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 ASSESSMENTThe 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 ASSESSMENTAssessment 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: GoodAssessment trend: UnclearConfidence grade: Limited evidence or limited consensusConfidence trend: Limited evidence or limited consensusComparability: Grade and trend are comparable to the 2011 assessment• 2011 •Assessment grade: GoodAssessment trend: StableConfidence grade: Limited evidence or limited consensusConfidence trend: Limited evidence or limited consensus----------------------------------------CHANGES SINCE 2011 SOE ASSESSMENTNot 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.

2016年《环境状况（State of the Environment, SoE）》报告的海洋章节整合了多套基于海洋数据流（Data Stream）构建的专家模板。本元数据记录用于说明这份专家评估（Expert Assessment）报告：《生境与群落质量状况及趋势——海底、内陆架（0-25米）》。本记录附带完整的专家评估报告（含已提供的图表与表格）；若有可用数据，生成该评估所用的数据流可通过本记录的"在线资源"板块获取。

----------------------------------------【专家评估生境/群落说明】
内陆架海底涵盖多种生境类型，从岩礁、珊瑚礁、海草床、藻类群落到软沉积底质均有分布，但本次评估聚焦内陆架（0-25米水深）的开阔海岸无植被软沉积生境，其余近岸生境已通过其他SoE评估指标完成评估。
需注意，本次评估与2011年版本略有差异：2011年评估聚焦0-50米水深范围，且同样限定于软沉积生境。2011年评估得出全国尺度下整体状况良好，但东南部与东部区域状况不佳的结论，且认为趋势趋于稳定，不过该结论基于有限的证据与前次评估的趋势数据。

内陆架软沉积生境在暴露海岸通常以粗砂至细砂为主，但在受掩护且邻近河口输入的生境中，随着水深增加，沉积物会逐渐过渡为更细的粉砂。在部分特定区域，针对性的生境制图与/或生物多样性采样项目已大幅提升了对这些生境空间分布的认知，并初步描述了其当前状况（例如Barrett等2001年；Pitcher等2007ab、2016年；Jordan等2010年；Kangas等2007年；Currie等2003、2009年）。
但在全国尺度上，目前尚无整合与综合这些信息的框架以支撑生境状况评估。此外，几乎没有足够数据可用于评估时间趋势的幅度，或基于基准条件的生境退化程度。尽管存在上述局限，仍可识别并评估若干威胁因子以研判当前潜在趋势，这些威胁包括：拖网作业（通过物理扰动海底底质）、沉积/硝化作用，以及外来入侵有害物种的扩散。

----------------------------------------【专家评估所用数据流】
本次评估基于已发表于同行评议文献与机构报告中的数据与分析结果，尚未提供用于生成该评估的特定数据集细节。

----------------------------------------【2016年SoE评估摘要（完整细节请见附带的专家评估报告）】
• 2016年版本
评估等级：良好
评估趋势：尚不明确
置信等级：证据有限或共识不足
趋势置信度：证据有限或共识不足
可比性：本次评估的等级与趋势可与2011年版本进行对比
• 2011年版本
评估等级：良好
评估趋势：趋于稳定
置信等级：证据有限或共识不足
趋势置信度：证据有限或共识不足

----------------------------------------【2011年SoE评估以来的变更】
目前尚不明确2011年评估的开展依据与具体方式。需再次说明，本次评估与2011年版本略有差异：2011年评估聚焦0-50米水深范围，且同样限定于软沉积生境。