Environment

Concrete pods promise faster reef restoration

Concrete pods promise faster r...
A diver with a batch of the seeding units
A diver with a batch of the seeding units
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A diver with a batch of the seeding units
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A diver with a batch of the seeding units
Some of the seeding units, ready to be installed on the reef
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Some of the seeding units, ready to be installed on the reef
A seeding unit with a coral growing close to its center
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A seeding unit with a coral growing close to its center
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Typically, when conservationists are trying to restore dead or dying coral reefs, they do so by manually fastening fragments of live coral to the existing reef. It's a painstaking and time-consuming process. Thanks to new technology developed by marine ecology group SECORE International, however, reef restoration may soon be as quick and easy as sowing seeds in a garden.

As part of a pilot project taking place in Curaçao, researchers started by collecting larvae released by colonies of golf ball corals (Favia fragum) at a local reef. In a lab, these larvae were then settled onto small tetrapod-shaped concrete structures. A few weeks later, after the settled larvae had developed into coral polyps on the concrete, the structures were introduced to the reef simply by hand-wedging them into existing crevices.

One year later, over half of the planted "seeding units" still had at least one coral growing on them. This number would likely be higher if algae growing on the structures' sunlit surfaces hadn't outcompeted the polyps. To that end, the scientists believe that they might have better luck with seeding units made from a less porous material such as glass or glazed ceramics.

Some of the seeding units, ready to be installed on the reef
Some of the seeding units, ready to be installed on the reef

According to SECORE, transplanting approximately 10,000 individual corals over one hectare of reef using traditional methods would take several hundred to a few thousand person-hours. By contrast, utilizing the new technology, the same task could reportedly be completed in under 50 hours. Before that can happen, however, the process needs to be scaled up.

"Until now, the number of substrates was limited as they were produced manually using moulds," says project leader, Dr. Dirk Petersen. "We are currently working together with our partners to implement industrial manufacture of the tetrapod substrates in large numbers at significantly lower costs. If we are able to combine our new sowing approach with more effective coral larvae rearing techniques, which we are developing right now, costs of reef restoration could become comparable to the costs of existing mangrove and salt marsh restoration efforts."

Source: SECORE International

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2 comments
David
What's the purpose of the plastic ties? Wouldn't biodegradable cotton string would be a more ecofriendly option?
Deres
Maybe using heavier structure with multiple polypes and launching them directly from the surface randomly would highly speed the process.