Revealed immediately (Wednesday 9 August), AIMS’ Annual Abstract Report on Coral Reef Situation for 2022/23 discovered that whereas some reefs continued to get well, their elevated exhausting coral cowl was offset by coral loss on different reefs. Most reefs underwent little change in coral cowl.

This follows final yr’s report, which noticed the Northern and Central areas recording their highest quantity of coral cowl since AIMS started monitoring 37 years in the past.

The pauses in restoration within the Northern and Central areas had been due partly to the 2022 mass coral bleaching occasion. Low numbers of coral-eating crown-of-thorns starfish and a cyclone in January 2022 additionally contributed to coral loss within the Northern area. Continued crown-of-thorns starfish outbreaks and coral illness saved coral cowl much like final yr’s ranges within the Southern area, with bleaching taking part in much less of a task.

AIMS Analysis Program Director Dr David Wachenfeld mentioned that whereas continued restoration on some reefs was excellent news, the pause in restoration confirmed that even comparatively milder mass bleaching occasions had penalties for the Reef.

“The 2022 coral bleaching occasion was not as extreme because the 2016 or 2017 occasions however precipitated sufficient mortality to pause current regional positive factors in exhausting coral cowl. The warmth stress throughout the bleaching occasion additionally probably had sub-lethal results, together with reductions in coral development and replica,” Dr Wachenfeld mentioned.

“Situations had been comparatively gentle over the 2023 summer time with low ranges of coral bleaching and no cyclones crossing the Reef. Nevertheless, we’re just one massive scale disturbance away from a speedy reversal of current restoration.

“The Reef stays a beautiful, advanced and exquisite system, however it’s at elevated threat with local weather change driving extra frequent and extreme bleaching occasions, placing growing stress on the ecosystem’s resilience.”

The Report discovered the next in common exhausting coral protection for 2022/23:

• Northern area (north of Cooktown) — 35.7%, down from 36.5% final yr;
• Central area (Cooktown to Proserpine) — 30.8%, down from 32.6%;
• Southern area (south of Proserpine) — 33.8%, down from 33.9%.

Reef slopes on the sides of 111 reefs had been surveyed between August 2022 and Might 2023 for the report below the AIMS Lengthy Time period Monitoring Program (LTMP) — a 37-year-long dataset which is the most important, longest and most complete info supply on the standing of the Nice Barrier Reef.

AIMS Lengthy-Time period Monitoring Program chief Dr Mike Emslie mentioned restoration over the previous few years has been pushed primarily, however not completely, by fast-growing branching and plate corals, or Acropora. These vital habitat builders are additionally weak to disturbances comparable to cyclones, crown-of-thorns starfish and coral bleaching.

“Acropora are extremely ample, chargeable for many of the ups and downs in exhausting coral cowl, and have been going by means of a speedy development part lately. However different corals on the Reef have additionally contributed to this restoration,” he mentioned.

Dr Emslie famous the elevated frequency of mass coral bleaching occasions on the Nice Barrier Reef with 4 occurring since 2016.

“The 2022 bleaching occasion was the primary ever recorded throughout a La Niña yr, that are often characterised by cooler temperatures,” he mentioned.

“If there have been no disturbances, we might anticipate the current will increase in coral cowl to proceed this yr. Nevertheless, this pause signifies {that a} mass bleaching occasion, even when much less extreme, with low mortality, continues to be sufficient to place the brakes on this coral restoration.

“This implies the Reef continues to be vulnerable to decline from extra frequent disturbances. AIMS is working to know the impact of this climatic instability by means of monitoring and analysis.”

Dr Wachenfeld added: “The very best hope for the way forward for the Nice Barrier Reef and all coral reefs globally requires discount in greenhouse fuel emissions to stabilise temperatures, finest apply administration of native pressures, and the event of interventions to assist increase local weather tolerance and resilience for coral reefs.”

BACKGROUND

The LTMP quantifies long run tendencies within the standing of coral communities throughout the Nice Barrier Reef.

Researchers use exhausting coral cowl as one indicator of the situation of every reef, though there are various others. Share exhausting coral cowl is estimated by skilled scientists throughout manta tow surveys and is a metric which permits AIMS scientists to offer an outline of the Nice Barrier Reef’s standing and maintain coverage makers, managers and different scientists knowledgeable in a well timed method.

Manta tow surveys are an environment friendly option to survey massive areas of reef. It’s a customary methodology to evaluate % exhausting coral cowl, estimates of crown-of-thorns starfish, ranges of coral bleaching, and fish and shark populations.

The LTMP additionally does detailed surveys on fastened websites on 73 reefs throughout the Nice Barrier Reef. These information present deeper insights into the corals, fishes and crown of thorns starfish at these websites, their abundance, their age and extra detailed details about coral illness and bleaching. 3D photos are taken of those reefs to evaluate reef complexity and their altering constructions.

The AIMS monitoring group spent 120 days at sea throughout this survey interval. They travelled 1016km across the perimeter of the 111 reefs they surveyed.

The AIMS LTMP group start their new survey season in late August. Surveys will proceed by means of the summer time and conclude round Might 2024.

The LTMP contributes to the Reef 2050 Built-in Monitoring and Reporting Program.