“If they do wash up it’s normally because they are sick, old or struck by a ship,” Ms Farrell said.
Authorities left the whale in place to allow it to decompose naturally because machinery or vehicles were unable to access the carcass and towing it out to sea posed navigational hazards.
The department spokeswoman said there was an exclusion zone set up around the carcass.
“Members of the public are reminded it is an offence for people to be within 300 metres of the whale,” she said.
An advice message is in place for Woolamai Beach and Surf Beach, including all coastline between the two beaches, because the carcass has the potential to attract sharks.