krill feed great gatherings of other animals.
Minke whales and humpbacks come to scoop
up mouthfuls. Squid, fish, and penguins eat
krill too. Many of those krill feeders in turn are
hunted by top-level predators—leopard seals
from below, skuas and giant petrels from above.
Take away krill, and the ecosystem unravels.
It’s unclear what quantity of krill has been lost
to warming conditions. Meanwhile, the waters
around the Antarctic Peninsula supply the largest
industrial krill fishery in the Southern Ocean; fac-
tory ships extract more than 800 tons a day. Krill
are pumped up continuously from nets that may
remain submerged for several weeks at a time.
The crustaceans are processed on board to make
products rich in omega-3 fatty acids, such as fish
meal used in livestock feeds and krill oil that’s
added to nutritional supplements for humans
and pets. Climate change threats and industrial
fishing are closely entwined, Lynch says.
“As the sea ice declines, the krill fishing boats
are able to move in.”
Against the backdrop of these pressures, an
international team of Antarctic scientists has
drawn up plans for a marine protected area
(MPA) covering 250,000 square miles—almost
the size of Texas—to safeguard the seas along the
western coast of the Antarctic Peninsula.
Decisions on whether to create such protected
areas are made by the Commission for the Con-
servation of Antarctic Marine Living Resources,
an international body formed in 1982 to conserve
Antarctic marine life in response to increas-
ing commercial interest in krill fishing. ThePairs of chinstrap
penguins, their bellies
muddy from scrambling
over ice-free spots
where they build their
nests, point their bills
skyward and emit a
honking call, perhaps
to signal: “This is my
patch.” Neighbors join
in with a noisy chorus
that ripples in waves
across the colony.
Chinstrap numbers
along the peninsula
appear to be declining,
a sign that the South-
ern Ocean ecosystem
is changing drastically,
possibly because of a
combination of climate
change and commer-
cial fishing for krill, a
penguin staple.
116 NATIONAL GEOGRAPHIC