Population ecology of the finless porpoise

该项目旨在通过分析从飞机上拍摄的照片、检查标本以及从飞机和船只上进行目测调查，来估计长崎附近沿海水域江豚(Neopocaena Phocaenodes)种群的生态参数。总共拍摄了46个个体的照片。体长估计在0.7米到2.2米之间。根据这些照片，阿里亚克海湾和大板湾的种群规模估计超过800只。根据空中目击调查，对这一群体的另一个估计是3093人。发表了一篇根据船只目击调查评估的分布和季节密度的论文。在长崎附近的沿海水域，该物种主要分布在有宅湾、立花湾和大村湾。阿里亚克海湾中部的密度估计为1.31-1.60只/km2。平均学校规模为1.7人。发表了一篇关于年龄、生长和生殖的论文。该物种出生时身长80厘米，5岁时长到140厘米。雌性在6-9岁时达到性成熟。长崎附近的分娩是从秋天的春天开始的。发表了两篇关于骨骼形态的论文。一种描述了年龄和性别二形性的发育。另一种是试图根据头骨形态的地理差异来识别种群。本种在4年前达到头端成熟。在大多数颅骨特征中未检测到性别二型性。我们建议在中崎附近的沿海水域存在两种种群，即有宅湾种群和大村湾种群。

This project aimed to estimate the ecological parameters of the finless porpoise (Neophocaena phocaenoides) populations in the coastal waters near Nagasaki by analysing photos taken from an airplane, examining specimens, and sighting surveys from the plane and boats.A total of photos for 46 individuals were taken. Estimates of body length ranged from 0.7 to 2.2m. Using these photos, the population size in Ariake Sound and Tachiban Bay was estimated to be more than 800 individuals. From airo sighting surveys, another estimate for this population was 3093 individuals.A paper was published on distribution and seasonal density evaluated from the boat sighting surveys. In the coastal waters near Nagasaki, the species is distributed mainly in Ariake Sound, Tachibana Bay and Omura Bay. Density was estimated 1.31-1.60 individuals/km^2 in the middle part of Ariake Sound. The mean school size was 1.7 individualsA paper was publised on age, growth and reproduction. The species is born at length of 80 cm and grows up to 140 cm at age of 5 years old. Females attain sexual maturity at ages of 6-9 years. Parturition near Nagasaki is from autumn spring.Two papers were published on morphology of skeltons. One describes development with age and sexual dimorphism. The other attempted to identify stocks based on geographical difference in the skull morphology. This species attains cranial maturity by 4 years. Sexual dimorphism was not detectable in most of cranial characters. We suggested two stocks exist in the coastal waters near Nakasaki, that is, Ariake Sound-Tachibana Bay stock and Omura Bay stock.