When it comes to invasive alien species, the first thing that comes to everyone's mind is that they have no natural enemies and reproduce like crazy, seriously threatening the local ecological balance. Since the spring of 2022, a large number of invasive alien species have appeared in the waters near Qingdao City, Shandong Province, my country. These include starfish that invaded the waters of Qingdao last year and the white mud ant that was first discovered this year. Starfish also have certain edible value.
However, the white mud ants that invaded the Jiaozhou Bay of Qingdao for the first time are not only more harmful, but also have no use value and are more difficult to deal with. So, what exactly happened when the white mud ants invaded the waters of Jiaozhou Bay, Qingdao?
What happened
In July 2022, farmers near Jiaozhou Bay in Qingdao City said that their clams and other seafood had been preyed on by invasive alien species, causing great losses. This invasion of alien species is the second consecutive year that the sea area of Jiaozhou Bay has been invaded by alien species. Last year’s alien species were mainly sea stars. Although starfish have brought considerable losses to farmers, starfish also have Edible, farmers make up for part of their losses by hunting and selling starfish. However, not only is the breeding situation this year far worse than last year, the losses suffered this year are even much higher than last year.
Since the spring of 2022, the waters of Jiaozhou Bay have once again been invaded by alien species. Exotic species of starfish prey on clams and oysters raised by farmers, sucking out clams and oysters that originally grew well, leaving them with empty shells. Although the scale of this year's starfish invasion is much smaller than last year, farmers say they have suffered greater losses.
A seafood farmer said that in his breeding area of more than 600 acres, he originally put more than 1,500 clam seedlings per square meter, but after being eaten away by starfish and other exotic species, only about 600 clams per square meter were left. Clams, this means that the invasion of alien species alone caused him a loss of more than 2 million yuan, and he also lost two-thirds of the clam seedlings. Since the scale of the starfish invasion this time is much smaller than last year, why is the damage caused greater?
The reason behind this is Bai Ni Ma. This alien species, the white mud ant, was discovered in the waters of Jiaozhou Bay for the first time. This species is more harmful to the seafood raised by farmers. At the same time, the number of its invasions is far more than that of starfish. According to a fisherman's description, he went to sea More than 200 kilograms of white mud ants can be caught at one time. When fishermen are fishing for clams, a large number of white mud ants are mixed with the clams. When the belly of the white mud ants is opened, it is filled with eaten clam meat. , which makes seafood farmers feel distressed. The ratio of these salvaged white mud ants to clams has almost reached 1:1, which shows how many white mud ants there are in the waters of Jiaozhou Bay.
At the same time, these white mud ants prey more on clams and other seafood, and their "appetite" is much greater than that of starfish. They are not as edible as starfish, and they are more difficult to handle after being captured, which brings problems to farmers. The losses are also greater. So, what kind of creature is this invasive alien species, the white mud ant?
White mud ant
When it comes to White mud ant, many people are unfamiliar with it. In fact, this is not its real name. Its scientific name is Jingshi shell slug . The white mud ant is an animal of the genus Slugidae of the family Slugidae. Its shells are generally oval or square in shape. The shells are thin, brittle and easily broken. They are translucent and have the luster of pearls. The animal body is long cylindrical, white or light red in color, and has well-developed teeth in the abdominal cavity. It can easily catch clams and oysters, and it grows very fast and has a strong reproductive capacity. It is currently widely distributed in my country's Temperate sea areas such as the Bohai Sea , Yellow Sea , East China Sea .
The harm of white mud ants
Although white mud ants are small in size, they are very harmful to clams and oysters. When it preys on clams and oysters, its body will first secrete a kind of mucus. Although this mucus is not very toxic, a considerable number of white mud ants will secrete a very large amount of mucus, which will look like a It covers the bottom of the sea like a net, and also adheres to the shells of clams and oysters, causing the clams and oysters to die from lack of oxygen. Then the white mud ants suck them all up, leaving only an empty shell in the end, and The white mud ant feeds almost exclusively on clams and oysters, and its number is much greater than that of starfish, causing great economic losses to farmers.
At the same time, the white mud ant is not as edible as a starfish, and it can even cause poisoning in those who eat it. This kind of white mud ant has a close relative called mud ant in Qingdao. This kind of mud ant is actually an edible mud snail, but the white mud ant discovered in Jiaozhou Bay this time is very different from the mud snail. , not only is it not as delicious as mud snails, but it can also cause allergic symptoms in the eater, and in serious cases can endanger the life of the eater. Therefore, this kind of white mud ant is not like starfish. It allows farmers to reduce some economic losses by catching and buying and selling starfish. It will even increase farmers' processing costs and increase the difficulty of handling white mud ant.
So, what is the reason why so many white mud ants suddenly broke out in the waters of Jiaozhou Bay?
Reasons for the surge in the number of white mud ants
White mud ants can reproduce in large numbers in Jiaozhou Bay in a short period of time. The main reasons are as follows. First of all, the white mud ant has a strong reproductive ability. The white mud ant, as an animal of the genus Chestus in the family Slugidae, has a very strong reproductive ability and can grow from juveniles to adults with reproductive capabilities in a short period of time. At the same time, there is almost no white mud in the waters of Jiaozhou Bay. The natural enemy of the ant, because 2022 is the first time that the white mud ant was discovered in the waters of Jiaozhou Bay. A brand new ecological environment can provide it with rich nutrients and less competition.
Secondly, the clams and oysters artificially raised by fish farmers in Jiaozhou Bay are too dense. The area that can be artificially cultured in the offshore waters of Jiaozhou Bay is fixed. In order to obtain greater economic benefits, farmers also have the problem of placing too many clams and oyster seedlings. At the same time, almost all the offshore waters of Jiaozhou Bay are occupied by clam and oyster farmers. There are hundreds of millions of clams and oysters in this sea area.
And the white mud ant is an animal that specializes in eating clams and oysters. These huge numbers of clams and oysters provide it with a steady stream of food, and at the same time attract more white mud ants from other sea areas to Jiaozhou Bay. waters, forming a vicious cycle until all the clams and oysters in Jiaozhou Bay are hunted.
Furthermore, the water environment near Jiaozhou Bay has changed. When farmers cultivate clams and oysters in Jiaozhou Bay, it is indispensable to artificially put bait into the sea to speed up the growth of clams and oysters and produce large and fat seafood. This also brings about The water quality in Jiaozhou Bay has become eutrophic, and the water contains too many nutrients. These rich nutrients also provide food for the growth of white mud ants.
So, faced with such a large number of white mud ants and such great harm, haven’t the government and farmers taken active and effective measures to deal with them?
Measures to hunt and kill white mud ants
Faced with such heavy economic losses, local farmers and fishermen have already taken measures to self-rescue. They hunt and kill white mud ants through artificial fishing, but this method is too efficient. low, the effect is not obvious. At the same time, during this period of time, during the fishing moratorium, it is impossible to hunt by using ground cage . This hunting method can be said to be the best way to solve the excessive number of white mud ants.
Finally, as the Qingdao Municipal Ocean Development Bureau continued to pay attention to and investigate the white mud ants in the Jiaozhou Bay waters, and consulted relevant fishery experts, and after consulting the Shandong Provincial Department of Agriculture, it was finally decided that starting from July 1, 2022, in Jiaozhou Bay Within the delimited sea areas, clam and oyster farmers are allowed to use ground cage nets and bottom trawls to conduct a comprehensive cleanup of starfish and white mud ants in the delimited sea areas. The ground cage net is mainly used to clean up starfish, while the bottom trawl net can clean up all starfish and white mud ants like "buying the bottom".
However, there is a limit to the time period during which ground cage nets and bottom trawls are allowed to be used for cleanup. The time window for cleaning with ground cage nets is from July 1 to July 31, 2022, and the service period of bottom trawls is from July 1 to July 20, 2022, and the operating vessels of bottom trawls can be For fish farming vessels, after this period, all processing equipment must be collected and destroyed.
At the same time, the Qingdao Municipal Ocean Development Bureau also established a special task force to clean up starfish and white mud ants. After the outbreak of starfish and white mud ant invasion in relevant sea areas was determined, farmers and fishermen reported the longitude and latitude of the sea areas that needed to be cleaned with cage nets and bottom trawls, as well as the numbers of the cleaning ships at sea. The special work team immediately combined the actual situation to carry out the fastest We will simplify some cumbersome procedures and allow farmers and fishermen to clean up as soon as possible to reduce their economic losses.
believes that by taking the above effective cleaning measures, local farmers and fishermen will be able to complete the cleanup of starfish and white mud ants in the shortest time and reduce economic losses.
Author: Yaya Proofreading Editor: W
