NMML Harbor Porpoise Vessel Survey, SE Alaska, Summer 1991

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: In summer 1991, Southeast Alaska, Cook Inlet, and Bristol Bay, was surveyed for harbor porpoise (&lt;i&gt;Phocoena phocoena&lt;/i&gt;) from the NOAA John N. Cobb using line transect methodology. The shipboard platform was 28.36 m (93 ft) in length with a bridge height of 4.27 m (14 ft). To obtain data on seasonal movements of porpoise, a limited number of transects were made in areas of known porpoise concentrations. When a sighting was made, the following variables were recorded: time, angle, number of reticles to the sighting, radar distance (nm) to the shoreline at the same angle of the sighting, the species, the count of the porpoise seen (best, high, and low), and the animal(s) direction of travel. Search effort was recoded by noting the time and location of the ship at the beginning and end of each transect.原始提供方：国家海洋哺乳动物实验室（National Marine Mammal Laboratory） 数据集归属：国家海洋哺乳动物实验室 摘要：1991年夏季，研究团队搭乘NOAA约翰·N·科布号（NOAA John N. Cobb）科考船，采用线样带调查法（line transect methodology），对阿拉斯加东南部、库克湾与布里斯托尔湾的港湾鼠海豚（harbor porpoise，<i>Phocoena phocoena</i>）开展专项调查。该科考船船长28.36米（93英尺），驾驶台高度4.27米（14英尺）。为获取鼠海豚的季节移动数据，研究人员在已知鼠海豚聚集的区域布设了有限数量的调查样带。当观测到目标个体时，需记录以下变量：观测时间、观测角度、瞄准目标的分划刻度数、与该观测角度对应的海岸线雷达距离（单位：海里）、物种名称、目击鼠海豚的数量（最佳、最高与最低估值）以及动物的行进方向。研究人员通过记录每条样带起始与结束时刻的船舶位置与对应时间，统计搜索作业量。