COLOBMBIA (AP) – For decades, four penetrating carp have been seen in plankton-eating plants that have endangered the interconnected community of fish, plants and mollusks under the murky brown water of the Missouri River.
At the same time, environmentalists and officials across the country are struggling to control carp damage. Recruiting scientists, setting up barriers, signing contracts with commercial fishing companies, and even launching a campaign to serve more restaurants later this year. fish.
Scientists from the University of Missouri at the US Geological Survey have now discovered a potential breakthrough. They are studying the complex movement of carp eggs in rivers, hoping that they can kill them at a young age, reports St. Louis Post-Dispatch.
“We are developing greater ways to remove large numbers of carp,” said Duan Chapman, a fish biologist who oversees USGS. “But you have to think about the other end.”
Carp eggs rotate for miles, երբ when they slide, the fish develop. If researchers can find out where they are landing, և if those places are suitable for growing young carp, they can target places և break the eggs.
Water moves in three dimensions: downstream, side-by-side. But river models have so far been relatively straightforward, generally based on one or two dimensions, the researchers say. However, now that they are available on more powerful computers, they have spent hundreds of hours collecting new water flow data and finding some help from an expert in liquid physics. This means that scientists now hope to use three-dimensional data on water flow to chart the path of eggs.
There are four types of invasive carps in the Missouri River: big head, carp, and silver carp. All of them are important foods in China that have been cultivated there for over 1000 years.
US fish farmers introduced them mainly in the 1960s and early 1970s to keep fish farms and other ponds clean. But the farmers failed to provide the fish properly, scientists say, and the carp jumped by boat, making their way to the Missouri, Mississippi Rivers and quickly spreading throughout the Midwest.
The population of Missouri grew in the early 2000s, said USGS biologist Chapman.
Adult grass uses aquatic plants that serve as food: habitat for native fish. The bighead and the silver carp feed on plankton, pulling aside native fish that rely on the same food source.
The silver carp is sometimes referred to as the “flying carp”, which is known to fly up to 10 feet in fright, sometimes injuring sailors.
The carp is just leaning on the Missouri River. But they eat mollusks, such as mussels, and mussels are already extremely endangered in Missouri, in part because of their susceptibility to pollution. More than 40% of Missouri’s 69 mussels are protected.
The effect is shocking. The US Fisheries և Wildlife Service estimates that invasive carp can almost completely eradicate native fish, especially in some rivers with severe impact.
“They really do have an impact on sporty fish, such as valley crepe,” Chapman said.
Specialists in the field of nature protection have achieved some success in removing carp in lakes. For example, in 2018, at Creve Coeur Lake, government agencies adapted Chinese technology called the “unified method” – systematically sound – electricity to feed fish, then catch them in large networks, removing about 47,000 carp, or 119 tons.
It is more difficult to remove in rivers.
In 2006, in Bat, Illinois, the organizers came up with a creative idea – the annual Redneck Fishing Tournament, during which competitors try to collect as many silver carp as possible. Hunting? Fishing rods are not allowed. The jumping carp must land in the boats or the participants will jump out of the air while flying.
In some states, commercial fishermen harvest carp mainly for pet food and fertilizer. Later this year, the state of Illinois plans to launch The Perfect Catch, The Carp, to increase the popularity of fish as human food. to increase its attractiveness in the “sea bass” market.
But carp are still spreading.
“They continue to invade new places,” said Robert Jacobson, a USGS supervising research hydrologist. “There are many countries that are now very worried about what will happen next.”
In Columbia, Missouri, scientists have been working for almost two decades to stop the spread.
The USGS Columbia Environmental Research Center is a complex of building ponds with a chain link fence. But one lab hosts most of the work with carp. It is “biosafety” equipped with a specialized wastewater treatment system that has mechanical UV filters to prevent even the smallest egg from leaking out of a live egg.
Inside the lab are carp baths of all sizes, connected by a maze of water pipes.
One day last month, researchers were experimenting with larvae that had just emerged last week. They placed the pup in running water containers, which was a powerful sensation for the young fish. After swimming for three minutes, the scientists removed the fish and froze them, then splitting their brains to see which areas were activated by the moving water.
“What we’re trying to figure out is when the larvae come out, how their senses develop, how they are used to move to the nursery,” said Amy George, a fisherman at the research center.
The center has two groups working on carp, each with 12-15 employees. Studies are different. They measure the effects of toxins on carp. They are developing a sterile large head with tracing labels in the hope that once released, they will lead scientists to existing populations.
They even traced the growth of carp eggs every 15-30 minutes before they hatched, about 30 hours later.
In June, the USGS awarded Mizzou և a $ 200,000 grant to USGS researchers to use computer modeling on the Missouri River և to use field measurements to predict how eggs move.
The team has a new member who brings specific expertise. Binbin Wang, Mizzou’s Civic ճ Environmental Engineering Assistant, is a liquid physics expert who will model the turbulence of the Missouri River.
Scientists could even work backwards to calculate where the fish lay their eggs, which would tell them where to catch the larvae, or where to cause confusion while trying to destroy the eggs.
Carp eggs need river conditions like Goldilocks, neither too slow nor too restless. Still, water allows the eggs to sink to the ground and die, and fast-moving water can kill them. River managers can eventually exploit the dynamics of the water to damage the eggs.
The work will also help researchers find out if undisturbed rivers have conditions conducive to carp survival, and then prioritize resources for high-risk aquifers.
Scientists are particularly concerned about the northern voyage ավել taking place in the Great Lakes, which endangers the ecosystem և the fishing industry.
Jacobson, a USGS hydrologist, says their findings will help understand how all kinds of materials are distributed across rivers.
“It’s not just about invasive carp,” he said. “It also refers to endangered species, it refers to things like the transfer of pollutants in the event of an oil spill, or something like that.”
Now, finally, researchers can reach the ground to catch carp eggs.
“People ask. “Well, because they’re dominated by muddy rivers, we can’t really see what they’re doing for a long time.”
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