A review of mitigation measures for corals in designated projects in Hong Kong EIA ordinance

Abstract

As one of the most biodiverse ecosystem on the earth, corals supply a lot of valuable biological goods and ecosystem services, yet such sensitive receivers may suffer from sub-lethal or lethal damages caused by direct or indirect impacts arising from coastal or marine development projects. In Hong Kong, a number of mitigations specific to corals have been proposed and implemented under Hong Kong’s EIA Ordinance. However, as no academic review of these mitigations has been done in Hong Kong, we have no idea about the effectiveness of such measures. The primary purpose of this study is to evaluate the adequacy and effectiveness of mitigation measures implemented on corals and to explore how it can be enhanced and strengthened. To achieve this, firstly, all EIA reports approved by the authority were screened for designated projects with significant impacts on corals. These EIA reports were then reviewed so as to gather the necessary information about the predicted impacts and the proposed mitigation measures on corals. Secondly, specific monitoring requirements for the mitigation measures were identified in the corresponding environmental monitoring and audit (EM&A) manuals. Thirdly, the corresponding EM&A reports were studied in order to examine the effectiveness of implemented mitigations. Fourthly, the current mitigation-related procedures/approaches are discussed, compared with those adopted in the international world and recommendations were made for better mitigations in future. Fourteen designated projects are comprehensively reviewed and analysed as they are considered of having significant impacts on corals. Based on the reviewed results, the overall effectiveness of mitigation measures is about 29%, which seems to be unsatisfactory because 10 of the 14 projects lacked various components in the mitigation process. Discussions of the advantages and disadvantages of the relevant procedures or approaches are made: (a) assessment methods can be improved by providing more description of coral health status other than bleaching; (b) measurable indicators or specifically objective standards should be added to either ecological evaluation or impact assessment; (c) coral transplantations should pay attention to coral reattachments and regular maintenance; (d) post-translocation monitoring need to be enhanced with respect to control indicators, monitoring frequency and duration; (e) the Action and Limit Levels for both non-biological and biological indicators need to be further explored through the implementation of site-specific environmental assessments; (f) transparency of the current EIA system should be reviewed and strengthened. The study demonstrates the low effectiveness of mitigation measures for corals in terms of the mitigation process and mitigation-related methods in Hong Kong. The recommendations for the enhancement include (a) developing a database for tracking the entire mitigation process; (b) showing the on-line EM&A reports in an ordered and appropriate way ; (c) evaluating the long-term effects of the existing mitigations; (d) drawing lessons from other countries’ active restorations; (e) establishing a sustainable financing mechanism for long term coral management.