2016 SoE Marine Chapter - State and Trends - Mesopelagic fish species

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 species and groups – mesopelagic fish species". 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.

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DESCRIPTION OF ECOLOGICAL SPECIES/COMMUNITY FOR EXPERT ASSESSMENT
Mesopeolagic fish species (200 to 1000 m depths) of the Australian region are thought to be in very good condition as there is limited direct impact by human activities (e.g. no targeted commercial fishing, and limited seismic surveys). Therefore factors affecting the mesopelagic fishes and their habitats will most likely be due to overall changes in environmental conditions associated with climate change and variability influencing factors such as primary production, ocean acidification and changing oxygen levels (Hobday and Pecl, 2014). This estimate of mesopelagic fish status and trend is uncertain due to the low amount of monitoring that is done, but monitoring has increased since the last assessment in 2011.
Monitoring of mesopelagic fishes has recently been included in Australia’s Integrated Marine Observing System (IMOS) through a bio-acoustics sub-facility in 2010 with one focus being the Tasman Sea (www.imos.org.au). Mesopelagic fishes are very diverse in Australian waters where in a recent field guide of the southern Tasman Sea 143 species in 43 families were identified (Flynn and Pogonoski, 2012). Using the IMOS bioacoustics Tasman Sea transect along 40oS there has been no detectable change in the annual acoustic index of mesopelagic fish biomass off the east coast of Tasmania between 2004 and 2013 (Kloser et al pers comms, www.imos.org.au). This region has a diverse range of fishes that have complex depth distributions and trophic interactions (Flynn and Kloser, 2012).
Ecosystem models and observational studies of mesopelagic fishes highlight their importance to ecosystem structure and function where they transfer energy to higher order predators such as commercial fish species in Australian waters (Fulton et al., 2005; Lehodey et al., 2010; Young et al., 2011). This is particularly important for Australia’s continental slope commercial species and other top predators for ecosystem based management (Smith et al., 2011). The importance of mesopelagic fishes to ecosystem services has been shown yet their biomass and production is uncertain with several recent net and acoustic estimates differing by 2 orders of magnitude in Tasman Sea Australian waters (Kloser et al., 2009; Irigoien et al., 2014). This difference is based on using different sampling gear and methods to interpret the data.
The outlook for mesopelagic fish in the Australian region is very good given the low direct impact of human activities (e.g. fishing) and increased monitoring through the IMOS bioacoustics program. Spatial and temporal shifts in mesopelagic fishes are expected to occur due to climate change and variability which will influence the distribution of their predators (Ridgway et al., 2008; Hobday and Pecl, 2014). To understand shifts in higher order predators and their ecological and human impact monitoring and ecosystem modelling of mesopelagic fish status and future trends is necessary.

DATA STREAM(S) USED IN EXPERT ASSESSMENT
Data from the IMOS bio-acoustics sub-facility, data from surveys along a transect line in the Tasman Sea repeated across 2004-2013.

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2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]

• 2016 •
Assessment grade: Very good
Assessment trend: Stable
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: Very good
Assessment trend: Stable
Confidence grade: Limited evidence or limited consensus
Confidence trend: Limited evidence or limited consensus

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CHANGES SINCE 2011 SOE ASSESSMENT
N/A

2016年环境状况（State of the Environment, SoE）报告海洋章节纳入了多套基于海洋数据流构建的专家模板。本元数据记录所描述的专家评估报告为《物种与类群质量现状及趋势——中层鱼类（mesopelagic fish）》。本记录附件包含完整的专家评估报告，含附图与附表（如已提供）。若可获取，本专家评估报告所用的数据流可通过本记录的"在线资源"板块查阅。

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DESCRIPTION OF ECOLOGICAL SPECIES/COMMUNITY FOR EXPERT ASSESSMENT
澳大利亚海域范围内的中层鱼类（栖息深度200至1000米）现状被评估为极佳，原因是人类活动对其直接影响有限（例如无针对性商业捕捞，且地震勘探活动极少）。因此，影响中层鱼类及其栖息地的因素，大概率与气候变化及气候变率所引发的整体环境变化相关，这些变化会影响初级生产、海洋酸化与氧含量变化等过程（Hobday与Pecl，2014）。由于现有监测覆盖度较低，本次对中层鱼类现状与趋势的评估存在不确定性，但自2011年上一次评估以来，监测工作已有所加强。

2010年起，澳大利亚综合海洋观测系统（Integrated Marine Observing System, IMOS）通过其生物声学（bio-acoustics）子设施纳入了中层鱼类监测工作，其中一个监测重点为塔斯曼海（www.imos.org.au）。澳大利亚海域中层鱼类物种多样性极高，最新的塔斯曼海南部海域野外调查指南显示，该区域共记录到43科143种中层鱼类（Flynn与Pogonoski，2012）。基于IMOS生物声学项目在南纬40°沿线的塔斯曼海断面监测数据，2004至2013年间，塔斯曼尼亚东海岸外海域的中层鱼类生物量年度声学指数未出现可检测到的变化（Kloser等人，私人通信，www.imos.org.au）。该区域鱼类类群丰富，且具有复杂的深度分布与营养级相互作用模式（Flynn与Kloser，2012）。

中层鱼类的生态系统模型与观测研究均证实，其在生态系统结构与功能中发挥关键作用——可将能量传递至更高营养级的捕食者，例如澳大利亚海域的商业捕捞鱼类（Fulton等人，2005；Lehodey等人，2010；Young等人，2011）。这一点对于基于生态系统的管理而言尤为重要，尤其是针对澳大利亚大陆坡海域的商业捕捞物种与其他顶级捕食者（Smith等人，2011）。现有研究已证实中层鱼类对生态系统服务的重要性，但其生物量与生产量仍存在较大不确定性：澳大利亚塔斯曼海海域近期的网采与声学估算结果之间相差达两个数量级（Kloser等人，2009；Irigoien等人，2014）。该差异源于不同采样设备与数据解译方法的使用。

鉴于人类活动直接影响有限，且IMOS生物声学项目的监测工作有所加强，澳大利亚海域中层鱼类的发展前景极佳。受气候变化与气候变率影响，中层鱼类的时空分布预计将发生变化，进而影响其捕食者的分布格局（Ridgway等人，2008；Hobday与Pecl，2014）。为明晰顶级捕食者的分布变化及其生态与人类影响，需针对中层鱼类现状与未来趋势开展监测与生态系统建模工作。

DATA STREAM(S) USED IN EXPERT ASSESSMENT
IMOS生物声学子设施采集的数据；2004至2013年间在塔斯曼海断面重复开展的调查数据。

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2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]
2016年环境状况评估摘要[完整细节请参阅附件中的专家评估报告]
• 2016 •
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
可比性：本次评估等级与趋势可与2011年评估结果进行对比
• 2011 •
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

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CHANGES SINCE 2011 SOE ASSESSMENT
2011年环境状况评估以来的变更
无