Coastal processes within a coral reef lagoon, Erakor, Vanuatu

Coral reef processes

No data monitoring was done in Erakor Lagoon on Efate, in Vanuatu, to assess current and future risks to the coral reefs. We have led a month data collection in Erakor to improve our knowledge of coastal processes in this area and of wave transformation over the reef.

We wrote a paper on a month of intensive data collection campaign within a Coral reef lagoon in Efate Island to improve knowledge of the local coastal processes, increase the capacity building and better understand the reef environments, especially wave transformations.

While processes on sandy beaches are widely studied, processes in reef environments are still not fully understood and more data and analyses are needed to fill this gap. The increased knowledge will increase capacity building in small islands in the South Pacific surrounded by a reef. This paper was published in the Journal of Coastal Research and presented online at the International Coastal symposium bringing together scientific and academia from all over the world to collaborate and discuss the most current coastal research studies and projects.

Much of the Pacific SIDSSIDS Small Island Developing States are a distinct group of 38 UN Member States and 20 Non-UN Members/Associate Members of United Nations regional commissions that face unique social, economic and environmental vulnerabilities. population reside within the coastal zone as does the majority of critical infrastructure where resilience is challenged by exposure to natural hazards including inundation and erosion and impacts from cyclones and tsunamis. During extreme events, wave energy is a significant damage vector whose impact on populations and infrastructure is mediated by the presence and structural characteristics of adjacent coral reefs. Data are needed to validate the accuracy of the model developed.

The approach is based on using field data to calibrate a numerical model of coastal processes. A wave buoy spotter and five pressure sensors (RBR duets) were deployed to measure wave dissipation over the Erakor lagoon’s reef and current meters used in the lagoon to measure circulation and residential time. Data processing shows the importance of the reef geomorphology and water levels on wave dissipation. Cross-shore and alongshore wave variations were shown to be highly dependent on reef geomorphologies. The width and the slope of the reef were found really important in the wave dissipation. During the average wave conditions, the reef flat in Erakor dissipates up to 88% of the wave energy from the reef crest.

The information from this assessment could help inform coastal adaptation planning in response to climate change and rising sea levels.

Citizen science in action

Above: Citizen science in action. Collecting coral reef data in Erakor Lagoon on Efate.


Faivre, G., da Silva, G. V., Aimbie, J., Ware, D., Tomlinson, R., Mackey, B., & Zhang, H. (2020). Coastal processes within a coral reef lagoon system: Erakor lagoon, Efate Island, Vanuatu. Journal of Coastal Research, 95(SI), 1427-1432.

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