Crash investigators are calling for the public to send them videos of a crash between a ship and tug boats in Devonport, with videos of the bungle now appearing on social media.
On Friday, the commercial cement carrier Goliath crashed into two berthed and stationary TasPorts tugs, Campbell Cove and York Cove, at 11:50am at the Port of Devonport.
No crew members were on board the tugs, and no-one was injured.
In footage posted online, baffled witnesses could be heard saying "what happened there?" shortly after the impact.
TasPorts chief operating officer Stephen Casey said early assessments indicated the two tugs, which are now submerged, were not repairable.
Mr Casey said replacing the damaged tugs, repairing the wharf, which was also damaged, and salvaging the tugs, could cost millions of dollars.
"The priority at work right now is to control and contain the oil spill, we obviously have a large amount of fuel and oils coming off the two tugs," he said.
Mr Casey said between them, the two tugs had 60,000 litres of fuel onboard.
He said an expert salvage contractor was coming from New South Wales.
"Sometime this week, they'll take over the site and take on the salvage operation, which includes recovering any more of the fuel that might still be in the tanks and then planning for the recovery of the vessels."
Floating oil spill prevention booms were deployed around the tugs, and another is being used further south in the Mersey River.
Environment Protection Authority state pollution control officer Tony Port said the quick use of the booms had contained most of the oil.
"It's really minimised the impacts it's had on the environment … as far as we can ascertain," Mr Port said.
He said the shoreline along the coast and along the Mersey River was being assessed for any impact on wildlife.
"We haven't seen any significant impacts of oiling yet."
BirdLife Tasmania convenor Eric Woehler said gulls, cormorants and shorebirds could be affected by oil.
Dr Woehler said even a small amount of oil could be deadly for birds.
"If there's only a little bit of oil and the birds try to preen the oil out of their feathers, they'll ingest the oil and then they'll die potentially from the toxins and the poisons in the oil," he said.
"It's important that if any member of the public sees any oiled wildlife, be it a bird sitting on the ground or … flapping around in the water, notify the authorities and they'll get a clean-up team in there and get the animal to a registered carer."
The Australian Transport Safety Bureau (ATSB) is investigating the incident.
Chief commissioner Angus Mitchell said the purpose of the investigation was to determine what happened and to determine whether any safety improvements were needed.
"An incident of this nature is significant in any port. Fortunately in this case there was no injuries … but there is significant economic consequences," Mr Mitchell said.
"A team of transport safety investigators from ATSB's Canberra, Melbourne and Sydney offices with expertise in marine operations and data recorders are deploying to the accident site," he said.
"On site, investigators will examine the vessels and site surrounds, conduct interviews with involved parties and witnesses and review logs.
"The ATSB will download data from the ship's voyage data recorder and other recordings for detailed examination in the ATSB's technical facilities in Canberra."
The ATSB is calling for anyone who may have seen the incident, or who may have CCTV or other footage to make contact via the witness form on the ATSB website.
"A report will be published at the conclusion of the investigation. However, should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties so appropriate safety action can be taken," Mr Mitchell said.
