When one of our resident killer whales, L-112, was found dead
north of Long Beach on Feb. 11, people wondered immediately if the
death might be related to a sonar incident reported a few days
before.
Could the two events be linked or could the timing be just a
coincidence?
The two-year-old killer whale,
L-112, was laid out after death and prepared for a
necropsy.
Photo by Cascadia Research
So far, I have been unable to find a ship that was deploying
sonar off the coast. At the same time, it appears highly unlikely
that L-112 could have been injured by sonar in the Strait of Juan
de Fuca and then somehow swam out of the strait and down the full
length of the Washington coast, succumb to death and then wash up
on the beach, all in less than five days.
New evidence may come to light, but for now I would caution that
we need to wait for an investigation by the National Marine
Fisheries Service and not jump to conclusions over our concerns
about sonar.
I discussed the investigation with marine mammal expert Lynne
Barre of NMFS. She said the endangered listing of Southern
Residents has heightened interest in all killer whale strandings,
particularly unusual deaths like that of this 2-year-old female
orca.
Lynne seems to confirm the idea that the investigation will
proceed along three tracks. First, there’s the physical condition
of L-112, as will be determined through careful examinations.
Second, there’s the question of where L-112 and her family group
were located during the time of injury. And, third, investigators
need to locate ships with sonar capabilities and determine whether
any of them had been using them in the time period in question.
Jessie Huggins of Cascadia Research and Dyanna Lambourn of the
Washington Department of Fish and Wildlife provided an
initial report from the necropsy:
“The whale was moderately decomposed and in good overall body
condition. Internal exam revealed significant trauma around the
head, chest and right side; at this point the cause of these
injuries is unknown.”
Jessie told me that the whale was probably dead two to four days
before it washed up on the beach. Trauma to the head was consistent
with a blunt force, such as a boat collision or an attack by
another large animal. The report mentions the prospects for what
researchers may learn from various tissue samples taken from the
whale.
Of particular interest to the sonar question is the skull, which
has been frozen for the time being. Lynne Barre said it will
undergo a CT scan with the hope of obtaining information about the
condition of the inner ear and the delicate tissues involved in
echolocation. Damage to those tissues could be an indication of
trauma from a sound source, but experts will need to account for
any decomposition after death. These issues are more complicated
than they might seem.
As for the location of L-112 and her family, that probably will
never be known unless one of the hydrophones picked up and recorded
calls from L pod. Scott Veirs, associated with OrcaSound, has been
working tirelessly the past few days to locate any orca sounds that
may have been picked up throughout the area.
Scott has noted that killer whale calls consistent with K and L
pods were picked up on two hydrophones in the San Juan Islands on
Monday, Feb. 6, just 18 hours after a Canadian frigate, the HMCS
Ottawa, transmitted loud pings throughout the area
(Water Ways, Feb. 11). The two hydrophones picked up the sounds
one after the other, suggesting that those whales were heading
south toward the Strait of Juan de Fuca
(OrcaSound, Feb. 8).
The next day, Tuesday, Feb. 7, some members of K and L pod were
spotted in Discovery Bay between Sequim and Port Townsend,
according to reports to Orca
Network. Nobody can remember seeing Southern Resident killer
whales there before. Could they have gone into the bay one day
earlier, seeking refuge from the sonar? We may never know.
But if we’re talking about the death of L-112, subsequent IDs of
the whales in Discovery Bay suggest that the group probably did not
include L-112 or her family. I’m still trying to learn which whales
likely would have been with L-112 around the time of her death. But
chances are she and her family were out in the ocean when all this
excitement was taking place in Puget Sound.
So that leaves the question of whether a ship could have been
using sonar off the coast when L-112 was within range. I have been
in touch with both U.S. and Canadian Navy public affairs officials,
and both have denied that their ships were using sonar in the ocean
during this time.
Lt. Diane Larose of the Canadian Navy confirms that two
sonar-equipped Canadian Navy ships, the HMSC Ottawa and the HMCS
Algonquin, were out at sea before entering the Salish Sea at the
time of Exercise
Pacific Guardian. But neither ship deployed their sonar before
reaching the Salish Sea on Feb. 6, when Ottawa’s pinging was picked
up on local hydrophones, she said. Navy officials say they followed
procedures to avoid harm to marine mammals and have seen no
evidence that marine mammals were in the area at the time.
A lot of gaps remain to be filled in, including the source of an
unusual explosive-type sound at the beginning of the hydrophone
recording that includes the Ottawa sonar, which Scott Veirs
discovered
(OrcaSound, Feb. 6).
Lynne Barre of NMFS agreed that the best thing for now is to
wait until the investigation begins to answer some of the lingering
questions. Sometimes the cause of death may include contributing
factors, such as weakened immune systems that lead to disease that
ultimately lead to a physical injury of some kind.
This is the third dead killer whale to be found in the vicinity
since November. The others were a newborn calf from an offshore
group of orcas and a very decomposed adult orca from the offshore
population.
In all the discussions about sonar, we should not forget that
the loss of this young female killer whale is significant for a
variety of reasons. I remember the optimism that came with her
birth back in the spring of 2009. See Kitsap
Sun, March 5, 2009. L-112 also was one of the orcas who
received two names, in this case Sooke and Victoria, because Ken
Balcomb also named some whales at the time.
(See Water Ways, Aug. 25, 2010.)
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