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Why do we need a new method of locating the presence of whales? top
Our goal is to protect whales from ship
collisions and the acoustic effects of man-made activities that can
endanger whales. Federal regulations are in place, or are being drafted,
that require these activities to be suspended if whales are detected in
the vicinity. However, the two current methods of detecting the presence
of whales – visual identification and passive sonar -- are inadequate.
Visual identification does not work at night or when weather and sea
conditions are inclement. Passive sonar does not work during those
frequent periods when whales are silent.
How many whales are injured, killed, or significantly harassed annually by ship collisions or man-made acoustical events? top
Numbers are not known because it is
impossible to observe all the whales in the vicinity of a potentially
harmful activity (which is precisely the problem we are trying to solve).
However, there is evidence that a large number of whales are impacted
every year. Our goal is to reduce these numbers by developing a safe way of
detecting the presence of whales under any conditions.
What are dangerous man-made acoustic events? top
Whales use their hearing for navigating the
world’s oceans, for communicating with each other, and for identifying the
presence of food sources and predators. Some loud activities can damage
whales’ hearing, just as standing too close to a rock concert amplifier
can injure human hearing. Dangerous acoustic events can occur during
seismic exploration, demolition, and submarine detection. Our goal is to
protect whales from the acoustic effects of these activities by developing
a safe way of detecting the presence of whales under any conditions.
How does the new method work? top
Our approach turns sound to our advantage.
It uses low-power and high-frequency active sonar soundings to detect the presence of whales when they are silent, and
regardless of weather or sea conditions. This is important knowledge. If we know whales are near, we can be more vigilant
in navigation and can stop potentially dangerous activities until the whales pass to safety.
How does active sonar differ from passive
sonar? top
Passive sonar, as the name implies, involves
listening only. It only works when whales are vocalizing, and that simply
is not frequently enough to protect whale populations. Active sonar, by
contrast, emits a sound wave and then listens for the sound to bounce
back.
What is the difference between the sound
that you are using and dangerous sound? top
Not all sound is the same. The new proposed
method for protecting whales uses active sonar at low power levels and at
high frequencies. There is strong scientific evidence that the selected
frequency is beyond the hearing range of most whales. However, even if they
could hear the
sound there is strong scientific evidence that it would not be loud enough
to cause any damage to their hearing. The transmitted sound is also
much shorter than whale vocalizations, and would sound like is a small click
roughly every four
seconds.
What are the risks to whales? top
We have worked closely with leading marine
mammal experts to understand safe acoustic limits that are accepted by the
scientific community. There is strong scientific evidence that the
selected frequency under research is beyond the hearing range of most
whales. However, we are taking no chances since science is about learning
and building upon established knowledge. To further protect the safety of
the whales, marine mammal experts participating in every facet of the
research will have the authority to suspend testing if they observe
abnormal behavior. Our goal is to protect whales, so it makes no sense to
continue any research that causes abnormal behavior.
What are examples of abnormal behavior that would cause the research to be
suspended? top
The whales migrate from north to south and
generally continue on that path. An anomalous rapid turn or sudden
breaching would be the most likely signs of stress.
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