Developing protocols for assessing the performance of Artificial Surfing Reefs- a new breed of coastal engineering

Artificial surfing reefs (ASRs) are a new breed of coastal engineering structures claimed to enhance local biodiversity, provide coastal protection and improve wave quality for surfing. By providing multiple functions, ASRs are often expected to contribute positively to the local economy, especially through tourism related to surfing and other water sports or beach uses. However, only few ASRs have been built worldwide and their performance is still debatable. At present, seven of these structures have been built worldwide, including one that has been uninstalled (California, USA) due to its poor performance and one that is unfinished due to increase in construction costs (Opunake, NZ). Unlike traditional coastal engineering structures (i.e. breakwaters and revetments), no regulations or protocols of good practice exist for the construction of ASRs. Due to the lack of independent studies and established monitoring protocols, relatively little is known about the impacts of ASRs on the coastal environment. Therefore, it is necessary to establish specific criteria to assess environmental and socio-economic impacts of ASRs, which can be used to objectively quantify their performance. Using the Boscombe reef as case study, this study suggests a set of criteria and methods that can form a protocol of good practice for the monitoring and performance assessment of ASRs. Implementation of protocols and regulations can provide information to support decision-making and inform stakeholders and end-users