Authorities are hunting off the coast of Western Australia for a killer shark with a spear lodged in its throat.

Jay Muscat, 17, died when a suspected white pointer attacked him at Cheynes Beach, near Albany yesterday.

The shark then reportedly turned on his friend, Matt Pullella, but he was able to shoot the shark in the mouth with his spear gun.

Mr Pullella paid tribute to his mate in a Facebook message posted just hours after the fatal encounter.

"The shark hit me first then attacked Jay," he wrote.

"The shark turned and came for me, I pushed the spear gun down its throat and fired the gun."

Jay Muscat, 17, was fatally attacked by a shark off Western Australia's south coast. (Facebook) (Facebook)

Albany mayor Dennis Wellington said Mr Muscat was attacked about 40 metres off shore at a popular spear fishing site.

Local spearfisherman Leon Durrant told ABC radio Mr Muscat was a great larrikin who loved his diving.

He said the teenager was one of the new generation of up and coming divers and was both competent and comfortable in the water.

"He made an effort to get there and was always by my side," Mr Durrant said.

Cheynes Beach remained closed on Tuesday as the Fisheries Department deployed drumlines in the area to catch any shark larger than three metres as part of the state's imminent threat policy.

Fisheries spokesman Rick Fletcher told ABC radio that because Mr Muscat was attacked by a large shark it was likely it would be disposed of if caught, even though in most cases sharks responsible for attacks can't be identified.

"Obviously if we find a shark with a spear in it that's clear cut but that's probably unlikely," Mr Fletcher said.

A caravan park worker told AAP that, with the exception of bronze whalers, sharks aren't commonly seen in the area.

It is peak season for the holiday park, which is now full.

If the state coroner confirms the 17-year-old's death as a shark attack, it will be the eighth fatality in the past five years and the first for 2014 in WA.

In October, 23-year-old surfer Sean Pollard lost an arm and his other hand in an attack at Kelpids Beach near Esperance.

Two sharks were caught and killed when drumlines were deployed off that beach after that incident.

Experts say attacks by sharks, which are common in Australian waters, are increasing as water sports become more popular.