National Coral Reef Monitoring Plan: Towed-diver Surveys of Benthic Habitat, Key Benthic Species, including Marine Debris Sightings, of the Pacific Remote Island Areas from 2014-03-16 to 2014-03-17 (NCEI Accession 0157552)

The towed-diver method is used to conduct benthic surveys, assessing large-scale disturbances (e.g., bleaching) and quantifying benthic components such as habitat complexity/type and the general distribution and abundance patterns of live coral, CCA, macroalgae, and macroinvertebrates. Surveys are conducted 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 which includes percentage cover of total live hard corals, stressed hard corals, soft corals, sand, coralline algae, and macroalgae, and the number of individual macroinvertebrates (crown of thorns starfish (COTS), sea urchins, and giant clams). Benthic habitat complexity and type data are also collected as part of the survey with the following habitat type categories: continuous reef, spur and groove, patch reefs, rock boulders, pavement, rubble flat, sand flats, pinnacle, and wall.

The data were collected around the Pacific Remote Island Areas as part of the NOAA Pacific Islands Fisheries Science Center (PIFSC), Coral Reef Ecosystem Program (CREP) led missions since 2014. These data can be accessed online via the NOAA National Centers for Environmental Information (NCEI) Ocean Archive.

本数据集采用拖曳潜水员法（towed-diver method）开展底栖调查，用以评估珊瑚礁的大规模扰动（如珊瑚白化），并量化各类底栖组分：包括生境复杂度与类型，以及活珊瑚、钙化藻（Crustose Coralline Algae, CCA）、大型藻类和大型无脊椎动物的整体分布与丰度格局。
本调查覆盖夏威夷群岛、马里亚纳群岛、美属萨摩亚及太平洋偏远岛群，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）的组成部分实施。作为适用于较大范围礁区生境评估的方法，该调查流程为：在小型船艇后方拖曳两名水肺潜水员（Self-Contained Underwater Breathing Apparatus, SCUBA），其中一名负责底栖类群观测、另一名负责鱼类类群观测，沿约15米深度的等深线行进约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板，需在整个调查过程中保持距礁体表面约1米的恒定高度。一次完整的拖曳潜水员调查被划分为10个5分钟的分段，所有目视观测结果均按该分段单元进行记录。

本数据集包含的目视估算数据采集自拖曳潜水员调查，涵盖以下指标：活硬珊瑚总盖度、受胁迫硬珊瑚盖度、软珊瑚盖度、沙质覆盖度、珊瑚藻盖度及大型藻类盖度，以及各类大型无脊椎动物的个体数量：包括长棘海星（Crown-of-Thorns Starfish, COTS）、海胆与砗磲。调查同时采集底栖生境复杂度与类型数据，生境类型分类包括：连续礁、脊槽型礁、斑块礁、岩块、礁坪、碎石滩、沙质滩、尖礁与礁壁。

自2014年起，上述数据作为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）牵头实施的珊瑚礁生态系统计划（Coral Reef Ecosystem Program, CREP）任务的一部分，在太平洋偏远岛群周边采集完成。研究人员可通过美国国家海洋和大气管理局国家环境信息中心（National Centers for Environmental Information, NCEI）海洋档案库在线获取这些数据。