2021 State of the Environment Report Marine Chapter – Expert Assessment – State and Trend – Seabed, shallow/inner shelf (0-30 m)

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, shallow/inner shelf (0-30 m)". 
<strong><em>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 - State and Trend – Seabed, shallow/inner shelf (0-30 m)"</em></strong>



DESCRIPTION OF HABITAT/OMMUNITY FOR EXPERT ASSESSMENT
The inner shelf seabed consist of a mix of habitats that range from rocky reef through coral reef, seagrass, algae and soft sediment, although this assessment focusses on open coast unvegetated soft sediment habitats on the inner shelf (0-30 m depth) as the other inshore habitats are assessed in other SoE metrics. Note that this assessment differs slightly from that in 2011 that focussed on the 0-50 m depth range, and the 2016 assessment that focussed on the 0-25 m depth range, and we assume the 2011 assessment (undocumented) was also confined to soft sediment habitat. The 2011 and 2016 assessments concluded that the overall condition was good at a national scale, but poor in the SE and East, this was likely to be stable, but it was based on limited evidence and trends from the previous assessments.
Inner shelf soft sediment habitats are usually dominated by coarse to fine sand in exposed coast locations but can grade to finer silts in sheltered habitats with nearby estuarine inputs and with depth. In specific locations, significant habitat mapping and/or biodiversity sampling programs have substantially improved knowledge of the spatial distribution of these habitats, and have provided an initial description of their current condition (e.g. Barrett et al. 2001; Pitcher et al. 2007ab, 2016; Jordan et al. 2010; Kangas et al. 2007; Currie et al. 2003, 2009; Keesing et al 2018ab). However, at a national scale there has been little integration and synthesis of this information on which to base condition assessments. In addition, there is little information to assess the extent of temporal trends or habitat degradation from baseline conditions. Despite this, there are a number of threats that can be identified and assessed to determine the potential current trends. These are outlined below.  

DATA STREAM(S) USED IN EXPERT ASSESSMENT
Information used in this assessment is contained in reports listed in the reference section for historical condition and reports published since 2016 for updates to condition.



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

• 2021 •
Assessment grade: Good
Assessment trend:  Unclear
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus
Comparability: Grade and trend are comparable to the 2016 assessment
• 2016 •
Assessment grade: Good
Assessment trend:  Unclear
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: Good
Assessment trend:  Unclear
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus



CHANGES SINCE 2016 SOE ASSESSMENT
No change.

Tags: expert assessment, shallow seabed, state and trend
Organization: Australian Ocean Data Network