Alien species are a double-edged sword.

In some cases, the introduction of alien species does contribute to the economic development and ecological conservation of specific regions.

But in other cases, alien species may constitute a biological invasion.

  【Produced by Shentong Studio】

  Written by: Intern reporter Sun Mingyuan

  Our reporter Ma Aiping

  Planner: Liu Li

  On January 1 this year, the Ministry of Agriculture and Rural Affairs, together with the Ministry of Natural Resources, the Ministry of Ecology and Environment, the Ministry of Housing and Urban-Rural Development, the General Administration of Customs and the State Forestry and Grassland Administration, organized the "List of Key Management Invasive Alien Species" to come into effect.

  "There are so many alien species" "This 'blacklist' came in a timely manner"... Once released, this catalog has attracted heated discussions among netizens, and the number of topics on the Internet has reached more than 2.98 million.

  Based on the nationwide survey of alien species in 2022 and the monitoring and research of scientific researchers over the years, the content of this latest list has been updated from the original 52 species to 59 species.

  Alligator gar, Canadian goldenrod, American white moth... People may only have heard of these invasive species.

In fact, the invasion of alien species is not a new problem in our country.

Most of the time, these invasive alien species are inconspicuous, and they quietly bring ecological disasters to certain areas, making it difficult for people outside the affected areas to pay attention to them.

Until August last year, the alligator gar entered the public eye in a strange form, letting more people know what an "alien invasive species" is.

  The lake was drained for only two alien "strange fish"

  "Did you catch any fish?"

  On August 26, 2022, among the hundreds of bullet screens on a live broadcast platform, this question was "scrambled".

Behind the comments and bullet screens, at least 37 million netizens watched the live broadcast.

  The live broadcast was in Ruzhou, a small town in Henan Province, where the staff drained nearly 300,000 tons of lake water in the park just to catch two "weird fish" called alligator gar.

  The next day, Ruzhou reported that two alligator gars, one male and one female, had been captured and undergone harmless treatment.

So far, the month-long "Lake Pumping Fishing War" has come to an end.

  During the period, there were even doubts on the Internet that this operation was a waste of money.

  But this incident can be said to have given the whole people a popular science lesson on the invasion of alien species.

  As early as 2002, under the leadership of the founder researcher Hu Yinchang, the Alien Species and Ecological Security Innovation Team of the Chinese Academy of Fishery Sciences has begun to pay attention to alien invasive aquatic organisms.

Gu Dangen is the Chief Scientist of the Alien Species and Ecological Security Innovation Team of the Chinese Academy of Fishery Sciences, and an expert on the prevention and control of alien species invasion in the National Bulk Freshwater Fish Industry Technology System.

Since 2009, the team has conducted long-term large-scale surveys and monitoring of a variety of exotic aquatic organisms, including alligator gar.

  Alligator gar eats an astonishing amount of food. Once flooded, it will not only affect fishery production and threaten food security, but also lead to a sharp decline in the population of native fish and other aquatic animals through predation, thereby affecting aquatic biodiversity and aquatic ecosystems. Threat to ecological security.

  Survey data show that alligator gar has spread very rapidly in my country in recent years, and there are records of wild capture of alligator gar in most provinces from Hainan to Beijing, and from Shanghai to the southwest.

If not intervened early, it has the potential to spread to most natural rivers.

  In order to find out the distribution and quantity changes of exotic aquatic organisms such as alligator gar, Gu Dangen's team cast nets, took water samples, and "fished" in various waters in the south all year round.

  The entry of alligator gar into the new list has a lot to do with the large amount of first-hand survey data and risk assessment reports provided by the scientific research team. It can be said that it is inseparable from the years of hard work of these scientific researchers.

  According to the person in charge of the Office of the Inter-Ministerial Coordination Mechanism for the Prevention and Control of Invasive Alien Species, the list of invasive alien species under key management has four criteria for species selection: serious damage, rapid spread, difficult prevention and control, and various forms of damage.

"Not all invasive alien species can be 'on the list'." Gu Dangen told the reporter of Science and Technology Daily that the alligator gar can be "on the list" because it can cause serious harm and spread quickly. It is difficult to get effective control.

  The annual loss is as high as 200 billion yuan

  Through public information retrieval, the reporter found that the earliest invasive alien species in my country was a snail from Madagascar, Africa.

  In the 1930s, this kind of snail crossed mountains and seas, and first appeared in Xiamen and Taipei of my country along with the global trade of Britain and Japan.

Today, it has been widely distributed in many provinces in southern my country.

The scientific name of this snail is brown cloud agate snail, which is often called the "large African snail".

  It is a typical invasive alien species. It not only does great harm to vegetables and other crops, but also carries a variety of pathogens that can harm the human body.

  With the increasing global trade, the risk of the spread of invasive alien species is increasing, and the harm caused by invasive alien species is also gradually increasing.

  Liu Wanxue, director of the Key Laboratory of Alien Invasive Organisms Prevention and Control of the Ministry of Agriculture and Rural Affairs, and director of the Biological Invasion Research Innovation Center of the Institute of Plant Protection, Chinese Academy of Agricultural Sciences, said that in the past ten years, 55 new invasive species have been added in my country, and 5-6 new invasive species have been added every year. species, 30 times the frequency of newly added invasive species before the 1990s.

  Zhao Wenxia, ​​deputy director of the Forest Ecological Environment and Protection Institute of the Chinese Academy of Forestry and chief expert of the exotic pest and plant quarantine discipline group, remembers that in 2010, a large area of ​​alpine oak died in Nyingchi City, Tibet Autonomous Region, and many hills appeared in patches. The dead wood of the plateau seems to suffer from "alopecia areata".

Zhao Wenxia and relevant experts traveled all over these hills with altitude sickness, and finally confirmed that the "murderer" behind the large-scale death of Quercus alpine was actually a noctuid insect.

Although Quercus alpine can stand tall and straight on the plateau, it may encounter survival crisis in the face of invasive alien species.

  Another invasive species that impressed Zhao Wenxia was solidago canadensis.

This Compositae plant is very easy to breed in southern my country.

"The abandoned Shanghai shipyard is full of invasive alien species. Their seeds are scattered everywhere like dandelions, and the wind blows all over the sky, leaving no room for other plants to grow where they take root." Zhao Wenxia said.

  "No grass grows wherever I go", this is Gu Dangen's evaluation of another exotic species-Tilapia chinensis.

This kind of fish has a very strong ability to eat aquatic plants. Under the experimental environmental conditions, a few fish can eat all the aquatic plants in a pool in a week or two.

Dongshan Lake, one of the four major ecological storage lakes in Guangzhou, was often destroyed by the tilapia chrysalis used to purify the water quality. As a result, the water purification work of Dongshan Lake stagnated, and the water quality was once reduced to inferior V class.

  Another invasive alien species that is extremely dangerous and devastating to forests worldwide is the pine xylophilus.

Yang Zhongqi, chief scientist and professor of the Chinese Academy of Forestry, said that the pine wood nematode disease caused by it is highly contagious and is called the "cancer" of pine trees.

Once the pine wood nematode invades the forest area, the coniferous forest dominated by pine trees will be infected with pine wood nematode, which will cause devastating damage to the entire forest area.

  "Can you imagine that one day, Huangshan pine, the main landscape resource of Huangshan, will be completely destroyed, and there will be no welcoming pine in Huangshan?" Yang Zhongqi told reporters. In 1982, my country first discovered pine wood nematode disease in Nanjing Zhongshan Mausoleum. For 40 years, pine wood nematode It has caused huge losses and ecological disasters to my country's forestry.

  Regarding the disasters caused by invasive alien species, Liu Wanxue provided a set of shocking figures: when the fall armyworm is seriously damaged, it may cause more than 50% of the yield loss of corn, wheat and other crops; %—100%; the potential economic loss caused by codling moth to my country’s apple, pear and other fruit industries is as high as 14 billion yuan per year; in 1 square meter of corn field, 30—50 ragweed seedlings can reduce production by 30% —40%; a golden apple snail contains more than 3,000 parasites...and they are only a small part of the invasive species.

  Invasive alien species have a serious negative impact on my country's ecological environment and economic development.

According to incomplete statistics, in my country, the total direct and indirect losses caused by alien invasive species are as high as 200 billion yuan every year, and comprehensive control of alien invasive species is urgent.

  Scientific research provides new basis and new method for governance

  Compared with the history of the invasion of alien species, the research on invasive alien species in my country started relatively late.

  Zhao Wenxia is one of the earliest scholars who studied invasive alien species in China. She began to study invasive alien species in 2002, but it had been 70 years since the giant African snail arrived in my country.

  Zhao Wenxia recalled that her main job at that time was to translate foreign classic books, works and papers on invasion biology.

Later, with the introduction of the concept of alien invasive species and the development of some applied practices, domestic scholars published a series of representative theoretical works and papers.

  Zhao Wenxia told the reporter that foreign invasion biology research began in the 1930s and flourished in the 1950s.

The study of alien species in my country started at the beginning of this century. After more than 20 years of hard work by scientists, the level of relevant technology in my country has been comparable to that of foreign countries. However, due to the late start, my country still does not understand the history, route and time of invasion of many invasive species. Raw data is quite scarce, and it takes a long time to accumulate to make up for the shortcomings.

  Since the beginning of the new century, one of the most important brainchild of Chinese invasion biology scholars is the "list" mentioned above that was released in 2013 and updated on January 1, 2023.

  In 2013, the former Ministry of Agriculture released the first list of invasive alien species managed at the national level——"List of Invasive Alien Species under National Key Management" (the first batch).

This list contains 52 invasive species, including invasive plants and animals such as Eupatorium adenophorum, Tribulus terrestris, African giant snail, apple snail, harmful insects such as American white moth, Bactrocera dorsalis, and tomato bacterial species. Harmful pathogens such as canker bacteria.

  Liu Wanxue told reporters that the publication of the first batch of catalogs is a milestone.

Since 2013, the Chinese scientific community has gained a clearer understanding of invasive alien species, and research on invasive alien species has entered a period of rapid development.

  At the same time, laws are constantly being revised and improved.

  On December 30, 2022, the Standing Committee of the National People's Congress passed the newly revised Wildlife Protection Law.

The law clearly stipulates that when introducing wild animal species from abroad, safe and reliable preventive measures should be taken to prevent them from entering the wild environment and avoid causing harm to the ecological system.

  Before the promulgation of the newly revised Wildlife Protection Law, in order to prevent the invasion of alien species, my country formulated laws, regulations and policy documents such as the Biosafety Law, the Entry and Exit Animal and Plant Quarantine Law, and the Approval and Management Measures for the Type and Quantity of Alien Species Introduced from Terrestrial Wild Animals. , also released 4 batches of "List of Alien Invasive Species in China's Natural Ecosystem", and formulated the "List of National Key Management of Alien Invasive Species (First Batch)".

  "It can be said that my country has established a legal and policy system to prevent the invasion of alien species." Professor Yang Zhaoxia, director of the Ecological Law Research Center of Beijing Forestry University, told reporters.

  Yang Zhaoxia has participated in seminars on draft amendments to the Wildlife Protection Law organized or entrusted by the Legislative Affairs Committee of the Standing Committee of the National People's Congress many times, and many of his suggestions have also been incorporated into the revised Wildlife Protection Law.

The revised Wildlife Protection Law also specifically emphasizes that it is not allowed to release or discard illegally, and if it is really necessary to release them into the wild, they should abide by the relevant laws and regulations.

  The scientific community is also acting, constantly providing new evidence and methods for governance and decision-making.

  my country implements dynamic adjustment and classified management of the list of invasive alien species, and organizes a national census of invasive alien species every 10 years.

In 2022, my country will launch a census of invasive alien species, including on-site inspections, face-to-face investigations, and key investigations.

Invasive species such as fall armyworm and alligator gar discovered in recent years are all within the scope of the census.

  According to Zhao Wenxia, ​​in this update of the catalogue, the initial list of alien species submitted by all parties included more than 800 species. After several rounds of screening, the list was reduced from more than 800 species to more than 200 species, and then from more than 200 species to more than 100 species. Finally, 59 species were identified from more than 100 species.

  Scientific research also plays a role in the management of various alien species.

For example, Gu Dangen's team and the General Station of Agricultural Ecology and Resource Protection have jointly developed multiple prevention and control technologies, which are applied to the management of tilapia in Dongshan Lake, Guangzhou.

The results showed that before the control test, Tilapia chinensis was the dominant species in the lake area, accounting for 79.41% of the catch weight. After 20 days of the control test, the staff did not collect tilapia chinensis in the fishery sampling survey.

  A large number of scientific researchers have participated in the prevention and control of alien species from survey statistics, identification of dominant species and hazards, identification of whether an alien species is an invasive species, to providing governance solutions.

  Relevant parties are actively working hard to fight resolutely with alien species.

  Keeping alien species out of the country is the first step in preventing alien species.

On September 4, 2022, Shanghai Customs discovered a batch of suspicious shipments.

The staff opened it and found 300 epoxy resin tubes of the same size, stuffed with damp cotton, and each tube contained a live ant.

  After identification, these ants were wild harvester ants from southern Europe, and the domestic consignee probably wanted to keep them as pets.

However, such ants do not have a natural distribution in my country, and their introduction has the risk of making them an invasive alien species.

  It is understood that as of November 2022, my country's customs has set up 471 monitoring points for various alien pests at the Shanghai port alone.

According to the report of the General Administration of Customs, in the first half of 2022 alone, customs across the country intercepted 173 species of quarantine pests 31,000 times and 2,925 batches of live animals and plants from channels such as passengers carrying and mailing.

  Prevention and control of invasive alien species is still on the way

  Liu Wanxue said that the species listed in the "List of Key Management of Invasive Alien Species" are the focus of the prevention and control of invasive alien species at present and in the future, and they are also the action guide for the management of invasive alien species.

  On the road of preventing and controlling alien invasive species, we still need to do a lot of work.

  First, the relevant laws need to be further improved.

For example, Yang Zhaoxia said that the newly revised Wildlife Protection Law has added relevant content on the prevention and control of alien species.

However, at present, the online transactions of "exotic pets" such as crocodile gar and Brazilian tortoise have not been curbed. The main reason is that the current legislation is insufficient to regulate the transaction process, especially the online transaction.

If these pets do not enter the natural world, it does not constitute an invasion of alien species.

However, these pets have the possibility of escaping or being released, and trading and raising them objectively increases the risk of them invading the natural world.

To this end, relevant laws should be further improved.

  "Taking the alligator gar as an example, the laws of our country have not made clear regulations on the sale of the alligator gar. To a certain extent, this has led to the inability to strictly supervise the sales channels and methods of the alligator gar. The release behavior is extremely hidden and difficult to find. The alligator gar is likely to be mixed with other fry and released into the natural environment, and it will be difficult to track the releasers after the fish grow up and be found." Yang Zhaoxia said.

  Second, relevant scientific research needs to be further deepened.

Liu Wanxue pointed out that the prevention and control of alien species invasion and harm, monitoring and early warning, diffusion and interception, emergency response, and comprehensive management all need to be strengthened.

  "We need to further improve the risk prediction and early warning mechanism, such as establishing a large database of invasive species risk early warnings, and grasping the real-time dynamics of invasive species. For example, which species are likely to invade, where do they come in, and how do they come in? We all need to There is research and prediction.” Liu Wanxue said.

  Third, the prevention and control of alien species invasion urgently requires public participation.

Gu Dangen reminded that it is not only the responsibility of managers and scholars to understand and prevent alien species. If we want to do a good job in prevention and control, we must have the participation of the whole society.

  "If key managed invasive species such as American bullfrog, red-eared painted turtle, and alligator gar are only in controllable aquaculture water bodies or aquariums, they will not directly cause harm and form invasions, and they have certain economic and ornamental value. However, the random introduction, release and discarding due to various reasons have turned them into real invasive alien species in the wild. In addition, if they are listed as key invasive species for management, they will be regarded as 'pest animals' 'And being discarded or abandoned will cause serious ecological disasters. It is of great significance for the prevention and control of alien invasive species to make the public aware of the dangers of releasing and discarding alien species. Of course, scientists should also invest more energy To provide the public with necessary popular science services." Gu Dangen said.

  "Alien species are a double-edged sword." Zhao Wenxia said that in some cases, the introduction of alien species does help the economic development and ecological conservation of specific regions.

But in other cases, alien species may constitute a biological invasion.

For example, Solidago canadensis, as an invasive alien species, is rampantly expanding in Jiangsu and Zhejiang, occupying a large amount of land.

However, in the north, such as Shijiazhuang, Hebei, it is difficult to spread on a large scale due to climate reasons, but it can be used as a cash crop and bring income to people as an accessory for fresh cut flowers.

  "After scientific understanding of alien species, in addition to not discarding or releasing them at will, ordinary citizens can also take the initiative to report alien species found around them and provide clues for the management of alien species. If everyone can start from the small things within their power, wipe out the alien species around them. We can truly build a 'Great Wall' of alien species invasion prevention and control, and win this battle against alien species invasion." Gu Dangen said.

  (The pictures in this version are provided by the interviewees unless marked)