Transplanting corals a maturing technology

It turns out corals can be transplanted, just like garden plants.

(Image: The latest major coral transplanting effort in Hawai'i followed the grounding off Honolulu Harbor of the USS Port Royal in February 2009. Credit: Navy.)

This is a little of an open secret. Aquarium aficionados have known for a long time that they could crowbar a chunk of live coral from the wild and grow it in their salt-water containers.

But increasingly, the trend is going the other way. And it's a major conservation story.

Florida students a couple of years ago were able to grow threatened staghorn corals in captivity and transplant them into the wild.

Those corals are still doing well.

Early coral transplanting research was done at ship grounding sites in the Florida keys. And some of the seminal work in this field has been done in Hawai'i.

In the mid-90s, when a new small boat harbor threatened to destroy corals at Kawaihae on the Big Island, a project led by Paul Jokiel rescued some of those corals and transplanted them to 10 other locations. They survived well.

When coral growth threatened to interfere with marine traffic in the boat channel leading to Coconut Island in Kane'ohe Bay, rice and finger corals were transplanted out of the boat channel leading, and successfully transplanted to locations nearby.

By 2003 it was an established enough technique that the U.S. Fish and Wildlife Service was developing a system to require coral transplanting as a means of dealing with damage to the environment.

The technology is pretty basic. It involves glue and wire to stabilize transplanted coral heads into their new locations and simply letting them grow. Sometimes the glue is hydraulic cement and sometimes the wire is plastic, and occasionally some bolts and screws are involved, but the theory is elegantly simple.

Like transplanting a koa tree in a forest: stick it in an appropriate location where it ought to do well, make sure it's secure, and watch it grow.

When the Cape Flattery went aground off Barbers Point in 2005, teams quickly began collecting the busted corals before they had rolled around so much their coral colonies were killed, and began sticking back to the ocean floor.

And when the Navy warship USS Port Royal went aground off Honolulu in February this year, crushing a large field of corals off Honolulu Airport, it took a little while to get started, but the concept was the same. Thousands of corals were reattached to the substrate before the first big south swell came in to halt work.

It would seem that an issue now is to shorten the time before restoration starts. When there's a ship grounding or other coral damage incident, the coral restoration teams ought to be on site and working the moment it's safe to do so.

The reason for quick action is simple. Ships ground in shallow water, where there are both corals and waves. Broken corals rolled around in the surf for a few days are quickly converted from living colonies into chunks of dead, white rock.

© Jan TenBruggencate 2009