A new dive survey was recently conducted at the dredge site to get a better idea of the conditions and produce recommendations for optimal coral regrowth. The current approximate rehabilitation area to date is 7,139 square meters — much smaller than original projections — and the whole rehabilitation area is suitable for coral regrowth and would easily support artificial reef structures and large rock boulder piles, which are the proposed methods to be used for the re-propagation. As part of the efforts to mitigate any potential long-term risks to the environment, RMIPA continues to work closely with the RMI EPA on the coral reef rehabilitation project that has been underway since last year, to replant existing corals that are being affected by the dredging.
The replanting project has been underway since the beginning of the year, as new corals have been growing in cages in the lagoon at a previous dredge site alongside the road near the airport fire station. After the dredging work is completed for the RSA project, this coral will be relocated back to that site and used to repopulate the area, leaving the coral there strong and healthy. According to EPA’s coral expert, contracted to spearhead the current regrowth efforts, the new coral in the lagoon are growing even better than expected and should experience similar success at the RSA dredge site, once transplanted back again.
These photos taken December 2013 show the progress of the coral replanting near the airport fire station.
Coral fragmenting and attachment of coral plugs will begin soon as part of the next phase of the project, which will be in preparation for replanting onto boulders and marine-friendly concrete structures that are to be placed in the RSA dredging area. The concrete structures are designed artificial reefs used to restore coral reefs and to create new fishing and scuba diving sites.
The coral pieces growing onto the plugs at the farm site will be attached onto the structures at the dredging location when the dredging work is finished. Thereafter, the attached coral will be monitored regularly by local divers to ensure the corals are growing properly.
It was previously proposed that proprietary “reef ball” structures be used for the planting at the RSA dredge site, but it has been determined that this strategy would be inadequate and cost prohibitive. Instead the construction contractor pro- posed a new solution which would not only be just as effective as the reef balls but would utilize local Marshallese manpower and resources, benefiting the project and the local economy.
Instead of the reef balls, a concrete “reef planter” derived from flower planter molds, will be used. These planters are bell shaped, concrete/alkali cement, pitted structures, weighing about 400 pounds each. They can be stacked to raise the height. The planters would be the same structure and material as the previously proposed reef balls, just lighter weight and a slightly different shape. They will be more economical and versatile than the reef balls. They are much lighter than the originally proposed reef balls, but the height and weight should not be an issue, as the structures can be stacked to be elevated above the silt and at 400 pounds, are more than heavy enough to be used in the depth of the dredge site, which is about 30 feet at its deepest.
Reef Planters at the RSA Dredge Site waiting to be placed under water.
RMI EPA has no objections to using the concrete reef planter structures in place of the reef balls and has expressed support for the use of local solutions and the cost-effective benefits they provide. As it has with every aspect of the coral replanting project, RMI EPA will work closely with the construction and dive teams to test the system. EPA has publicly expressed its desire to maintain the highest protection standards and has backed the alternative planter system, citing the potential future benefits these planters could have for other projects in the RMI.