Habitat survey design grid and underwater camera fish observations from untrawlable habitats in the Gulf of Alaska, 2013-2019

This dataset has two main components: survey and assessment of the survey methods for each samplyng locations, and underwater image data 1. A survey grid consisting of geographic coordinates for sampling stations at 1 km square spacing throughout the Gulf of Alaska, along with the trawlability designations from multiple external datasets, their overall agreement metrics, and the species specific essential fish habitat scores. This data was derived by spatial cross-reference of several map products in a new sampling frame and is presented in a simple csv format with one row for each station including all relevant data. 2. Underwater camera observations of fish reactions based on a stereo-camera analysis which provided 3D positioning of fish relative to the seafloor and an analyst designation of fish orientation and reaction to the camera. Image data consisted of a pair of images taken once per second with each collection event lasting approximately 15 minutes. Analysis consisted of making annotations on corresponding points in paired images that were used to triangulate positions in real space. The changes in positions of fixed points along the seafloor was used to estimate camera motion. Fish motion was estimated relative to fixed points along the seafloor. Observations are from data collected in 2019 during the NOAA AFSC summer pollock acoustic survey and include twenty species commonly encountered in untrawlable rocky habitats in the Gulf of Alaska.

本数据集包含两大核心组成部分：一是各采样点位的调查方法调研与评估，二是水下图像数据。1. 调查网格数据集：覆盖阿拉斯加湾全域、间距为1平方千米的采样站位地理坐标网格，同时整合了多份外部数据集提供的拖网可作业性标注、各类标注的整体一致性指标，以及针对特定物种的关键鱼类栖息地评分。该数据通过在全新采样框架下对多款地图产品开展空间交叉比对生成，以简洁的CSV格式存储，每个采样站位对应一行数据，包含全部相关信息。2. 水下观测图像数据集：基于立体相机分析的鱼类行为响应观测数据，该分析可实现鱼类相对于海底的三维定位，并由分析师标注鱼类的朝向及其对相机的响应行为。图像数据采用每秒拍摄一对立体图像的方式采集，单次采集时长约15分钟。分析流程为：在配对图像的对应点位上标注特征点，以此通过三角测量法计算其在真实空间中的位置；利用沿海底固定点位的位置变化估算相机运动参数，进而推导鱼类相对于海底固定点的运动轨迹。本次观测数据源自2019年美国国家海洋和大气管理局阿拉斯加渔业科学中心（NOAA AFSC）夏季狭鳕声学调查项目，涵盖阿拉斯加湾难拖网岩质生境中常见的20个鱼类物种。