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The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

author:Bright Net

At present, the invasion of alien species as a global ecological problem is attracting extensive attention from international organizations such as the International Union for the Conservation of Natural Resources and the International Maritime Organization (IMO). On how to introduce alien species, how to prevent, eliminate and control the invasion of alien species, many countries have issued a series of appropriate technical guidance documents, through the establishment and improvement of various technical guidelines and guidelines for the prevention and control of alien species invasion, and formulated relevant laws for control. It has been reported that invasive alien species seriously harm local species in the mainland, causing them to reduce or even extinct, disrupt ecosystem functions, and deal fatal blows to economic production. Therefore, it is urgent to improve the mainland's defense capacity and comprehensive management capacity for invasive alien species, and the report of the 20th National Congress of the Communist Party of China clearly pointed out that it is necessary to strengthen biosecurity management and prevent and control the invasion of alien species. Nowadays, the problem of invasive alien species involving international trade and other exchanges in China is becoming increasingly prominent. More than 670 invasive alien species have been discovered, of which water hyacinth, which is listed as one of the world's top ten malignant weeds, is the most harmful.

What is Water Hyacinth?

Water hyacinth scientific name is phoenix blue (Eichhornia crassipes), rainflower family, native to Brazil in South America, its flowers grow very elegantly, once introduced by many countries, is known as "beautifying the world lilac flower crown". It is a fast-growing, fecundity, widely adapted to a wide range of floating aquatic plants, like warm and humid, full of light environment, suitable water temperature of 18-23 °C, can drift with the water, widely distributed in the mainland Yangtze River, Yellow River Basin and South China provinces. The plant varies in height, with an average height of 30-60 cm, a well-developed root system, an extremely short stem, a round leaf with a bright green color, a flower leaf sticking out from the base of the petiole, purple-blue petals, and blooms from July to October.

The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

Water hyacinth (Image source network)

How harmful is water hyacinth?

Why is the water hyacinth, once known as the "environmental warrior" known as the "environmental warrior" by absorbing organic pollutants in the water through a well-developed root system, now a notorious vicious weed? After the mainland was introduced as an ornamental flower in 1901, due to its strong asexual reproduction ability and lack of unique natural enemies, it grew wildly in 19 provinces and cities in North China, East China, South China and Southwest China in a short period of time, causing many adverse effects on the natural ecological environment. The main hazards are reflected in blocking the channel, restricting the flow of water bodies, breeding germs, mosquitoes and flies, increasing water surface evaporation, consuming dissolved oxygen and suffocating fish, etc., which shows that it is very necessary to adopt scientific and effective control methods for water hyacinths.

The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

Water hyacinth flooded (image source network)

How to effectively treat water hyacinth?

(1) Water eutrophication control, root cause treatment: With the continuous improvement of economic output, people's material life is greatly enriched, sewage discharge and organic matter are also increasing, providing an important source of nutrition for the growth of water hyacinth. Therefore, reducing the discharge of domestic sewage and industrial waste liquid, so that it can be discharged after treatment, can limit the growth of water hyacinth from the root.

The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

Waste liquid treatment device (image source network)

(2) Manual/mechanical removal, fence barrier, prevention of spread: the area of water involved in the initial spread of water hyacinth is small, and it can be effectively removed by manual salvage and mechanical crushing, and the drifting spread of water hyacinth can also be blocked by purse seine or floating objects; When too much water is involved, this method is time-consuming, labor-intensive and costly.

The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

Manual salvage (left) mechanical crushing (center) fence barrier (right) (Image source network)

(3) Chemical control, efficient control: In the face of the surge of water hyacinth, herbicides have a good inhibitory effect on water hyacinth. It should be noted that drinking water areas should be strictly avoided when applying pesticides to ensure the safety of people, animals and fish.

The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

Anti-water hyacinth herbicide (Form source: Quanzhou Plant Protection and Plant Inspection Station, Fujian Province)

Author: LI Siqun (Graduate student, College of Life Sciences, Hubei University)

Scientific checkpoint: Xu Lotian (Associate Professor, Hubei University)

The "lilac flower crown" that blocks the channel and suffocates fish - water hyacinth

Source: Guangming Network - Popular Science China

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