Some of the world’s biggest energy companies are lining up to defend their widely used offshore exploration technique from the conclusions of a small group of Australian scientists, who say the seismic surveys can kill zooplankton and harm invertebrates.

The American Petroleum Institute (API) and the International Association of Geophysical Contractors (IAGC) have been writing to authorities in the United States claiming the work of Associate Prof Robert McCauley, of Curtin University in Western Australia, and his colleagues is “seriously flawed”.

In a statement, an IAGC spokeswoman, Gail Adams-Jackson questioned the research’s “small sample sizes, the large day-to-day variability in both the baseline and experimental data, and the large number of speculative conclusions that appear to be inconsistent with the data collected over a two-day period.”



API is a powerful lobby group with more than 600 members, including BP, Chevron, Exxon and Shell, while IAGC is the trade association that represents the geophysical and exploration industry.

Seismic surveys using underwater air guns are the key tool used by the oil and gas industry to discover more fossil fuels.

The industry claims the technique is largely harmless, but the emerging science could be another spark for conflict between commercial fishing, conservationists, regulators and the oil and gas industry.

Speaking to Guardian Australia, McCauley defended his research and said critics would “throw as much mud and confusion” to try and discredit the findings.

In June 2017, McCauley published a study in the peer-reviewed journal Nature Ecology and Evolution about the results of a field experiment in the waters south of Tasmania.

McCauley, with scientists at the institute of marine and Antarctic studies at the University of Tasmania, found the air guns used in seismic surveys to find oil and gas could kill zooplankton – a vital organism at the base of the marine food web – at a distance of at least 1.2km.

McCauley was also part of research with the same group finding seismic surveys affected the immune systems of lobsters and were linked to deaths in scallops.

Yet in their November 2017 letter to US government agencies, API and IAGC say they asked three “leading plankton ecologists at well-respected scientific institutions” to review McCauley’s zooplankton study who found it “seriously flawed”. They also claimed that McCauley and his co-authors “have concurred with many of the shortcomings identified by the reviewers”.

McCauley says the reviews were a “whole load of whitewash”. He had only agreed his study needed replicating, a point made in his original research paper. “For them to say that I agreed with ‘shortcomings’ is rubbish,” he said.

“We knew it was going to cause a stir. There are a lot of experiments under way to look further at this issue and those are being done where they won’t be able to be discredited,” he said.

McCauley’s colleague, Associate Prof Jayson Semmens, of the institute of marine and Antarctic studies, said it was “absolutely not” the case that he had admitted to “shortcomings”.

“I’m guessing there is some confusion there. We have not hidden behind our science and we have spoken about it at conferences and at meetings.

“In terms of us agreeing there are all these issues … well … that’s not correct, because in that case we would not be publishing them. There’s no perfect experiment, but we are very confident in what we’ve done.”

Earlier this year, state authorities in North Carolina asked seismic survey companies to show their ongoing permits would not harm fisheries there, in light of the research from McCauley and others.

The North Carolina environmental quality department said it shared concerns “that seismic testing may have significant negative impacts on coastal commercial and recreational fishing and marine mammals”.

“These concerns are based on the science found in peer-reviewed scientific literature, including five recent studies, published between 2015 and 2018.”

Two companies, SpectrumGeo and CGG, sent the API and IAGC letter as attachments to authorities in North Carolina. Both companies have applied to Australia’s National Offshore Petroleum Safety and Environmental Management Authority to carry out seismic surveys in waters south of Australia the summer.

Also last year, the Australian Petroleum Production and Exploration Association paid for CSIRO scientists to carry out modelling based on McCauley’s results to assess the possible impacts of seismic surveys on one zooplankton species in waters in Australia’s northwest, where seismic surveys are routinely carried out. That study found the impacts were greatly reduced in warmer waters and with the zooplankton species they chose to model, although this was dependent on the parameters set in the computer modelling.

The IAGC letter to US agencies cited this CSIRO study, but did not disclose it was funded by industry. The letter claimed the CSIRO work showed the findings of McCauley had “no ecological consequence”.

But Prof Anthony Richardson, a senior CSIRO researcher who led that work, told Guardian Australia it was not right to apply the result to other areas and he did not agree with IAGC’s characterisation.

Richardson did have criticisms of McCauley’s study and said the results were “suggestive rather than conclusive”, with more research needed.

The IAGC asked seven experts to review McCauley’s study and Adams-Jackson said “several of them indicated that while the research findings were thought-provoking, they were certainly not convincing”. But IAGC’s spokeswoman Gail Adams-Jackson refused to name the researchers, citing confidentiality.

She said: “We look forward to discussing this topic further with the authors and other experts in this field to determine the best path forward toward more scientifically solid and consistent results that can be replicated and verified by other independent researchers, in the best traditions of science.”