the symmetry of the carcass, looking
for abnormalities in alignment of the
bones or unusual colouring that might
suggest a lack of nutrition or injury.
Since the team can’t flip the hulking
whale over, the back of the animal,
including the top side of its spinal col-
umn, is largely inaccessible during the
necropsy. Rising tides, the challenging
access and a small necropsy team also
hinder a fuller skeletal examination.
The whale is pockmarked with beak
bites from scavenging bald eagles—
now relegated to the shoreline trees,
their squeaky-door calls imploring
Raverty to get on with it.
The whale’s tongue is a gooey greyish
blob protruding from the mouth. Rav-
erty looks inside for foreign debris, such
as plastics or fishing gear, or evidence
of damage to the baleen, but finds
none. Black skin peels from the tail
flukes, which are tied to a tree with
close to 50 metres of rope to prevent the
tides from returning the carcass to sea.
Raverty leans over for a closer inspec-
tion of the pectoral fins on the sides of
the whale—white on the bottom, dark
on top, and mottled with freeloading
barnacles. He observes scar lines near
the base of each fin, suggesting the
whale may have encountered fishing
gear at some point in its life.
There’s more than idle curiosity at
stake today. The necropsy results will
form part of a baseline of information
on the overall health of the humpback
population—estimated at 25,000 or
more in the North Pacific—and could
potentially point to problems that
humans are in a position to tackle,
such as entanglement with fishing gear
and ship strikes.the necropsy is just one part of the
investigation. Raverty relies upon a
host of experts—lab technicians to
analyze tissue samples, biologists, ecol-
ogists, oceanographers and climate-
change specialists—whose findings
will later contribute to a broader under-
standing of why marine mammals die.
Half the time, necropsies don’t deter-
mine cause of death. “Each is a learn-
ing process,” he explains. “It provides
a glimpse into the natural history of
these animals.”
Raverty has performed more than
2,200 necropsies of marine mammals
from across North America over the past
two decades—not just of humpbacks,
but killer, grey, fin and beluga whales,
as well as seals and sea lions, porpoises,
dolphins and sea otters. About 20 per
cent of the necropsies are conducted
in the field—generally on the whales,
which are too big for transport—and
the remainder are done in his lab under
more controlled conditions.
DFO technically owns the carcass and
issues permits to allow Raverty to take
tissue samples for research purposes
and to better inform federal manage-
ment of marine mammals. It’s not
unusual for him to work for free on his
own time, such is his devotion to the job.rd.ca 73