A dolphin is being monitored by a marine rescue charity after chasing fish miles up a Welsh river and arriving into English waters.
The disorientated mammal was first sighted in Connah's Quay docks in Flintshire, North Wales, on Monday but then swam further up river to Saltney, near Chester, in Cheshire.
Despite being native to the deep seawater of the Bay of Biscay, the dolphin carried on swimming up the river and was most recently spotted near Chester Racecourse.
Marine experts believe the common dolphin must have been chasing fish up the River Dee in North Wales.
Locals have been tweeting pictures of the dolphin jumping and flipping out of the water, which has been nicknamed 'Dave' by residents, according to Sky News.
They have been warned not to gather on the banks of the river or disturb the dolphin.
The animal is now being observed by the British Divers Life Rescue. Stephen Marsh, operations manager at the charity said they are keeping a close eye on the dolphin in case it gets stranded on a sandbank.
Mr Marsh said the creature seemed to be heading back out to sea yesterday but returned to Chester today.
He said: "It's probably been chasing fish in from the sea and then got caught up in the tidal system."
He said tides at this time of year can be both very high and very low and that is probably confusing the dolphin, which is more used to much deeper water.
Mr Marsh said such an event is quite rare, adding that they would step in to escort it back out to sea if it does get into trouble, but it looked healthy and would probably
A member of Environment Agency staff doing maintenance work on the River Dee spotted the dolphin around Sealand Road in Chester yesterday and took a photograph as it jumped out of the water.
An Environment Agency spokesman said the dolphins appearance highlights the quality of the water in the area.
"It's likely that the dolphin entered the River Dee searching for food", the spokesperson said.
"Our rivers are the healthiest that they have been for over 20 years. Because of this we've seen an increase in the numbers of wildlife including otters and salmon returning to our waters."