Palau and El Niño

El Niño probably hit Palau harder than anywhere else except the Maldives. A little over a year ago Palau’s waters reached temperatures over 90° and held in these high ranges for several months. Apparently this killed most of the hard coral and the mushroom/leather coral. Some sites were hit harder than others; the coral at Peleliu is reportedly in better shape, probably because the strong, upwelling currents of cold ocean water protected it from El Niño.

Why did coral in Palau die, while elsewhere bleached coral is recovering? Above a certain temperature, hard corals lose the endo-symbiotic algae (zooxanthellae) they’re dependent upon, their external tissues become transparent, and their limestone skeletons show through. They can survive for a time as “bleached” coral, but if they’re unable to take up the algae again, the coral will die and leave only a hard, dead skeleton. Some of Palau’s beautiful skeletons are already beginning to crumble, although the remaining hard coral is making a comeback. Obviously, it’s a long process.

El Niño also took a toll on one of Palau’s most famous sites, Jellyfish Lake. The lake is no longer dived, since only the moon jellyfish appear to have survived the El Niño warming and the Mastigias species that were the main population have not returned. It is feared that none survived, although the Palauans hope the lake will recover and thus are not allowing it to be dived. The Mastigias species reportedly survived in other inland lakes, however, and it may be possible to transplant them and restock Jellyfish Lake.

Losing the hard coral and the jellyfish in Jellyfish Lake has been a hard blow for a destination that bills itself as “the best diving on earth,” but plenty of bright spots remain. The beautiful soft corals and fish populations, including the sharks, were not affected. As one well-traveled diver who just got back said, “the trip was absolutely worth the money. I’d recommend it in a heartbeat.”