explains. “They’re individually long lived. I’m working with a breeding
female that was first banded in 1965. They’re also small in number,
about 50,000 breeding pair in total.” She points out some penguin
bones near one of the bird’s nests. “I found a penguin heart there yes-
terday. Around the nests we’ve also found seal skin, squid beaks, krill.”
I shake my head sadly, poking at the penguin bones.
“They’re doing their job cleaning up the Southern Ocean,”
Patterson says somewhat defensively.
Along with rocks, many of the giant petrels make their nests of
shell. Both the rock and shell nests have a surprisingly sculptural
appearance, pleasing in their symmetry.
Patterson tracks each of her birds by island of origin, nest number,
and band number (for leg-banded birds). One of the things these cen-
suses have helped establish is the recent decline of the species’ popu-
lation. As many as 100,000 Antarctic seabirds, mainly albatrosses, but
also giant petrels, are thought to be dying every year in encounters with
long-line fishing fleets that have expanded their operations into the
Southern Ocean. The birds dive for the baits as the long lines, often
containing several thousand hooks, are unreeled from the high-seas
fishing boats. If the birds catch the bait at the surface, they are often
dragged under and drowned, or else entangled and injured.
“We’ve found hooks and lines around the nests as well as hooks
engorged in the bird’s throats,” Patterson reports. As a result, slow-to-
breed giant petrel populations are now crashing along with various
species of albatross.
Much of the long-line fishery threatening the birds involves the
unregulated and often illegal taking of Patagonian toothfish, a deep-
water Antarctic species that biologists say is also being pushed toward
extinction by over-fishing. Toothfish are frequently mislabeled,
shipped, and sold in the United States as Chilean Sea Bass.
Another concern in Patterson ’s study is climate change. “With this
warming trend we’re seeing more elephant seals moving south and an
increase in elephant seal populations could prove disastrous for nest-
ing petrels because of the competition for space,” she explains. “Also
warming has increased snowfall, and if there’s too much snow that
could reduce their nesting sites.”
Antarctica 167