Remote sensing of coral reef and Coral Reef bleaching in the South China Sea

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1 Remote sensing of coral reef and Coral Reef bleaching in the South China Sea (Lingzis) 唐丹玲 (Tang Dynasty of China) Research Center of Remote Sensing of Marine Ecology/Environment (REMEE) South China Sea Institute of Oceanology, Chinese Academy of Sciences China

2 Study Area - Asian Waters Goa Indian ocean China Scsio, Guangzhou South China Sea

3 Wenchuan earthquake of 12 May 2008 The formation of Barrier Lake in Beichuan County A, 14 May 2006 B, 14 May 2008 C, 19 May 2008 Formosat-2 images From NSPO/NASA

4 Tang et al., JGR, MEPS, JGR, JGR Tang et al., MEPS

5 科学研究 Lab Remote Sensing In situ 交叉学科 Remote sensin Temperature, Ocean color, sea high, wind, current Primary production Phytoplankton bloom Harmful algal blooms Biology Nutrient, temperature, light. Monsoon, typhoon, tsunami, upwelling, sand storm, Ocean Environmental changes Responses and management Environment

6 Contents coral reef and Coral Reef bleaching 1 Introduction 2 Research methods 3 Results and discussions 4 Conclusions

7 Study area South China Sea Distribution of reefs in the South China Sea Zhongye Reefs Atoll reefs in the SCS is divided into four parts Jiuzhang Reefs Xijiao Reefs BaijiaoReefs

8 Remote sensing of coral reefs in the SCS Zhongye Reefs Nansha Reefs Landsat7 ETM + images Jiuzhang Reefs Jiuzhang Reefs Xiaojiao Reefs Baijiao Reefs

9 Coral reef bleaching Coral reef bleaching has attracted broad attention in recent years. There is a closest relationship between high sea surface temperature (SST) and coral reef bleaching.

10 NOAA/NESDIS developed the methodology of monitoring coral reef bleaching based on AVHRR Methods Coral Bleaching HotSpots: HotSpots = SST_analysis - SST_interpolated_MMM SST_analysis: the 50km nighttime only SST analysis SST_interpolated_MMM: the interpolated SST Maximum Monthly Climatology with 50 km resolution. It s interpolated from the Satelliteonly SST Maximum Monthly Climatology with 36 km resolution. Degree Heating Weeks (DHW): DHWs represent the accumulation of thermal stress that coral reefs have experienced over the past 12 weeks. The half-week approach is based on the data of the twice-a-week nature of the coral, the DHWs are accumulated based on half-weekly HotSpot data DHWs = Sum (over the last 12 weeks) 0.5* half-weekly HotSpot (HotSpot > 1.0 )

11 Satellite Bleaching Alert System: NOAA's Coral Reef Watch (CRW) Satellite Bleaching Alert (SBA) system was developed by the NOAA CRW satellite team as a tool for coral reef managers, scientists and other interested people. The SBA became operational in July 2005.

12 Results & discussions: HotSpot in the SCS in 1998 The HotSpot value in July is usually higher than 0.5( ) in 1998, the intensity of HotSpot is higher in August than in July. In the first ten days of September, the area with HotSpot above 1 ( ) was still large in the SCS, and it kept between 0.25~1.0( ) in the middle ten days, decreased to below 1( ) in October.

13 Results and discussions DHW analysis in the SCS in 1998 DHWs represent the dangerous degree of the coral reefs caused by high thermal stress. The images show that in Dongsha and Zhongsha the biggest DHW value reached 16 (DHW) from July to September, in Xisha and Nansha was 9 from August to October. The coral reefs in Dongsha and Zhongsha were in worse condition than in Xisha and Nansha. DHW value decreased in the four coral reef zones from September to November, in Dongsha it decreased to 4-5(DHW), Xisha 4-7 (DHW), Zhongsha 4-7(DHW) and Nansha 3-7 (DHW).

14 Results and discussions Coral bleaching in the SCS in 1998 According to the HotSpot and DHW of the four coral reef areas in the SCS, we summarized the bleaching alert status from July to September in Nearly all coral reefs in SCS are threatened by bleaching, in different levels.

15 Conclusions With the trend of Global Climate Warming, global coral reefs are in danger of mass bleaching or even mortality. predicting of coral bleaching and protecting of coral reef are very important. From July to September in 1998 in the SCS, four main parts of coral reefs, i.e. Dongsha, Xisha, Zhongsha and Nansha, were all impacted by elevated SST and presented potential bleaching. It is urgent for us to pay attention to coral reef bleaching in SCS and to take plans to protect coral reefs in this area.

16 Land use Cultural and Religious Invasive Species Wind Land Cover Agriculture Changes in Climate Marine Ecology drivers tourism Drivers Habitat Loss Ecosystem HAB Tang DanLing 唐丹玲 Hazard Eutrophication Pollution

17 第 9 届全球海洋全球海洋遥感大感大会 Tang DanLing 唐丹玲 The 9th Pan Ocean Remote Sensing Conference

18 Tang DanLing 唐丹玲 唐丹玲 ( 玲子 ) Welcome to

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