Sei whale beached in Farewell Spit, Golden Bay

Locals and DoC staff have been trying to keep the 14-metre Sei whale alive. Photo / Jo Richards, The GB Weekly

A huge 14m Sei whale has beached itself in Golden Bay this afternoon.

Dozens of locals and Department of Conservation staff are tonight attempting to comfort the animal which is not in good shape.

The whale is stranded at Farewell Spit and is around 1km from the high water mark of the hide tide. It is hoped the whale will be able to refloat itself when the tide is at its peak, around 1.30am.

General manager of the Kiwi whale saving organisation Project Jonah, Daren Grover, said the whale is unlikely to survive.

"For a whale this big to come to shore and strand that indicates it is very likely there is an underlying health problem within it, whether that be an illness or an injury," Grover said.

"As a result it's quite likely that this whale may not survive."

Project Jonah have been providing advice to volunteers on the scene today on how to care for the whale.

"I doubt people will be working with the whale at night because that blood in the water, you're going to have nocturnal creatures coming up that are going to be attracted by that, sharks and stingrays," Grover said.

"So it will be dangerous for anyone to remain with the whale overnight."

DoC staff were close by and arrived on scene quickly after the first report.

Grover said there are concerns about the whale's health and it is showing signs of poor condition.

DoC explained that the stranded marine mammal was only breathing with one lung and it was clearly in some discomfort, the GB Today reported.

The Sei whale is the third largest species of whale, after the blue whale and the fin whale.

Photos of the whale show it in a pool of blood.

"Because they move their tail around and the blood vessels are very close to the surface of the skin and that can cause a lot of bleeding," Grover said.

"There could be an underlying condition that has caused it to bleed that way. We're unaware because we can't asses the health of the whole animal because of its sheer size."