Robert Harman, who took this photo, says it appeared the whale had been hit by a boat propeller.

However, staff from the Pet Porpoise Pool believe the young male had become entangled in a net or was caught in some strong fishing line.

Vet Duan March said that whale was already dead, possibly for two or three days by the time he was beached.

In the meantime sharks had fed on the carcass with large bites taken from the whale's tail section.

Mr March said it was not unusual to see a humpback whale stranded alone.

"Typically with humpbacks you don't get strandings en masse," Mr March said.

"Usually they're single strandings."

The vet added that the sight of an 11 metre gentle giant of the sea washed ashore is one that will be seen more often during the migration season.

"There's probably more strandings to come," he said.

"With the humpback population increasing you're going to get more if these during the migratory period which is May on the way north and November on the way back."