Deep water fish and shark surveys of South Scott Reef lagoon, Western Australia, using baited remote underwater video stations (BRUVS (TM))

Baited remote underwater video stations (BRUVS (TM)) were deployed to census deep water fish communities (30-70 m) at 19 sites in South Scott Reef lagoon in November and December 1999. The sites were selected to cover nominally representative habitat types and depth contours across 6 regions of South Scott Reef lagoon. These regions, were East Hook Entrance, East Hook, East Lagoon, Central Lagoon, South Lagoon and West Lagoon. A total of 112 deployments were made along three transects running outward from the centre of South Scott Reef lagoon to both East Hook and West Hook and to the southern shallow region, as well as along the drop-off at the entrance to the lagoon. Six BRUVS (TM) were deployed at each site, at similar depths, separated by intervals of approximately 150 m. A GPS fix was taken for all BRUVS (TM) deployed. Each BRUVS (TM) was lowered to the seafloor, with an attached rope and surface float marking its position, enabling recovery later in the day. Normal daily operations were to deploy all six units in one site during the morning, followed by a second deployment at a new site in the afternoon. As a test, on one occasion, two BRUVS (TM) were deployed at night with underwater torches attached for illumination. Each BRUVS (TM) recorded onto a 90 minute Hi-8 video tape until the tape was full. The deployed units were recovered after the maximum recording time and generally within 4 hours of deployment. Tapes were scanned on a Sony Trinitron 14 inch Monitor using a Sony Video Hi-8 Cassette Recorder with a Sony Control Unit editing deck. This allowed fast-forward, play-back, zoom X2 and freeze to enable definitive species identifications, and to speed data collection. Data collected from each tape included a brief description of the seabed topography and benthic community, a species name, the time (hr:min:sec) of first sighting of the individual species, the species activities/behaviours (in 6 categories) in the field of view, the time that an individual species began to feed at the bait canister and/or the time at which the most number of individuals was active in the field of view, and the maximum number of each species sighted simultaneously in any one field of view. These data were initially entered into a Microsoft Excel spreadsheet. This study was undertaken to determine species richness and diversity of fishes, sharks, rays and sea snakes below the limits of safe SCUBA diving in South Scott Reef lagoon, using baited remote underwater video stations (BRUVS (TM)).BRUVS (TM) data was used in combination with benthic community data derived from surveys with television recordings from a remotely operated vehicle (ROV) to provide;1. a statistical clustering by similar fish communities of the different habitats and regions in the South Scott Reef lagoon and2. a measure of association between fish communities and broad habitat classifications. This study was part of a more extensive survey of North Scott Reef lagoon and South Scott Reef lagoon, "Characterisation of Scott Reef lagoon biota - fish and macrobenthos" carried out during November and December, 1999. Work in North Scott Reef lagoon focused on shallow water benthic communities, which were sampled by the divers using hand-held underwater video cameras. Sampling in South Scott Reef lagoon used more diverse methods and focused on not only the benthic communities but the demersal fish communities as well. In South Scott Reef lagoon the benthic communities were sampled using divers, ROVs and grabs, while fish communities were sampled using deployed baited remote underwater video stations (BRUVS (TM)).

1999年11月至12月，研究团队于南斯科特礁泻湖（South Scott Reef lagoon）的19个站位部署诱饵式远程水下视频站（BRUVS (TM)），以普查30至70米水深的深水鱼类群落。站位选取旨在覆盖南斯科特礁泻湖6个区域内具有代表性的典型生境类型与深度剖面，这6个区域分别为东钩入口（East Hook Entrance）、东钩（East Hook）、东泻湖（East Lagoon）、中央泻湖（Central Lagoon）、南泻湖（South Lagoon）与西泻湖（West Lagoon）。本次研究共完成112次设备部署：沿三条从南斯科特礁泻湖中心向外延伸至东钩、西钩及南部浅水区的断面布设，同时沿泻湖入口处的陡坡布置；每个站位在相近水深处部署6台BRUVS (TM)，设备间距约150米。所有部署的BRUVS (TM)均记录了GPS定位信息。每台设备通过系绳与水面浮标标记位置，便于当日晚些时候回收。常规日间作业流程为：晨间在一个站位完成全部6台设备的部署，午后在新站位开展第二次部署。另有一次测试性作业：夜间在两台BRUVS (TM)上加装水下照明手电以实现照明。每台BRUVS (TM)使用90分钟时长的Hi-8录像带进行录制，直至磁带录满。部署的设备通常在达到最长录制时长后回收，整体回收时间一般不超过部署后4小时。录像带通过Sony Trinitron 14 inch Monitor搭配Sony Video Hi-8 Cassette Recorder与Sony Control Unit editing deck进行扫描浏览，支持快进、回放、2倍变焦与定格功能，以实现准确的物种鉴定并加快数据采集效率。从每盘录像带中采集的数据包括：海底地形与底栖生物群落的简要描述、物种名称、各物种首次被观测到的时间（时:分:秒）、视野内该物种的活动/行为（分为6类）、单个物种开始在饵料罐处取食的时间，以及视野内该物种个体数量最多的时刻，同时记录单次视野内同时观测到的该物种最大个体数。这些数据最初录入Microsoft Excel电子表格中。本研究旨在利用BRUVS (TM)普查南斯科特礁泻湖中超出水肺潜水安全极限水深区域的鱼类、鲨鱼、鳐类与海蛇的物种丰富度与多样性。研究结合BRUVS (TM)采集的数据与遥控潜水器（Remotely Operated Vehicle，ROV）电视录像调查获得的底栖生物群落数据，以实现两大目标：1. 对南斯科特礁泻湖内不同生境与区域的鱼类群落进行相似性统计聚类；2. 量化鱼类群落与宽泛生境分类之间的关联。本研究是1999年11月至12月开展的"Characterisation of Scott Reef lagoon biota - fish and macrobenthos"北斯科特礁泻湖与南斯科特礁泻湖综合调查的一部分。北斯科特礁泻湖的调查聚焦浅水底栖生物群落，由潜水员使用手持水下摄像机完成采样；南斯科特礁泻湖的采样方法更为多样，不仅涵盖底栖生物群落，还包括底层鱼类群落：底栖生物群落通过潜水员、遥控潜水器与采泥器进行采样，而鱼类群落则通过部署BRUVS (TM)完成采样。