Summary of the Winter Coral Bleaching Event at Ningaloo Marine Park, July 2006

Brief description

Mass coral bleaching events triggered by anomalously high seawater temperatures have been reported worldwide with growing frequency over the past two decades. However, the impacts of low temperature coral bleaching (winter bleaching) on reefs are less well known. The first major coral bleaching event recorded for Ningaloo Reef was a winter bleaching event in July 2006. The combination of cold air temperatures and aerial exposure of corals due to a low spring tide and a high pressure system appeared to cause bleaching of shallow-water corals. Observations made during an aerial survey indicated that bleaching had occurred along the entire length of the Ningaloo Reef. The most severe bleaching was recorded at Pelican Point, where approximately 83% of live hard coral was bleached. Bleaching was mainly restricted to shallow-water corals of back-reef and patch reef environments dominated by plate and corymbose acroporids. Submerged corals appeared to remain unbleached. To investigate the recovery of bleached corals, two surveys were undertaken at Coral Bay and Pelican Point. At Coral Bay, approximately 90% of bleached coral had recovered by 14 weeks after the event, and approximately 100% of bleached coral had recovered at Pelican Point 30 weeks after the event. This report describes the recovery of corals after a winter bleaching event and provides information regarding the first major bleaching event to be observed at Ningaloo Reef, Western Australia. The potential combination of both winter and summer bleaching occurring in one year at the same reef could result in an increased threat to corals and should be considered among the climate change projections for coral reefs at some locations.

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Maintenance and Update Frequency: unknown

Statement: Original record compiled for the Western Australian Marine Science Institution (WAMSI), Project 3.8, 2008. Originally sourced from several databases compiled by WA DEC Marine Science Branch of projects relevant to the marine parks of WA. Variable metadata information was available.

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Credit
Shannon Armstrong