Non-native lionfish, Pterois volitans, have been found off the East Coast of the USA, many miles away from their natural home in the Indo Pacific.
According to Yahoo News, the National Oceanic and Atmospheric Administration released a report last week which claimed that the increase in abundance of lionfish off the US East Coast is irreversible.
Sightings of lionfish have been on the rise since 2000 when three fish were spotted. In 2001 a dozen were seen, but in 2002 this had increased to 41 sightings. The researchers are planning to conduct a survey around North Carolina to see how far the fish have spread.
The fish are believed to have been either illegally released by fishkeepers, or by dive tourism companies.
Dean Wilkinson of the National Invasive Species Council told Yahoo News: "We have had enough bad experiences we should not be introducing new fish species."
Divers have been warned to avoid the fish which are equipped with venomous spines.