A 'brainstorming' meeting on the effects of anthropogenic noise on cetaceans in the Agreement area was therefore held on 19 November, the day before the 2003 Committee meeting, to allow for an extensive, preparatory discussion of the subject. The results of the 'brainstorming' meeting were briefly summarised before opening the floor to a discussion aimed at helping to draw up a recommendation. Concern was expressed by Committee members on the actual and potential negative effects of anthropogenic noise on cetaceans in the Agreement area. A long discussion took place, and some Committee members noted that concerning the issue of the anthropogenic noise in the sea and particularly the use of military sonar, there may be various ways to face the threats to cetaceans.

Interesting arguments supporting various views on what should be the recommendation of the Scientific Committee were heard. There is now general acceptance that mass strandings of cetaceans, and most notably of beaked whales (family Ziphiidae) may result from military sonar activities, also within the Agreement area. It was recognised that a number of monitoring and research projects need to be initiated to address questions related to the possible effects of anthropogenic noise in the ACCOBAMS area, including:

The Committee therefore recommended that existing guidelines for the use of such sonar, developed by NATO and possibly by other organisations, be made available for review, with a view to developing common sets of guidelines for use in the Agreement area.

Throughout the discussion, it was noted that the Committee did not imply that military sonar represents the only important threat to cetaceans related to anthropogenic noise in the Agreement area. Rather, it reflects the fact that the cause-effect link in this situation is best understood at present. Other sources of underwater man-made noise known or presumed to affect cetaceans, such as those deriving from seismic exploration, are known to occur in the ACCOBAMS area. The Committee therefore recommended that guidelines existing in some countries for the use of such non-military sonic devices be also submitted for review. The Committee further recommended that preventive notification be obtained by the Permanent Secretariat of all activities, including military and industrial, that are known to produce underwater noise likely to harm cetaceans.

Recommendation 2.7 on man-made noise in the ACCOBAMS area was adopted by the Committee.