Airai

I watched the screen of the GPS eagerly as we drew closer. 100 m, then 50 m. I scanned the coast around me - it looked familiar. 40 m, then 30 m. The bow of the boat bounced in the waves, and I did my best to brace against the motion. 20 m. I asked Matthew to prepare the anchor. 10 m. 9 m. 8 m. We were within the resolution of the GPS for a moving boat, so I gave the order to cut the engines and drop the anchor. We were here. 

"Here" is a rather random spot on the eastern side of Palau. It feels just like the middle of nowhere - you're not in the bay or on the barrier reef. The water transitions from calm coastal water to wave-driven offshore water, but you're not really in either water mass. It's just this random spot where the seafloor gets a little shallower. We come here because a previous research team from WHOI sampled here in 2015. 

A baby coral at Airai (person's fingers for scale)

I wanted to use the site, Airai, for our transplant experiment, but when Kharis and I came to check out the site last November, all the corals were dead. We couldn't use the site for our transplant experiment because there were no living corals to collect. We settled on a different site, Ngerur, for the experiment, but I still wanted to track the recovery of the coral community at Airai. 

Disturbance is a fact of life. Every once in a while, there will be fires or droughts or floods or volcanic eruptions that disturb ecosystems. For corals, disturbance usually takes the form of heat waves or typhoons. Both can completely decimate a community. I'm not sure what the disturbance was for Airai (maybe Typhoon Surigae in April 2021?), but what's interesting to me is the recovery process. When a coral community recovers from disturbance, does it come back the same as it was, or do different species dominate? 

A baby branching coral (I think Pocillopora sp.) at Airai

I was actually really impressed at how many corals there were at Airai. I remember there were a few little babies on the limestone last November, but this time, we found all sorts of corals. Mounding corals, branching corals, big polyps, small polyps, even a nudibranch and a giant anemone! The coral cover was still pretty low - it was mostly limestone with a coral living here and there, rather than a field of corals, like most places in Palau - but it was definitely more than I expected. 

We spent about an hour swimming around the reef with cameras, hunting for the smallest corals we could find. Part of my strategy this trip is to sample baby corals where they're at - living on bits of limestone throughout the reef. My camera's macro lens has proved extremely useful, and we collected a lot of good data. Back in the lab, we'll use the photos to identify all of the species recruiting at Airai. Then we'll compare what we found to previous data collected by the WHOI team in 2015 to see if the species recruiting now are the same species that dominated the site before the disturbance. 

I was extremely pleased to see that the coral community at Airai is coming back. It was a fun and encouraging day of data collection!