Campus Beat
Listening to Minkes
"It's always been a dream of mine towork in the Bay Area," says Jonathan
Stern. "The fact that I get to teach
here at the place that turned me on
to whales and ecology is an added
bonus." Photos courtesy of Jonathan
Stern
Minke whales might be the smallest of the big whales, but they hold the key
to answering some of the biggest scientific questions about the environment
-- questions that Jonathan Stern (M.A., '90), biology lecturer, is determined
to answer.
After 20 years of research in the San Juan Islands of Washington state, Stern
has learned more about the species than just about anyone. Some of his accomplishments:
insight into how minkes eat, where minkes go, and what their health (or lack
thereof) says about the ecology of our oceans as a whole. "These whales hold
keys to all sorts of information about our ecosystem and the ecosystems of
the sea," says Stern. "In a sense, they are the ultimate bellwethers."
Minke whales are significant for their numbers. Conservation organizations
estimate the worldwide population to be more than 500,000, and the animals
are considered pan-oceanic. Some go so far as to call them the "deer of the
sea."
Because minkes are so prevalent, nations such as Japan, Norway and Iceland
have targeted them for annual hunts since the heyday of sperm whale fishery.
A recent International Whaling Commission (IWC) study indicated more than 116,000
minkes were killed between 1904 and 2000. These were only the reported numbers;
Stern fears the actual figures are two or three times this amount.
At the 2007 IWC meeting, pro-whaling nations insisted that since minkes eat
fish and fish stocks are dwindling, killing the mammals is the only way to
defend the "nutritional security" of us all. Stern’s work refutes this assertion.
He’s been following the animals for so long that he has calculated an ecological
model called a Levy Flight, the specific triangular behavioral patterns the
whales adopt while feeding. Not surprisingly, these patterns have changed as
fish stocks have declined. His data suggest that Minkes are victims of broader
issues, such as over-fishing by humans, climate change, pollution, and habitat
destruction.
"The irony is that while whaling nations blame the whales for depleted fish
stocks, the whales are suffering too," Stern says.
Evidence of these changes is particularly poignant in our own backyard. While
most of the Pacific is literally teeming with minkes, marine observers have
reported a suspicious absence of the animals in the waters west of the Golden
Gate Bridge. A recent survey revealed fewer than 15 individuals. Some think
even that figure was an exaggeration.
Historical records show that minkes inhabited our waters more profusely at
one point. What happened? Stern hypothesizes that the animals have opted to
forage elsewhere because the other mammals between Bodega and Monterey bays
provide far too much competition for an already depleted menu. During the next
few years, he hopes to head into the Gulf of the Farallones and apply Levy
Flight models to prove these theories right.
In the meantime, Stern will continue to teach in the Biology Department. He
looks back fondly on his time as a student at SF State, and enjoys leading
a new generation in search of answers to the great unknowns. "Being in this
environment and interacting with professors got me interested in these bigger
issues," he says. "Hopefully, some of my students will be just as inspired."
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