In some parts of the world the next two decades will probably see increasing levels of offshore industrial development and this will almost certainly lead to increased amounts of noise pollution in the oceans. Added to this, there is a great deal of speculation about whether current or future levels of anthropogenic sound are likely to be harmful to marine life. Some people advocate banning or curtailing some forms of activity and many of these people cite the potential sensitivity of marine mammals to anthropogenic sound as the reason for their concern. A few incidents involving the stranding of cetaceans in proximity to some sources of anthropogenic sound have brought this opinion into sharp relief. This position has been accompanied by some speculation about possible effects of anthropogenic sound on marine mammals that moves well beyond the knowledge available from current data and information.
Marine mammals could be one of the more sensitive groups of marine species because some species have a highly developed auditory system and use sound actively for feeding and for social communication. It is also known that some marine mammal populations are vulnerable to the effects of habitat loss or reduced survival and reproductive rate. Marine mammals have also become totems of environmental awareness and sustainability and this has resulted in a controversial stand-off between environmental groups and those who are responsible for producing sound in the oceans.
The problem faced by society is that many economically important activities are at risk because of a lack of information about the effects of anthropogenic sound on marine mammals. The Precautionary Principle has probably achieved customary status in international maritime legislation where the marine environment is involved, which means that the Precautionary Principle is likely to be applied even if it is not specifically stated. This also probably means that it is no longer satisfactory for users of the oceans to ask for evidence of the effects of some activities before they take action to mitigate these effects. Precautionary regulation is leading to considerable burdens being placed upon future development in some areas, but implementation is patchy. This patchy implementation is evident when one considers the different levels of regulation placed on the oil and gas industry compared with those imposed on the fishing industry. The report presented here brings forward a view from the marine mammal specialists within the scientific community about the research effort that is needed to assess the effects of anthropogenic sound upon marine mammals.
The test of a research strategy is whether funding organisations use it to provide an underpinning rationale for investing in research. Since the workshop that resulted in this report took place, two new research initiatives have been developed. Both initiatives involve multi-stakeholder collaborations because, as recognised in this report, the biological problems associated with investigating the effects of anthropogenic sound on marine life are so large that probably no single organisation is capable of funding the research effort. In one case, a consortium of oil and gas companies has built a fund of more than $25 million to investigate the effects of sound on marine life (see www.soundandmarinelife.org) and in the other case, the US Navy, assisted by other funders that also includes the oil and gas industry Sound and Marine Life Program, have sponsored a sound playback experiment on beaked whales. These initiatives reflect a serious intent on the part of organisations that actively emit sound into the oceans to address current environmental concerns. In both these cases, the research strategy in the report presented here has helped to focus their research effort on the principal research questions and approaches.
The report is a consensus of views from across the community of active researchers in the field of marine mammals. Where there are such controversial issues a consensus is often difficult to achieve. I am grateful to all those involved for entering into this initiative in a spirit of cooperation and for not allowing the debate to become polarised to such an extent that it undermined the outcome. I am also very grateful to the Marine Board of the European Science Foundation for sponsoring the workshop and for endorsing the emerging research strategy. I hope that others will find the research strategy presented here to be a useful reference for a long time into the future.