The 2010 Expedition has arrived in the Northern Line Islands. First stop: Palmyra Atoll.
Today Palmyra Atoll looks like the sort of place where one would expect to find a genuinely pristine coral reef. As part of the Northern Line Islands, it is located in a particularly remote region of the central Pacific. Along with Kingman Reef, Palmyra and its surrounding coral reefs is part of the Pacific Remote Islands Marine National Monument, thus protected. The small amount of land above water is uninhabited except for a few eco-conscious overseers, the staff at the research station, and the researchers who come and go throughout the year. Research activities are carried out under the auspices of the Palmyra Atoll Research Consortium (PARC) that was formed in 2005 as an interdisciplinary partnership of research, conservation, and educational institutions (including Scripps Oceanography). The atoll's isolation and exceptionally rich ecosystem make it a valuable site for studying not only coral reef biodiversity, but also reef restoration and the effects of changing climate, at ecological levels spanning the range from microbial metagenomics to ecosystem dynamics.
The legendary reefs of Palmyra with their colorful coral gardens and numerous sharks have often been touted as pristine. You might expect its CHI to be very high, close to that of the gold standard: Kingman Reef. And indeed, its microbial health is excellent. But there are less than half as many tons of fish in the waters here as at Kingman, with a particularly marked decrease in the number of sharks and other big predators. And the coral cover on the bottom is also only half that of Kingman Reef. Overall, of the eight reefs surveyed so far in the Line Islands, only heavily populated Christmas and Fanning have a lower CHI. Does this contradict the proposition that local human activities are the primary factor responsible for the degradation of the reefs at Christmas and Fanning? No, but it does remind us that we must consider past human impacts, as well as present.
The first landing here by Westerners came with a thunk when the US ship Palmyra was wrecked on the reefs in 1802—just four years after the atoll had been sighted by the American captain Edmund Fanning. The large scale destruction, however, came later, under the guise of construction, when the atoll served as the Palmyra Island Naval Air Station during World War II. Personnel reshaped the atoll by dredging a channel to allow ships to enter the protected lagoon, then added dikes across the lagoon to provide even more shelter by reducing the water flow. Coral rubble was bulldozed to make an airstrip. Before leaving, the military dumped several tons of ammunition and ordnance into one of the ponds created by the dikes. They left behind an atoll that could no longer be called pristine.
Preparing for a cruise like this is an enormous undertaking. Viewed from the outside, chaos would undoubtedly be the go-to word. For weeks leading up to departure our team is in a constant state of, at best, controlled chaos, which slides into outright madness for the days just before our main shipping dates and our own travel dates as we scramble to handle every last minute item. During the early stages of planning for this trip (months ago), we flesh out our main scientific questions and goals, then design the experiments that we hope to carry out to answer those questions. At this point everyone is eager and excited. Since the logistics haven’t yet been fully considered, we are sure we can accomplish about a million different things, far more than in practicality we'll have enough time, space, money, supplies, and manpower to do.
About two years ago a bug landed in my ear. Not a literal bug, but an academic bug. Our research in the Line Islands and elsewhere had told us quite a bit about how coral reefs used to look before humans changed the underwater landscape in most locations on the planet. We had determined conclusively that human activities systematically reduce the number of large fish, favor fleshy seaweeds (algae) on the substrate over long-lived corals, and create an environment that supports more microbes. But we still did not know what these consistent findings meant for the future of coral reefs.
For many of us on this expedition, our first trip to the Northern Line Islands had come in 2005. Our goal during that cruise was to establish what is a ‘pristine’ coral reef. Seeking reefs that could tell us this, we turned to the most remote islands that we could find, islands such as Palmyra Atoll and Kingman Reef. These islands lie so far from most people on the planet and had been visited so seldom that the stories about their reefs seemed to have grown to mythical proportions. They were fabled to hold multitudes of sharks and other big fish, lavish coral gardens, and water so clear you could see forever. These descriptions sounded like fairy tales compared to our real-life diving experiences on reefs near populated islands in the Pacific, the Caribbean, and the Indian Ocean. There it was a fabulous dive if we saw even one shark or a fish over two feet long. Our research surveys of those reefs suggested that corals were vying for space with the seaweeds, and frequently losing. Our photos reminded us that clear water days were rare. Were those legendary remote coral reefs real? We set out to the Northern Line Islands in 2005 to see for ourselves.
