Fourteen ships have been identified as possible sources of a film of oil stretching, in broken sections, 30 kilometres long and five kilometres wide south of Townsville, Patrick Quirk, general manager of Maritime Services Queensland said on Saturday.
An oil slick was confirmed 18 nautical miles (33 kilometres) NNE of Cape Upstart on Friday evening, but was broken up into metre-sized blotches of oily film by the weather.
"We know the ships that went past the area," Mr Quirk said.
"There are 14 ships that we consider are possible sources of oil and we plan to take oil samples from all of those ships," he said.
"We already have samples from five ships in Australian ports and when the others port in Australia or overseas we will get samples."
Townsville water Police took samples from the oily film confirmed on Friday night, after an 800-metre diameter slick it was reported by a fisherman to Townsville's Coast Guard on Friday morning.
"So we will try a chemical match," Mr Quirk said.
A Maritime Safety Queensland inspector will fly to Weipa tomorrow to test oil from one ship, he said.
"So we are pulling out all stops to find the culprit."
In 2010 the Chinese ship, Shen Neng 1, which leaked a 3km ribbon of oil from a ruptured fuel tank near Great Keppel Island, was fined $1 million by the Queensland Government.
Mr Quirk said the 2015 oil slick south of Townsville had spread with the currents and broken down into an oily film.
"In an area about 30 kilometres wide and around five kilometres wide, within that rectangle there are areas of sheen and small patties of oil," he said.
"The whole area is not covered by oil or sheen. It is very patchy."
The oily film could not be detected on Saturday morning by planes using ultra violet light sensors – which detects water temperature variations caused by oil – because it was below the threshold specifications for the equipment finding oil, Mr Quirk explained.
"But we are about to do another visual inspection of the area, because want to make sure that we are managing the situation correctly," Mr Quirk said.
He said the oil spill was "not a huge slick of oil from a massive spill from a tanker."
"We are talking about areas of sheen – and within that - there are thicker patties of oil," he said.
Mr Quirk said the oil was weathering in south-easterly winds in slight to moderate seas and was most likely to break-down before reaching beaches.
He said while the oil was not visible to plane equipment, it was still in the water.
"It is quite possible that in a week's time – maybe in three days time – on some of the beaches around Townsville – there will be small globules of a spongy material found on the beach, because it doesn't all deteriorate."
Mr Quirk said it would not be like the 2009 spill from the storm-wracked MV Pacific Adventurer spilled 100,000 litres of oil along 60 kilometres of Moreton Bay coastline.
"It would be little tiny oily patches on the beaches. That is most likely what will happen."
Maritime Safety Queensland is concerned at the possible impacts on reefs to coastal side of the oil slick.
"There are some reefs four to five nautical miles from where we saw the slicks of oil yesterday and we are going there with our aircraft straightaway," he said.
A helicopter which was to inspect the site has been diverted to a road accident.
Mr Quirk said he was confident steps were in place to prevent oil damaging the environment.
"We believe we are doing everything we can – in a practical sense – to monitor the environment – to determine the risk and we are ready to respond, if required."
Source: www.brisbanetimes.com.au