This article is a follow-up to my article in which I discussed the manipulation of science by environmental groups (eNGOs) and some researchers.  It was actually a comment by Wild Migration that led me to publish my critique of the Aguilar de Soto et al and Engas et al papers.  At that time I was not aware of this shocker that can be found on the Wild Migration website.

Given that the authors, Prideaux and Prideaux, state that “Section two of this review provides a primer for regulators, policy makers and marine stakeholders to understand the complexities of sound in water,” one would have thought that they would have been less biased and more balanced with the science.

Although a full critique of the publication would be too long to include in this article, the following are a few key points on which the readers can decide for themselves whether or not to rely on the extremely biased review by the authors:

1. In their introduction on p5 they state: “Acoustic energy (sound) is a new threat to this shared realm”.  What an inaccurate statement!  The marine environment is actually a very noisy place as a result of biological sounds (vocalisations, breaching, etc) and natural sounds (cracking/colliding icebergs, earthquakes, lightning strikes, etc).  Thus, species living in the ocean have evolved over millions of years to adapt to sounds that are often at similar intensities, frequency and periodicity as seismic survey sounds.  Perhaps the authors meant to include the word “anthropogenic” in this statement?  Regardless, it would be inconceivable that any species would evolve to generate sounds in the ocean (such as vocalisations and breaching) that would trigger their own temporary or permanent hearing threshold shift and hence ultimately lead to the demise of their population.  Given natural and biological sounds in the ocean are often similar to seismic sounds, this is what the authors are asking readers to believe – that anthropogenic sounds harm them but biological/natural sounds at similar levels do not .

2. Furthermore, in their section on “Noise impact potential” (note the word “potential”!) they attempt to divert the focus from the above point with the statement: “Industry comparisons of anthropogenic noise to natural sounds is neither defensible nor relevant.”  I find it remarkable that they can feel free to state this opinion without even justifying it! Also, this section relies heavily on studies conducted by Engas et al and Aguilar de Soto et al which I’ve already roundly criticised.  There are several other publications used in this section that are effectively poor science lacking in rigour.

3. Their section entitled “Sound in water: It’s complicated!” at worse, appears to deliberately set out to confuse the reader even though they claim it is a simplistic review!  At best, perhaps the authors are confused themselves so are unable to explain sound in water.  Although the whole section is somewhat suspect, I have two key concerns with it:

a. even though they include 2 tables (top of p9) showing the very rapid attenuation that occurs with spherical transmission and even cylindrical transmission, their text does not highlight this rapid attenuation in the near-field and they prefer to leave the reader with the message that “sound travels almost five times faster through sea water than it does through air, potentially extending hundreds of kilometers with little loss in energy.”  Yes, there can be little loss of energy over 100’s of km but that is only in the far-field, which will be 10’s or 100’s of kilometres from the source, when the signal has already attenuated to, say 100-140 dB re 1 μPa2. s, and is not all that far above ambient noise levels.

b. even though this section is on transmission (or attenuation!) of sound in water, they appear to deliberately avoid showing a graph of sound levels at different distances from the source.  I wonder why?  Perhaps it is because it will expose their bias?  The interested reader can access an article I’ve previously written on this site to see how sound actually attenuates in water.

4. It is their section on “conventional seismic surveys and alternative technologies” that really demonstrates some issues. At worse, their deliberate manipulation of the science or, at best, their misunderstanding of it!  There are numerous obvious errors but, to maintain the reader’s attention, I will only mention a few:

i) there are no single air-guns that are as large as 3250 in3.  The authors should have said “airgun arrays” which can consist of 20-30 individual elements (single airguns);

ii) the sound intensity level produced by SINGLE air-guns do NOT vary considerably (however, the sound intensity levels of ARRAYS do).

iii) the upper level of 250 dB (re 1 μPa2) of the range quoted by the authors is NOT the upper level for a single airgun. A single air-gun will have a pressure output (peak-to-peak) of approximately 232 dB Re 1 μPa. This would correspond to less than 210 dB re 1 μPa2.s, significantly less than the authors are stating. The 250 dB (re 1 μPa2) is more like the THEORETICAL level for an array due to the fact it is back-calculated to represent a point source value at 1m. An array, with dimensions of approximately 10m x 15m, cannot possibly be a point source and the actual level is generally 10-20dB below the theoretical level.

iv). In terms of alternative technologies, although marine vibrators are being developed by the industry and would still have to be assessed for environmental (and prospect imaging) suitability, they are so misguided on the other two technologies that their suggestions are laughable:

         a). CSEM would only ever be used as a complementary tool to seismic; and

         b). What good is 500m penetration below the sea-bed for imaging potential structures that are significantly deeper than this?

5. Section 6 entitled “Natural Justice: Consultation, transparency and commercial sensitivity” is highly hypocritical in some of its claims. For example:

         i). “In the case of decisions for activities in the marine environment, confidence that there is no hidden bias can be developed by ensuring there is full transparency”.  There is significant transparency in the environmental applications submitted by proponents to the regulator.  There has to be!  To not be transparent would consign the application to rejection.  For eNGOs like Wild Migration to demand full review of, for example, an Environmental Plan submitted under the Offshore Petroleum & Greenhouse Gas Storage Act and its associated Environmental Regulations (OPGGSA&ER) is tantamount to distrust of the regulator (not actually the industry) and claiming that they have assessment skills far beyond their capabilities (as aptly demonstrated by the publication which is the subject of this review).

         ii). “the necessity for proof always lies with the person who makes the claim.”  I totally agree with this but would suggest it should apply to eNGOs and stakeholders as well as proponents.  After all, it is generally the eNGOs and some stakeholders that claim, despite no known adverse impacts after 40 years of using compressed air seismic pulses, that there are actually dramatic impacts (that have not been detected!?).  As Carl Sagan said “Extraordinary claims require extraordinary evidence” but the authors try to excuse themselves by claiming “Stakeholders do not carry the burden of proof but instead carry the benefit of assumption, meaning they need no evidence to support their position.”  The seismic industry has a 40-year track record of no known adverse impacts, despite very close monitoring during the last 15-20 years.  Furthermore, where longitudinal studies of whale populations have occurred (eg humpbacks on the NW Shelf and Southern Right Whales at the Head of Bight, SA), the populations are increasing at close to biological maximum “despite” seismic survey activities proceeding in the same area.  Thus, the industry is not making extraordinary claims, just stating what has happened.

6. Finally, their comment “The absence of studies is mostly because industry has been reluctant to fund or facilitate the studies. ” on page 16 demonstrates, at worse, a total disregard for the facts or at best an inexcusable ignorance of the facts.  Most genuine practitioners in this field are fully aware of the Sound and Marine Life Joint Industry Program (JIP) that has been run by the International Association of Oil & Gas Producers (OGP) since 2006. Even if they had not known what was going on internationally (which is inexcusable), given that the authors live in Australia, surely they would have been aware of one of the key projects being conducted under this program by the University of Queensland, Sydney University and Curtin University: the Behavioural Response of Australian Humpback whales to Seismic Surveys (BRAHSS). 

In conclusion, need I go on?  While the original objective of this document is good and I commend the Purves Environmental Fund for supporting the initiative, the resultant document totally fails to provide a balanced review of the facts and science.