New species of carp likely to threaten native fish have been found in British waters for the first time, the Environment Agency (EA) has warned.
The agency’s Fisheries Laboratory is currently investigating all suspected cases of Prussian carp, which are known to invade native fish populations.
But it has also detected two additional non-native fish species, known commonly as ginbuna and nigorobuna.
Ginbuna, also known as silver crucian carp, are native to Asia, but have been recorded in Europe and North America. Meanwhile, nigorobuna are native to Japan.
The impact of their introduction to UK waters is currently unclear, but the EA says they are likely to carry similar environmental risks to Prussian carp.
Once introduced, Prussian carp can rapidly expand their population size, disrupting native species and ecosystems.
They can outcompete native fish for food and habitats, and also interbreed with other species, threatening British populations.
Anglers and fishery owners are being urged to report any potential sightings to help stop the spread, while the EA has produced an identification guide, hosted by the Angling Trust.
‘Environment Agency is remaining vigilant’
Dr Gareth D Davies, a technical specialist at the Environment Agency, said: “The Environment Agency is remaining vigilant and our lab is working hard to ensure robust detection and mitigation measures are in place to determine the risk posed by Prussian carp, ginbuna or nigorobuna to our native stocks and the wider environment.
“We encourage fishery owners, managers and anglers to report any suspected cases of Prussian Carp, ginbuna, nigorobuna and other non-native species to us as soon as possible.
“This allows us to respond promptly to reports, limiting the harm to native fish species and helping our specialists research invasive species to prevent further spread.”
How the two new species entered the UK is under investigation.
However, carp tend to be difficult to identify, and it is believed they may have been imported unintentionally with consignments of other more commonly stocked fish.
They have been introduced to many countries because of their similarities with crucians, brown goldfish and carp hybrids.
It is illegal to import any of these fish into the UK because of the risk they pose to native fish populations and fisheries.