Ken Balcomb calls for further review of orca’s deathMarch 6th, 2014 by cdunagan
Ken Balcomb, the dean of killer whale research in Puget Sound, is asking federal authorities to reopen the investigation into the death of L-112, a young female orca who died two years ago of mysterious causes.
Ken maintains that an underwater “blast” remains the mostly likely cause of death for the whale, who was known as Sooke — or Victoria, as Ken originally named her.
A draft final report (PDF 2.3 mb) by the National Marine Fisheries Service, dated Feb. 24, states that “blunt trauma to the head and neck is the prime consideration for the cause of mortality. Despite extensive diagnostic evaluation, the cause of the head and neck injuries could not be determined.”
See Water Ways, Feb. 25, for a discussion of the final report and links to other stories.
The official investigation could find no military operations in the area off the Washington/Oregon coast, where the young whale was found dead on Feb. 11, 2012. In looking for a cause of the trauma, the report essentially rules out several underwater explosions set off by the Canadian Navy a week before, on Feb. 4, 5 and 6 off Vancouver Island. These activities occurred too far north — and prevailing winds and currents were in the opposite direction, according to the report.
But Ken Balcomb argues that the report fails to fully consider how L-112 could have ended up south of these military exercises. Currents are not certain, he said. They can change, and eddies can even flow in the opposite direction from prevailing currents. Ken also raises the prospect that a dead or dying orca calf could be carried a great distance by other members of the pod.
“I consider the evidence presented in the NMFS report to be selected and filtered to depict a preferred hypothetical scenario, rather than one that may be more realistic,” he wrote to NMFS, the federal agency in charge of protecting marine mammals.
Ken’s 12 pages of comments (PDF 1.1 mb) address numerous statements in the report, and here are a few:
On the brain:
Report: “The absence of right cerebral hemisphere and right cerebellum of the brain was secondary to loss of tissue during disarticulation of the head. Significance is uncertain based on imaging alone, but unilateral loss of brain tissue is unusual.”
Ken’s comment: “UNUSUAL! The right cerebral hemisphere and cerebellum were completely mushed and there was evidence of hemorrhage in the calvarium, both significant findings of brain damage from a blast impact. The observation is consistent with blast trauma.”
On the ear bones:
Report: “The CT results showed no evidence
of bone fractures or damage to the middle or inner ear bones. These
results do not conflict with gross observations and the proposed
cause of acute or peracute death by blunt force trauma; however,
blast- or seismic-related injuries cannot be
Ken’s comment: ”Upon gross dissection both tympanic bullae were found to be dislocated from their fragile bony pedestals anchoring them to the cranium. While it may be accurate to say that no evidence of fractures or damage to the middle or inner ear bones on the CT scans, it is misleading to infer that no damage was evident to the ears (see page 11 of Necropsy report).”
On possible attack by another marine
Report: “The primary signs of injury reported from aggressive attacks are rake marks, musculoskeletal and/or intra tissue trauma (bruising, tearing) attributed to ramming and sometimes death. Contrary to the cases reported in the literature, L-112 was a juvenile animal (older and larger than a calf or neonate), and the examiners did not document tooth rake marks associated with the signs of hemorrhage they observed during the gross examination. Nevertheless, we cannot rule out the possibility that L-112 suffered injuries from an aggressive attack, such as ramming, by a larger animal.”
Ken’s comment: “The presumed hypothesis suggested by the last sentence is absolutely preposterous, given the evidence of a massive single traumatic event causing the mortal injury. To not rule out the attack hypothesis while ruling out blast trauma is ludicrous.”
Report: “Because of prevailing currents and
eddies it is unlikely that L-112 died in Canadian waters or the
Strait of Juan de Fuca and drifted south, but instead likely died
in the Columbia River plume or farther to the south along the coast
of Oregon. Given the state of decomposition at the time of
stranding the body was either carried by eddies for several days or
may have drifted a substantial distance from the south before being
trapped by the eddies and cast ashore on the Long Beach
Ken’s comment: “The drift patterns can be quite different from year to year, as well as from season to season, or even week to week. It is regrettable that drifters were not deployed near the west entrance to the Strait of Juan de Fuca in February 2012. There was a NOAA cruise in these waters at that time, and I asked the chief scientist to deploy drifters or some identifiable devices to ascertain the real time drift pattern at that time. One can surmise from the temperature regimes that were documented real-time that there was an anomalous cold water regime moving in a southerly direction in February 2012, but there were no current measurements.”
On the possibility of transport by another
Ken’s comment: “I further request that the investigation team thoughtfully consider the relevant cetacean epimeletic behavior … (He mentions two studies.) Hoyt (1981) in ‘Orca, the Whale Called killer” on page 92 states: ‘Among cetaceans, and especially the dolphin family (including orca), care-giving behavior to sick or wounded family members seems exemplary. Moby Doll was supported by members of his family after he was harpooned in 1964. On another occasion off the B.C. coast, a young killer whale was hit by a government ferry boat, the propeller accidentally slashing its back. The ferry captain stopped the boat and watched a male and a female supporting the bleeding calf. Fifteen days later, two whales supporting a third – presumably the same group — were observed at the same place.’”
Ken concludes his remarks with this: “These comments are dedicated to L86 and L112, the most overtly affectionate mother/offspring pair of whales I have ever seen. Rest in peace, L112. We miss you.”