CRE Brazil Comments on UNEP Noise Report

UNEP is meeting within the next two weeks on a draft report dealing with the impact of noise on marine mammals.

 CRE Brazil  is  not aware  of any request by UNEP for comments from the public on the current version of the report although they might have made done so on an earlier version.

 In that UNEP consists of nearly 200 countries throughout the world a publication by UNEP could have a long and lasting impact on public policy.

 CRE Brazil concludes that the report is highly inaccurate in that it does not reflect the current state of science dealing with noise and its impact on marine mammals.

 The attached document prepared by CRE Brazil highlights a number of shortcomings in the report, including:


  The Noise Report  Does Not Accurately Describe  Current Science On The Effects of Anthropogenic Sound on  Ocean  Life

The Noise Report takes the position that a precautionary principle should be applied to regulating ocean sound because there is so much uncertainty about the effects of ocean sound.

 The positions set forth in the Noise Report are inconsistent with the growing body of evidence discussed in various regulatory risk assessments for ocean sound, including those produced by the U.S. Department of the Interior and NOAA/NMFS. These risk assessments correctly conclude that, under the long-standing regulation criticized by the Noise Report, cetacean and pinniped stocks are growing concurrent with decades of oil and gas seismic and other sound-producing operations. The Noise Report does not mention these risk assessments, which show that there is no basis for the Report’s recommended excessive precaution and over-regulation. There is no basis for questioning current regulatory requirements because the record shows they are the working. 

 Despite its criticism of current regulatory requirements, the Noise Report does not and cannot cite a single study that has found a population level change in marine mammals caused by exposure to anthropogenic sound from seismic operations.

See the attachments  below; stakeholders and the public are encouraged to submit comments.


 UNEP Noise






  1. Ian Boyd says:

    I am Director of the Sea Mammal Research Unit at the University of St Andrews. We have been responsible for the development of PAMGUARD and we maintain this open-source software. I have had no input whatever to the UNEP report or any other similar reports so have no conflict of interest.

    The CBD report is one of many such reports and not much in it is either terribly original of surprising. All these reports are hedged around the problem of general lack of information and high uncertainty. The suggestion of bias could be correct in respect of the way in which language has been used in some places, especially because many of the effects are built around theoretical assumptions rather than rigorous data collection and analysis. For example, the general statements about increasing noise levels are founded on only a few regional studies at certain frequencies combined with as assumption that such an increase is almost self-evident when considering other data (economic, ship movement etc). Much the same can be said for the issue of masking. However, I do not agree with the comment that the report is “highly inaccurate”.

    An issue that CRE need to take great care to consider in their response is that “lack of evidence” or “no published studies showing…” does not mean there are no effects. The CRE comment, for example, “The Noise Report should be revised to state that oil and gas seismic under current regulation does not adversely affect sperm whales” is very misleading and reflects some level of naivity in the CRE response. I think an accurate statement would read much more like “Based on a limited range of recent studies and more general observations, sperm whales appear to be robust, at least in terms of their behavioural responses, to disturbance from noise due to seismic exploration. However, it is important not to extrapolate from these studies of sperm whales to other species that are likely to be more sensitive.”

    This arises because of the immense difficulty there is with carrying out studies that would have a fair chance of showing effects if they exist. The current evidence is full of biases but those studies where a proper experimental approach has been taken (e.g. Tyack et al 2011, PLoS One) generally show effects up to a point and the latest work, especially on the effects of sonars are beginning to come up with some consistent strands of evidence. These can be quickly summarised as follows for marine mammals at least:

    1. Some species are much more sensitive than others. In fact, there may be a group of “sensitive species” that includes porpoises and beaked whales, but could include others as well. Many studies and anecdotal observations have focussed upon the non-senstitive species group and this has tended to lead people to extrapolate these observation to all marine mammals.
    2. There is a general presumption that all effects are negative. In fact, for some of the less-sensitive species, additional noise could have positive effects, albeit within some upper limit of noise.
    2. The use of TTS and PTS is not necessarily a useful indicator of an effect – we have moved on from Southall et al 2007, which is a much mis-used and mis-understood paper. The focus on not causing physical damage to animals and the use of TTS and PTS as indicators tends to ignore the behavioural responses. In general the TTS threshold has been assumed to lie in the 160-180 dB re 1 microPa region so avoidance of exposure to 160 dB has often been set as a cut-off. More recent evidence from a variety of unrelated studies is beginning to show that the behavioural response threshold is around 135 dB.
    3. Of course, some will then say that behavioural response is not relevant because it does not translate automatically in to a “biologically significant” response. This is true, but there is very high uncertainty around this assumption. The problem is exacerbated by the fact that a response threshold of 135 dB possibly exposes very large numbers of species and individuals to disturbance because the radius of effect aound an operation like a seismic survey could be as much as 50 km. It is also almost impossible to mitigate for this effect and PAM and viual observation, as currently deployed by seismic vessels, is ineffective.
    4. In circumstances where the disturbance is short-term this is probably not important, but when one adds in the cumulative effects of disturbance either form a continuous or semi-continuous industrial process, or from other sources, such as shipping or other co-occurring industrial sources, one can quickly build very plausible scenarios in which disturbance is so prevalent as to exclude animals for their chosen habitat. It then follows that the probability of a population-level effect becomes quite high.

    Finally, I will comment upon the CRE promotion of PAMGUARD. As indicated above, my institute has been responsible for producing and maintaining PAMGUARD so I have a conflict of interest and would certainly wish to see it used. However, seeing it as a panacea that will resolve the potential conficts between marine life and seismic exploration is highly inaccurate and should be strongly discouraged. PAMGUARD is a tool that has clear limitations I suspect it is beig promoted without proper consideration of those limitations.

    I hope these comments are helpful.

  2. CRE Brazil says:

    We acknowledge Mr. Boyd’s perplexing comment. CRE is in the process of preparing a response.

    1. CRE Brasil says:

      CRE Brasil Responds to Ian Boyd on UNEP Noise Report

      We first want to thank Dr. Boyd for his thoughtful and helpful reply to CRE Brasil’s comments on the UNEP Marine Noise Report. Unlike some environmental NGOs, CRE Brasil posts all comments it receives, whether or not they agree with our position. We also want to thank UNEP for allowing us the opportunity to comment on the Noise Report. UNEP has always striven to be a science based organization. We hope that our comments will help UNEP achieve this goal.

      We also emphasize that our comments are focused on marine sound from seismic oil and gas operations, and not on other sound sources such as sonar. Seismic is our primary concern because offshore oil and gas is so important to the well being of Brasil, and to other countries as well.

      Our Response has two parts: first, points on which we apparently agree with Dr. Boyd; second, points on which we apparently disagree.

      Where We Agree

      ● Oil and gas seismic should be regulated by the appropriate government entity, as it has been for years in the United States by NOAA/NMFS and BOEM (formerly MMS).

      ● Seismic as regulated by nations like the U.S. is unlikely to cause physical injury to marine mammals.

      ● Despite years of study, there are no studies showing that seismic as regulated by nations like the U.S. causes population level effects to marine mammals.

      ● The initial Marine Noise Report by the CBD working group is biased.

      This bias greatly concerns CRE Brasil. We do not know who prepared the initial Report, but it is biased against oil and gas seismic. We concluded that it was necessary for someone to present the other side to this story. It is for this reason that we contacted UNEP. We are most appreciative of UNEP’s response to our concerns.

      Where We Disagree

      Dr. Boyd apparently argues that more study is needed because additional research may show that seismic causes adverse behavioral effects on marine mammals which may rise to population-level effects. He argues that a behavioral effects: “response threshold of 135 dB possibly exposes very large numbers of species and individuals to disturbance because the radius of effect around an operation like a seismic survey could be as much as 50 km. It is also almost impossible to mitigate for this effect and PAM and visual observation, as currently deployed by seismic vessels, is ineffective.”

      With regard to PAMGUARD, Dr. Boyd now argues that “seeing it as a panacea that will resolve the potential conflicts between marine life and seismic exploration is highly inaccurate and should be strongly discouraged. PAMGUARD is a tool that has clear limitations.”

      In support of his arguments Dr. Boyd cites Beaked Whales Respond to Simulated and Actual Navy Sonar, Tyack, Boyd, et al. (2011), http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0017009.

      In response to his arguments, we concede that anything is possible, and it’s hard to prove a negative. However, CRE Brasil’s comments on the UNEP report emphasize that studies in areas of intense oil and gas activity (e.g., the U.S. Gulf of Mexico) show no population-level effects on the marine mammals there. The U.S. oil and gas activity has been and is subject to seismic mitigation requirements. Despite years and millions of dollars worth of study, Dr. Boyd has not cited a single study showing any population level effects from seismic conducted in accordance with those mitigation requirements. By contrast, CRE Brasil’s comments cite studies which show NO effects.

      We also point out that there are many known threats to marine mammals: e.g., bycatch and ship strikes. We believe that scarce regulatory, academic and industry resources would be better spent on these real and very serious threats.

      We also believe that some environmental NGOs use the ‘need more study’ argument to further their actual goal which is stopping oil and gas exploration and production.

      We don’t see what Tyack, Boyd et al. (2011) has to do with the seismic issue. That report only discusses sonar. It does not address oil and gas seismic. We note, however, that the reported study did use PAM.

      We do not believe that PAM in general or PAMGUARD in particular is a “panacea,” but they are useful tools which should be employed to help protect marine mammals from anthropogenic sound. We agree with Dr. Boyd’s own previous statements:

      “PAMGUARD helps industry workers to locate sea mammals efficiently and protect them from noise disturbance. Marine mammals are affected by activities like piling, using air guns for oil and gas seismic surveys, or military and commercial uses of sonar. Workers usually avoid this by looking out for whales or dolphins. If any sea mammal is spotted, work may have to stop. But passive acoustic monitoring (PAM) surveys are more efficient, because they spot animals under water by listening for their distinctive sounds. ‘Making it open access means everyone who uses it can help to expand and improve it. It’s a way of tapping into the research community’s intellectual resources and encouraging development that’s available to all,’ says Ian Boyd, director of SMRU.” See http://sid.nerc.ac.uk/details.aspx?id=107&cookieConsent=A

      We once again thank Dr. Boyd for his reply, and we will publish any additional comments he might have.

      We also encourage other stakeholders to present their views.

      Click here to view CRE Brasil’s response

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