Restoring Finger Coral

We’ve been very busy lately working on our coral restoration experiment, as well as several other projects. Time to finally talk about the coral restoration experiment, since I actually have photos of what we’re doing.

Bleached Pocillopora head surrounded by dead reef

Most of the patch reefs near Sand Island have very little to no coral cover, but we can tell that the rubble and dead coral used to be primarily Porites compressa, known as finger coral in Hawaii. As recently as the 1970s, people reported seeing large Porites compressa reefs there. We’re not sure exactly why these reefs have so little live coral, but it may be related to sewage outflows or dredging in that area. Reefs farther out in the center of the atoll, however, have huge stands of finger coral. The Papahanaumokuakea Marine National Monument, which manages all the Northwestern Hawaiian Islands, has prioritized restoring these degraded patch reefs near Sand Island.

Huge stand of of finger coral

My labmate Wendy Cover, who will be Dr. Cover within a year, designed and applied for funding and permits to conduct a coral restoration experiment which involves transplanting “fingers” of Porites compressa to these nearshore patch reefs. Wendy’s hypothesis is that Porites compressa would survive at these nearshore patch reefs, but they aren’t receiving recruitment (i.e., babies), so restoration by transplanting would be effective. 

First, we explored the nearshore patch reefs (“transplant sites”) and the patch reefs with Porites compressa (“source sites”) and selected transplant and source sites. Second, we cleared small areas of algae and labeled them with metal tags (which hopefully the fish won’t eat, unlike our plastic eartags!). Third, we collected fingers of Porites compressa at the source site, transported them in coolers to the transplant sites, and glued them down using epoxy. 

Now we’re going back to both transplant and source sites to take photos and measurements, survey for benthic cover (algae, coral, etc.) and urchins, and deploy coral recruitment tiles.

Wendy selects transplants

Wendy & Anne glue down transplants

Anne leaves today, so I'll have to make another post soon on the amazing dive we did yesterday and other things we've been observing, like coral bleaching of a few species and a spawning party of saddle wrasses!