~e; underwater acoustic monitoring
brian carroll <email@example.com>
Fri, 14 Jan 2005 09:38:59 -0600
// the following article is a case-in-point regarding
// the 'scientific' rationale for no effects of EM on
// other lifeforms. there are obviously effects, that
// are left outside a particular assessment, and thus
// the claim of 'no harm' is absurd and disingenuous.
Environmental Activist Say Sound Wave Research
Off Yucatan Peninsula Threatens Marine Life
MEXICO CITY Jan 13, 2005 — Scientists working off the Yucatan Peninsula
are preparing to use sound waves to search for information about an
asteroid that may have wiped out the dinosaurs 65 million years ago.
But environmental activists are trying to shut the project down, saying
the technology could harm whales, sea turtles and several varieties of
fish that provide a livelihood for thousands of Mexicans along the gulf
Marine seismologists from the University of Texas Institute of
Geophysics, the Geophysics Institute at Mexico's Autonomous National
University and Cambridge and London universities will use underwater
seismic pulses to learn more about the Chicxulub (pronounced
Sheek-shoo-LOOB) Crater, a depression measuring about 120 miles in
diameter and centered just outside the port of Progreso, 190 miles west
The same technique is routinely used by scientific research vessels
around the world to study earthquake faults, tsunami dangers and
climate change, scientists say. It is used in Mexico by the state oil
monopoly, Pemex, to search for new energy reserves.
But Rosario Sosa, president of the Yucatan-based civilian Association
for the Rights of Animals and their Habitat, said the sound waves
"damage the brain, or damage the cochlea of the ear, and disorient the
animals so that they beach themselves or crash into boats."
"They are no longer capable of looking for food using their sonar," she
Scientists acknowledge there's evidence that points to Navy sonar
causing whales to beach themselves. But they say there's no proof that
seismic pulses have harmed marine animals, though much more research is
needed to draw firm conclusions.
Thus far "there has not been any significant evidence that there is any
harm being done to the marine animal population," said Maya Tolstoy, a
research scientist with Columbia University's Lamont-Doherty Earth
The observatory is in charge of operating the Maurice Ewing, the
research vessel from which the scientists will work, about 50 miles
offshore. The boat is owned by the U.S. National Science Foundation.
Located half-onshore and half-offshore, the Chicxulub Crater is
believed to have been carved by a comet or asteroid 65 million years
ago, and occurred simultaneously with the mass extinction of species,
including the dinosaur.
It is the largest and best-preserved "impact" crater on Earth, said
Gail Christeson, a University of Texas marine seismologist involved in
Researchers will send sound waves into the seabed via compressed-air
guns to try to create the three-dimensional structure of the crater and
learn the speed of the asteroid or comet, the angle at which it hit the
Earth, and its effects on the environment.
The information could lead to knowledge of how to respond to possible
future asteroid hits, Christeson said. She said the research also will
help scientists to better understand the aquifer system of the Yucatan
because the crater controls the water supply.
But Sosa says that after the Maurice Ewing conducted research in the
waters between the Baja California peninsula and mainland Mexico in
October 2002, two beached whales were found in the area with evidence
of damage to their ears.
She also says activists have come across dead dolphins and turtles in
the gulf coast state of Campeche, where Pemex uses seismic pulses to
explore for oil. An additional concern is that the sound waves could
threaten fish stocks the livelihood of about 30,000 families along
the Gulf coast.
Christeson says she has participated in at least four seismic cruises,
"and we have never seen any effect on marine life."
"It has been observed that the Navy sonar may have contributed to
strandings of marine mammals," said Christeson. "Our sounds source is
different from navy sonar. The amplitude is less and we also fire
intermittently, so we will put a short burst of sound in water every 20
seconds. The Navy sweeps through different frequencies."
Mexico's national Environment Department granted the Maurice Ewing
permission to operate after the scientists agreed to take along
independent specialists to monitor sea animals; allow flight and
underwater acoustic monitoring; work only during the day when it is
easier to notice the animals; and maintain a 3,800-yard safety radius
around the ship. The government will conduct its own monitoring flights
as well, officials said.
The scientists also have agreed to stop testing when the presence of
marine mammals is detected, and will gradually raise the sound wave
decibels to warn the animals and give them a chance to leave the area.
The activists, who claim to represent 100 national and international
organizations, say that's not good enough.
Benjamin White of the Washington-based non-governmental Animal Welfare
Institute initially planned to tie himself with a rope to a fishermen's
boat that would ride alongside the Maurice Ewing to prevent it from
conducting the tests.
Now faced with orders banning them from approaching the boat, the
protesters are considering peaceful weekend demonstrations in front of
Yucatan state offices.
"I'm here as long as it takes to shut them down," White said.
On the Net: www.ldeo.columbia.edu/res/fac/oma/ewing
Copyright 2005 The Associated Press. All rights reserved. This material
may not be published, broadcast, rewritten, or redistributed.
(educational fair-use, electronetwork.org 2005, related
to discussion of electromagnetism, tsunami, and life.)
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