Sea otters on the Pacific coast were once hunted almost to extinction. Thanks to bans on fur trading and the efforts of biologists, their numbers have rebounded. But one group of researchers is seeking more explanations for the dwindling populations.
As dawn breaks on the rugged Big Sur coast, you can't help but
think of a military operation. A mobile surgical unit is ready to
swing into operation. There are divers off shore divers wearing the
rebreather suits favored by navy seals because they produce no
bubbles.
Tim Tinker a sea otter expert with the USGS's Western Ecological
Research Center responds to an otter sighting relayed by
radio.
TINKER: They are trying to line up on a possible target. We
refer to targets as being desirable animals that we want to
recapture so there is a female with one of the instruments that we
want to recapture in a kelp bed just off shore.
About three thousand sea otters live in California waters.
Tinker and his team want to know why that population has been
declining in recent years despite efforts to protect the endangered
otters.
TINKER: One of the
reasons that you may have heard us refer to them as sentinel
species is because they reflect local conditions, and we have
taken advantage of that by comparing them from Alaska right down
here to Califonia and that is because there are really good
reflectors of what is happening in the local near shore
environment.
Tinker says Not only do sea otters not stray far from
shore, they don't stray far period. It turns out sea otters
are hyper local, eating, breeding, and dying all within 15-30 mile
area.
TINKER: And what our study is doing is taking
a random sample of animals here in Big Sur , this relatively
pristine environment and studying them for a three year period
intensively, and compare that to another random sample that
we have collected around Monterey peninsula, right off shore of the
Monterey aquarium and cannery row.
About a mile away, on top of a hill with a panoramic
view of the coastline, Caroline Cummings, focuses a
telescope. She has spotted a group of about ten sea otters which
have tied themselves to a kelp bed and are resting face
up.
CAROLINE CUMMINGS: Pursuit, pursuit, this is
Caroline,
RADIO: Come in Caroline
CUMMINGS: Just wanted to let you know that one of the pups
is awake and being kind of squirrelly.
Cummings works with
the United States Geological Survey sea otter research
division. She has been watching and listening intently to
radio signals being broadcast from one of the otters which has a
small transmitter in its abdomen.
With the information the spotter has provided the divers
capture two otters with a device called a Wilson
trap.
The divers were aiming for the radio tagged female and her
pup. Back on shore Tim Tinker says they missed.
TINKER: Keeping track of your animal when it doesn't have
flipper tags and there in a group of animals is very difficult. So
these guys got two animals, we were hoping it was the right one,
but that turns out to be ok because we still want some blood
samples and other tissue samples.
On shore the first step is to administer general anesthesia so
the researchers can conduct their work quickly without fear of the
otters fierce teeth.
Overseeing the vetererenary team who work on the otters
simultaneously is Mike Murray, veterinarian from the Monterey
aquarium. Sea otter research is one of his passions; he has
performed surgeries in Alaska and remote parts of Russia.
MURRAY: Ithink our safety record rivals many
species including humans. I've done thousands of anesthetic
intervention on sea otters, and I don't need all of my fingers to
count the times I've had a mortal problem. But we recognize that we
are in fact taking a risk, but we feel that the data and studying
the system that they live in, is worth taking the risk.
As the sun sets on Big Sur, the researchers complete taking
samples from the two captured otters. One of the divers wades into
the surf and opens the box containing one of the otters.
DIVER: As soon as the water is as calm as it can be we open
the top and she swims off.
Watching the otters swim off to find their mates, the
researchers here say that this has been a good day. The data
gathered here will advance human understanding of ways to protect
this fragile species from extinction.