APPLIED ACOUSTICS CSP-S 4000, Manual

Page: 9 / 30

CSP-CSPS-8000/B Section 1 Page 9 of 30
Seismic Sound Sources And Marine Life.
Although not proven, there is concern in some quarters that marine mammals may be
harmed or their behaviour changed by seismic activity. The sound pulses from sparkers
and boomers is much lower in amplitude and higher in frequency (so it will travel less far)
than air guns. However it makes sense that a precautionary approach to emitting sounds
in the whales and dolphins’ natural habitat should be observed.
The CSP energy sources described in this manual have the ability to “soft-start” and
increase the energy emitted in the water slowly over time and this technique will give any
marine mammals nearby the opportunity to escape before maximum signal amplitude is
reached. It will also give them a chance to get used to the noise if they choose to stay (!)
rather than being subjected to a sudden shock of a full power seismic signal.
Another factor to consider is to ensure that the start of any survey line is not in such a
location that any cetacian is trapped by the vessel and the noise, for example in a small
harbour. In such an instance, the survey should start in such a place that any cetacian in
the vicinity has a clear and rapid means of escape into open water and away from any
unnatural noise source. Further details and advice can be obtained from the following
web site:- http://www.jncc.gov.uk/pdf/Seismic_survey_guidelines_200404.pdf. This web
site refers to UK waters and relates to air guns as the sound source (in many ways
different to a sparker or boomer), but should serve as a useful guide nonetheless.