Active Coral Restoration to Preserve the Biodiversity of a Highly Impacted Reef in the Maldives

Abstract

Maldivian coral reefs have been experiencing significant degradation due to a combination of global climate change and local anthropogenic pressures. To enforce the conservation of coral reefs worldwide, coral restoration is becoming a popular tool to restore ecosystems actively. In the Maldives, restoration interventions are performed only around touristic islands, where there are economic resources available to support these projects. Unfortunately, on local islands, coral restoration does not benefit from the same support and is rarely boosted. A challenging coral restoration experiment has been performed, for the first time, on a local island of the Maldives affected by intense human pressures that caused the degradation of its reefs. A total of 242 coral fragments were collected from impacted colonies and transferred to the coral nursery of the island. Survival and growth rates of the fragments were monitored for 12 months. After one year, a survival rate of 70% was recorded. Although this rate might appear lower when compared to other restoration experiences, it is very promising considering the origin of the fragments and the poor quality of the environment where they have been transplanted. Some potential threats to the success of this restoration have also been identified, i.e., water temperature anomaly, diseases, and parasites, the latter being the leading causes of coral mortality. The procedure presented here is less expensive compared to the typical relocation of entire coral colonies from donor-healthy reefs to degraded reefs, thus providing an opportunity and a viable option for local islands to restore their reefs and preserve local biodiversity.