‘Intensive care nursery’ for Hawaiian corals gets tender loving care in West Hawai‘i

Thought of an “intensive care” unit for Hawaiian corals, the ʻĀkoʻakoʻa Coral Restoration Nursery near the Ellison Onizuka Kona International Airport has been up and running since last spring. Now, the West Hawai‘i facility is the largest outdoor nursery of its type in the Pacific, according to an announcement from the Department of Land and Natural Resources.

A partnership between Arizona State University and the DLNR Division of Aquatic Resources, the nursery was built to support research and conservation management of the West Hawai‘i coastline.

Greg Asner, Ph.D, is the director for the ASU Center for Global Discovery and Conservation Science based on Hawai‘i Island. “Our facility is the outcome of years of research focused on the reef system of Hawai‘i Island,” Asner said. “It’s a large reef system, about 124 miles in length. So, it’s a very large nursery because our reef in West Hawai‘i is very large, so it’s scaled to support projects and interventions for West Hawai‘i’s reefs.

Most recently university, state and the Nature Conservancy teamed up to remove hundreds of intact corals from a decommissioned fish pen that was used offshore to farm kampachi.

At the nursery, Sydney Lewis, a Division of Aquatic Resources coral restoration technician, cleaned a tank (raceway) housing some of the rescued corals. There are 72 raceways in all, representing the number of culturally important watersheds (ahupuaʻa) in West Hawai‘i.

Many of the fish pen corals have already been returned to the ocean, near where they originally came from.

Lewis said: “Oh my gosh, it’s super exciting. These corals have so much structure, so many fish immediately come, and they’re like so excited. We were monitoring recently, there’s just fish sitting in the corals already, making it their home.”

The building and development of ʻĀkoʻakoʻa was informed by other coral nurseries around the world, like the Hawaiʻi Coral Restoration Nursery at the Aquatic Division’s Ānuenue Fisheries Research Center on O‘ahu.

In a building next to the outside raceways a large pumping system brings in warm ocean water from near the surface, as well as colder deep water, mixes them to achieve and duplicate the seasonal temperatures corals live in.

“Our highly automated system allows us to monitor in very minute detail the quality and temperature of the sea water,” Asner said. “This is December 2024, 78.8 degrees Fahrenheit is about the right temperature to simulate what’s happening on the reef from depths of 15 to 45 feet, which is where the bulk of our corals live in West Hawai‘i. It’s super important that we’re not creating another ecosystem on land, but one in which to rehabilitate corals to connect them back to the reef.”

Back outside, Zachary Craig, Aquatic Division’s Hawai‘i Island coral restoration coordinator, said: “I feel incredibly proud to be part of this organization and part of the coral restoration practitioners here in Hawai‘i. It’s an incredible time to get to work with these restoration scientists and to feel the passion that goes into each project and how they want to better the reefs.”