Invasive Asian fish that can jump up to 3m is causing US to demand to block its migration route

This fish has cost US authorities more than 200 million USD to prevent their invasion .

Fish species "invading" waters in Canada and the US

In the 1970s, Americans introduced an Asian fish species to fish farms in the South of the country. That was the Asian carp. Initially, the farm owners intended to use carp to clean catfish ponds and make them healthier. Because carp are filter feeders (a type of eating fish that filters out particles and food floating from the water by opening their mouths very wide). This was also the ideal water filtration method for fish ponds and ponds at that time.

In 1970, Americans imported Asian fish into farms for the purpose of improving water resources. (Photo: NYTimes)

Asian carp is the common name in English for common carp species that live and are raised in many regions of Asia such as China, Japan, Korea, and Vietnam. They are a common food source in the daily meals of residents in this region, and are raised in the largest quantity in the world.

However, after a flood occurred, two species of carp, the bighead and silver carp, escaped with the floodwaters and "moved their residence" to the Mississippi River basin. At that time, people thought that these carp could be used as food.

The fish imported into the US at that time was Asian carp. (Photo: NYTimes)

In 1994, a flood hit Illinois. When the water receded, people were shocked to find that nine times more Asian carp than local fish had died. At that time, many people wondered how Asian carp could migrate so far.

In 2002, the "nightmare" of the US authorities officially began when Asian carp grew too fast and they seriously destroyed the habitat of local aquatic species. Asian carp are known to be a species of fish that adapts very well to the new environment. In addition to being strong swimmers and avoiding nets very well, they are also omnivorous, able to eat up to 40% of their body weight. With a length of usually 50-90 cm, and weighing more than 50 kg, Asian carp consume a large amount of food including other aquatic species. They have destroyed many local fish species on the way, destroying the ecosystem where they live.

Asian carp can lay up to 2 million eggs at a time , so they grow quickly, forming large schools of hundreds. To prevent them from invading Lake Michigan, the first electronic fence was installed in the lake. Two more fences were added in 2009 and 2011.

Asian carp have rapidly invaded many parts of the United States and have even reached Canada. (Photo: NYTimes)

Over the past 30 years, the Asian fish has invaded waterways in Minnesota, Wisconsin, and Michigan to the west; New York and Pennsylvania to the east; Illinois, Indiana, and Ohio to the south; and as far north as Ontario, Canada. Asian carp have invaded the Great Lakes, consuming up to a fifth of the Great Lakes' plankton, threatening the $4 billion-a-year fishing and tourism industries in the five lakes.

The fish species that makes US authorities "lose sleep"

For many people, Asian carp are the true "monsters" of the river . With a large appetite, they can reach a body size of more than 100 cm. They are aggressive fish, many weighing from 28 to more than 45 kg/fish and can live up to 80 years. They will rush out of the water when they hear the sound of a boat engine. They can jump up to 3 m out of the water when the water surface is "turbulent".

Several boating groups on the lake have had schools of Asian carp suddenly jump aboard and attack those who disturbed the surface of the lake. In 2014, the National Wildlife Federation issued a warning about Asian carp jumping onto boats and putting people at risk. The Illinois Natural History Survey even had to wrap nets around the rudders and control systems of its research vessels to prevent attacks from these fish.

Asian carp are fish that can jump up to 3m high when the water surface is disturbed. (Photo: NYTimes)

The Illinois Department of Natural Resources has warned that since the Asian carp have invaded, they must close the entrance to the Great Lakes or else the entire flora and fauna of America's largest freshwater region will be destroyed. Electric fences have been installed at the mouth of the Chicago River to "block 100 percent of the chance of these ferocious immigrants entering Lake Michigan." However, Asian carp have learned to slip through the fence. Officials then plan to create "choke points" at both ends of the waterway connecting the Illinois River to the Chicago River.

However, experts from the Illinois Chamber of Commerce say that closing the canal, which is open to cargo ships 24 hours a day, would cause severe economic damage. The cost of transporting goods by road and rail would increase, while the water transport industry would lose about $8 billion a year. Therefore, how to effectively block the migration route of Asian carp is one of the urgent issues that keeps US authorities up at night.

Millions of dollars spent trying to eradicate invasive fish species

Local people have tried every means such as netting, fishing, and even electrocution, but have not been able to reduce the increase of Asian carp.

Americans have tried many ways to kill this fish species but still cannot stop its increasing numbers. (Photo: NYTimes)

Other, more cost-effective options are also being considered, such as producing carp burgers to eradicate the fish. Scientists have also proposed dumping poison into waters where they have found Asian carp DNA.

In 2003–2004, the United States and Canada collaborated on strategies to prevent Asian carp from entering Lake Michigan. In 2005, Ontario banned the farming of invasive species, including Asian carp, but continued to allow dead carp to be imported into the province. In 2008, Canada instituted a strict 'border patrol' on live Asian carp imports by land and air. In 2010, British Columbia banned the possession and sale of Asian carp.

More than $388 million has been spent by US authorities to fight Asian carp. (Photo: NYTimes)

In fact, since 2010, more than $388 million has been spent on the fight against Asian carp, including the production of water guns that have adapted well to the pressure from the guns.

The fish are banned in Michigan and Minnesota; in Wisconsin, they are only used for research purposes. But five other Great Lakes states—Illinois, Indiana, Ohio, Pennsylvania and New York—allow them with special permits.