Animal remains found in Antarctic lake
Tiny carcasses raise questions about what lives beneath the ice
B Y MARIA TEMMING
Much to their surprise, scientists in
Antarctica have uncovered what appear
to be remnants of tiny animals in mud
dredged from a lake that has been
covered by a thick mantle of ice for thousands of years.
The researchers on this expedition —
known as the Subglacial Antarctic
Lakes Scientific Access, or SALSA — are
the first to sample Lake Mercer, about
600 kilometers from the South Pole.
After drilling about a kilometer through
the ice in late December, the researchers
lowered instruments that brought water
and sediment up to the surface.
Looking at these samples under a
microscope, the team found creatures
“that looked like squished spiders
and crustacean-type things with legs
[and] … some other things that looked
like they could be worms,” says expedition
member David Harwood, a micro-
paleontologist at the University of
Nebraska–Lincoln. The researchers also
spotted what appeared to be the vestige
of a famously durable microscopic critter
called a water bear, or tardigrade. Exam-
ining the DNA of these remnants will help
researchers ID them more precisely.
The find, first reported January 18 by
a reporter with Nature, “is really intriguing,” says Slawek Tulaczyk, a glaciologist
at the University of California, Santa Cruz
who is not part of the SALSA team. Until
now, scientists hadn’t thought Antarctic
lakes would be suitable environments for
organisms larger than microbes.
When researchers in 2013 sampled
another ice-lidded lake in Antarctica,
Lake Whillans (SN: 9/20/14, p. 10), “we
didn’t uncover any evidence of anything
more complex than a microbe,” says
SALSA team member Brent Christner,
a microbiologist at the University of
Florida in Gainesville. “We had a simi-
lar expectation here.”
It’s still unclear if the carcasses were
left behind by creatures that actually
lived in Lake Mercer, Tulaczyk says. Ice or
water may have carried these fragments in
from the ocean or lakes farther upstream
in the Transantarctic Mountains.
Carbon dating could help pinpoint the
critters’ age, which may provide a clue as
to how and when these minuscule animal
remains arrived in the lake, he says.
If any of the animals were Lake Mercer
inhabitants, it’s possible that some of
them may still be kicking around down
there, Harwood says. “It’s interesting to
think that life can exist in really extreme
environments,” such as an Antarctic lake
that has been cut off from both the ocean
and atmosphere for thousands of years,
he says. “If life is still persisting there,
that’s important for our thoughts about
what we might find out in space.” s
Society for Science & the Public’s Science News in High Schools program brings
Science News magazine to more than 4,200 high schools across the U. S. and worldwide.
Educators: Get Science News for your high school!
Learn how your school can receive Science News in High Schools:
www.societyforscience.org/science-news-high-schools IN HIGH SCHOOLS