High-tech search finds no large reef spill

Aerial searches of water along the Great Barrier Reef have failed to spot any evidence of large patches of crude oil.

Maritime Safety Queensland general manager Patrick Quirk said there had been visual evidence of oil on the water near Cape Upstart late on Friday.

But aerial searches with ultra-violet sensors on Saturday morning had come back negative, he said.

it's a big ocean and a little bit of oil goes a long way," Mr Quirk said in Brisbane.

"The aircraft this morning had the (ultra-violet) equipment on board because we thought there may have been large patches of crude oil. But we didn't find that."

The reported area of light sheen that was assessed was up to 30 kilometres in length and five kilometres wide.

Visual, or "eyeball", searches will continue on Saturday afternoon and Sunday.

An aircraft will leave Townsville about 3pm to conduct another search, report back and help determine a potential plan of action.

But no on-water response was needed as the residue is being broken up by the weather and chemical dispersants will not be used at this stage, Mr Quirk said.

He said a sample of oil had been taken from the water by a police vessel and would be compared with samples also drawn from about 14 nearby oil tankers.

"Chemical matches are not perfect but we are certainly going to try our best," he said.

Meanwhile, conservationists have seized on the spill scare to call for a cap on shipping traffic in the area.

"The reef needs better protection, not more industrial activity, and the last thing it needs is oil spills and other hazards from increased shipping," said Greenpeace Australia Reef campaigner Shani Tager.

The Australian Marine Conservation Society's Felicity Wishart agreed the proposed Abbot Point expansion would add to the strain on the marine ecosystem.