The danger from invasive strange creatures

The Ministry of Fisheries survey shows that in the past 50 years, Vietnam has imported 41 strange aquatic animal species. The introduction of exotic aquatic animals has shown some adverse effects on biodiversity in water bodies.

So far, Vietnam has banned the feeding of three species: beaver mice, yellow snails and tiger fish. Up to seven species need to be strictly monitored due to harm to ecological balance.

Initially, these strange creatures were often imported for the purpose of economic development, poverty reduction. Most strange aquatic plants are fish. In addition, there are four species of invertebrates, an amphibian, a reptile and an animal. Some strange aquatic species after entering Vietnam have a high economic value, typically tilapia, carp, spiny fish, white pomfret. Some other species have been imported, but nowadays they are not met or very rarely seen in Vietnam, such as Chinese sturgeon, Asian fish, Little mouth bass, European catfish, European eel due to many reasons, mainly because adaptable.

The survey shows that the Northern Delta is home to many of the most unusual aquatic species, with 34 species . However, because it has not been thoroughly tested, so after a while, quite a number of strange creatures have proved to be invasive with the ability to spread quickly, compete residence and food with native species, destroy the season. membrane, causing ecological imbalance. The Department of Exploitation and Protection of Aquatic Resources, when surveying 13 species of strange aquatic animals in six agricultural regions, found that the introduction of some strange creatures into farming in Vietnam has caused a degradation of biodiversity. study in our country.

Yellow snails and tiger fish are strange creatures imported into Vietnam before

Some native species become scarce due to their poor ability to compete for food and shelter than imported species such as Vietnamese white carp, Vietnamese drift fish, and Vietnamese carp. Some native species, such as catfish, have a mixed appearance.

Some species of strange creatures that invade our country have grown on a large scale, to the extent that they cannot destroy them thoroughly, but can only control and limit somewhat. Typical of the alien invasion in Vietnam is the yellow snail epidemic. This is a species that has been imported into our country for more than 10 years, with very fast fertility and mainly rice leaves, it has caused a major epidemic of rice destruction in many provinces in the Mekong Delta. gradually developing to the central and northern provinces. So far, yellow snail has caused great harm in the ecosystem of fields, ponds and lakes of some southern provinces, and destroying them thoroughly is not easy, although it has to spend billions of dong.

In 1996, it was discovered that the trader imported an insect to feed the birds, which was a species of Tenebrio monitor. This insect is harmful to many agricultural products, so it was immediately banned. In the 1996 to 1998 period, the aquarium fish appeared the pirana tiger fish, or diamond fish and the toothed fish - the scientific name is Serralmus nattereri. This is a fish native to the Amazon basin (South America), carnivorous and aggressive. If this species comes out to live in a natural environment, it will destroy all aquatic animals, then it is difficult to predict all the economic losses of aquatic products and at the same time endanger human life. Many countries have strict rules for importing this species. Ministry of Fisheries had to instruct to prohibit the import and development of this fish.

Most recently, the lesson about importing and testing South American beaver mice. This is a large rodent that breeds very quickly, can dig burrows and destroy riverbanks, dikes and irrigation systems . Due to the timely detection of their potential harms, the Ministry of Agriculture and Rural Development has decided to destroy all experimental beaver rats in the country.

Then the blue rock flute, the voracious bird, feeds almost everything and significantly reduces the indigenous insects, endemic species, and destroys crops. They have appeared in Hai Duong and Hung Yen provinces, except for the elimination of many native birds, occupying the nesting place and creating the risk of biodiversity change.

Similarly, Japanese duckweed (water hyacinth) imported into Vietnam in the 30s of the previous century by sea, has now spread to most of our freshwater lakes, causing serious degradation of biodiversity. important.

In the Mekong Delta, U Minh cajuput forest is also facing the widespread development of virgin trees (Mimosa) native to the Americas. This species encroaches on agricultural lands, vegetation, especially harming rice fields and wetlands.

In Tram Chim National Park, Mai Duong has infiltrated two A4 and A5 plots, which is a large area of ​​grassland, which provides the most important food for the Sarus Crane. This is one of the reasons for the cranes of this national park to decline. Other areas of the garden have also appeared many Mimosa trees. In Cat Tien National Park, Bau Chim area of ​​about 100 hectares has been covered by Mai Duong.

Every year, the National Park has to invest 50 to 100 million VND to destroy Mai Duong, but it has no results because every year in the flood season, Dong Nai river brings millions of seeds from the vast Mai Duong fields of Cat Tien district, upstream, follows Dong Nai river to flow into the waterways of Cat Tien National Park such as Bau Chim and Bau Ca.

Currently many reservoirs such as Tri An Lake, Dong Mo - Ngai Son Lake . are also invaded by Mai Duong trees and affect the function of water supply and tourism service of the lakes.

Through the Ngang Pass (Quang Binh), everyone now sees non-native five-colored flower plants growing dense. Belonging to the verbena family or the family of daisies, the plants adapt and grow very fast like weeds from the spot just making the scene come to the place where the wild environment pleases the traveler. Then glue, the thorny plant that grows into bushes and is able to compete with all other species.

Our country currently has six out of 14 species of animals with great threats such as wild boars, forest rats, mice, foxes, long-tailed monkeys, and crabs. Leaving management and statistics of strange creatures in our country, therefore, is also a concern of the world. The invasion of strange organisms, especially newly invasive species, is still at a large level, but there is a potential for development that directly affects agricultural production. Therefore, there should be limited effective solutions, prohibiting the import and farming, proceeding to destroy them.

In addition to encouraging domesticated breeding of local species and strict management of imported species in aquaculture facilities, it is not advisable to release introduced species that have not studied the biological characteristics, impacts on biodiversity. learning and traditional farming in natural water sources.