2021 State of the Environment Report Marine Chapter – Expert Assessment – State and Trend – Deep seabed (>700m)

Updated: 2021-08-20

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 Deep seabed (>700m)". ***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 - Deep seabed (>700m)"*** ---------------------------------------- DESCRIPTION OF HABITAT/COMMUNITY FOR EXPERT ASSESSMENT This specified depth range (> 700 m) aggregates several habitats and communities that are clearly distinct in geological, environmental and biological characteristics: the mid-continental slope, lower slope and rise, and abyss. Our knowledge of very deep-sea habitats around Australia has increased substantially since the 2016 assessment due to recent survey effort in the Great Australian Bight and off the Eastern Australian Margin (Williams et al. 2018a, b; O’Hara et al. 2020a, b). For example, the slope topography of the latter was shown to be more complex and rugged than originally expected (O’Hara et al. 2020b), which suggests a higher diversity of habitats, and by implication opportunity for more diverse faunal assemblages. DATA STREAM(S) USED IN EXPERT ASSESSMENT Metadata records related to surveys can be found on MarLIN (http://www.marine.csiro.au/marlin/search.html); and on the CSIRO Data trawler (https://www.marine.csiro.au/data/trawler/) the reference indicates Survey names for effectively searching the databases ---------------------------------------- 2021 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details] • 2021 • Assessment grade: Good Assessment trend: Stable Confidence grade: Limited evidence; uncertain climate effects Confidence trend: Limited evidence; uncertain climate effects Comparability: Grade and trend are comparable to the 2016 assessment • 2016 • Assessment grade: Good Assessment trend: Stable Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus Comparability: Grade and trend are comparable to the 2011 assessment • 2011 • Assessment grade: Very good Assessment trend: Stable Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus ---------------------------------------- CHANGES SINCE 2016 SOE ASSESSMENT not supplied