2021 State of the Environment Report Marine Chapter – Expert Assessment – State and Trend – Marine turtles

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 Expert Assessment "State and Trend of marine turtles".
***A PDF of the full Expert Assessment, including figures and tables (where provided) is downloadable in the "On-line Resources" section of this record as "EXPERT ASSESSMENT 2021 - Marine Turtles"***

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DESCRIPTION OF TAXONOMIC GROUP FOR EXPERT ASSESSMENT
Six species of marine turtles reside in the marine habitats of Australia, predominantly north of 29ºS and south to the extent of boundary currents sweeping the continental coasts. All six species migrate between marine foraging areas and terrestrial nesting sites. Post hatchlings of five species undertake oceanic migrations that take them outside of Australia’s EEZ. The flatback turtle has a life history largely contained within the waters of the Australian EEZ. Each species can be separated into genetically distinct stocks and Australia shares many of these stocks with neighbouring countries. Marine turtles are of great cultural significance to many Indigenous communities.
This assessment focusses marine turtles in their nearshore and offshore foraging areas. Nesting beaches are covered in the coasts chapter.

DATA STREAM(S) USED IN EXPERT ASSESSMENT
Data derived from formal surveys and published summary documents.

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2021 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]

• 2021 •
Assessment grade: Very poor-good
Assessment trend: Unclear
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus
Comparability: Grade and trend comparable to 2016 assessment
• 2016 •
Assessment grade: Poor-good
Assessment trend: Unclear
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus
Comparability: Grade and trend comparable to 2011 assessment
• 2011 •
Assessment grade: Poor
Assessment trend: Stable
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus

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CHANGES SINCE 2016 SOE ASSESSMENT
Since 2016 some foraging populations of marine turtles are now considered very poor rather than poor. This is primarily due to climate change impacts, particularly the feminisation of the northern Great Barrier Reef green turtle population. Hawksbill turtles in the GBR are now considered very poor due to climate change and overseas fishing pressure.

Lineage

Statement: QUALITY OF DATA USED IN THE ASSESSMENT
Peer reviewed.

Notes

Credit
Peer reviews of this assessment were provided by: Tony Tucker (Marine Science Program, Western Australian Department of Biodiversity, Conservation and Attractions) Scott Whiting (Marine Science Program, Department of Biodiversity, Conservation and Attractions, WA)