A loggerhead turtle, injured in a boat
collision is
treated at a rescue centre in Greece. (WSPA) |
Over
the past 30 years there has been a documented increase in
ambient sound levels (9-to 10-dB) in some coastal marine environments.
With the increase in the usage of recreational boats in the
last decade and additional new sources such as seismic exploration
are increasing worldwide. These new anthropogenic sources
all contribute to pervasive noise levels in marine areas.
Sea
turtles have an ability to perceive low-frequency sound (mainly
below 1000Hz) Exposure to low-frequency sound emitted underwater
by anthropogenic sources can have direct influence on sea
turtle health and ecology. Little is known about the potential
effects of noise exposure on the short-term or longer-term
behaviour and health of sea turtles.
Observed sresponses of sea turtles to low-frequency signals
include: agitated behaviour, abrupt body movements, startle
responses, changes in swimming patterns and orientation.
|
Prolonged
exposure could potentially affect sea turtles by encouraging
avoidance behaviour; increasing stress and aggression levels;
causing physiological damage to the ears; altering surfacing
or diving rates or confounding orientation cues.
Source:
Samuel, Y., Morreale, S., Clark, C., Greene, C., Richmond,
M. (2005) Underwater; low-frequency noise in a coastal sea
turtle habitat. J. Acoust. Soc. Am. 117 (3) p.p. 1465- |
