Impacts of trawling on benthic habitats in the subantarctic and high antarctic - Final report and data

Objectives of the project:1. To develop deep-sea camera technologies that can be easily deployed during fishing operations, to facilitate widespread observations of demersal fishing activities (trawl, longline and trap) and their interactions with benthic environments.2. To assess the vulnerability of benthic communities in Subantarctic (Australian AFZ) and high latitude areas of the Southern Ocean (Australian EEZ) to demersal fishing using trawls, longlines or traps, using video and still camera technologies.3. To assess the risk of demersal fishing to long-term sustainability of benthic communities in these areas, based on the assessment of vulnerability and information from the literature on potential recovery of benthic species and habitats.4. To recommend mitigation strategies by avoidance or gear modification, where identified to be needed, and practical guidelines to minimise fishing impacts on benthic communities.Non-Technical SummaryAustralia's domestic legislation and obligations under international agreements such as the Convention for the Conservation of Antarctic Marine living Resources (CCAMLR) requires that Australia's fishing activities in the Subantarctic and Antarctic Southern Ocean avoids unsustainable impacts to the ecosystem and biodiversity. As Australia uses bottom fishing methods, including demersal trawls and longlines to target Patagonian toothfish and mackerel icefish in this region there is the potential to impact upon benthic habitats. However, understanding the scale of disturbance caused by Australia's bottom fishing activities in the deep Southern Ocean is hampered by a paucity of data, theory and procedures. This project set out to address these issues by developing tools to allow such an assessment, with a focus on the fishery that has operating since 1997 targeting Patagonian toothfish and mackerel icefish in the EEZ around Heard Island and the McDonald Islands (HIMI).A significant output of this project was the development of a versatile camera system which was successfully deployed on trawls and longlines during commercial and research fishing activities in the EEZ at HIMI, BANZARE Bank and East Antarctica. It revealed for the first time the in situ nature and extent of demersal longline interactions in the deep ocean, as well as revealing the types of habitats and organisms on the seafloor where fishing takes place. This information, combined with comprehensive effort data from the fishery and scientific sampling of the types and abundance of organisms living on the seafloor across a range of depths and seafloor features, enabled the development of an assessment model to estimate the amount of disturbance caused by the fishery.This assessment indicates that the great majority of vulnerable organisms live on the seafloor in depths less than 1200 m. This range overlaps with the depths targeted by the trawl fishery, and to a lesser extent by the longline fishery. However due to the fact that the majority of trawling has focussed on a few relatively small fishing grounds, less than 1.5% of all the biomass in waters less than 1200 m are estimated to have been damaged or destroyed. Furthermore, the HIMI Marine Reserve, established in 2003, is estimated to contain over 40% of the biomass of the groups of benthic organisms considered as most vulnerable to bottom fishing at HIMI. Overall, an estimated 0.7% of the seafloor area within the EEZ at HIMI has had some level of interaction with bottom fishing gear between 1997 and 2013.The results of this project provide a process for assessing the levels of disturbance by bottom fishing which complements the existing processes that have been developed recently to conduct the Ecological Risk Assessment for the Effects of Fishing (ERA-EF) in other Commonwealth fisheries, as well as measures being developed by CCAMLR to avoid significant adverse impacts to vulnerable marine ecosystems. DataThese data are commercial in confidence and therefore embargoed. They are located at aad\files\ERM and access is controlled due to the commercial in confidence nature of the raw data. There are approximately 1 TB of data and metadata including videos (.avi and .mov formats), spreadsheets (.xls), databases (.mdb), R scripts and data files (.r and .rdata) and documents (.txt. and .doc). They are organised into folders which broadly map onto the chapters in the final report, with subfolders for data, analyses and text development.

项目目标：1. 开发可在捕捞作业中便捷部署的深海摄像技术，以广泛观测底层捕捞活动（demersal fishing activities，包括拖网、延绳钓与陷阱捕捞）及其与底栖环境的相互作用。2. 利用摄像与静态摄影技术，评估亚南极海域（澳大利亚专属渔区，Australian Fishing Zone，简称AFZ）及南大洋高纬度海域（澳大利亚专属经济区，Exclusive Economic Zone，简称EEZ）内的底栖群落对拖网、延绳钓或陷阱类底层捕捞活动的脆弱性。3. 基于脆弱性评估结果，结合已发表文献中关于底栖物种与栖息地潜在恢复能力的信息，评估底层捕捞活动对上述区域底栖群落长期可持续性的风险。4. 针对已识别的需求，提出通过规避或渔具改造实现的减缓策略，以及最小化捕捞对底栖群落影响的实用指南。

非技术摘要：澳大利亚的国内立法及《南极海洋生物资源养护公约》（Convention for the Conservation of Antarctic Marine Living Resources，简称CCAMLR）等国际协定下的义务要求，澳大利亚在亚南极与南极南大洋的捕捞活动需避免对生态系统与生物多样性造成不可持续的影响。由于澳大利亚在该海域使用底层捕捞方式（包括底拖网与延绳钓）以巴塔哥尼亚犬牙鱼与鲭冰鱼为目标捕捞物种，可能会对底栖栖息地造成影响。然而，由于缺乏相关数据、理论与研究方法，我们对澳大利亚在南大洋深海开展的底层捕捞活动所造成的干扰规模仍知之甚少。本项目旨在通过开发相关评估工具解决上述问题，重点关注1997年起在赫德岛和麦克唐纳群岛（Heard Island and the McDonald Islands，简称HIMI）专属经济区开展的、以巴塔哥尼亚犬牙鱼与鲭冰鱼为目标物种的捕捞作业。

本项目的一项重要产出是开发了一套多功能摄像系统，并成功在赫德岛和麦克唐纳群岛、班扎雷海岭（BANZARE Bank）与南极东部的专属经济区的商业与科研捕捞活动中，部署于拖网与延绳钓作业设备上。该系统首次揭示了深海底层延绳钓相互作用的原位特征与范围，同时展现了捕捞作业所在海底的栖息地类型与生物群落。结合该渔业的全面作业数据，以及覆盖不同深度与海底地形的海底生物种类与丰度的科学采样结果，研究团队得以开发出一套评估模型，用以估算该渔业造成的干扰程度。

评估结果显示，绝大多数脆弱生物栖息于水深不足1200米的海底。该水深范围与拖网渔业的目标作业水深重叠，与延绳钓渔业的目标水深重叠程度相对较低。不过，由于绝大多数拖网作业集中于少数相对狭小的渔场，据估算，水深不足1200米海域中仅有不到1.5%的生物量遭到破坏或损毁。此外，2003年设立的赫德岛和麦克唐纳群岛海洋保护区，据估算包含了该区域内最易受底层捕捞影响的底栖生物群落总生物量的40%以上。总体而言，1997年至2013年间，赫德岛和麦克唐纳群岛专属经济区内约0.7%的海底区域与底层捕捞设备发生过不同程度的接触。

本项目的研究结果提供了一套评估底层捕捞干扰程度的流程，可补充近期为其他英联邦国家渔业制定的《渔业影响生态风险评估》（Ecological Risk Assessment for the Effects of Fishing，简称ERA-EF）现有流程，以及CCAMLR正在制定的、用以避免对脆弱海洋生态系统造成重大不利影响的相关措施。

数据说明：本批数据涉及商业敏感信息，因此处于保密限制期。数据存储于 aadfilesERM 路径下，由于原始数据具有商业机密属性，其访问需受权限管控。本批数据与元数据总容量约1TB，包含视频文件（.avi与.mov格式）、电子表格（.xls）、数据库（.mdb）、R脚本与数据文件（.r与.rdata）以及文档（.txt与.doc）。数据按文件夹组织，大致对应最终报告的章节结构，下设数据、分析与文本撰写三个子文件夹。