Healthy Oceans Technology Innovation Challenge: Restoring and protecting coral reefs using an innovative and low-cost solution

The Philippines’ coral reef area is the second largest in Southeast Asia, with over 500 species of corals supporting marine life. The coral reefs face various threats, both human-induced (mainly destructive fishing practices) and natural (including climate change and typhoons).  The degradation of coral reefs threatens biodiversity, food security, and livelihoods.

 Out of 34 teams, Kajima Corporation (Kajima) was selected under the “Restore and Protect Coral Reefs” category of ADB’s “Healthy Oceans Technology Innovation Challenge” in 2020.

Kajima’s solution was the integrated approach for coral reef conservation and rehabilitation (InCORE), which it implemented in collaboration with its partners. The comprehensive solution included Also activities such as remote sensing for environmental assessment, using numerical simulation technology to develop an integrated ecosystem model, awareness raising, capacity building of local stakeholders, and developing a watershed management plan.

An integral part of Kajima’s offered solution was the installation of Coral Net, the trademarked technology of Kajima Corporation. Coral Net is an innovative and low-cost solution that enables more stable rehabilitation than conventional coral transplantation methods. It uses a stainless steel plate raised above the seabed, on a rebar foundation to protect coral juveniles and fragments from threats and hazards such as sediment accumulation. The technological innovation is coupled with ‘back-casting’, or the overlaying of historical data from multiple sources to inform site selection. The effectiveness of Coral Net in promoting coral restoration was already tested and proven in Okinawa, Japan.

A three-phase approach was used in this initiative. Environmental assessment through field surveys, remote sensing, environmental measurements, and numerical simulation technology was done in the first phase. The research team collaborated with the local government of Tangalan and Aklan State University to get information on the historical and current situation of the coral reefs around the municipality. The research team determined that the stainless steel version of the Coral Net would be best suited for the identified installation sites given the environmental conditions. Samples were subsequently installed with the assistance of local divers and researchers. The results were presented by the research team to the local government of Tangalan in July 2023.

The second phase focused on coral rehabilitation. Two installations of the Coral Net were performed in 2023. Besides installing Coral Net, this phase also saw the implementation of a passive intervention that involved the reduction of anthropogenic stressors such as water pollution.  

The third phase was monitoring and evaluation. The research team also collaborated with the local government to continuously monitor the sites where Coral Net was installed.  

The demonstration sites where Coral Net was installed showed coral growth. If sustained, this can support sustainable fishery and tourism in Tangalan. The initiative also covered the development and management of a coastal habitats database.

The closing seminar took place in July 2024, which served as the avenue for Kajima Corporation to present the results of the initiative, as well as share recommendations to local stakeholders on coral reef conservation and restoration. Kajima Corporation also took the opportunity to request a no-cost extension until January 2025 to continue monitoring whether Coral Net was able to increase the survival potential of the recruited coral larvae in the study sites. The extension, which was granted, was also expected to cover the verification of the accuracy of the environmental simulation models that were developed to determine the effectiveness of the coral rehabilitation initiatives.   

The local government of Tangalan committed to prepare a municipal ordinance declaring the demonstration sites as marine protected areas. In addition, the local stakeholders pledged to continue monitoring the sites to sustain the coral conservation efforts started by the initiative. Local governments near Tangalan also expressed interest in Coral Net because of the results of the initiative.