NMML Harbor Porpoise Aerial Survey, Kodiak Island, Replicate 3, 1992

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: On 6 July to 9 August 1992, as part of a larger study, Alaska harbor porpoise (<i>Phocoena phocoena</i>) abundance was investigated during an aerial survey off Kodiak Island. Employing a Twin Otter as the survey platform, the third of three identical sawtooth tracklines was flown at an altitude of 152.2 m (500 ft) and at an airspeed of 185 km/h. Line-transect methodology was used, and only those observations made during optimal conditions were analyzed. Density of harbor porpoises was calculated using line transect estimates based on perpendicular distances of sightings to the cruise track of the airplane. On average, porpoise group size and density off Kodiak Island was 1.41 (SE = 0.13) and 1.85 groups/100 km2 (SE = 6.03).原始提供方：国家海洋哺乳动物实验室（National Marine Mammal Laboratory） 数据集致谢：国家海洋哺乳动物实验室 摘要：1992年7月6日至8月9日，作为一项大型研究的子课题，科研人员在科迪亚克岛周边海域开展航空调查，以评估阿拉斯加港湾鼠海豚（*Phocoena phocoena*）的种群丰度。本次调查以双水獭（Twin Otter）型飞机作为观测平台，飞行了三条完全一致的锯齿状航线中的第三条，飞行高度为152.2米（500英尺），空速为185千米/小时。调查采用线样带（line-transect）法，仅对最优观测条件下获取的目击记录进行分析。研究人员基于目击事件至飞机巡航航线的垂直距离，通过线样带估算法计算港湾鼠海豚的种群密度。科迪亚克岛周边海域的港湾鼠海豚平均群规模为1.41（标准误SE=0.13），平均种群密度为1.85群/100平方千米（标准误SE=6.03）。