Biology Reference
In-Depth Information
Acoustic masking in marine ecosystem from human building activity (e.g., pile-
driving) may have severe consequences for pelagic fauna for a range up to 80 km
away, impacting, for instance, on the behavior of social marine mammals. Ships
and boats seem have a minor impact on pelagic fauna, but few studies have been
devoted to the potential effects on their behavior. For instance, the presence of boats
close to whale pods produces an increase of their acoustic communication.
The noise produced by road traffic is of great concern in conservation biology.
Species can react differently to traffic noise, by avoiding noisy areas or by increas-
ing the frequency of their acoustic signals. Accordingly, the groups of animals
considered for the effects of traffic noise may have dramatic differences. In frogs,
acoustic activity is innate and costly in terms of energy invested in reproductive
choruses. When choruses are masked by ambient noise, males shift their repertoire
toward higher frequencies, but this contrasts with the fact that females select the
largest males, which usually have a low-frequency repertoire. Thus, the shift toward
higher frequencies alters the relationship between male selection and acoustic
frequency.
In marine systems, noise can be considered a sonic context important to orienta-
tion. Well documented are the pelagic larvae of coral reef dwellers, which are
clearly attracted by the noise produced by wind on coral reef barriers. In this way,
many organisms can orient during the delicate trip toward coral reef settlement
locations. On the other hand, permanent pelagic organisms can use the sonic
ambience perceived close to a coral reef as a repellent. Changes in physiology
can be observed in some species of crabs with a decreased metamorphic rate in
presence of coastal noise.
In the presence of multiple sources of sounds, species must make a careful
selection of the important frequencies, excluding in their evaluation those less
informative. This capacity, which has been recognized in people, has been found
also in some vocal animals such as the Cope's gray treefrog (
Hyla chrysoscelis
).
Oil spills and other seismic geological prospecting, usually carried out in remote
land areas and in the deep seas and oceans, are important sources of noise that
reduce wildlife populations, change their behavior, and reduce overall productivity
and biodiversity.
Wind turbines are common devices displaced in terrestrial and aquatic systems.
This no-emission energy producer has at least three important impacts on the
environment: visual, physical, and acoustic. The acoustic impact has complex
implications resulting from the wind condition at which the turbines operate. Strong
winds increase the noise produced by rotating blades, and regulations are imposed
at country scale to limit the negative effects.
Little attention is paid to military noise, but the noise produced by land vehicles,
airplanes, vessels, and submarines and by the explosion of bombs, artillery, and rifle
shots is an important source of sonic pollution, especially in remote areas.
Health and well-being are two correlated aspects of the everyday metabolism of
humanity. Loud sounds and noise contribute to the health deficit and feelings of
annoyance. The great concern that noise pollution creates in the technological
Search WWH ::
Custom Search