The Environment Agency (EA) is urging borough anglers to report catches or unusual sightings of invasive pink salmon, after unprecedented numbers were detected further south than previously seen.

Pink salmon, which can be identified by large black oval spots on their tails, could carry diseases that threaten native fish stocks.

EA specialists predicted that the fish (also known as humpback salmon) would be spotted in the Northeast and Northwest rivers in the coming weeks.

Fishing managers, fishermen and cleaners are therefore asked to remain vigilant and report any sightings or catches to the EA national hotline: 0800 80 70 60

The data collected will help the Environment Agency and fisheries researchers better understand how to deal with the arrival of pink salmon in the UK.

Simon Toms, head of the National Fisheries Management Team at the Environment Agency, said: “Wild Atlantic salmon stocks are already under great pressure from various sources. The introduction of new parasites or diseases from invasive species, such as Pacific pink salmon, could pose an additional risk to the species.

“We want to better understand the immediate risk pink salmon could pose to our important wild salmon stocks. We urge fishermen to report any catch or sightings of all pink salmon to us as soon as possible. ”

Pink salmon (Onchorhyncus gorbuscha) is native to the northern Pacific Ocean. As a result of an initiative to develop a net fishery in northern Russia, pink salmon established self-sustaining populations in the rivers of Russia, Finland and northern Norway. This is the most likely origin of pink salmon recently caught in the UK and Ireland.

Previously, pink salmon had been caught in the River Tyne at Wylam and other places across Cornwall, Wales, Scotland and the West of Ireland. Examinations revealed that no significant disease or new parasite had been detected. However, the Environment Agency has stressed the need to remain vigilant and will continue to investigate the possible risk posed by pink salmon.

The Environment Agency has produced a useful information sheet with all the advice needed by people who catch a pink Pacific salmon.

Anglers with a salmon license who catch pink salmon are urged not to release the fish. Instead, they are asked to ship them humane and, if possible, make the fish available to the Environment Agency for inspection and further analysis.

If this is not possible, they are asked to send a sample of the scales.

Anglers for trout and large fish are asked to call the Environment Agency on 0800 80 70 60 and, if this is not successful, return the salmon. This guidance also applies to rivers where capture and release are mandatory for Atlantic salmon or trout and fishing rod license holders. In either case, it is important that if you detain a pink salmon, please call the Environment Agency immediately to report the capture and retention of that fish.

If it is not possible to make this call, the fish must be released alive into the river.