Abstract:
The exploration of deep-sea resources has been on hold for decades. It is
therefore of paramount importance to provide a framework and adequate tools for
monitoring environmental impact. Among other disturbance parameters, stands noise
produced by seabed exploration machinery and associated platforms. At medium and
long range, the extent of noise impact depends on the intensity, frequency, and location of
the noise sources, as well as sound pressure distribution in space and time. Ultimately,
noise impact depends on the receptor species' acoustic sensitivity and their spatial
distribution. This paper addresses this concern through a noise risk assessment study
carried out at the Tropic Seamount that encompasses the estimation of the sound
field distribution through a noise model calibrated with field data, and uses a Maxent
model fed in with direct observations as well as environmental data over 5 years,
for estimating habitat suitability distribution of noise-sensitive cetacean species. As
expected, experimental data show a baseline mild risk centred on the seamount and
decreasing to the borders of the target area. A proposal for the usage of risk assessment
and acoustic threshold for real-time exploitation monitoring is made.