Hundreds of people are continuing to scoop up oil stuck on Moreton Island's eastern beaches, off Brisbane.
The cargo ship Pacific Adventurer leaked around 200,000 litres of oil in the ocean after 31 containers of ammonium nitrate fell off the ship's deck near Stradbroke Island, off Brisbane, in the early hours of last Wednesday morning.
Moreton Bay is a marine sanctuary that is home to a range of sea birds as well as turtles, dolphins and pelicans. Environmental experts are assessing where the clean-up efforts should be concentrated there.
Three hundred people have been cleaning the worst-affected areas in 200 metre sections. More heavy earth-moving equipment has arrived on the island to help in the mammoth clean-up task.
Oil-covered pelicans and reptiles are being shipped back to Brisbane for treatment.
Legal action has started and three investigations are underway into the cause of the oil spill.
Federal and state authorities took the first step in pursuing the ship's captain, with legal papers formally served on Sunday. The captain surrendered his passport immediately.
The three investigations involve the Australian Transport Safety Bureau, Maritime Safety Queensland and the Australian Maritime Safety Authority. They will examine the ship's seaworthiness, how the containers were stowed and the circumstances before and after the accident.
The Swire Shipping Group, which owns and operates the cargo ship, has denied suggestions it knowingly lied about the amount of oil that leaked from the Pacific Adventurer.
The Queensland government says it will be seeking tough penalties if the crew is found to have lied about it.
It was initially thought 20,000 litres leaked from the Pacific Adventurer when it was damaged on Wednesday, but it has now been revealed that 230,000 litres leaked into the ocean.
Swire Shipping could be fined up to $A2 million and may also be liable for up to $A250 million for environmental damage to the shoreline. It is already facing costs of $100,000 a day.