2021 State of the Environment Report Marine Chapter – Case Study – Australia's changing reefs

Brief description

The Marine chapter of the 2021 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Case Study "Australia's Changing Reefs".
***A PDF of the full Case Study, including figures and tables (where provided) is downloadable in the "On-line Resources" section of this record as "CASE STUDY 2021 – Australia's Changing Reefs"***

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DESCRIPTION OF THE FOCUS OF THE CASE STUDY
Shallow temperate and tropical reefs around Australia, including their macroalgal and coral habitats, fishes and mobile invertebrates. A nationally standardised dataset is used to provide a quantitative metric-based analysis of state and trends in these components across the continent, rather than presenting a review of location-specific knowledge.

PRESSURES/ISSUES OF IMPORTANCE
Changes in the ocean climate have been widespread on shallow reefs since the last SoE report (2016), including three major tropical heatwaves responsible for widespread coral bleaching (2016, 2017 and 2020), and increasing annual maximum sea temperatures along much of the Australian coastline [1].

DATA STREAM(S) USED IN CASE STUDY
All trends are calculated from compatible underwater visual census data from the Reef Life Survey (RLS; https://reeflifesurvey.com/), Australian Temperate Reef Collaboration (ATRC; https://atrc.org.au/) and the Australian Institute of Marine Science (AIMS; https://www.aims.gov.au/docs/research/monitoring/reef/reef-monitoring.html) Long Term Monitoring program. All RLS and ATRC data used are available through the National Reef Monitoring Network database through IMOS. Only data collected between the years 2008-2020 (inclusive) were used, with spatial coverage as shown in plots. Indicator calculation is provided in reference 5, and at https://reeflifesurvey.com/indicators/.
A number of other monitoring programs exist around Australia, albeit not all with directly compatible and/or open access data with which to calculate the indicators used for this case study. As such, trends reported are those from analysis of this national standardised dataset and the knowledge of the authors, and should not be taken to reflect a synopsis of all published research and results of other monitoring programs.

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Statement: QUALITY OF DATA USED IN THE ASSESSMENT
High. Quantitative and standardised data collected using consistent methods by experienced observers.

Notes

Credit
Peer reviews of this case study were provided by: Adriana Vergés (University of NSW) Angus Thompson (Australian Institute of Marine Science)