2016 SoE Marine Chapter - State and Trends - Seabed, abyss (>700 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, abyss (>700 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 ASSESSMENTThis 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, continental rise, and abyss. Bottom fishing, the single biggest pressure on seabed habitats, is restricted to mid-slope depths (700-1500 m) (e.g. Pitcher et al. in review); oil and gas activity (or planned activity) extends across the continental slope and rise in restricted locations, e.g. the Great Australian Bight (GAB). Over 70% of Australia’s marine estate lies beyond 700 m depth; by region the percentage of planar area is >70% for all regions except the GBR (19%), north-west (51%) and the north (0%). The mid-slope 700-1500 m is a steep, narrow band comprising only comprising only 10% of the planar area. Habitats of the mid-slope have been studied through imagery and sampling as part of extensive biodiversity surveys off Western Australia, southern Tasmania and off shore in the Lord Howe Rise (Williams et al. 2010, McEnnulty et al. 2011, Williams et al. 2011, Zintzen et al. 2011, Althaus et al. 2012; Harris et al 2012); habitats beyond 1500 m have been little studied so far, with the exception of the western Australian margin (Daniell et al 2010). Considering the zonation of impacts and knowledge, our assessment is structured into mid-slope and remaining depths.The temperate mid-slope is used by fisheries targeting deep sea sharks, orange roughy and oreos. Although substrates are predominantly muddy and extensive, hard substrates in these depths support biogenic habitats formed by attached fauna such as cold-water corals and glass sponges (separate SER). Fauna was believed to be sparse in abyssal depths, however, recent sampling in depths to 4000 m in the Tasman Fracture zone in the south-east region discovered corals and a high biomass community of large barnacles and anemones on steep rockwalls (Thresher et al. 2014). In contrast seafloor images and limited sampling from Daniels et al 2009 found very little fauna along the western margin, even on expanses of basalt rock walls. Benthic communities of soft sediments below 700 m depth are dominated by small-bodied infauna (worms and crustaceans) sampled in sediment grabs or cores and evident through traces (Lebensspuren) in low-disturbance abyssal environment (Przeslawski et al 2012), and patchy distributions, including dense aggregations, of echinoderms (urchins, sea cucumbers or ophiuroids) (MNF 2015a & b, unpublished data). DATA STREAM(S) USED IN EXPERT ASSESSMENTThis assessment is based on data derived from Marine National Facility Surveys described in MarLIN (http://www.marine.csiro.au/marlin/search.html) and accessible through the CSIRO Data trawler (http://www.cmar.csiro.au/data/trawler/). Links to specific data sets are provided in the "On-line resources" section of this record.• Voyage of Discovery north-west (SS05/2007)• Voyage of Discovery south-west (SS07/2005 & SS10/2005)• Great Australian Bight Deepwater Marine Program (GABDMP 2016) (IN2015_C01)• Great Australian Bight Research Program (GABRP 2016) (SS2013_C02 & IN2015_C02)• Habitat Mapping (SS01/2000, SS04/2004)• Habitat and population assessment of giant crabs (2003 - 2005) • Tasmanian seamounts surveys, including samples on the slope (SS02/2006 & SS02/2007)• NORFANZ survey of Lord Howe Rise and Norfolk Ridge (TAN0308 - NORFANZ)----------------------------------------2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]• 2016 •Assessment grade: GoodAssessment trend: StableConfidence grade: Limited evidence or limited consensusConfidence trend: Limited evidence or limited consensusComparability: Grade and trend are comparable to the 2011 assessment• 2011 •Assessment grade: Very goodAssessment trend: StableConfidence grade: Limited evidence or limited consensusConfidence trend: Limited evidence or limited consensus----------------------------------------CHANGES SINCE 2011 SOE ASSESSMENTN/A2016年环境状况（State of the Environment, SoE）报告海洋章节纳入了多份基于海洋数据流编制的专家模板。本元数据记录对应专家评估报告《生境与群落质量现状及趋势——海底、深渊（>700米）》。本记录附件包含完整的专家评估报告，含附图及附表（如已提供）。若有可用数据，本评估所依托的数据流可通过本记录的"在线资源"板块获取。 ----------------------------------------DESCRIPTION OF HABITAT/COMMUNITY FOR EXPERT ASSESSMENT 专家评估项下的生境与群落描述 本次划定的深度区间（>700米）涵盖了多个在地质、环境与生物特征上显著不同的生境与群落：大陆坡中部、大陆坡下部、大陆隆以及深渊带。海底拖网捕捞是对海底生境影响最大的单一人类活动，仅在700-1500米的中部大陆坡海域受到限制（例如Pitcher等，待刊）；油气活动（或规划中活动）则在部分限定区域的大陆坡与大陆隆海域开展，例如大澳大利亚湾（Great Australian Bight, GAB）。澳大利亚逾70%的海洋管辖海域水深超过700米；按区域划分，除大堡礁（Great Barrier Reef, GBR，占比19%）、西北海域（占比51%）与北部海域（占比0%）外，其余所有区域的平面海域面积占比均超过70%。700-1500米的中部大陆坡为狭窄陡峭的海域带，仅占总平面海域面积的10%。 针对西澳大利亚近海、塔斯马尼亚南部以及豪勋爵海隆（Lord Howe Rise）近海区域的大规模生物多样性调查，已通过影像与采样手段对中部大陆坡生境开展了研究（Williams等，2010；McEnnulty等，2011；Williams等，2011；Zintzen等，2011；Althaus等，2012；Harris等，2012）。而1500米以深的生境目前研究甚少，仅西澳大利亚陆缘海域有相关研究（Daniell等，2010）。结合人类影响的分区特征与现有认知水平，本次评估将划分为中部大陆坡与其余深度区间两部分展开。 温带中部大陆坡海域为针对深海鲨鱼、橘棘鲷和奥里奥鲷类的渔业作业海域。尽管该海域底质以大范围泥质为主，但该深度的硬质底质可形成由附着性动物构建的生物生境，例如冷水珊瑚与玻璃海绵（另有单独的物种生态记录（Species Ecological Record, SER））。 此前学界曾认为深渊带海域的生物群落较为稀疏，但2014年在东南部海域塔斯曼断裂带4000米水深区域开展的最新采样发现，陡峭岩壁上分布有珊瑚以及由大型藤壶和海葵构成的高生物量群落（Thresher等，2014）。与之形成对比的是，Daniels等（2009）通过海底影像与有限采样发现，西澳大利亚陆缘海域几乎无生物分布，即便在大片玄武岩岩壁区域亦是如此。700米以深软沉积物底栖生物群落以小型底内生物（蠕虫与甲壳类）为主，这类生物可通过沉积物抓斗或岩芯采样获取，在低扰动的深渊环境中可通过其活动痕迹（Lebensspuren）被观测到（Przeslawski等，2012）；同时还存在棘皮动物（海胆、海参或阳遂足）的斑块状分布，包括密集聚集群（海洋国家设施（Marine National Facility, MNF）2015a & b，未公开数据）。 ----------------------------------------DATA STREAM(S) USED IN EXPERT ASSESSMENT 专家评估所使用的数据流 本次评估所依托的数据源自海洋国家设施调查，相关数据可通过MarLIN数据库（http://www.marine.csiro.au/marlin/search.html）以及澳大利亚联邦科学与工业研究组织（CSIRO）数据拖网系统（http://www.cmar.csiro.au/data/trawler/）获取。本记录的"在线资源"板块已提供对应数据集的链接。 • "发现号"西北海域航次（SS05/2007） • "发现号"西南海域航次（SS07/2005与SS10/2005） • 大澳大利亚湾深水海洋计划（Great Australian Bight Deepwater Marine Program, GABDMP 2016）（IN2015_C01） • 大澳大利亚湾研究计划（Great Australian Bight Research Program, GABRP 2016）（SS2013_C02与IN2015_C02） • 生境制图（SS01/2000、SS04/2004） • 巨型螃蟹生境与种群评估（2003 - 2005） • 塔斯马尼亚海山调查（含陆坡采样，SS02/2006与SS02/2007） • 豪勋爵海隆与诺福克海岭NORFANZ调查（TAN0308 - NORFANZ） ----------------------------------------2016 SOE ASSESSMENT SUMMARY [完整详情请见附件专家评估报告] • 2016年 评估等级：良好 评估趋势：稳定 置信等级：证据有限或共识不足 置信趋势：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年评估结果进行对标 • 2011年 评估等级：极佳 评估趋势：稳定 置信等级：证据有限或共识不足 置信趋势：证据有限或共识不足 ----------------------------------------CHANGES SINCE 2011 SOE ASSESSMENT 2011年SoE评估以来的变更：无（N/A）