The potential effects of
Noise may be defined as a sound which is undesired
by the recipient and therefore the perception of a sound is
of crucial importance in assessing potential 'noise nuisance'.
The subjective nature of noise makes it one of the most difficult
of all environmental impacts to quantify. The problem of noise
nuisance assessment is compounded by the difference in perception
of noise between participants and non-participants and also
between participants in the same activity.
Certain types of water-based recreation, such
as personal watercraft activities, are considered to cause noise
nuisance whether recorded sound levels of the activity are high
or low relative to other sound sources. This is often because
the 'quality', or tonal note, of a sound is more important to
the listeners perception of that sound than its magnitude.
However, this is an entirely subjective concept and is therefore
unmeasurable. This creates problems with the assessment of whether
a particular sound constitutes a noise nuisance.
Sound generated by recreational craft originate
from a number of different sources including:
- craft hull striking or ploughing through waves (hull slap)
- boat generated waves striking the shore
- mechanical noise (from engines)
- deck and cabin fittings, people noise (human propulsion
or interaction on board)
Noise disturbance relates largely to impacts
upon other people rather than impacts upon the natural environment.
Such issues lie outside the scope of this study. However, the
potential impacts of noise disturbance on sublittoral and other
marine communities are not known. In addition, disturbance to
seals and dolphins and other wildlife is attributable to sound
as well as to physical proximity and this is discussed below
in more detail. Many representative and industry bodies produce
codes of practice which address the issue of noise disturbance.