New research by the Australian Institute of Marine Science (AIMS) has found that corals around the Keppel Islands of the southern Great Barrier Reef, typically fast-growing species in the Acropora family, demonstrated high resilience by recovering from a severe bleaching event in 2020.
Part of the wider 2020 mass bleaching, the event in the Woppaburra sea affected 75%-98% of coral around the islands. Despite this coral cover in the region was found to have remained stable, with very little mortality occurring.
AIMS scientist Dr. Cathie Page said the recovery following the bleaching event was potentially assisted by the easing of thermal stress in the region. While this may have stemmed from environmental factors typical of the area like increased turbidity and large tidal flows, Dr Page warned that the corals might not fare so well in future events. “Reefs in this region are considered ‘highly disturbed’ and have been impacted by six major flooding events, four cyclones, four major storms and six coral bleaching events driven by marine heatwaves over the last 30 years,” she said. “They have been through a lot and we wanted to know more about what makes them so tough.
For the study, the team surveyed six reefs in different areas of the Keppel Island region in early April 2020 during the marine heatwave which caused severe bleaching. They surveyed these reefs, and an additional three sites, again in June and October 2020 to document the recovery of different species.
The research was published in the journal Ecosphere.
Image: Photograph of a coral reef near North Keppel Island. Iotaquilegiazure
More information: Cathie A. Page et al, High survival following bleaching underscores the resilience of a frequently disturbed region of the Great Barrier Reef, Ecosphere (2023). DOI: 10.1002/ecs2.4280