2021 State of the Environment Report Marine Chapter – Expert Assessment – State and Trend – Seabed, upper slope (200-700 m)

Researchers: Althaus, Franzis (Author) ,  Althaus, Franziska (Author) ,  Emma Flukes (Point of contact) ,  Pitcher, Roland (Author) ,  Williams, Alan (Author)

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 Seabed, upper slope (200-700 m)". ***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 - Seabed, upper slope (200-700 m)"*** ---------------------------------------- DESCRIPTION OF HABITAT/COMMUNITY FOR EXPERT ASSESSMENT This specified depth range (200 m to 700 m) defines the upper continental slope. This habitat is mostly an extremely narrow and typically steep ribbon of seabed beyond the shelf-break (Figure 1), but wider in places (GBR/Coral Sea and North-west Regions) (Table 1). Where it is narrowest and steepest in the Temperate East and South-east Regions, it is typified by sediment draped slopes interspersed with deep reefs and canyons (assessed separately). The narrow ribbon of upper slope is the core habitat to many demersal fish species including many commercially targeted species, as well as threatened or management dependent species such as many deepwater sharks including gulper sharks (Centrophorus spp.) (Williams et al. 2012). In addition, it harbours a highly diverse benthic fauna (Schlacher et al. 2007, Williams et al. 2010, McEnnulty et al. 2011, Dunstan et al. 2012, McCallum et al. 2013). Off Australia’s west-coast (South-west Region), the upper slope is predominantly sediment-draped with soft coral and sponge dominated communities on the relatively few, small deep reefs (Althaus et al. 2012). In the South-east Region bryozoan communities (assessed separately) dominate the shallower, softer part of the slope (Williams et al. 2009) whereas deep reefs harbour sponge gardens, corals and crinoids. There is little specific knowledge of upper slope habitats and biota in other regions. DATA STREAM(S) USED IN EXPERT ASSESSMENT not supplied ---------------------------------------- 2021 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details] • 2021 • Assessment grade: Poor- Very good Assessment trend: Stable Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus Comparability: Grade and trend are somewhat comparable to the 2016 assessment • 2016 • Assessment grade: Good-Poor Assessment trend: Improving Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus Comparability: Grade and trend are somewhat 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

Lineage Statement: QUALITY OF DATA USED IN THE ASSESSMENT not supplied

Lineage

Notes Credit
Peer reviews of this assessment were provided by: Rich Little (CSIRO)

162.42188,-7.20703 162.42188,-47.46094 102.65625,-47.46094 102.65625,-7.20703 162.42188,-7.20703

132.5390625,-27.333984375

text: westlimit=102.65625000000001; southlimit=-47.4609375; eastlimit=162.421875; northlimit=-7.207031249999999