National Coral Reef Monitoring Program: Towed-diver Surveys of Large-bodied Fishes of the Mariana Archipelago in 2017 (NCEI Accession 0166382)

The towed-diver method is used to conduct surveys of large-bodied (> 50 cm) fishes in the Hawaiian and Mariana Archipelagos, American Samoa, and the Pacific Remote Island Areas as part of the NOAA National Coral Reef Monitoring Program (NCRMP). A suitable method for assessing relatively large areas of reef habitat, the method involves towing a pair of SCUBA divers—one benthic and one fish—behind a small boat for approximately 50 min following the ~15-m depth contour and covering about 2–3 km of habitat. Each diver is equipped with a towboard and attempts to maintain a constant elevation above the surface of the reef (~1 m) for the duration of the survey. A complete towed-diver survey is divided into 10 5-min segments, with visual observations recorded by 5-min segment. The visual estimate data provided in this dataset were collected during towed-diver surveys in which the number, size, and species of all large-bodied fishes observed within a visually estimated 5-m transect on either side of the fish diver and 10 m in front were recorded. The data were collected around the Mariana archipelago as part of the NOAA Pacific Islands Fisheries Science Center (PIFSC), Coral Reef Ecosystem Program (CREP) led mission in 2017.本数据集作为美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）国家珊瑚礁监测计划（National Coral Reef Monitoring Program, NCRMP）的一部分，采用拖曳潜水员法（towed-diver method）对夏威夷群岛、马里亚纳群岛、美属萨摩亚及太平洋偏远岛屿区域的体长大于50厘米的大型鱼类开展调查。该方法适用于评估大面积珊瑚礁生境，具体流程为：将两名水肺潜水员（Self-Contained Underwater Breathing Apparatus, SCUBA）——一名负责底栖生境观测、一名负责鱼类观测——拖曳于小型船艇后方，沿约15米等深线航行约50分钟，覆盖约2至3公里的生境范围。每名潜水员均配备拖曳板，需在整个调查过程中保持与礁体表面约1米的恒定高度。完整的拖曳潜水员调查被划分为10个5分钟分段，观测数据按每5分钟分段进行记录。 本数据集提供的目视估算数据采集自拖曳潜水员调查任务，调查过程中记录了以鱼类观测潜水员为中心，两侧各5米、前方10米范围内的目视估算5米宽样带内所有大型鱼类的数量、体长及物种信息。本次数据采集工作于马里亚纳群岛周边海域开展，属于美国国家海洋和大气管理局太平洋岛屿渔业科学中心（Pacific Islands Fisheries Science Center, PIFSC）珊瑚礁生态系统计划（Coral Reef Ecosystem Program, CREP）牵头的2017年科考任务的一部分。