions, even higher than the 2006 expedition, which is very encouraging news. This result indicates that the growth of finless porpoises is very promising in the future stage, indicating that the reproductive situation is very good. From the results point of view, the probability of finding mother and child dolphins is relatively high, including Yichang, Jingjiangmen, Honghu, Ezhou, Daijiazhou, Anqing, Tongling, Nanjing River section, the probability of mother and child discovery is relatively high, why the probability of mother and child discovery is high last year We also analyzed a reason.
The first observation conditions are good, compared with the previous in September and October last year, the inspection time was 3 months earlier, and the birth time of the baby finless porpoise is generally in May and June, at this time, the body ratio of the little finless porpoise and the mother is relatively large, and it is easier to find that it is a mother and child dolphin.
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Of course, this data is a more realistic reflection of the proportion of finless porpoises born, which is encouraging information. Shown here is the sighting rate of finless porpoises in Dongting Lake, which is simply understood as the number of finless porpoises seen in one kilometer. Monitoring began in 2006, from 2006 to 2009 was a rapid decline, from 2009 to 2015 basically remained stable, although looking at the data has risen, but the data itself will have a certain error, basically little change. But after 2015, the number of sightings increased significantly, reaching 1.59 per kilometer in 2022, and the increase in data is very obvious and very encouraging.
The finless porpoises in Dongting Lake are mainly distributed in East Dongting Lake, and the density of antlers and catfish mouths is relatively high, and this area basically shows a continuous distribution. Last year, due to extreme drought, some finless porpoises entered the tributaries of Dongting Lake, including the Xiangjiang River and Songzi River, and finless porpoises were also found.
The distribution of porpoises in Poyang Lake, the witness rate fluctuates, but it is basically relatively stable, there is no rapid decline process like Dongting Lake, the overall process is a slow rising state, relatively stable, but the witness rate is much higher than that of Dongting Lake, because it is an investigation conducted in the dry season. In the dry season, finless porpoises are basically concentrated in the main channel of the lake area, Poyang Lake is a very typical seasonal lake, in the rich water area like the sea, the so-called "abundant water", in the dry period is a small river ditch, so "dry water line". The finless porpoise is forced to compress into the main channel, so the sighting rate is very high, close to 3 at the highest time, close to 3 finless porpoises per investigation kilometer, and the density is very high.
From the overall results, it is relatively stable and slow to rise, of course, the increase in 2022 is also related to last year's extreme drought, last year was a very dry year in Poyang Lake, and the distribution of finless porpoises was very concentrated. Last year's expedition coincided with extreme drought, and porpoises were mainly concentrated in the main waterway, from Duchang Zhupao Mountain to the mouth of the Zhuxi River. Affected by extreme drought, the main lake area of Poyang Lake is relatively shallow, some finless porpoises want to enter the Yangtze River through the main channel, and some cannot go up into the tributaries of Poyang Lake, including the Gan River and the Xinjiang River.
The total number of 1,249 head in the survey showed a population recovery, with an average annual increase of 4.3%, which is very encouraging. After all, the number is only more than 1,200, so the critically endangered status has not improved, and the follow-up protection task is very heavy. From the distribution point of view, the main stream 595, Poyang Lake 492, showing a certain growth, Dongting Lake growth is very obvious, Dongting Lake 2017 inspection results of 110, this expedition increased to 162, the increase is very obvious. From the perspective of distribution patterns, the main stream is basically the same as the original, but more continuous, the so-called distribution blank area has become smaller and less, and the distribution above Wuhan and below Nanjing is relatively fragmented.
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It is very encouraging that in the 2022 expedition, the number of mother and child dolphins has increased significantly, and the distribution area has also increased, indicating a better recovery of the population.
The rebound trend of finless porpoise population coincides with ecological changes
Four expeditions, this expedition in 2022 is the first time to stop falling and recover, the news is very exciting, and everyone is also thinking about what factors have had a positive effect on the recovery of finless porpoises. Just now I listened to Dean Chen's report and learned a lot, I understand it from our point of view, and it will be better to divide it into three categories from his point of view.
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According to my overall thinking, the first is the change in development concept, especially the development concept of the Yangtze River Economic Belt. The concept of "Yangtze River protection" is gradually advancing, and the development concept of "green development and ecological priority" in the Yangtze River Economic Belt has played a very important guiding role in the improvement of the ecological environment of the Yangtze River. Under the guidance of the concept of "Yangtze River protection", a series of relevant laws and regulations, including the most important is the "ten-year fishing ban", which is very good news for finless porpoise. The Yangtze River Protection Law has been promulgated, which systematically provides legal guarantees for the ecological protection and hydrological protection of the Yangtze River.
In 2021, the finless porpoise was officially upgraded to a first-class protected animal, and the protection level was upgraded. Due to relevant legal guarantees, the management of ecological restoration of the Yangtze River has been gradually strengthened, including the strengthening of the management of protected areas, and eight Yangtze finless porpoise nature reserves have been established in the Yangtze River, but for a long time, these reserves have not really effectively played the role of ecological environment and aquatic biological protection.
In the past few years, the management capacity of the reserve has been continuously strengthened, which has played a very important role in the management, planning, shoreline improvement, regreening and ecological restoration of sand mining in the Yangtze River. It is important to participate in the whole society, the finless porpoise is a star animal, many people like it very much, and the mesmerizing smile has become the object of protection of many non-governmental protection organizations.
We first established the first foundation in 1996 called the Wuhan Baiji Dolphin Protection Foundation, which was a lonely and lonely person, and there was only this NGO organization. But in less than a decade, dozens of NGOs have been established. Including carrying out assistance in patrolling, some fishermen became rangers after the ten-year fishing ban, and actively participated in the ecological environment, aquatic life protection, finless porpoise protection and other related work of the Yangtze River.
From the perspective of the law of population development and change, the process of rapid decline of finless porpoise population is the most serious time for the development of the Yangtze River, including dock construction, waterway improvement, urban riverside belt construction and so on. This process has the greatest disturbance to the habitat and living environment of finless porpoises. In the past few years, the environment has slowly recovered, and the finless porpoise has continued to adapt to the changed environment, and the population has recovered to a certain extent. This is a superficial interpretation of the current decline and recovery of the finless porpoise population.
From the results of the four investigations, the population change pattern of the Yangtze finless porpoise is consistent, especially from the number of the main stream of the Yangtze River, which declined rapidly from 2006 to 2012, was relatively stable in 2017, did not decline significantly, and showed a relatively obvious increase in 2022, and the trend is very consistent with the overall ecological environment changes of the Yangtze River. It is precisely for this reason that I firmly believe that the Yangtze finless porpoise is a barometer of the vitality of the Yangtze River, and its population change process is very consistent with the change of the ecological environment of the Yangtze River.
To protect the finless porpoise, it is necessary to restore the natural vitality of the Yangtze River
What are the implications of the findings? Let us realize that the direction of protection is right, adhere to green development, ecological priority, and promote the restoration of the ecological environment of the Yangtze River, which is the most effective measure to protect the Yangtze River. To protect the finless porpoise, it is necessary to restore the natural vitality of the Yangtze River.
In 1986, the mainland first proposed measures to protect the Yangtze River porpoise and baiji dolphin, and the most fundamental measures proposed at that time were in-situ protection, protecting natural habitats, protecting natural habitats, and establishing protected areas. It has been proposed since 1986, but for a long time the reserve did not really play a role, and recently with the advancement of the Yangtze River protection project, the ecological environment of the Yangtze River has gradually recovered, and the natural population of finless porpoises has also begun to rise.
In addition, in the past many years, we have gradually promoted ex situ conservation, and now we have established three ex situ reserves for the Yangtze finless porpoise, with a population of more than 150 individuals, which provides a very important guarantee for species protection. A lot of work has also been done in captive breeding and breeding, and many finless porpoises have been born and survived in artificial environment, and relatively complete artificial environment feeding management technology has been established. This is the national technical system for the protection of the Yangtze finless porpoise, which plays a very important role in promoting the restoration of the vitality of the Yangtze River and the protection and restoration of the finless porpoise population.
Based on the past four times, especially the fourth inspection in 2022, I have put forward several suggestions for the protection of the Yangtze finless porpoise, many of which are consistent with what Dean Chen mentioned, but Dean Chen basically talks about the environment from the three major indicators of the vitality of the Yangtze River.
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First, it is very important to restore the natural shoreline of the Yangtze River, protect the natural Yangtze River, and protect the beaches of the Yangtze River.
Second, ensure the connection of rivers and lakes and restore the smooth flow of the Yangtze River. Now most of the Yangtze River is blocked, only Poyang Lake and Dongting Lake are connected to the Yangtze River, and the rest are controlled by gates, and the migration channels of aquatic organisms have been blocked, hoping to restore the smooth flow of the Yangtze River.
Third, standardize Yangtze River shipping, create a quiet Yangtze River, noise has a relatively large impact on the hearing and sonar capacity of the Yangtze finless porpoise, shipping needs to be regulated, which is a very important economic lifeline for the country's economic development, and it is hoped that to a certain extent, the Yangtze finless porpoise shipping will be further regulated, including waterways, including deceleration, quantity, technology improvement, etc., to create a "quiet Yangtze River".
Fourth, control pollution, the control of point source pollution is very obvious, now non-point source pollution is the focus of attention, hope to restore the clean Yangtze River through protection actions.
Fifth, improve ex situ conservation, there are now 3 ex situ protected areas, the scale is not small, and it is hoped that the next step will further improve the quality and management efficiency of ex situ protected areas. In addition, due to the restoration of the natural environment of the Yangtze River, it is hoped that the ex situ protected population can be gradually rewilded and released to promote the recovery of natural populations.
Extreme climate change, it seems that extreme climate has a very large impact on aquatic organisms, aquatic ecology and water environment in the Yangtze River Basin. Last year, we organized two rescue activities, one was in Poyang Lake, due to extreme drought, a large number of finless porpoises were concentrated in the bunker, we spent nearly one month, under the guidance of the Ministry of Agriculture and Rural Affairs Jiang Office, under the coordination of the Jiangxi fishery administration department, more than 110 finless porpoises were transferred from Poyang Lake and transferred from the bunker to the main channel, avoiding relatively large losses. Due to extreme drought in the Tianwanzhou Reserve, the population density of finless porpoises was too large, and 27 finless porpoises were transferred from the reserve and transferred to other ex situ reserves. This is an issue that needs to be paid attention to in the future, but in addition to the overall measures to address climate change, it is necessary to establish an emergency protection mechanism (for the protection of) finless porpoise.
Seventh, strengthen multi-party linkage, everyone is very clear about the situation of the Yangtze River, involving various departments. The protection of Yangtze finless porpoise species is under the management of the agricultural department, and the protected area is the forestry department, and also involves waterways, maritime affairs, environmental protection and other departments. It is hoped that under the unified leadership of the Yangtze River Protection Action, a coordination mechanism can be established, especially after the introduction of the Yangtze River Protection Law, the legal basis for everyone is the same, and it is easier to coordinate.
8. National participation, what has been most deeply felt in the past few years is that many NGOs have joined the protection of the Yangtze River porpoise. The protection of the Yangtze finless porpoise is to protect the ecological environment of the Yangtze River, which is an indicator species of the health of the Yangtze River ecosystem, a flagship species of ecological diversity, and an umbrella species, and its protection is to protect the Yangtze River. Only the participation of the whole people can truly promote the restoration of the Yangtze River ecosystem.
I believe that through last year's scientific investigation of the Yangtze finless porpoise, we have a very positive signal and confidence, and we are now more confident than ever, and more capable of protecting the Yangtze finless porpoise, protecting the mother river Yangtze River, so that the beautiful smile of the Yangtze finless porpoise will always remain in the Yangtze River, so that the Yangtze River will always become the home of human beings and their harmonious coexistence, thank you!