Palau’s Reefs: Journey from Destruction to Recovery

Photo: scientist conducting benthic surveys of coral reef in Palau
Scientist conducting benthic surveys of a coral reef in Palau

Written by Alison Barrat and Andy Bruckner

On a scientific expedition to Palau this January we saw thriving coral reefs that contained many species of large, healthy corals, and only a few miles away we found desolate looking reefs that had virtually no coral at all.

Our science team recorded conditions that were optimal for coral growth; clear aquamarine waters, no sedimentation and limited nutrients, typical water temperatures, and a gentle reef slope covered in crustose coralline algae – all conditions that are about as good as it gets for coral.

Overturned colony of Porites lobata following typhoon Bopha

But the Republic of Palau lies just outside of the northern Pacific typhoon belt. Normally tropical storms bypass the islands. However, in December 2012 Super Typhoon Bopha battered Palau. Although the eye of the storm was over 50 miles to the south storm waves of 35 feet or more pummeled the eastern barrier reef system. Once vibrant reefs were turned into fields of rubble as storm waves shattered fragile branching acroporids and overturned immense (2 m) massive boulders of Porites. In places underwater it was as if the reef surface had been scoured clean.

This gave our research team a chance to explore the transformation of a coral reef from bare ground to a mature ecosystem, which scientists call a climax community. After an event that wipes the slate clean a reef begins to recover, but repopulating a reef is not a single event. Algae, corals and other invertebrates arrive and take root, over the years some species flourish while others get replaced. Scientists have a name for this too, it’s called ecological succession. It has been well studied on land following events like a forest fire but underwater it’s —> Read More