A PORPOISE has been spotted swimming in the River Ouse near Selby.

The mammal, more commonly associated with the ocean than a river 50 miles inland, was spotted on the stretch of river near Naburn.

These photos were taken by David Stanton, a member of The Press Camera Club.

There have since been reports of it in the river near Selby’s old Toll Bridge.

While ducks, geese, swans and herons are common sightings around the waterways, a number of rare sightings are made each year by members of the public including seals and, in this case, a porpoise.

York Press:

In fact, this isn't the first time a porpoise has been seen. There were similar reports in 2009.

Back then, Jonathan Hart-Woods, environment manager for British Waterways Yorkshire said: “It’s anticipated that the porpoise followed a shoal of fish out of its saltwater environment into the River Ouse. It is not common for these animals to venture up into the inland waterways although we do have a number of sightings every year of porpoises and seals on the Ouse as well as the River Aire.”

Mr Hart-Woods said the RSPCA had been contacted in the past about such sightings and their advice had always been that the mammals would usually find their way back to the sea once the food supply they have been pursuing has escaped or been consumed.

He said: “We believe the increase in large predatory marine mammals in our estuarine rivers and inlets may well be linked to the passage of large migratory fish as they move from the seas into our inland freshwater courses as they return to breed.

“The increase in the number of sightings we are receiving would suggest that numbers of these fish are slowly increasing. We thank the couple who contacted us to explain their sighting as it helps us to monitor and record common, rare and non-native species and help us work out why, where and when these sightings are occurring which helps us to establish a pattern to this behaviour.

“We rely on our boaters, anglers and other regular visitors to our waterways to act as our ears and eyes out on the banks as there are many enthusiastic wildlife observers regularly out on the water taking an avid interest in the varied wildlife on the BW network. All these reports help us to compile data on the varied biodiversity around the waterways.”