National Coral Reef Monitoring Program: Coral demographic data (adult and juvenile corals, species, colony length, condition, etc.) collected during Stratified Random Surveys (StRS) across the US Pacific since 2013 derived from in-situ diver surveys and structure-from-motion imagery (NCEI Accession 0298217)

The data described here result from benthic coral demographic surveys within belt transects of specified length and width for two life stages (juveniles and adults) across the US Pacific since 2013. This data is collected as part of the NOAA Pacific Islands Fisheries Science Center (PIFSC) and Ecosystem Sciences Division (ESD; formerly the Coral Reef Ecosystem Division) led National Coral Reef Monitoring Program (NCRMP) missions around the Mariana Archipelago, American Samoa, Pacific Remote Island Areas, and the Hawaiian Archipelago since 2013. Originally coral demographic data was derived by in-situ diver surveys, and starting in 2023 the data collection transitioned to derivation from models generated with structure-from-motion imagery.

The in-situ diver coral demographic surveys are part of the Rapid Ecological Assessment (REA) surveys for corals and fish conducted during ESD-led NCRMP missions. From 2013 to 2017, a two-stage stratified random sampling (StRS) design was used to survey the coral reef ecosystems across sub-island sectors and three depth strata (shallow: 0-6m, mid: 6-18m and deep: >18m). Starting in 2018 a one-stage StRS design was employed. These sites represent a broad range of depths (1-25 m), habitat types (aggregate reef, patch reef, pavement, rock and boulder and rubble), coral cover, and diving conditions. Allocation of sampling effort was proportional to strata area and variance in coral density. The StRS design effectively reduces estimate variance through stratification using environmental covariates and by sampling more sites rather than sampling more transects at a site. Therefore, site-level estimates and site to site comparisons should be used with caution.

Starting in 2023 coral demographic data was also derived by the GIS analysis of benthic Structure from Motion (SfM) imagery. The source imagery was collected during in-water surveys conducted by divers, and is documented separately here: https://www.fisheries.noaa.gov/inport/item/63095. During each SfM survey, an 18m transect line was deployed along the isobath and photographed using underwater cameras while swimming in a back and forth swim pattern for later processing. At depths of 0-18m, SfM surveys were conducted over a 3 x 20m area and at depths >18m, a 3 x 13m area was surveyed, both with the transect running down the middle of the survey area. The photographs were processed using Agisoft Metashape software to generate orthomosaic images that were analyzed in ArcGIS for juvenile and adult coral colony demographic metrics. SfM imagery was not submitted as part of this archive package.

The data provide information on adult coral colony counts, morphology, size, partial mortality (old and recent dead), presence and causation of disease and other compromised health conditions, including bleaching. Juvenile colony surveys include morphology and size. Taxonomic identification of adult colonies is to the lowest taxonomic level possible and genus level for juveniles. Some segment observations were repeated for internal quality control starting in 2019, and indicated with a repeat segment flag and transectnum = -999; use column OG_OR_RPT_SEG to filter for only original segments. Refer to data dictionaries for details on column conditions.

The raw data also include individual observations of crustose coralline algae diseases and Alcyonarian disease type and lesion size as well as the presence of other Anthozoans, such as other cnidarians including Alcyonareans, Zoantharians, Corallimorpharians, and Antipatharians (does not apply to PMNM surveys conducted in 2014 and 2015 or surveys conducted after 2017).

本数据集所描述的内容源自自2013年以来，美国太平洋沿岸带状样带内特定长度和宽度下，针对两个生命阶段（幼体和成体）进行的底栖珊瑚人口调查。该数据收集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（NOAA太平洋岛屿渔业科学中心，PIFSC）和生态系统科学部（ESD；前身为珊瑚礁生态系统部）主导的国家珊瑚礁监测计划（NCRMP）任务的一部分，这些任务自2013年以来围绕马里亚纳群岛、美属萨摩亚、太平洋偏远岛屿地区和夏威夷群岛进行。最初，珊瑚人口数据是通过现场潜水员调查获得的，而自2023年起，数据收集转变为利用运动结构图像生成的模型推导而来。

现场潜水员珊瑚人口调查是ESD领导的NCRMP任务中进行的珊瑚和鱼类快速生态评估（REA）调查的一部分。从2013年到2017年，采用了两阶段分层随机抽样（StRS）设计，以调查岛屿次区域和三个深度层（浅层：0-6米，中层：6-18米和深层：>18米）的珊瑚礁生态系统。从2018年开始，采用了单阶段StRS设计。这些地点代表了广泛的深度（1-25米）、栖息地类型（聚集礁、斑块礁、路面、岩石和砾石）、珊瑚覆盖率以及潜水条件。采样努力的分配与层面积和珊瑚密度方差成比例。StRS设计通过使用环境协变量进行分层以及通过在更多地点而不是在单个地点进行更多样带抽样来有效地减少了估计方差。因此，应谨慎使用站点级估计和站点间比较。

从2023年开始，珊瑚人口数据还通过GIS分析底栖运动结构（SfM）图像获得。源图像由潜水员进行的水下调查收集，并在此处另行记录：https://www.fisheries.noaa.gov/inport/item/63095。在每次SfM调查中，沿等深线部署一条18米样带，并使用水下相机在往返游泳的模式下进行拍照，以便后续处理。在0-18米的深度，SfM调查在一个3 x 20米的区域内进行，而在>18米的深度，则在一个3 x 13米的区域内进行，样带均位于调查区域的中间。照片使用Agisoft Metashape软件进行处理，以生成正射影像图，这些图像在ArcGIS中用于分析幼体和成年珊瑚群体的人口指标。SfM图像未作为本存档包的一部分提交。

数据提供了关于成年珊瑚群体计数、形态、大小、部分死亡率（旧的和最近的死亡）、疾病及健康受损状况（包括漂白）的存在和原因的信息。幼体群体调查包括形态和大小。成年珊瑚群体的分类鉴定至最低的分类级别，对于幼体则至属级。自2019年起，一些段落观察重复进行，以进行内部质量控制，并带有重复段落标志和transectnum = -999；使用OG_OR_RPT_SEG列进行过滤，以仅选择原始段落。有关列条件的详细信息，请参阅数据字典。

原始数据还包括石珊瑚藻类疾病和软珊瑚疾病类型及病变大小的个体观察，以及其他珊瑚类群（如其他刺胞动物，包括软珊瑚、海葵类、珊瑚水母类和海葵类）的存在。此部分不适用于2014年和2015年或2017年之后的PMNM调查。