A virus has been discovered in the U.S. that causes fish to infect one another with black skin cancer

Researchers from the University of Vermont have published the results of a study in the scientific journal *Nature* regarding a mass outbreak of disease among catfish in Lake Memphremagog, located on the border between the United States and the Canadian province of Quebec. The researchers found that the fish transmit black skin cancer to one another through a viral disease. 

The first cases of infection were recorded by fishermen and scientists as early as 2012, but since then, the disease has spread relentlessly, and currently, about 30 percent of the entire catfish population in this 51-kilometer-long body of water has been affected.

The transmission of cancerous tumors from one individual to another is an extremely rare phenomenon in nature. According to scientists’ observations, the disease is most often detected in large fish at spawning sites. The primary route of transmission is believed to be direct physical contact between catfish during the spawning season, as well as skin contact with the environment in the lake.

Lake Memphremagog is a source of drinking water for more than 175,000 local residents, but scientists have assured the public that the situation poses no threat to human health. Cancer cells and viruses of this type are species-specific, so they are unable to survive or infect any other animal species or humans.

Experts have also refuted the theory that the disease was caused by toxins leaking from a nearby landfill, as the water quality in the lake remains stable. Instead, the likely cause of the outbreak is believed to be a naturally high concentration of arsenic in the soil surrounding the body of water. This hypothesis is supported by the fact that similarly affected fish have been found in other bodies of water in the states of Vermont, New Hampshire, Maine, as well as in the Canadian province of New Brunswick, where the soil is also rich in this chemical element.

Source: Nature.

In Kyiv’s Verbne Lake, anglers spotted a sunfish—an invasive species, meaning a non-native fish originally from North America, which is gradually spreading throughout the capital’s bodies of water. It is now impossible to eradicate it.

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