Adventures in a Disappearing Land
By James McClintock
St. Martin's Press Copyright © 2012 James McClintock
All rights reserved.
I will never forget the austral spring day thirty years ago when I was aboard the Marion DuFresne as she anchored offshore the Crozet Island Archipelago, an otherworldly cluster of French islands. These islands are nestled deep in the southern Indian Ocean, and their seas, shores, and valleys teem with the iconic penguins, seals, and seabirds that are an integral component of quintessential Antarctica. The sky was crystal clear, the breezes were mild, and the seas were calm. As we approached the shore in our small motor boat, I was taken aback by what appeared at first to be groups of miniature dolphins swimming in orchestrated synchrony in the deep blue waters. As we drew closer, I realized that these were not small dolphins at all, but rather schools of penguins cresting above and sliding below the sea's surface in unison, porpoise-like, to increase speed and save energy while temporarily airborne as they darted back and forth between shore and sea. On the beach, what appeared to be a welcoming party of king penguins assembled before us. They stood about waist-high, second to the world's largest penguin, the slightly taller emperor. These regal birds were distinguished by a progressive gradation of light-yellow to deep-gold feathers that graced the upper reaches of their snow-white chests. On either side of their black heads, tear-dropped patches of gold complemented the gold slashes that adorned the lower sides of their beaks, as if their beaks were painted by a final stroke of a brush for good measure.
After debarking, I wound my way along the beach, past nests with females sitting on their eggs and sidestepping the occasional squawking downy-feathered chick. I worked my way up a steep hillside that framed the mouth of the immense valley where the penguins had set up their colony. Several hundred feet above the valley floor, I stopped to take a photograph of our landing spot with its sprinkle of elephant seals sprawling amid the king penguins. Then, turning to face the opposite direction, I snapped the photograph that would later land on the June 1984 cover of BioScience. Over fifty thousand king penguins stretched across the river valley floor, disappearing around the distant bend. Their braying chorus and pungent guano overwhelmed my senses and fully complemented the stunning view. Above me, against the verdant hillsides, a smattering of white dots marked the locations of nesting giant wandering albatross, the largest of the world's seabirds.
My enduring fondness for Antarctic marine biology blossomed during that first expedition south. To this day, I don't know exactly what possessed John Lawrence, my professor and doctoral mentor at the time, to ask me in the summer of 1982 if I would join him on an expedition to the Kerguelen Archipelago, a remote cluster of volcanic islands at fifty degrees latitude approximately one thousand miles off the northeastern coast of Antarctica in the southern Indian Ocean. I have always considered these subantarctic islands, although not in Antarctica proper, to be "Antarctic" because they are teeming with iconic Antarctic seabirds, penguins, seals, and whales. We would study the reproduction, nutrition, and ecology of echinoderms, a wondrous group of marine animals comprised of such familiar creatures as starfish, sea urchins, sea cucumbers, and brittle and feather stars. The research expedition would be jointly funded by the National Science Foundation and the French government (Centre National de la Recherche Scientifique). As a graduate student, I was thrilled because of its inherent adventure and also because very little was known about the biology of Antarctic echinoderms or any other group of marine invertebrates at that time. We embodied the scientific equivalent of "kids in a candy store."
With John Lawrence and with great anticipation, we prepared to leave for Antarctica. We first stopped in Paris, where we met briefly with Professor Allain Guille, an expert on echinoderms at the Muséum d'Histoire Naturelle who had arranged permission from the French Antarctic Program for John and me to work at the French base on Grand Terre Island in the Kerguelen Archipelago. Very few Americans had ever been to the Kerguelen Islands, and we were the first American scientists to stay on the island since the 1874–1875 American, British, and German expeditions that went there to best observe the transit of Venus: an astronomical event occurring once every 240 years during which Venus passes directly between the sun and the earth. Over a century later, we two Americans would travel there to explore an equally wondrous and mysterious frontier: the depths of the sea rather than the solar system.
The next leg of our journey took us across northern Africa with a brief respite to refuel in the tiny country of Djibouti, bordered by Ethiopia to the west and south, Somalia to the southeast, and Eritrea to the north. We next refueled on the tropical Seychelles Archipelago, a cluster of 115 paradisiacal islands about 900 miles east of the African coast. The plane almost skidded off the runway as we landed in the midst of a torrential downpour at the international airport in the capital city of Victoria. The pilot threw the engines into full reverse and slammed on the brakes. I looked out the window as, still skidding, we closed in on the final few meters of runway. After we stopped, I could just make out a sheer precipice that dropped to the crashing sea.
On the tropical mountainous island of Reunion, just to the east of Madagascar and where John and I would meet our ship, we spent several days at the home of Sonya Ribes, an echinoderm researcher and John's good friend. Her husband Nicholas took us for an unforgettable drive on the steep and narrow winding mountain roads. He drove like a maniac, and though I had to maintain a death grip on the seat in front of me, I was still able to gape at the gorgeous vistas, flowering hibiscus, bougainvillea, orchids, bamboo, ferns and palms, and jet-black volcanic sand beaches scalded by the afternoon sun. Because I had months of cold weather, endless seascapes, and volcanic islands with limited plant life ahead of me, I soaked up as much of the warmth and the lush tropical vegetation as I could take.
John and I spent the next two weeks on the open sea aboard the Marion DuFresne, which was manned by a crew of French sailors and was bound for the Kerguelen Archipelago, some 1,800 nautical miles to our southeast. The Marion DuFresne is named for an eighteenth-century French minister and was the first ship built to specifically service the Terres Australes et Antarctiques Françaises (translated from French meaning "Southern and Antarctic Lands"). At 360 feet in length and with a sleek, deep hull and powerful engines, the beam of the Marion DuFresne cut efficiently and smoothly through the seas. In French society, scientists rank high in stature, and as such the captain invited us to dine with him and his officers each evening in a special stateroom. These meals were grand affairs, as the captain and his officers dressed in their finest formal white uniforms, waiters served us from silver platters, and John and I were treated to carefully orchestrated selections of fine wines and aperitifs. Although they were enjoyable at first, these three-hour dinners soon became interminable. My French was so rusty that I quickly lost my bearings in the rapid banter, which, alcohol-greased, was too quick to comprehend. John Lawrence finally came up with the appropriate excuse that lunch was so sufficient in scope that we did not need another large meal, and we spent the rest of the voyage eating our dinners in the crew mess.
Before arriving at Kerguelen, the captain treated us to a day-long visit to the Crozet Islands, an archipelago comprised of six small volcanic outcroppings. These are uninhabited except for a small research station called Alfred Faure, manned by about a dozen scientists and support personnel and located on the eastern side of Île de la Possession. While there, the ship's crew resupplied the station with food and fuel using the ship's helicopter to sling loads back and forth in a huge net basket. Later, while the ship rested at anchor in Île de la Possession's Alfred Bay, we went ashore to visit one of the world's largest king penguin rookeries, which is where I truly had my first encounter with Antarctica.
Following our wondrous day at Alfred Bay, our five-day voyage to the Kerguelen Island Archipelago was colored by a growing anticipation of at long last arriving at our destination. Similar to the Crozet Islands, Grand Terre Island in the Kerguelen Archipelago is covered with vegetation, primarily a low-lying plant with dull reddish flowers known as Acaena magellanica. Whalers and sealers that visited the island in the nineteenth century released rabbits to ensure they would have a food source if they were ever stranded. Unfortunately, the furry herbivores drove many of the native plants to extinction, but Acaena, distasteful to rabbits because of a chemical defense, survived and eventually took over the landscape. The French introduced cats to the island in the 1950s to control the rabbits. This was a monumental mistake. The cats soon learned it was easier to eat the chicks and eggs of birds than to chase rabbits. As I hiked across the Kerguelen countryside taking in views of snow-covered Grand-Ross Peak, which at 6,040 feet is the highest mountain on Grand Terre Island, I watched some of these feral cats and rabbits darting about in the vegetation. Kerguelen, like most islands around the world, suffers from the ecological wrath of introduced species. I would learn later that climate changes are lowering natural barriers to introduced species. For instance, as temperatures rapidly rise, subpolar archipelagos such as Kerguelen are subject to invasions of plants, insects, and birds originating from warmer climates.
John and my home away from home, the station of Port-aux-Français, rested on the edge of the Bay of Morbihan on Grand Terre Island, and its small cluster of lime-green buildings housed about eighty French scientists and support staff. From the small marine biology laboratory perched above the sea, I could look out over a dark blue expanse dense with kelp forests. Late at night, I lay in my bed listening to the dorm windows rattle incessantly as the winds howled near hurricane force. Everyone who visits Kerguelen must make his or her peace with the wind. Thousands of miles of Indian Ocean surrounded us, and, uninterrupted by land, the powerful gales gained force before slamming into the island. Each morning, John Lawrence and I woke early for a breakfast of coffee and fresh baked rolls before striking out by foot across the hills to our study site on the rocky intertidal coast, sometimes leaning into winds so violent that they nearly knocked us backward.
We followed a well-worn path, now christened the "Promenade des Amerlocks" (American Promenade). But the official naming of our path apparently has a twist for the literal French translation of Amerlocks, which is a joke. The suffix is purposely misspelled as an American might spell the word if he did not know much French. Perhaps the French wondered what these two crazy Americans were doing traversing this path day in and day out despite the inclement weather.
Timing our visit to coincide with low tide, we arrived to find generously exposed boulders, rocky platforms, and tide pools, the latter of which are home to beds of mussels, an assortment of green sea anemones, brown snails with shells resembling pointed top hats known as limpets; chitons, which are flattened, cradle-shaped mollusks, and small, delicate pink sea cucumbers. In the lowest reaches of the intertidal zone, closest to the open sea, we discovered a dense coverage of holdfasts of the massive bull kelp Durvillaea antarctica, an organism whose unique honeycombed architecture renders its golden-brown leathery blades tough and buoyant. The energetic surf whipped the twelve-foot long fronds back and forth across the rocks. Remarkably, scientists had never documented this unique marine community. John and I eagerly extended rope transects across strategic stretches of the rocky intertidal zone, marking the area we planned to evaluate, and over the following weeks meticulously measured and described its inhabitants for a scientific paper.
I noticed dime-sized smooth spots or "scars" on some of the boulders where limpets rested at low tide. Running my finger across the rock scars, I was reminded of the smooth texture of human skin over which scar tissue forms after a wound has healed. I wondered if these scars could be evidence of what is referred to as "homing behavior." Some tropical and temperate limpets are known to make rock scars by repeatedly scraping the rocks' textured surface with their conveyor belts of grinding teeth, known as "radulae." After completing their foraging excursions at high tide, they return "home" to their own personal rock scars with each receding tide. This behavior, which may seem like mere decoration, protects them from predators as the smooth rock scars provide a more secure gripping surface for the limpets' muscular rubbery feet. A predatory starfish hoping for a tasty meal would find it difficult to pry a limpet off its scar once it had suctioned itself with its plunger-like grip.
We tested our homing theory by marking the Antarctic limpets with an ink pen and then mapping their daily movements. We concluded, however, that despite their scars they do not home. One reason could be that fewer direct predators of the limpet live in the subantarctic. While scuba diving one day near the station, I discovered limpets and starfish sharing the same fronds of kelp. My follow-up observations of this predator and its prey in the laboratory indicated that when the tube-feet of the starfish touch the limpets, the snails wildly gyrate their cone-shaped shells, like a dog shaking off water, thus dislodging the starfish before rapidly turning and fleeing.
The predator-avoidance tactics of an organism so small might not seem to be important when discussing a warming climate. However, Antarctic limpets have turned out to be a crucial component of the Antarctic web of life, providing nutrients and energy for higher trophic level organisms such as fish and especially seabirds. Should climate warming or ocean acidification cause limpet populations to decline, the consequences for consumers further up the food chain could be severe. Similar to many locations around Antarctica, Grand Terre Island features mounds of limpet shells, or "shell middens," along the shores of Kerguelen, indicating that seabirds such as giant petrels and kelp gulls have consumed vast quantities of snails. I often observed "shell dropping" behavior as I sheltered myself from the high winds against the base of the cliffs bordering the rocky intertidal, as kelp gulls rose high into the air to drop mussels and limpets onto the rock platform. Diving to retrieve their cracked prey, the birds would land on the nearby shell middens to pick the soft flesh from the broken shells.
Antarctic limpets have turned out to be important beyond their status as a crucial component in food webs. My current research on the impacts of ocean acidification on Antarctic marine organisms is exploiting limpets as a model for studying what has widely become known as "the other CO2 problem." The original CO2 problem, the warming of the earth due to the accumulation of CO2 (a potent greenhouse gas), has received considerable attention. The other CO2 problem, the absorption of CO2 by the world's oceans, rendering them increasingly acidic, is less recognized to date, but just as important. As such, just as mice have yielded important insights into understanding human cancers, limpets may play a key role in understanding of the impacts of human-induced ocean acidification.
John and I were overwhelmed with the possibilities for further discoveries that presented themselves in this amazing place. Before ourship departed Kerguelen, we had completed yet another of our scientific objectives, a study of the reproductive habits of an Antarctic starfish that, like a chicken, roosts on its large yolky eggs to protect them as they develop. This type of reproduction, known as "brooding," is an unusual strategy. Unlike their Antarctic cousins, warmer-water starfish release millions of eggs and sperm directly into the sea. Their embryos develop into tiny swimming larvae covered with little hairs or "cilia" that beat in a coordinated fashion to assist in swimming and capturing food particles. Eventually, the larvae settle to the seafloor, and, through a metamorphosis as dramatic as a caterpillar changing to a butterfly, they transform into baby starfish. So why instead do most Antarctic starfish brood their young? The answer may reside in the extraordinary length of time it takes for the starfish to develop at such low temperatures. In warmer seas, marine invertebrate embryos and larvae develop in a few days or, at most, several weeks. In Antarctica, development can take four to six months. Maybe allowing one's offspring to swim about in the Antarctic plankton for months on end rather than under mom's protective arms is too risky. As we sailed north and I ruminated at great length upon what I had observed, it hit me: Kerguelen had worked its spell on me, and I became obsessed with solving the riddles of Antarctic marine life. (Continues...)
Excerpted from Lost Antarctica by James McClintock. Copyright © 2012 James McClintock. Excerpted by permission of St. Martin's Press.
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