2016 SoE Marine Chapter - State and Trends - Seabed, inner shelf (0 - 25 m)

The Marine chapter of the 2016 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Expert Assessment "The state and trends of quality of habitats and communities – seabed, inner shelf (0 - 25 m)". The full Expert Assessment, including figures and tables (where provided), is attached to this record. Where available, the Data Stream(s) used to generate this Expert Assessment are accessible through the "On-line Resources" section of this record.

DESCRIPTION OF HABITAT/COMMUNITY 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 (0-25 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 it is assumed was also confined to soft sediment habitat. It concluded that the overall condition was good at a national scale, but poor in the SE and East, was likely to be stable, but it was based on limited evidence and trends from the previous assessment.
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). However, at a national scale there is currently no 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 include trawling (through physical disturbance of the seabed), sedimentation/nitrification, and the spread of introduced pest species. 
DATA STREAM(S) USED IN EXPERT ASSESSMENT
Assessment is based on data and analyses published in peer reviewed literature and agency reports. Details of specific data sets used to generate the assessment have not been provided.

2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]
• 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: Stable
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus

CHANGES SINCE 2011 SOE ASSESSMENT
Not clear on what basis and how the 2011 was conducted. Note that this assessment differs slightly from the 2011 assessment which was focused on the 0-50 m depth range, and it is assumed was also confined to soft sediment habitat.

Tags: benthic habitat, expert assessment, inner shelf, seabed
Organization: Australian Ocean Data Network