The petrol and oil testing to be undertaken by Asset Energy has outraged the local whale watching industry, which wants it halted pending an environmental review.

Greenpeace Australia Pacific has lodged a complaint with the federal regulator - the National Offshore Petroleum Safety and Environmental Management Authority - calling it a "fatally flawed plan".

Testing was approved by NOPSEMA to be completed sometime between now and May 31.

Senior Greenpeace campaigner Nathaniel Pelle wants all activity put on hold until the environmental plan is reviewed and the relevant people consulted.

The seismic survey involves the firing of a sonic gun every 6.25 metres along a site stretching across about 12.25 square kilometres of coastline which becomes a playground for migrating whales every year.

Frank Future, who operates whale watching company Imagine Cruises in Port Stephens, says three humpback whales have already been spotted travelling through the area and dolphins are seen regularly.

He's concerned about the "destructive" impacts of pressure waves created by the blasts and says whales have died in other areas exposed to testing.

"Sometimes a whale's navigation system gets torn apart by the sound wave," he told AAP on Tuesday.

"There's been notable evidence of things - tiny creatures all the way up to whales - dying."

A NOPSEMA spokesman confirmed the authority had received "a number of objections and claims" from Greenpeace regarding the project.

Australian Associated Press