Localized bleaching and quick recovery in Hong Kong's coral communities

Mar Pollut Bull. 2020 Apr:153:110950. doi: 10.1016/j.marpolbul.2020.110950. Epub 2020 Feb 6.

Abstract

During the summer of 2017 we visited 33 sites with substantial coral cover across Hong Kong waters. At six sites where coral bleaching was observed, video-transect surveys were conducted, which revealed 18.7% to 56.1% bleached colonies and 5.9% to 57.6% bleached coral covered area per site. Mainly affected were three plate-like and three massive coral species. Water quality parameters were analyzed, which indicated that hyposalinity might have triggered the bleaching event. Tagging and follow-up field observation revealed a pattern of recovery depending on coral growth form, with high recovery rates (>93%) at five sites dominated by massive and submassive corals, but moderate (70%) at a site dominated by plate-like corals. Our study shows that the corals of Hong Kong exhibit differential susceptibility to bleaching and ability to recover, therefore it is imperative to establish a long-term monitoring programme to detect the changes in community structure over time.

Keywords: Coral community; Coral health; Global warming; Hyposalinity; South China Sea.

MeSH terms

  • Animals
  • Anthozoa*
  • Coral Reefs*
  • Environmental Monitoring
  • Hong Kong
  • Seasons
  • Water Quality