Ranger led marine ecological surveys within the Joseph Bonaparte Gulf Marine Park

The Joseph Bonaparte Gulf Marine Park (JBGMP) is located across the Northern Territory and Western Australian border. The remote nature of the park has limited what information we have of the marine environment, fauna and flora within this region. The Thamarrurr Traditional Owners and by extension the Thamarrur Rangers, based in the township of Wadeye are key custodians for the land and sea country for this region. This project delivered a training program to the Thamarrurr Rangers to enable them to conduct marine monitoring within and adjacent to the JBGMP and collect baseline information on the fish fauna and benthic habitats within a section of the Marine Park. This report presents the results of the two-year project that outlines the training conducted by the Australian Institute of Marine Science (AIMS), and the baseline data collected by AIMS and the Thamarrurr Rangers on the marine biodiversity at multiple locations within the JBGMP. The Rangers conducted fish biodiversity surveys using Baited Remote Underwater Video surveys (BRUVs) and collected information on the benthic seabed community using drop camera surveys (DropCam). Sites selected for these surveys were identified through previous participatory mapping work conducted with Traditional Owners and Rangers from the Wadeye community, and included Emu Reefs, Emu Break and Howland Shoals within the JBGMP, and an additional coastal site, Tchinbilli Reef, adjacent to the Marine Park.

A total of 59 BRUVs deployments and 26 DropCam transects were conducted over four one-week trips between October 2020 and July 2022. The BRUVs surveys identified 79 species across the four locations, including 10 threatened and endangered species of elasmobranchs (sharks and rays). High turbidity conditions at Tchinbilli Reef limited the amount of information on fish fauna at the coastal location, however still provided some baseline information on the fish biodiversity in coastal regions adjacent to the JBGMP. Spatial patterns of deployments within the Marine Park suggested locations on the central and southern Emu Reefs were key hotspots for marine biodiversity, with all locations recording healthy populations of key species identified as important to the Traditional Owners (i.e., Emperors, Snappers, Rockcods, Trout & Mackerel). Habitat information extracted from BRUVs videos were also used to assess species-habitat associations across the region, highlighting the increased biodiversity value of hard substrate (e.g., patch reefs, bedrock and rocky reefs) within the JBGMP, that is more broadly dominated by soft substrate habitats. DropCam surveys provided novel information on the spatial distribution of habitat types across Emu Reefs, again identifying key patch reefs and sandflat habitats around the southern and central Emu Reefs.

The collection of baseline information on the fish composition, distribution and benthic habitat associations now enables the development of a continued monitoring to evaluate the health of the sea country over multiple years. The successful training of the Thamarrurr Rangers in marine monitoring techniques can now enable the Ranger group to carry out yearly monitoring trips at Emu Reefs. This report uses the findings from the baseline information and learnings from working with the Rangers to provide guidance to develop a further program with the Thamarrurr Rangers to monitor the health of the sea country within and adjacent to the JBGMP.

约瑟夫·波拿巴湾海洋公园（Joseph Bonaparte Gulf Marine Park, JBGMP）横跨北领地与西澳大利亚州边界。该公园地处偏远，导致目前对该海域海洋环境、动植物的认知资料极为匮乏。驻扎于瓦德耶镇的塔马鲁传统所有者及其下属的塔马鲁护林员，是该区域陆海领地的核心管护方。本项目为塔马鲁护林员开设专项培训课程，使其可在JBGMP及周边海域开展海洋监测工作，并采集该海洋公园部分区域的鱼类群落与底栖生境基线数据。本报告呈现了这项为期两年的项目成果，内容涵盖澳大利亚海洋科学研究所（Australian Institute of Marine Science, AIMS）实施的培训工作，以及AIMS与塔马鲁护林员在JBGMP多个点位采集的海洋生物多样性基线数据。护林员采用诱饵远程水下视频调查（Baited Remote Underwater Video Surveys, BRUVs）开展鱼类生物多样性普查，并通过下放式海底摄像调查（Drop Camera Surveys, DropCam）收集底栖海底群落相关信息。本次调查点位通过此前与瓦德耶社区传统所有者及护林员合作开展的参与式绘图工作确定，包括JBGMP内的鸸鹋礁群、鸸鹋水道与豪兰浅滩，以及毗邻该海洋公园的额外沿海点位钦比利礁（Tchinbilli Reef）。

2020年10月至2022年7月期间，项目团队分四次为期一周的航次，累计完成59次BRUVs布设与26条DropCam样带调查。BRUVs调查在四个点位共记录到79个物种，其中包括10种受威胁与濒危的板鳃类软骨鱼类（elasmobranchs，鲨类与鳐类）。钦比利礁海域的高浊度条件限制了该沿海点位的鱼类群落数据采集量，但仍为JBGMP毗邻的沿海区域提供了部分鱼类生物多样性基线信息。园区内调查点位的空间分布格局显示，鸸鹋礁群中部与南部海域是海洋生物多样性的核心热点区域，所有点位均记录到对传统所有者具有重要意义的关键物种种群状态良好，包括石鲈、笛鲷、石斑鱼、鳟鱼与鲭鱼。研究人员还通过分析BRUVs视频中的生境信息，评估了该区域的物种-生境关联关系，结果凸显出JBGMP内硬质底质（如斑礁、基岩与岩礁）的生物多样性价值更高——该区域整体以软质底质生境为主。DropCam调查则首次获取了鸸鹋礁群生境类型的空间分布数据，再次确认了鸸鹋礁群南部与中部的核心斑礁与沙质滩涂生境。

本次收集的鱼类组成、分布及底栖生境关联基线数据，为后续开展多年期海洋领地健康评估监测工作奠定了基础。本次成功为塔马鲁护林员开展海洋监测技术培训，使其后续可每年前往鸸鹋礁群开展监测航次。本报告结合基线信息成果与护林员协作经验，为后续与塔马鲁护林员合作开展进一步项目提供指导，以持续监测JBGMP及周边海域的海洋领地健康状况。