Scientists say they can grow coral in anursery to help replenish the reefs

A rare species of Hawaiian coral being used to create a seed bank grows in a tank at the Anuenue Fisheries Research

Center’s coral nursery in Honolulu, Hawaii, Feb. 11, 2016. Photo: AP/Caleb Jones

HONOLULU, Hawaii — Much of the coral in the waters around Hawaii is unique. It is unlike

any other coral in the world because it grows so slowly. Its slow growth makes replacing

Hawaii's coral reefs difficult when the reefs become sick.

Corals are sea animals that stay in one place throughout their adult lives. Some types

create a skeleton that stays in place after they die. The skeleton is also called coral. A reef

is a mound of living coral, coral skeletons and mineral deposits from other living creatures.

Most coral reefs form in warm, shallow sea waters close to the surface.

Hospital For Native Corals

Scientists in Hawaii have come up with a plan to grow large chunks of coral. It will take a

much shorter time than it would normally. They hope to create a stock of coral to build up

damaged or unhealthy reefs in the future.

Biologist David Gulko manages Hawaii's Coral Restoration Nursery. It is part coral hospital

and part seed bank for storing samples of Hawaii’s native corals.

By Associated Press, adapted by Newsela staff on 02.22.16

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Gulko says that Hawaii's coral grows only about 1 centimeter per year. The more common

species of coral around the world grows up to 30 centimeters a year. Those species are

found mostly in warmer waters closer to the equator.

He says that the way Hawaii's coral grows makes it difficult to have a traditional

replacement program. The coral are usually housed in natural settings while they are

grown. Therefore, it would take many years to make large enough coral pieces to rebuild

reefs.

"The larger the coral, the more space it provides for fish and invertebrates and all the

things that are important," Gulko says. Invertebrates are creatures without a backbone

such as corals, insects, worms, jellyfish, starfish and snails. "You can't replace a hundred-

year-old coral in less than 100 years — until now with what we're doing," he says.

Growing Coral Step By Careful Step

With the process that they are using, Gulko says they will have a volleyball-sized chunk of

coral in about one year. The coral will grow in a fraction of the time it would take to grow

naturally. "Bigger coral is much more important," he says. "If a coral this size is important to

keep the shoreline from eroding, it can't wait 100 years."

The nursery grows coral quickly by using harbor coral that is not part of the natural reef. It

does this so the natural coral ecosystem, including the fish and creatures near the coral,

are not harmed. The coral is then kept separate to ensure it is healthy and has no other

sea creatures living on it. Next, it is chopped up into tiny portions because smaller portions

grow faster. Those small pieces of healthy coral are then grown in specially designed

tanks.

When scientists first begin growing the coral, they are put in artificial seawater that is

watched closely to keep it healthy. They carefully expose the coral to light. Scientists make

sure that it is the same as it would be at the depth of the ocean where the coral is found.

Minerals are also provided to help it grow quickly.

After the coral has been in that setting for long enough, it is moved into a natural seawater

tank. It is still controlled, but grows in closer to its natural conditions. Once grown, the coral

chunks are fused back together to make a single large portion of coral. Then the large

chunk can be transplanted back onto a natural ocean reef.

"We Manipulate Our Ecosystems"

Zac Forsman is a coral-recovery scientist. He has helped to develop this

process. Forsman says more research needs to be done to find the best combination of

conditions to help the coral to grow as fast as possible.

"Human beings, we manipulate our ecosystems. We've done it with forests, we've done it

with planting trees. We've done it with farms and greenhouses. With the oceans we haven't

done any of that," Forsman says. "It's all been just kind of decline. We've impacted it

negatively, but we haven't really tried to go the other way."

Bruce Anderson runs Hawaii's Division of Aquatic Resources. He says the building is

unique. Scientists can actually use the research done there to maintain and manage their

reefs.

"We're not growing enough coral here to make a huge difference immediately," Anderson

says. However, he hopes the project will help them to better understand what it takes for

coral to grow faster. The findings should help more reefs in the future.

Hawaii's Division of Aquatic Resources also keeps several rare coral tanks. The team is

using them to create a seed bank to store threatened species. Gulko says the seed tanks

make sure those species will not be lost forever.