Whale beached at Aust near First Severn Crossing
Rescue teams have spent the night trying to save a young whale washed up at Aust near the First Severn Crossing.
The 9ft (2.7m) beaked whale became beached at about 22:00 BST on Wednesday and was put down by a vet at about 03:30 BST.
Marine mammal medic Elspeth Hardie, who attended the rescue attempt, said the whale calf had been at risk of starving to death.
She said she had seen dolphins there before but never a whale.
The Zoological Society of London is now working to retrieve the creature, which it believes to be a Sowerby's beaked whale, and take it back to the capital for a post-mortem examination.
Miss Hardie, a volunteer with Severn Area Rescue Association (SARA), said they were called out by British Divers Marine Life Rescue after they received a report of a porpoise stranded in the River Severn at Aust.
"We sent two crews to look at the animal to assess it and it was alive and on its side," she said.
"Then, with the assistance of the Coastguard, British Divers Marine Life Rescue and Avon Fire and Rescue Service, we dug a trench alongside the animal to right it so its organs were in the right place.
"We then maintained the animal as comfortably as possible, keeping it wet and maintaining its blow hole, until a vet was able to come and assess it."
She said the vet identified the creature as a beaked whale calf which should have been with its mother.
"If we had managed to refloat the animal it would have starved to death because its mother wasn't anywhere near and the likelihood of them finding each other was limited," she said.
"It's extremely rare to see one here. We've had a few porpoises and maybe a dolphin spotted in the Severn, and lots of seals, but I've never seen or heard of a whale."
Mervyn Fleming, from SARA's Beachley lifeboat station, also helped with the rescue.
He said: "It's the first one we've had at Aust.
"Once they get into the coloured water they can't see and rely on sonar, but the shallow sloping mud is not very good for echoes.
"They also don't float so well because of the water density."
Rob Deaville, from the UK Cetacean Strandings Investigation Programme at the Zoological Society of London, said the post-mortem examination would likely take place on Friday with the results expected a week later.
He said they were currently "working out the logistics" of getting it to London.
"Last year there were 600 stranded cetaceans around the UK," Mr Deaville said.
"The Sowerby's beaked whale is one of the more common species of beaked whale but it's still a fairly uncommon species."