corals; and in a third, by baby sea cucumbers
with finely branched plumes for capturing food
particles in the rich seawater.
To our astonishment, the kelps in each bay still
harbored the same species. The oceanographic
conditions appeared to have remained similar
here for the past half century: Climate change
had made no permanent mark yet. This seemed
a wonderful gift, and I felt a burst of joy.
We were amazed as well by the abundance of
life. Every square inch of the bottom was occu-
pied by a living organism: white and yellow
sponges, pink encrusting algae, lollipop-like
sea squirts. Giant kelps bent to the seafloor from
the weight of the mussels growing on them. Blue
starfish gorged on the mussels, along with snails
and hermit crabs. A year before, on the Chilean
side of this ocean ecosystem not far from Cape
Horn, we’d stumbled upon a massive aggregation
of another crab species, called false southern king
crabs. Two layers of them covered the bottom
while many more climbed the giant kelps and
parachuted down on their fellow crustaceans—
and on our heads. It was as if we were part of a
Japanese science fiction film. Crabzilla!
ONE DAY WE TOOK A BREAK from the diving
and ventured to the basin beyond the edge of
the continental shelf. The Yaganes Basin is the
heart of a massive, connected ocean ecosystem
that ranges across the southern tip of Chile and
Argentina to Antarctica, in a convergence of
Pacific, Atlantic, and Antarctic waters. Our engi-
neer, Brad Henning, had brought along several
National Geographic Dropcams, glass (borosil-
icate) spheres enclosing cinema-grade cameras
and lights. They have a weight system that car-
ries the camera to the bottom, then returns it to
the surface hours later—perhaps with a trove of
never seen before footage of the seafloor.
The Dropcams did not disappoint. When Brad
showed us a selection of video clips the cam-
eras had captured, our jaws dropped. Toothfish,
hake, and other deep-sea fishes flocked to the
bait Brad had attached to the Dropcam. At one
point a fat red squid approached the camera,
then vanished in an explosion of ink. Many of
these species are overexploited in the basin. To
the bleaching and death of coral reefs and the
shrinking of Arctic sea ice during summer. What
were we going to find here beneath the surface,
45 years after Paul’s visit?
CLAUDIO AND I STEPPED on the beach and imme-
diately realized we were walking on a mass grave.
Old sea lion bones crunched underfoot with
every step—the legacy of hunters in the first half
of the 20th century. Some skulls had holes made
by metal picks. There were jaws and teeth from
huge old males and little juveniles. Sea lions and
fur seals had been taken indiscriminately, mainly
for pelts and for blubber to boil for oil.
By Paul Dayton’s time, the Argentine govern-
ment had protected these species by law, but they
have yet to recover. According to researchers,
local sea lion numbers are a fifth of what they
were more than 70 years ago, possibly because
of the dramatic decline of reproductive females
and the vast footprint of industrial fishing.
“In the past, people killed them directly,”
Claudio said. “Now we’re depriving them of
their food too.” Three days before our visit to
Thetis Bay we’d seen a 360-foot-long super-
trawler at the port of Ushuaia. Its nets were
big enough to hold a dozen Boeing 747s. Such
bottom trawlers and long- liners operate at the
edge of the continental shelf of Tierra del Fuego,
where the deep basin begins.
Nearer to shore, the weather is so brutal most
of the year that few go through the effort to dive
at Thetis Bay and Isla de los Estados, but hav-
ing arrived in relative calm, we were able to dive
around the island for two weeks.
The cold, nutrient-rich waters feed giant kelp
forests that harbor one of the most magnificent
marine ecosystems on the planet. Pillars reach
from as deep as 150 feet to the surface, sometimes
adding a foot and a half in a day. Giant kelps con-
tinue to grow once they reach the surface, creat-
ing a canopy through which sunlight filters as if
through the stained glass of a cathedral.
Paul had graciously scanned and copied his
handwritten notebooks for us; the pages were
filled with detailed natural history observations
from 1973. We carried them like treasure. Giant
kelp forests all look the same from the surface,
but underwater it’s a different story.
Paul had found that every little bay had its
peculiarities, sort of an ecological personality.
In one bay the kelps were covered only by one
or two species of clams; in another, by little soft
than 10 percent of the
world’s population of
this vulnerable penguin
species lives here.
A petrel flies over a
colony of southern
rockhopper penguins at
Isla de los Estados. More
108 NATIONAL GEOGRAPHIC