Tagging Gray Whales
Reprinted from: Oregon State University Marine
Mammal Program
During the March 2005 field season, our research
team went to Scammon's Lagoon, Mexico [Laguna Ojo de Liebre],
to tag gray whales for the first time in nine years.
"Tagging" for Research
This research took place with shared funding from the BBC, Exxon/Mobil,
the Sakhalin Energy Investment Company, and LGL Limited Research
Company. The BBC is making a documentary on gray whale migration
and calf mortality,
so they sent a film crew to record our efforts. The crew chartered
a panga (a local fishing skiff used by whale watching companies)
and accompanied
the tag team as they spent 10-hour days on the water. With our volunteer
pilot flying overhead, locating whales and directing the tag team
and film crew onto them, the season was an unqualified success. A
total
of 17 tags were placed, 16 on mothers with calves and one on a single
individual.
We actually ended the field season early, having accomplished our
objectives. (We'd hoped to tag more singles, but they were
very scarce so late in the season.)
Do Tags
Hurt the Whales?
We're often asked if the whales react to being tagged. It's
a difficult question to answer, since whales often demonstrate
avoidance behavior around boats whether or not they‚ve been
tagged. But this season, one of the gray whales came back to the
surface
about
15 minutes
after being tagged, swam right to the boat and passed just beneath
it. It seems safe to say the animal was not traumatized.
What
Do Researchers Hope to Learn?
We're
now watching the tagged whales as they transmit their location
data. The plan is that as soon as they cross the U.S. border,
the team will return to San Diego to begin relocation efforts
in partnership with
the BBC film crew. The BBC folks, of course, want footage
of the gray whales during their migration. We want to assess
the tag status and any
possible physiological responses to the tags, as well as
establish
a calf count at various places along the migration route.
If a calf disappears
between Point A and Point B, then we‚ll know roughly
where it vanished. Since calves have a fairly high mortality
rate during
the
migration,
this information is of considerable interest.
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