An island is not an island is not an island
Saturday | August 20, 2005
Over the last two days of diving Palmyra has shown us once again the dual nature of islands. We have been both mesmerized and depressed. On one hand, the absence of fishing works miracles for fishes. On the other hand, corals cannot escape from global threats such as global warming, regardless of how remote Palmyra is.
The last two days of diving have been in places where sharks came to the surface to check us out even before we jumped in the water; where countless large snappers swam around us and made fish counting almost impractical; where jacks swam towards us and then disappeared like blue lightning; and where green parrotfish with large bumps on their heads bit coral rock as though it was butter. We dived in places where the biomass of top predators, that is, sharks and large fishes that feed on other fishes, is much greater than the biomass of their prey. To date, such apparent impossibility has only been described in a couple of coral reefs, including the Northwest Hawaiian archipelago, which is, like Palmyra, another large protected area. With regard to fishes, Palmyra is what we had been dreaming about: a place of sea monsters, a reef where predators rule.
The coral reefs of Palmyra have a great deal of vertical relief, with staghorn corals forming towers aiming at the surface and table coral terraces. Palmyra�s reefs are a limestone garden. Unfortunately, the garden is only a skeleton of what used to be there. Most corals bleached and died because of unusually high water temperatures in 1997-98. What remains is coral skeletons or coral rubble. However, not all places were equally affected by that warming event. In some places on the eastern side of the atoll corals still thrive. The good news is that where corals were most affected we can see a new generation of corals recolonizing the reef. Will they be able to replenish the reefs before the next warmer-than-usual year? Or is Palmyra condemned to a succession of failed recolonization attempts between warm years? We do not know.
Is Palmyra pristine? It certainly was as pristine as it gets not so long ago. However, presently Palmyra suffers from the globalization of human activities. Global warming is one of the most threatening human-related impacts, and no island, protected or not, can escape its reach. In our present world of planet-wide human footprint, an island is not an island anymore.