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3 September, 1997
Today the ship seemed to be plagued with problems that ended up benefiting
the acoustics research project. I noticed the first one when I opened the
door to the head and found that it was flooded with about three inches of
water. I know the ship's crew is expected to keep the water out of the boat
and this was not part of their normal routine. It turns out that we had
ruptured a saltwater line and we would have to hold our position for about
four hours while it was repaired. Fiona decided that this would be a good
time to have our team fly about twelve miles away from the ship and measure
the ambient noise levels beneath the ice.
Peter Scheifele has made measurements of noise levels in a number of
locations where beluga whales tend to congregate. He has observed that
autopsies of the ears of stranded animals show evidence of acoustical
trauma, similar to what is observed in humans who are exposed to high sound
intensities. His concern is that the noise pollution in areas where marine
mammals seasonally migrate is having a physiological impact.
About midnight, Peter, Gary Stern, a Canadian scientist who studies
contaminants in marine mammals, and I were talking about the day's events
over a late snack. Gary told us his studies show that the beluga whales are
accumulating high levels of contaminants in their fat. He mentioned that the
mercury levels high enough to kill a small mammal have been observed in
their brain tissue. He is concerned for the natives who regularly eat whale
blubber. If they have to limit their diets to avoid the contaminants, they
will become deficient in essential nutrients. This is an example of the
negative side of being at the top of the food chain. The contaminants that
are sequestered in the plankton are biomagnified by a factor of about ten at
each level up the food chain. This places the subsistence hunters in the
Arctic, who are at the fifth tropic level, at risk.
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