- After a series of natural and man-made disasters in the 1980s and 1990s, Jamaica lost 85% of its once-bountiful coral reefs. Meanwhile, fish catches declined to a sixth of what they had been in the 1950s, pushing families that depend on seafood closer to poverty. Many scientists thought that most of Jamaica’s coral reef had been permanently replaced by seaweed, like jungle overtaking a ruined cathedral.
But today, the corals and tropical fish are slowly reappearing, thanks in part to a series of careful interventions.
The delicate labor of the coral gardener is only one part of restoring a reef — and for all its intricacy, it’s actually the most straightforward part. Convincing lifelong fishermen to curtail when and where they fish and controlling the surging waste dumped into the ocean are trickier endeavors.
Still, slowly, the comeback effort is gaining momentum.
Growing corals can be big business, the cool looking ones can be highly valued for people’s fish tanks and harvesting is very sustainable if done correctly. If ocean acidification accelerates though it won’t matter, most corals are very sensitive to ph and water temperature. If the water gets too acidic or too hot most will die out and in general low ph significantly reduces growth.
Sending electrical current through growth frames can cause them to grow/regenerate even in very harsh conditions, though I don't know the exact extent of wishful thinking behind biorock building. To my knowledge, the more pressing problem behind coral's sensitivity to external conditions is algae bleaching, which impacts everything from sand production for nearby coasts, to biodiversity and biomatter production in the area.
Sounds like you are referring to this article. Which btw was a fascinating read http://www.globalcoral.org/_oldgcra/reef_restoration_using_seawater.htm