Conservationists were today battling to save two lost rare bottlenosed whales who are within a mile of beaching themselves on the Norfolk coast.
The stricken pair have been swimming around the shallow waters of The Wash for a week and experts fear they could soon become stranded.
If this happens, there are few alternatives but to euthanise the huge creatures, who were first spotted by a woman abroad a boat heading across the water last Sunday.
It is thought they became lost on their migration journey from the Norwegian seas to the North Atlantic, after turning left too early and wrongly joining the North Sea.
The mammals are the same breed as the 18ft northern bottlenosed whale who swam up the Thames in February 2006 and died during a rescue operation.
Gemma Veneruso (corr), sightings officer for national marine conservation research charity Sea Watch said she was ”very concerned” about the fate of the two rare creatures.
She said: ”The whales have now been spotted three times and each time they are getting further inshore.
”Sadly there is a great risk they will strand and then the kindest thing we can do is to euthanise them.
”It looks like these two have lost their way during migration from the Norwegian Sea past the North Atlantic which is why we sometimes see these animals off the British coast.
”They are currently in the southern end of the Wash between two large sandbanks and less than a mile away from land.
”There are usually a couple of such cases every year and sometimes there are efforts to save them, such as playing sounds to try and get them back on the right track.
”However, the water these two are in is too shallow and all we can do at the moment is to closely monitor their movements and hope they go back out.”
The whales were spotted ”actively swimming” in the Wash in Norfolk on August 1, August 5 and August 9, each time getting closer to land, Gemma said.
She appealed to the public to take part in Sea Watch’s annual National Whale and Dolphin Watch, which runs until August 15, in order to track the whales.
Regular updates on their position will help give Sea Watch and other local conservation groups the best chance at preventing the whales from stranding.
Members of the public should not try to move the whales or coax them out of the Wash as this will stress them and could force them even closer to land.
Dr Peter Evans, Sea Watch’s director said public sightings of marine life would help ”unlock some of the mysteries” of the seas.
He said: ”Marine mammals are an important barometer of the health of our waters.
”By monitoring where, when and how many are seen, we can pick up trends in populations, and identify human pressures such as pollution, disturbance or entanglement in fishing gear.
”There is still a great deal we need to understand about our marine mammals so that we can put in place effective conservation measures – where they go, how they interact with humans, and where they feed and breed.”
Bottlenosed whales, which have bulbous foreheads and short dolphin-like beaks, are 11.9ft long when born but can reach up to 32.3ft long in adulthood.
They are chocolate brown coloured on their bodies, lighter on their flanks and their heads turn buff or cream with age.