A humpback whale calf has been found dead in the propeller of a tugboat that was guiding a ship to a Queensland coal port on Tuesday night.
The cause of the calf’s death will probably remain a mystery, said Queensland parks and wildlife officers, who consider it possible it was dead before it collided with the 33-metre tug Bulgu.
“Given the state of the carcass it is highly unlikely we will be able to ascertain whether the animal was alive or dead at the time of the vessel strike,” according to a briefing note seen by Guardian Australia.
It is understood the tugboat was guiding a coal ship to a BHP berth at Hay Point, south of Mackay, when it struck the whale and suffered engine failure.
Commercial divers found the dead whale ensnared in the propeller beneath the vessel on Wednesday morning and called the RSPCA.
There are unconfirmed reports the calf was seen swimming with its mother nearby in recent days.
A WWF reef campaigner, Richard Leck, called for a full investigation to determine “exactly what went wrong here”.
The incident highlighted the challenges of “operating a mega industrial port alongside the natural wonders of the Great Barrier Reef”.
“Every effort should be made to determine what happened and what lessons can be possibly learned to prevent future whale fatalities,” he said.
“There are still plans on the table to expand shipping movements through the Great Barrier Reef. If more coal ships are allowed to pass through the reef’s waters the risk of ship strikes on whales would increase.
“A study last year found that whales hit by ships travelling at average speed face a 50% to 70% chance of dying.”
A commercial dive team will be responsible for freeing the carcass by Thursday. It will have to use the boat’s on-board crane to lift the five-metre calf on to a Mackay council truck for “disposal on land”.
QPWS officers on site would take blubber samples.
