Hong Kong Reef Check 2007 Results

Coral Coverage

Species Diversity

Change in Coral Coverage and Indicator Species

Other Observations

Coral Watch

Measures Taken by AFCD on Coral Conservation

Coral Coverage

• A variation in coral coverage (ranging from 19.4% to 72.5%) was recorded among 33 survey sites. The percentage of coral coverage for each survey site is shown in Figure 2.

• Out of 33 sites surveyed, 22 of them recorded high coral coverage (i.e. >=50%). These sites included A Ma Wan, A Ye Wan and Wong Ye Kwok of Tung Ping Chau, Kai Kung Tau and Tau Tun of Kat O, Lai Chi Wo, Au Yue Tsui, Wu Pai, South and West of Crescent Island, Tung Wan, Wong Chuk Kok Hoi, Port Island, Coral Beach, Gruff Head and the Public Pier of Hoi Ha Wan, Long Ke Wan, Tai She Wan, Shelter Island, East and North of Sharp Island and Bluff Island.

• Coral Beach at Hoi Ha Wan Marine Park is the site with the highest coral coverage (72.5%).

• Survey sites within Marine Parks (i.e. Hoi Ha Wan, Yan Chau Tong and Tung Ping Chau Marine Parks) recorded high coral coverage (i.e. >50%).

• Out of the 33 sites surveyed, corals at 14 sites were identified up to genus level by the team scientists. This reflects the increases interest of team members on coral identification and the success of the technical training we offered.

 Species diversity

• 18 out of the total 20 assigned indicator species were recorded in the survey. Most of the survey sites recorded high species diversity.

• A correlation was observed between coral coverage and species diversity, indicating sites with high coral coverage tend to support more fauna groups in close association with corals.

• Out of the 18 assigned indicator species, wrasses, groupers, butterfly fish, sea urchins, sea cucumbers and cowries are species commonly found in the survey sites.

• Most of the groupers, sweetlips, snappers and wrasses were found in survey sites at Port Shelter and North-eastern waters including the three Marine Parks.

Change in Coral Coverage and Indicator Species

• Change of coral cover and indicator species were examined and compared. This helps to assess the coral condition and fauna diversity of a coral reef ecosystem over time.

• Sites of high coral cover and surveyed by the same dive teams in the past 2 years were selected for comparison. 12 sites were selected.

• The growth and condition of corals at the 12 selected sites are stable with some sites showing slight improvement. The change of coral cover in the past 2 years is shown in Figure 3.

• Long-term change of indicator species was examined. Results from past 7 years survey indicated that they are very stable and the species diversity remains on the high side.

Other Observations

• Corals at all 33 sites were in general healthy condition.

• No signs of destructive fishing practices were observed at all sites. However, we have recorded abandoned nets and some coral damages at about 5 sites. The impacts were minor.

• Coral bleaching was observed at 6 sites. The impacts were minor (in average less than 5% of coral colonies affected) and localised. It may be caused by the extended period of elevated water temperature during this summer.

• Marker buoys were installed at Ung Kong Wan, Port Island and Sharp Island since 2002 for coral protection. Monitoring results from Reef Check indicate that there has been an overall improvement in cover coverage of these 3 sites following installation of the marker buoys. This may have been related to the success of coral marker buoys and continued effort in education and publicity on coral conservation.

 Coral Watch

• The health condition of corals was assessed using specially designed Coral Health Monitoring Chart. The colour intensity of corals reflects the amount of the symbiotic algae (zooxanthellae) inside the corals, which in turn indicates the health status of the corals. The deeper the colour, the healthier is the corals.

• The Coral Health Monitoring Chart has four sample colours and 6 degrees of darkness (Code 1 to 6) for each sample colour representing different stage of coral health condition. Code 1 is the lightest and Code 6 has the darkest colour.

• Corals at 20 sites were assessed using Coral Watch tool in Reef Check 2007. The average health index is 4.16 (ranging from 3.33 to 4.93). The results are similar to last year (4.24) and both compared favourably than that in 2005 (3.85). The average health index is well above the general average value (3), indicating corals were in healthy and stable condition.

Measures taken by AFCD in coral conservation

• Coral reefs are highly productive systems, which support a high diversity of marine life. AFCD has put in place a series of measures and programmes to protect and conserve the coral communities in Hong Kong. Key areas include:

          (a)       Designation of marine protected areas

We have designated four Marine Parks and one Marine Reserve for the conservation of marine environment and protection of corals.

(b)        Education and publicity

We have organized a range of educational and publicity activities including public lectures, seminars and exhibitions to enhance public understanding of the importance of protecting the marine environment and coral communities. A new booklet "Marine Conservation in Hong Kong" was published in mid-2007 to introduce the beauty and diversity of the marine life in Hong Kong and the department's work on marine conservation.

As part of the celebrating items of the 10th anniversary of establishment of HKSAR, AFCD, in collaboration with Hong Kong Underwater Association and Ocean Park Hong Kong, organized a large-scale photo and video competition in 2006. It was very successful. We received more than 500 entries with one-third from students. This reflects the high interest of the youth in conserving our marine environment. With the winning entries, we organized a roving photo exhibiton in mid-2007 and production of a photo album showing the winning entries, diverse marine life in Hong Kong and work of AFCD in marine conservation and management. In view of the popularity and success of the exhibition, we are going to extend it to 3 more venues with the following details:-

Venus	Date
Sheung Wan Civic Centre	11 to 23 January 2008
Hong Kong Central Library	19 February to 4 March 2008
Hong Kong Culture Centre	30 May to 13 June 2008

 (c)       Monitoring and studies

We actively monitor the status of coral communities of Hong Kong through annual "Reef Check". Results of the Reef Check are publicised to raise public awareness of the current status of our marine environment and to seek their cooperation in protecting our precious marine resources.

In addition to Reef Check, we also undertake comprehensive coral studies to provide information for sound and adaptive management.

(d)        Reduce coral damage caused by boating and recreational activities

To protect coral communities from anchor damage, mooring and marker buoys have been installed in Marine Parks where recreation pressure is high.

Also, specially-designed marker buoys were installed at Sharp Island, Port Island and Ung Kong Wan for better protection of coral from anchor damages. Long-term monitoring results indicate that there has been an overall increase in live coral cover in the marker area and damaged corals had shown signs of recovery.

Leaflets and posters on "No-anchoring area" at Ung Kong Wan, Port Island and Sharp Island and stickers on "Codes for visiting coral areas" have been published and distributed to the boaters and divers through various channels.

(e)        Scientific database

We have updated the taxonomic records of stony corals in Hong Kong waters. Samples of all 84 stony corals were collected and a complete set of which is now housed at the Endangered Species Resources Centre of the department for public education and exhibition. A "Field Guide to Hard Corals of Hong Kong" was also published to document the diversity and unique features of our local corals.

To extend our knowledge on the distribution and diversity of other coral fauna in Hong Kong, we have commissioned Chinese University to undertake a study to update the records of octocorals and black corals within Hong Kong waters. Study findings would be useful for conservation and management of local corals.