At present, more than 660 invasive alien species have been discovered in China, threatening native species and ecosystems——
Saying "No" to Invasion of Alien Species
A strange fish called the "Alligator Gar" has been rounded up by professionals for days; the bright-looking goldenrod has the nickname of "ecological killer"; "It is bigger than a snail and lays pink eggs" , Fushou snails can be seen everywhere in the fields... Recently, the topic of the invasion of alien species has caused heated discussions.
How do alien species invade?
How dangerous is it?
How to accurately and effectively prevent and control?
From August 1 this year, the "Administrative Measures for Invasive Alien Species" came into effect.
Experts suggest that we should strengthen supervision from the source, strictly control the entry of alien species, and jointly build a biosafety barrier.
How much do you know about invasive alien species?
——Among the more than 660 invasive alien species discovered in China, 215 have invaded national nature reserves, threatening local species and ecosystems
"What kind of strange fish is this? Can it be eaten?" "It looks very fierce, will it hurt people?" Recently, alligator gars have been reported in many places across the country.
Many people are very curious about this new invasive species.
Alligator gar comers are not "good".
According to reports, the alligator gar is native to North America and is a freshwater giant carnivorous fish.
It is the largest of the seven species of gar in North America. It can grow up to 3 meters, has a strong reproductive ability, and has a "great appetite". As long as it is almost all living things in the water, the hard scales are enough to prevent it from being protected. Threats from various ferocious predators.
Its flesh is highly poisonous and cannot be eaten.
"As an invasive alien species, the alligator gar is at the top of the aquatic food chain after entering China," said Liu Wanxue, director of the key laboratory for the prevention and control of invasive alien organisms of the Ministry of Agriculture and Rural Affairs. The water ecosystem has been devastated." At present, various localities have launched campaigns to round up alligator gars.
There are many other invasive species like the alligator gar, and some are distributed in urban residential areas.
"Every time it rains, many brown cloud agate snails, commonly known as 'African snails', will appear under the dead leaves of the flower beds." Zhang Mucen, who lives in Shenzhen, told reporters, "It is said that this snail is the same as the Fushou snail. Hundreds of parasites and bacteria are invasive species. My child sometimes plays in the park, and I tell her not to touch this snail."
What is an invasive alien species?
According to the definition of the International Union for Conservation of Nature, an alien species is a population established in natural and semi-natural ecosystems and habitats. When it changes and harms native biodiversity, it is an invasive alien species, and the harm caused by it is an alien biological invasion. .
According to statistics, about 10% of alien species can reproduce by themselves in new ecosystems, and about 10% of alien species that can reproduce themselves can cause biological disasters and become invasive alien species, that is, 1% of alien species become invasive alien species .
China is one of the countries most seriously affected by the invasion of alien species.
According to the "2020 China Ecological Environment Status Bulletin" released by the Ministry of Ecology and Environment in May last year, more than 660 invasive alien species have been discovered nationwide.
Among them, 71 species have caused or have potential threats to natural ecosystems and have been included in the List of Invasive Alien Species in China.
Among the more than 660 kinds of invasive alien species, the largest number are invasive plants, with 370 species, accounting for more than half; followed by animals, with 220 species, accounting for 1/3.
"Invasive species have caused serious harm to domestic planting, forestry, animal husbandry, etc." Liu Wanxue said, "Invasion of alien species is one of the important reasons for biodiversity loss and species extinction, and it is also one of the factors that threaten global food security. one."
How dangerous is it?
——In the past ten years, China's invasive species have increased rapidly, causing serious ecological damage and biological pollution, and endangering the development of agriculture and forestry economy.
How did invasive alien species enter China?
According to reports, the sources of invasive alien species are divided into natural spread, unintentional introduction and intentional introduction.
Unintentional introduction is generally unintentional entry into China with international trade, such as poplar mosaic virus introduced with seedlings and cuttings, Amaranthus amaranthus accidentally introduced with imported grain and oil, goods or luggage, and Amaranthus that entered China from Southeast Asia through natural diffusion Lan et al.
"In the past 10 years, China's invasive species have increased rapidly, with an average increase of 2 species a year. The main reason is that with the implementation of the domestic reform and opening up policy, frequent exchanges with foreign countries such as economy, trade, transportation, culture, and tourism have led to a large influx of goods and people into China. , significantly increasing the chances of carrying the invasion." said Xu Xinjie, vice chairman of the Henan Provincial Zoological Society.
The other is intentional introduction, such as amaranth and chrysanthemum introduced as vegetables, goldenrod and brazilian tortoise introduced as ornamental species, goldenrod as a medicinal plant, and fushou snail, bullfrog, Crayfish (crayfish) and so on.
Xu Xinjie reminded that with the improvement of people's living standards, the number of people raising exotic pets has increased rapidly, and the e-commerce network trading platform has also developed rapidly, making online and offline purchases more convenient, and exotic pets have spread to the natural environment through abandonment, release and escape. Unforeseen species invasions will occur.
"Raising exotic pets is related to personal preferences and ecological safety." Industry insiders told reporters that some pet lovers illegally buy new exotic pets from abroad that are not naturally distributed in China, not only may carry animal and plant epidemics, but also because there is no natural enemy to suppress, Once escaped or abandoned, it is very likely to damage the ecosystem.
It can be seen that the potential risk of alien species invasion in the exotic pet industry should not be underestimated, and the prevention work should not be careless.
How dangerous are invasive alien species?
First, it may cause serious ecological damage and biological pollution, leading to the loss of biodiversity.
Ma Fangzhou, an associate researcher at the Nanjing Institute of Environmental Science of the Ministry of Ecology and Environment, said that most alien species will explode after successful invasion, causing serious biological pollution.
"For example, the alien species macroalgae and samphire can compete with the native halophyte mangroves on the southeastern coast of my country for niche competition, resulting in the reduction or even extinction of mangrove resources, which in turn severely damages local biodiversity." Ma Fangzhou said "In addition, some invasive alien species hybridize with related native species, disturbing and contaminating the genetic diversity of native species."
Second, it is easy to cause ecological disasters and endanger the development of agriculture and forestry economy.
Ma Fangzhou introduced that, for example, the American white moth, which is native to North America, invaded China in 1979, and more than 100 native plants were harmed in the pest-infested areas of Liaoning Province alone.
"Another example is Bemisia tabaci, which ranks among the 100 malignant invasive alien species in the world announced by the World Conservation Union. It is the main invasive pest of field crops and can transmit more than 70 kinds of viruses. Bemisia tabaci has spread to most parts of the country. , the area of affected crops is as high as tens of millions of acres every year." Ma Fangzhou said.
Third, it may endanger the health of human and livestock.
For example, ragweed pollen can cause "hay fever"; snails can cause infection of parasites such as Angiostrongylus cantonii in the human body, which can cause dementia or even death in severe cases; livestock will suffer from diarrhea and asthma after eating the stems and leaves of E. , After pollen and achenes enter the eyes and nasal cavity of livestock, it will cause erosion and pus, and may even lead to death.
How to prevent it?
——Prevent from the source, strengthen port prevention and control, and implement classified management and restoration
China has always attached great importance to the prevention and control of invasive alien species. In 2003, 2010, 2014 and 2016, the "List of Invasive Alien Species in China" was published in four batches, and the prevention and control efforts have been increased year by year.
On April 22 this year, the fourth executive meeting of the Ministry of Agriculture and Rural Affairs reviewed and approved the "Measures for the Administration of Invasive Alien Species" (hereinafter referred to as the "Measures"). It will come into effect on the 1st.
The relevant person in charge of the Department of Science, Technology and Education of the Ministry of Agriculture and Rural Affairs introduced that the "Measures" stipulated the source prevention, monitoring and early warning, governance and restoration of invasive alien species, and further strengthened the prevention and control of invasive alien species from all aspects, and built a full-chain prevention and control system.
"The promulgation of the "Measures" provides a legal basis for preventing the invasion of alien species, and provides a policy guarantee for the prevention and control of the invasion of alien species in my country." Liu Wanxue said.
How to prevent and manage the invasion of alien species in the future?
The first is to standardize the introduction management.
The relevant person in charge of the Department of Science, Technology and Education of the Ministry of Agriculture and Rural Affairs introduced that if crops, forest and grass seedlings, aquatic seedlings and other exotic species are introduced from abroad due to special needs such as variety cultivation, import approval and quarantine approval should be handled according to the approval authority.
For the first-time introduction, the introducing unit shall conduct a risk analysis and submit a risk assessment report to the approval department.
At the same time, the "Measures" propose that the customs should strengthen port prevention and control, crack down on illegal acts such as the illegal introduction, carrying, delivery, and smuggling of alien species, and deal with the discovered invasive alien species in accordance with the law.
In addition, domestic quarantine will be strengthened.
The competent departments of agriculture and rural affairs, forestry and grassland at or above the county level shall strengthen the quarantine supervision of cross-regional transportation of crops, forest and grass seeds, seedlings, plant products, aquatic seedlings, etc., to prevent the spread of invasive alien species.
It is necessary to do a good job of prevention, but also to manage and repair.
According to the "Measures", for the control of invasive alien plants, measures such as manual plucking, mechanical eradication, spraying of green chemicals, and release of biological natural enemies can be taken according to the actual situation during the critical growth period such as the seedling stage, flowering stage or fruiting stage.
For the control of foreign invasive pests and diseases, measures such as selection of pest-resistant varieties, seedling pretreatment, physical removal, chemical elimination, and biological control should be adopted to effectively prevent the spread of pests and diseases.
For the management of invasive alien aquatic animals, measures such as targeted fishing should be taken to prevent their further spread of harm.
"Regardless of whether it has invasive characteristics, alien species cannot be introduced without approval, let alone discarded at will." The relevant person in charge of the Department of Science, Technology and Education of the Ministry of Agriculture and Rural Affairs introduced that the Biosafety Law stipulates that any unit or individual without approval, It is not allowed to introduce, release or discard alien species without authorization; the Yangtze River Protection Law stipulates that it is prohibited to cultivate or release alien species or other non-native species germplasm resources in the open waters of the Yangtze River Basin; the criminal law stipulates that, in violation of state regulations, illegally introduce, release or discard alien invasive species Species, if the circumstances are serious, shall be sentenced to fixed-term imprisonment of not more than three years or criminal detention, and shall also or only be fined.
Kong Dechen