Pause in Recent Coral Recovery on Much of Great Barrier Reef
Published:01 Sep.2023    Source:Australian Institute of Marine Science

In-water monitoring by the Australian Institute of Marine Science (AIMS) shows hard coral cover across the Great Barrier Reef remains at similar levels to that recorded in 2022, with small decreases in the Northern, Central and Southern regions. Published today (Wednesday 9 August), AIMS' Annual Summary Report on Coral Reef Condition for 2022/23 found that while some reefs continued to recover, their increased hard coral cover was offset by coral loss on other reefs. Most reefs underwent little change in coral cover. This follows last year's report, which saw the Northern and Central regions recording their highest amount of coral cover since AIMS began monitoring 37 years ago.

The pauses in recovery in the Northern and Central regions were due in part to the 2022 mass coral bleaching event. Low numbers of coral-eating crown-of-thorns starfish and a cyclone in January 2022 also contributed to coral loss in the Northern region. Continued crown-of-thorns starfish outbreaks and coral disease kept coral cover similar to last year's levels in the Southern region, with bleaching playing less of a role. AIMS Research Program Director Dr David Wachenfeld said that while continued recovery on some reefs was good news, the pause in recovery showed that even relatively milder mass bleaching events had consequences for the Reef.
The Report found the following in average hard coral coverage for 2022/23:
Northern region (north of Cooktown) -- 35.7%, down from 36.5% last year;
Central region (Cooktown to Proserpine) -- 30.8%, down from 32.6%;
Southern region (south of Proserpine) -- 33.8%, down from 33.9%.
Reef slopes on the perimeters of 111 reefs were surveyed between August 2022 and May 2023 for the report under the AIMS Long Term Monitoring Program (LTMP) -- a 37-year-long dataset which is the largest, longest and most comprehensive information source on the status of the Great Barrier Reef.