The red corals (Corallium rubrum) were seized by Catalan authorities in 2011. The corals are coveted, since they do not lose their red color when taken out of the water. In the past, the corals were described as red forests on the Mediterranean seabed, but poaching and exploitation have taken a heavy toll on the corals, which are important habitats for other species.
"May need a kickstart"
The researchers decided to give the illegally harvested corals a second chance, and planted 300 of them near the Medes Islands in northeastern Spain.
Often, it's best to let the reef recover naturally. But if it has gone too far, as here, then you may really need to kickstart it with a restoration and try to plant corals, says Fredrik Moberg, a doctor at the Stockholm Resilience Centre at Stockholm University, who specializes in coral reef ecology and was not involved in the study.
Subsequently, the researchers have followed the corals for ten years, an impressively long time, according to Moberg. It's ambitious to follow a reef for so long, but it's necessary to understand if the restoration works, according to him.
"There may be a risk"
The researchers looked at both how the corals grew and what characteristics they developed, and whether they attracted other species.
They did a fairly comprehensive control of the species composition before and after and compared it with a nearby reef, and saw that it recovered surprisingly well, says Moberg.
At the same time, he emphasizes that there may be a risk of being lulled into a false sense of security and believing that restoration will solve all coral reef problems.
But in the long run, it won't help much if water quality can't be secured and the warming of the oceans isn't slowed down, he says.
The study is published in Science Advances.
