Merry Youle's blog

Palmyra Atoll Yesterday and Today

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.

Microbial Countdown

No matter how early you start planning for an expedition like this, the pace gets hectic as departure approaches. Here's a story of those weeks and months recounted by a member of the Microbe Team who has arrived at Palmyra.


by Katie Barott, member of the Microbe Team

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.


Once our main objectives are set, we go through several rounds of calculating what supplies we'll need. For the Microbe Team, these essentials include much standard microbiology equipment, such as filters to capture bacteria and viruses, sterile containers of various types, and numerous pumps for collecting seawater. Although filtering water to collect the microbes therein seems simple enough, we have come up with three different ways to do this, ranging from the traditional to the innovative and maybe slightly crazy. The traditional approach uses vacuum pumps to pull reef water through filters or peristaltic pumps to move the water through tubing and cylindrical inline filters. Our own home-made filtration rigs use compressed air from a scuba tank to push water from collection bottles (niskins) through a variety of different inline filters. We've also designed our own system for deploying manual bilge pumps underwater to collect water from directly above the corals.

Why Did We Spend Our Past Year Preparing for This Trip?

Today the researchers are converging on Palmyra Atoll by land and by sea, the culmination of a year's planning and work. Excitement runs high, fueled by a touch of anxiety as minds race to remember what has been forgotten, misplaced, left behind. Time to pause and think about why all this effort.


 

by Stuart Sandin, head researcher on the Fish Team

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.

The services that coral reefs offer to humanity are many, probably the two most important being the harvests from their productive fisheries and their role in shoreline protection. The greatest value of the fisheries lies in the fish that can be caught and eaten. While it is interesting to know how many fish currently live on a reef, the fishing community cares more about how many fish will be there tomorrow and the day after. In other words, the asset of interest is not the current density of fish, but rather the productivity of the fishery. Similarly, from the standpoint of shoreline protection, what is important is not only how much coral exists today, but the rate of reef construction by the coral and other reef builders in the benthos. Our previous research measured what was living on the reef today (and how the organisms present correlated with local human activities), but we had no direct measure of the productivity of these organisms. Were the fish and the corals growing rapidly, or were they just lazing around, passing the time, maintaining, but not growing a bit?

CHI – The Three Dimensions of Reef Ecology

by Stuart Sandin, head researcher on the Fish Team

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.

The reality we found was stunning. We surveyed, counted, and collected to give a quantitative scientific description of the reefs at these remote and uninhabited locations. The coral reefs at Kingman and Palmyra really did support massive fish assemblages including an abundance of large animals; their surfaces really were covered by lots of corals and reef-building coralline algae; the amazingly clear reef waters really did contain shockingly few bacteria and viruses. When we compared these reefs to those at nearby inhabited islands, the contrast was striking. With just moderate human populations harvesting fish from the reef, the structure of the reef ecosystem was dramatically altered. The fish were smaller and even when combined added up to less fish biomass, the corals and other reef builders were less common, and the microbes were more abundant. In other words, we were back to the reefs that were familiar to us all.

A Gathering of Researchers

Sixteen scientists from three continents and one island are gathering in the Northern Line Islands with one purpose in mind—to increase our understanding of coral reef health and decline. Coral reefs are not only extraordinary in their beauty, but also mind-boggling in their complexity. When the corals die and a reef declines, many possible killers come to mind: overfishing, disease-causing microbes, or overfed algae, to name just three prime suspects, all aided and abetted by humans. The goal is to identify the primary factors, to understand how they interact and impact reef health, and ultimately to find a way for humans and reefs to thrive together.

The expedition researchers include three teams, each focused on a particular portion of the teeming reef life, each with their research hypotheses and planned experiments, each led by a veteran of previous expeditions. The Benthic Team led by Jen Smith focuses on the benthos—those organisms that live on the seabed, including the corals and the algae. Interactions between these two groups are important for the fate of the reefs. Stuart Sandin leads the Fish Team that is studying how the effects of fishing, especially the removal of sharks and other top predators,  reverberates through the entire reef ecosystem. The third team, the Microbe Team, is piloted by Forest Rohwer. Thought too small to be seen, the microbes are the most numerous and most diverse organisms on the reefs, and perhaps the most important for reef health.

Northern Line Islands Expedition - The Adventure Begins October 24th!

Few people have ever seen a healthy coral reef, not even most reef researchers themselves. Almost all the world's coral reefs are now degraded to a greater or lesser extent, the result of our encroaching activities. To find a pristine reef, you must travel to the most remote parts of the oceans, to places such as the Line Islands in the central Pacific.

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