Hong Kong Reef Check 2023 displays promising coral health and diversity


3rd December 2023 – (Hong Kong) The Agriculture, Fisheries and Conservation Department (AFCD) of Hong Kong revealed the encouraging results of the Hong Kong Reef Check 2023 today. The study concluded that the local region’s corals are generally healthy, and the species diversity continues to be robust.

The five-month-long Hong Kong Reef Check 2023, initiated this June, encompassed a variety of locations, many of which hold significant ecological value. It also included the most prolific coral sites in the eastern part of Hong Kong waters, extending from Tung Ping Chau in the north to the Ninepin Group in the south. The survey comprised 33 sites, with nine of these located within marine parks, including Hoi Ha Wan Marine Park, Yan Chau Tong Marine Park, and Tung Ping Chau Marine Park.

The study recorded a diverse range of coral coverage across the survey sites, with percentages varying from 12.8% to an impressive 74.3%. Ten of the sites surveyed showcased more than half of their area covered by coral, including five sites within marine parks. A Ma Wan of Tung Ping Chau stood out with the highest coral coverage of 74.3%.

Despite the overall promising results, the AFCD did note instances of coral bleaching at six survey sites during the summer, including Kai Kung Tau of Kat O and Coral Beach of Hoi Ha Wan. The bleaching, however, was minor and localised, possibly resulting from elevated water temperatures during the season.

The Reef Check also included volunteer dive teams assessing the condition of corals at 10 sites using the Coral Watch tool. This tool, which measures the colour intensity of the coral with a specially designed Coral Health Monitoring Chart, helps determine the health condition of corals. The average health index of the sites was 4.28, slightly better than last year’s figure of 4.06 and well above the general average value of 3, indicating that the corals are generally in a healthy condition.

The survey method and data collection of the Hong Kong Reef Check adhere to international standards. Reef Check divers recorded coral coverage and health status as well as other indicator species, including 20 species of fish and invertebrates. These indicator species, which include butterfly fish, groupers, and sea urchins, were found in abundance and suggest a high species diversity across the majority of the survey sites.

The AFCD reported no signs of destructive fishing practices at any of the surveyed sites. While abandoned nets were discovered at eight sites, their impact was deemed to be minor. The AFCD will arrange for a contractor to remove these nets.

The Hong Kong Reef Check is part of a global endeavour to encourage the sustainable management of coral reefs. It aims to raise public awareness about the ecological importance of corals and the need for their conservation. The first Reef Check was held in 1997 by the Hong Kong Reef Check Foundation, and since 2000, the AFCD has collaborated with the Foundation to conduct the survey. This year’s Reef Check saw the participation of 103 dive teams and over 1,150 volunteer divers, marking a dramatic increase from the inaugural event.