Coral Relocation

Coral Relocation

To mitigate the loss of habitat at Gulhifalhu as a result of the reclamation works, Boskalis has engaged local coral relocation expert Reefscapers  to perform relocation of coral from Gulhifalhu to recipient sites. The relocation process started with an initial survey of the Gulhifalhu lagoon and reef to determine numbers and types of live coral colonies available for relocation. Based on the survey results, a selection was made of which areas to focus harvesting activities. On 29 May 2020, harvesting activities started.

Initial Survey

An initial marine survey was conducted by Reefscapers prior to the start of the project. During the survey, the coral reef health and numbers of colonies were assessed on the eastern side of the reef and lagoon. Both Reef Flat (in red) and Lagoon (in green) were surveyed to estimate the right number of live corals to be relocated.

Relocating Acroporae

The most representative coral species in the Maldives are from the Acropora family. Acroporae can have different shapes including branches, digitates or tables. Those corals are fragile and when relocated, and need to be attached to a hard substrate, such as for example Coral Frames. The Acropora species are being relocated into one of Reefscapers’ Coral Reef Restoration Project Sites and transplanted onto Reefscapers’ Coral Frames.

The Reefscapers team collected the Acropora corals in buckets by diving/snorkelling and later placed them into the hold a a dhoani designed for the grouper fishery. This provided work for the fishermen, while their fisheries are halted because of the COVID-19 related export ban. The dhoani hold allows for sea water to be constantly flowing to guarantee the best water quality, supply enough oxygen and to maintain a cool water temperature for the corals while they are being transported to the recipient site.

The corals were transplanted onto coral frames. The corals were to some extent fragmented in the process.

Relocating Massives

Other reef building corals species are growing into a shape called “massive”. Those massive corals are heavy blocks of mineral reaching about 0,5m³ to 1m³ or more. Smaller colonies were hauled on board the boat and carried in the Dhoani holds with water recirculation.

Reefscapers determined on-site which and how many corals were feasible to be relocated.

Relocated Corals

In total, 7,500 coral colonies were harvested from the Gulhifalhu lagoon and reefs. In addition, many coral fragments were also collected.

5000

Branching Coral Colonies

2500

Massive Coral Colonies

7500

Total Colonies Harvested