Marine scientists given access to a petroleum industry survey vessel to test the impact of seismic air guns were surprised to find fish behaviour and health were unaffected.
Concerns have long been held about the impact of repeated loud noises from the air guns on marine life.
Senior principal research scientist with the Australian Institute of Marine Science, Mark Meekan, said these seismic surveys were commonly used by the oil and gas industry to try to find new reserves under the sea floor.
“They do that by basically towing along some huge air guns that let off an enormous noise,” Dr Meekan said.
“It passes through the water column, down into the rock below, and it’s reflected back … and from that sound, you can work out where the oil and gas is.”
Many previous studies and reports have looked at commercial fishing catches following seismic surveying and found what appeared to be concerning declines in fish numbers.
But these observational studies could not show that it was the seismic work that caused fish numbers to change rather than some other unmeasured process.
This was why Dr Meekan and his team were excited about the opportunity to design a large-scale experiment where a seismic survey vessel was directed by scientists to strategically fire air guns in some areas and not others.
“We got a dedicated seismic vessel and were able to tell it where to go and what to do, which enabled us to really get to the bottom of what the effects of the seismic survey were likely to be on fish,” he said.
The results, which may look like good news for commercial fishers, have been questioned by Darryl Hockey, the CEO of the West Australian Fishing Industry Council.
“This research finding is at odds with the concerns of commercial fishers out there on the water who can see real impacts to catch rates occurring at the moment,” Mr Hockey said.
“And it’s also at odds with the understandings from right across Australia.
“There’s even a Senate inquiry that’s going on at the moment to recognise the impacts of seismic on the catch rates of the commercial sector.”
2021 ABC