Courtney Hart
©
Copyright Vancouver Aquarium 2014
|
While
on vacation over winter break, my husband made an exciting proclamation. He
said: “I’ve decided that I want to be the kind of person who takes tours”. And we are not talking basic museum tour. Think big! Taking an old light-rail train
into one of the largest copper mines in Canada on a tour led by a guy who
actually worked there in the 50’s (did it!). Soar over Howe Sound with its
dramatic mountains and fjords in a seaplane tour (definitely didn’t do it $$$). We decided that the best way to have a fulfilling experience while traveling is to connect with the culture of your destination. But I digress. The most
important thing about this new proclamation and dubbing ourselves as “the couple that
likes to take tours” is that we spent at day at the Vancouver Aquarium in
Vancouver, British Columbia.
I’ve had a minor
obsession with Beluga whales since singing along to Raffi’s Baby Beluga
on my parent's car cassette player in 1989. The Vancouver aquarium has a mother-pup
pair of beluga whales named Aurora and Qita. With questions of acquisition and
treatment constantly debated, I have mixed feelings about marine mammals in captivity. But beluga whales
live in the Arctic, a place I have not been known to frequent, so we took
advantage of the opportunity to view them in captivity. And let me tell you
they are the cutest whales ever!!! Who knew that 3,300 pounds of white blubber
would be absolutely adorable? Watching beluga melons bounce
around like Jello got me to thinking about the purpose for adapting a
giant, giggly head. I am sure many of you have been introduced to the concept of echolocation, but I started to wonder about the massive amounts of noise occurring under the ocean surface at any one time. As it turns out, the affects of anthropogenic noise on the
behavior of beaked whales such as the beluga has been a recent topic in the
news and even in the Supreme Court.
Before we go further, lets take a closer look at the uses
and mechanisms of echolocation in whales. Utilized by the suborder Odontoceti
or toothed whales (sperm whales, beaked whales, dolphins, porpoises, river
dolphins, etc), echolocation is a sensory ability used to navigate and locate
food underwater. By moving air through sinuses in their heads, whales create a variety of
sounds and clicks by generating pressure waves from their melon. The sounds are
broadcasted and reflected back from objects and researchers believe they are
received by fat bodies which transmit sound from bones in the lower jaw through an oil-filled channel (Brill et al., 1988). Also
called biosonar, whales neurologically process the information and use it to identify, locate and categorize environmental objects.
© Timothy Morbey & Felix Marx |
- Beaked whale strandings in Greece in 1996 and again in the Bahamas in 2000 occurred at the same time that NATO and the U.S. Navy, respectively, were using high-powered sonar in nearby waters
- Fourteen beaked whales were stranded in the Canary Islands close to the site of international naval exercise in September of 2002.
- In 2003 five vacationing marine biologists came across two recently beached Cuvier’s beaked whales in the vicinity that a nearby ship (operated by Columbia University’s Lamont-Doherty Earth Observatory and funded by the National Science Foundation (NSF)) had been pulsing the ocean with high-powered sound waves to map the lithosphere beneath the ocean floor.
Sonar (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound
propagation to navigate, communicate with, or detect objects under the surface
of the water. Active sonar
is emitting pulses of sounds and listening for echoes – SOUND FAMILIAR? Donald
Schregardus, a Deputy Assistant Secretary of the Navy explains that: “Sonar is
the Navy’s eyes beneath the water”(A. Nevala, 2005). Along with
mid-frequency sonar, airgun arrays used for geophysical exploration (important
technologies with no alternatives) have been linked to whale strandings (Barlow et al., 2006). Mr. Schregardus does recognize that “one of our tools in use
for 50 years may have detrimental effects on marine mammals under certain
conditions” and the Office of Naval Research has launched a three-year $6
million research effort in fall 2007 ”(A. Nevala, 2005).
With a correlation between timing
of strandings and heavy use of Sonar, environmental lawyers, scientists and
the US military continue to argue about the actual effects that Sonar has on whales. Darlen
Ketten, a biologist at the Woods Hole Oceanographic Institute, examined a set of
stranded whales in the Bahamas in 2000 and reported the actual cause of death
resulting from stranding (dehydration, stress, etc.), not blasts of Sonar (K. Madin, 2009). However, a brief paper
published in Nature magazine presented
evidence of acute and chronic tissue damage in stranded cetaceans that resulted
from the formation in vivo of gas
bubbles (P.D. Jepson et al., 2003). The whales stranded on the Canary Islands
close to the site of a naval exercise in September 2002 were necropsied about 4
hours after the onset of mid-frequency Naval sonar activity. In theory the animals
may have suffered from a marine mammal form of decompression sickness.
© Pelagos Cetacean Research Institute |
When will we start valuing the welfare
of non-humans on a level commensurate with what we value for ourselves? Maybe now is the time.
Environmental organizations filed a lawsuit in December 2013 against the
National Marine Fisheries Service to demand it to force the Navy to consider
alternatives to its five-year plan that will intensify sonar use off Southern
California and Hawaii. On top of conducting more research on the relationship of
anthropogenic noise and Odontoceti strandings, we as a society have to decide
which is more important: whale welfare or national defense? An easy question
for some, but not for all.
Personally, I an just looking forward to all the future
tours with my husband; who knows what controversy will be
stirred up in next time!
NOTE: Non sibi ced patriae (not for self for country) is a Navy motto and cetus means whale.
REFERENCES:
Barlow, J., R. Gisiner. 2006. Mitigating, monitoring and
assessing the effects of anthropogenic sound on beaked whales. Journal of
Cetacean Research and Management. 7(3):239-249.
Brill, R.L., M.L. Sevenich, T.J. Sullivan, J.D. Sustman, and R.E. Witt. 1988. Behavioral evidence for hearing through the lower jaw by an
echolocating dolphin (Tursiops truncates).
Marine Mammal Science 4(3):223-230.
Jepson, P.D., M. Arbelo, R. Deaville, I.A.P. Patterson, P. Castro,
J.R. Baker, E. Degollado, R.M. Ross, P. Herraez, A.M. Pocknell, F. Rodriguez,
F.E. Howiell, A. Espinosa, R.J. Reid, J.R. Jaber, V. Marin, A.A. Cunningham,
and A. Fernandez. 2003. Gass-bubble lesions in stranded animals: was sonar
responsible for a spate of shale deaths after an Atlantic military exercise?
Nature 425(6958):575-76.
Madin, K. 2009. Supreme Court weights in on whales and sonar.
Oceanus 47:2.
Nevala, A. 2009. The sound of sonar and fury about whale
strandings. Oceanus 47:2.
Peterson, G. 2003. Whales beach seismic research. Geotimes
Jan2003:8-9 [Available at www.geotimes.org/jan03/NNwhaleshtml]
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