Journal of Tropical Oceanography ›› 2013, Vol. 32 ›› Issue (5): 79-84.doi: 10.11978/j.issn.1009-5470.2013.05.011cstr: 32234.14.j.issn.1009-5470.2013.05.011

• Marine Geology • Previous Articles     Next Articles

Variation of skeletal extension rate for Porites corals around Weizhou Island in response to global warming and increase of extreme events

CHEN Tian-ran1, ZHENG Zhao-yong2, MO Shao-hua3, ZHOU Xiong3, CHEN Te-gu1   

  1. 1. Key laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; 2. South China Sea Branch, State Oceanic Administration, Guangzhou 510300, China; 3. Beihai Marine Environmental Monitoring Center, State Oceanic Administration, Beihai 536000, China
  • Received:2012-05-21 Revised:2012-06-06 Online:2013-11-21 Published:2013-11-21

Abstract: Whether or not relatively higher latitude areas, say in the northern South China Sea, can become coral refuges under global warming is not clear, due to limited study cases. In this paper, we determined the skeletal extension rate of Poritescorals collected around Weizhou Island using X-ray photography. Using sea surface temperature (SST) data recorded at Weizhou Island, we calculated the degree heating weeks (DHW) and the positive and negative SST_anomalies ??(±SST anomalies), which revealed historical extreme high and low temperature events more clearly. We combined coral skeletal extension rate with the SST_anomalies and DHW and analyzed the variation of skeletal extension rate in response to global warming and increase of extreme events, and further explored the ‘refuge theory’ in the relatively higher latitude corals from the northern South China Sea. The Poritescorals were 27 years old, from 1984 to 2010. The skeletal growth rates ranged from 3.1 to 9.9 mm·year-1, with an averaged rate of 6.3 mm·year-1. The variation of skeletal growth rate for all Poritescorals collected consistently showed a downward trend, especially after 1997, decreased by 26% compared to the previous years from 1984-1997. Global warming, rapidly increasing SST, and increased extreme events caused the decline of skeletal growth rate of global corals, including corals from Weizhou Island. The relatively higher latitude corals in the South China Sea are vulnerable in the face of rapid climate change, especially the frequent extreme events.

Key words: Porites, skeletal extension rate, global warming, extreme event, Weizhou Island, northern South China Sea, relatively higher latitude

CLC Number: 

  • P736