Ghosts of the Phoenix Islands

And the Phoenix Islands "Greatest Hits" highlights continue...

#3: SHIP WRECKS, RUINS, PLASTICS, RATS, COCONUT TREES, FISHING, and STYROFOAM

During this entire expedition, we've been cautiously describing the Phoenix Islands Protected Area (PIPA) as "relatively free from human impact," or as "a reef with little/no current local impacts," etc. In case you missed the nuance, it's worth taking a moment to explain exactly how much human impact there is or has been in and around PIPA. First of all, these reefs are not pristine in the absolute sense of the word. Nowhere in the world is completely free from human impact, anymore. Climate change is impacting natural ecosystems from the equator to the poles. There are still wild and beautiful places in this world, but no place is truly pristine. Pristine has taken on new meaning, and is now used to describe places that are relatively pristine--or as free from human impact as they can get.

So, what are the ghosts of humanity (past and present) that haunt PIPA islands and reefs? To simplify things, I've created a few categories. First, there are long-lasting ghosts. This category basically is restricted to shipwrecks (of which there are surprisingly many!), plane wrecks (Amelia Earhart's plane, in theory anyway), and recent remnants of buildings created when the islands were used by PanAmerican Airlines, or by guano miners, or by military operations during WWII. These large ghosts are mostly made of metals (iron, copper, steel, etc), and are very long-lasting.

Some of the wrecks on the Phoenix Islands are likely over 100 years old, but they are still having a continual impact on the islands through their slow deterioration and the resulting metal poisoning (which facilitates algal growth, whereby restricting coral growth, for example). There is noticeable shipwreck debris on the reefs. To some extent, the debris has become part of the reef and provides complex structure for fish to hide in and for invertebrates and algae to settle on. However, the debris also changes the ecosystem. We were able to see visible impacts of iron poisoning (with a spread proportional to the size of the wreck). On such small reefs, shipwrecks can have a substantial impact for decades, if not centuries. Similarly, metals leach from abandoned metallic structures on land into the coral sands, and promote plant growth that would otherwise never be found on equatorial, Pacific atolls.

The next category is quick-release ghosts. These include plastic water bottles, flip-flops, Styrofoam floats, plastic buoys, glass bottles and buoys, and any other small-trash debris that is likely to last for only a decade or less. This small-scale debris can still have a big impact - as plastics break down, they release chemical compounds that remain in the water long after the original plastic object physically degrades. As we blogged about earlier, there is a surprising amount of trash that washes up on remote, uninhabited shores. The Pacific Garbage Patch is a testament to how much trash is visible from the surface, never mind how much trash lies on the ocean floor.

There are also low-impact ghosts. Ruins from long-ago island residents (Polynesian or otherwise) that were built with coral stones or other natural materials have very low impact. They do alter the landscape of the islands, but they are generally not leaching toxins or metals onto the islands.

There are also a lot of living reminders of humanity on these islands - including the small resident population of people on Kanton Island. However, Kanton is their home and the only inhabited island in the Phoenix Chain, and I give these residents lots of credit for living in an incredibly harsh environment with relatively low impact. Thus, I will restrict this commentary to the 7 uninhabited islands of the 8 total Phoenix Islands. So, living ghosts is my final category.

There are both marine and terrestrial living ghosts. In the marine realm, the abundance of small (and deficit of large) sharks is a living reminder of the shark finning that has occurred on these islands. Baby sharks are an encouraging sign, but they are also living ghosts of fishing past. Since PIPA is now protected with strong enforcement via satellites, on-board government agents, and regular boat patrols, hopefully there will be no over-fishing future.


Baby black-tip shark (photo: Jim Stringer)

However, we see living ghosts in the corals, too--large stands of dead coral rubble reflect the major bleaching event a few years ago (see previous posts by David for more on this), and the geological record of global change will be forever preserved in coral skeletons.


Contrasts between live versus dead coral (photos: Jim Stringer)

In the terrestrial realm, there are living ghosts as well. Rabbits and rats are not native to these islands, but we can see evidence of these (and other) small mammals that were introduced by man. As Greg posted earlier, rat eradication projects have been going very well, which has enhanced the nesting and reproductive success of native birds. But rodents are tough to remove, and their presence (decades after introduction) is a strong reminder of the fragility of these islands, and the long lasting impact of careless (or unfortunately-shipwrecked) rat-infested boats. Though the vegetation on these islands is beautiful, it is worth mentioning that some trees and plants are themselves living ghosts of human impact. Used by humans to provide sustenance, coconut trees would not likely have found their way to the Phoenix Islands without being directly planted. So too with other plants, I'm sure, but I didn't spend enough time exploring the land to see for myself (I was mostly underwater). But the point remains--living ghosts still abound on the most remote, uninhabited islands of the earth.

As we approach the Halloween season and ghosts and goblins abound, take a few minutes to consider the ghosts around you--remnants of society and humanity that still influence the natural world long after they have been abandoned by humans. And with that, I leave you with this eerie thought: Boo!

-Randi-