Editor's Note: The following dispatch was written on February 17, but
received on February 20, due to communications difficulties. For more on that
subject, see Transmitting from a Fish Bucket.
A Slow Poach
February 17, 1998
By Mark Hoover previous |
I've just finished a day that was about as full—of images, discoveries, and
revelations—as a day can possibly be. I'm sweating, ruing my sunburned
shoulders, and I can't wait for more. Once again, I find myself typing away in
the dark. It's the only quiet time of the day on a small boat with 12 other
people aboard. I'm having some trouble with the computer tonight, but I think
it's due to the heat. The author Jonathan Weiner commented that El Niño happens
when the Pacific Ocean runs a fever. Here at Ground Zero is where a lot of
that feverish heat is released back into the atmosphere. The ocean does not
refresh you when you swim in it; it feels like it's the same temperature as
your own body. I understand now how its heat can affect many of the creatures
that inhabit it. Call it a slow poach.
We are at anchor, in a narrow channel separating two islands, surrounded on
both sides by the rising masses of volcanoes that ascend a mile into the
atmosphere. To the west on Isabella is Volcán Darwin, and to the east,
on Fernandina, is Volcán Lacumbre. As Fernando, our naturalist,
explains it, island building is going on here following much the same model as
is found in Hawaii: lots of slow-motion eruptions that release floods of
low-viscosity lava that flow like chilled syrup over the hardened surface of
the previous eruption. The Galapagos, says Fernando, are among the most active
island volcanic groups in the world.
Because the islands are only a few million years old, they have not had time to
wear down much, except along the shore, where the waves cut the soft volcanic
rock into terraces. The Galapagos sit over a "hot spot" deep in the mantle,
which injects magma through the overlying crust with regularity, and renew the
surface. The last eruption was in 1995, very near our mooring point on
Fernandina. I ask Mike if there's anything to the idea that undersea volcanism
contributes to El Niño. He smiles, and it's clear this isn't the first
time he's been asked. "There's a principle in science called Occam's Razor,
dating back to William of Occam, a philosopher in the 13th century who battled
it out with Thomas Aquinas. A lot of scientists invoke it, including me. The
idea is, the simpler the explanation for something, the more likely it is to be
right. I can explain El Niño using only the interactions between the
atmosphere and the ocean. I don't need a volcano to help out." (See the
FAQ section for more discussion on this topic)
We've had to travel all night through a rolling sea to get here by morning. I
never realized how much territory the Galapagos Islands consume; by boat, which
is your only option, it can take days to traverse from one end of the range to
As we passed around the northern point of Isabella late last night, I watched
the wake of our boat. A bioluminescent alga inhabits the water, and when it is
stirred up by the boat's passage, something stimulates the release of a blue
spark of light. The effect is mesmerizing. As the boat slices through the
black water, it is illuminated from below by what seems a cascade of tiny
underwater meteors. A turbulent pale blue contrail marks our passage in the
waters behind us. These warm-water algae are not common in the cold upwelling
that usually surrounds the islands, and Mike McPhaden is surprised. "This is
something you usually only see far west of here." Mike has cruised to most of
the mooring points of the TOGA/TAO buoy array, which stretches from here almost
to Australia, so he should know.
We are here to examine El Niño in the context of the creatures who
inhabit these islands, to observe its effects on them, and to gather with our
own eyes, noses, and fingers information that cannot be gotten from a book.
Mike, our scientist-in-residence, and our Ecuadorian naturalists Froylan and
Fernando, are especially excited by the morning's junket—a trip to Punta
Espinosa, where a spit of rock leads to a weird rust-colored moonscape of
pahoehoe lava, riddled by giant cracks and fissures, and dotted with tidal
pools. Pahoehoe is a Hawaiian word referring to lava with a relatively smooth,
curtain-like surface that sometimes involutes, or folds over on itself, in
great sheets. It is the lava of Mauna Loa. This is prime territory for the
marine iguana, a docile vegetarian with protective spikes, black lips and a
dinosaur's vaguely evil mien. Yet these peaceful creatures dine only on a
seaweed found in abundance here, a seaweed that cannot tolerate sudden changes
in the temperature of the sea. During the disastrous 1982 El Niño, more
than half of these ancient lizards perished, and those that didn't looked
markedly thin. We are anxious to know their fate this year.
Part of the camera crew got up early this morning to shoot underwater sequences
in a place off Isla Fernandina favored by turtles. The television show next
fall will discuss the effects of El Niño on the green sea turtle, and
our diving advisor and naturalist Fernando was up before dawn getting things
ready. He's lived here a dozen years, but you'd think he got here yesterday,
to judge by his enthusiasm. The population of the entire Galapagos archipelago
is only 20,000, so Fernando is a member of a select community indeed.
While the crew was diving, I made my own discovery of a small geyser. It
periodically belched a spray of water and vile fumes into the air, and it gave
me a snootful the first time I peered at it. Unfortunately, this geyser was in
the bathroom sink drain on the Orca, and it was belching "tank gas" as the boat
rocked in the water. Sometimes one must suffer for one's art. I decided to
Soon we loaded the launch for the short journey to Punta Espinola. We landed
in craggy place of mangroves and tidal pools. The mangroves support one of the
very few mammals on the Galapagos, the Galapagos bat (the others are the rice
rat, and sea lions). Although we saw no bats, we saw communities of crabs
clinging to the rocks near the mangrove roots. No apparent problems there.
Farther up the point, an iguana squatted in the shade of a lava fissure. He
was not alone. Soon it was apparent that other iguanas had claimed most of the
shady places in the rocks around us. As we tread the broken stone and hardened
lava of the path, we came across dead iguanas as well, sometimes accompanied by
small lizards who picked at their bones. Victims of El Niño, or part of
the natural cycle of life and death, we could not say. Fernando said that the
seaweed upon which the iguanas feed had suffered, but not yet to the point of
starving the iguanas.
Straying from the film crew for a few minutes, I chanced across a series of
pools where a small group of sea lions had taken up residence. At one end, a
male and female lolled in the water, napping side by side. The males are twice
the size of the females, and develop a characteristic hump on the forehead.
They are also the ones who guard the pools and the young, and bark at
encroachers (although usually not at humans, whom they largely ignore). A
solitary female sleeps not far from the pool under a piece of driftwood,
groggily opening her eyes as I bend closer for a photograph. Her tiny ears
twitch, however, as the males vocalizes in the distance, and I conclude she is
part of his harem.
The majority of the sea lion diet is sardines, and along the South American
coast, sea lion populations are in trouble in direct proportion to the crash of
the sardine fishery. Here in Galapagos, there are still some sardines to eat,
and sea lion mortality has been low so far. In 1982, there was a massive
die-off, caused both by direct starvation, and by abandonment of young.
In a neighboring pool, sea lions made sport of a marine iguana, using the
unfortunate reptile as the ball in a game of water polo. Flipping the lizard
through the air with their noses, they seemed to delight in watching it land in
the water and resolutely begin swimming again for shore, and they would wait
until the lizard had almost made it ashore before launching it skyward again.
After a while, they tired of this, and the unharmed iguana pulled itself from
the water and retreated into a crevice.
In his notebooks Charles Darwin wrote about his own iguana sport, in which,
from this very spot, he repeatedly tossed an iguana out into the sea, only to
watch it swim directly back to him (the shortest distance to land), so he could
toss it out again, like a stick that fetches itself. As Mike says, it's curious
how nature shapes the brains of creatures without predators.
We reload the launch and head across the channel to Urvina, where we hope to
observe Darwin's finches. Arriving an hour later, we find the landscape is
utterly different from Punta Espinosa, a place of scrub trees, grasses and
plenty of green undergrowth attesting to the frequent rains El Niño has
brought. The finches are abundant; generally, they are net winners in El
Niño years here, because the seeds they prefer are more plentiful;
however, subtle changes in things like their beak and body shapes during El
Niño periods shows that they carry in their genes evidence of the
influence of past El Niños (<The Beak of the Finch>, listed in the
<Resources> section, tells more about this remarkable phenomenon).
After an hour of hiking we chance across a geochelone, whose name in Latin
means "earth turtle." During El Niño years, the giant tortoises come
down from their normal locations in the volcanic highlands to take up temporary
residence in the lowlands. We observe the tortoise in a rare behavior: picking
the desiccated meat off the bones of a dead lizard. Normally, these tortoises
are vegetarians; Fernando speculates that perhaps because the tortoise is off
his normal feed, so to speak, he is trying to obtain missing nutrients. After
a while the tortoise plods off into the underbrush.
Hiking back to shore, we perch on black boulders lining the beach. As the crew
puts it, "it's time for some beauty shots." The sun is setting, and Mike
points out in the high clouds above Volcán Lacumbre to the west as
evidence of diversion of the winds around the landmass of the islands, like a
rock deflecting the flow of a stream.
"In some ways, El Niño works on a large scale the same way these
volcanoes act on a small scale—as a deflection in a stream. Here we see the
winds curving around the obstruction of the islands, a mile or more up. Now
think on a global scale. El Niño sits out here in the central and
eastern Pacific, and the normal flow of winds is deflected around it. Ripples
from this effect create turbulence downstream. Now think of storms as leaves
in a stream. The storms are fluttered about by the ripples, like leaves, and
move to places they normally wouldn't go. Just ask someone from Oregon or
Suddenly it is dark. We scramble to load the boat before the blackness
completely overtakes us.