Development of monitoring systems for studying ecology and behavior of bottlenose dolphins-taking aerial pictures of schools using a captive balloon system and recording underwater vocalizations using a sonobuoy system-

在日本九州岛的阿马库萨沿海沃茨，全年都能看到印度-太平洋海豚。为了研究海豚的生态和行为，开发了监测系统;一个系留气球系统用于拍摄海豚群的空中照片，一个声纳浮标系统用于记录海豚群的水下发声。气球系统包括一个充满氦气的系留气球（直径2.5米），一个悬挂在气球上的视频子系统（2.1公斤）和一个船上的控制子系统。以下信息是从学校1的图像中获得的;学校成员的空中行为，浮出水面的个人数量的时间变化，学校的配置和个人的空间分布。当用长焦透镜拍摄鱼群的一小部分时，可以将母鲸和幼鲸区分开来。季节变化的比例母牛犊对所有的个人建议的主要分娩季节的春季至秋季。该系统适用于外鲸类，除了使用这两种系统进行调查外，还尝试了从船上直接记录鲸类的发声，从陆地上进行经纬仪跟踪，行为观察和照相调查以进行个体识别。发声记录显示，海豚有时会在前方几米或200米处搜索。经纬仪跟踪测量阐明了白天沿着海岸有规律的运动模式。行为观察表明，海豚在白天最热的时候会在有限的区域休息。个体识别调查估计种群规模约为200只，死亡率为每年3.4%。

Indo-Pacific bottlenose dolphins are found thoughout a year in the coastal waters of Amakusa, Kyushu, Japan. To study ecology and behavior of the dolphins, monitoring systems have been developed ; a captive balloon system for taking aerial pictures of schools and a sonobuoy system for recording underwater vocalizations from schools.The balloon system consists of a captive balloon(2.5 m in diameter)filled with the helium gas, a video sub-system(2.1 kg)suspended from the balloon and a control sub-system on a boat. The following information was obtained from images of a schoo1 ; aerial behavior of the school members, temporal changes in number of surfacing individuals, configuration of the school and spatial distribution of individuals. Mother-calf pairs were distinguishable from others when a small portion of the school was taken using a telephoto lens. Seasonal changes in ratios of mothercalf pairs to all the individuals suggest the main parturition season of spring to autumn. This system is applicable to outer cetaceans.Tother with surveys using the two systems, direct recordings of vocalizations by a hydrophon from a boat, theodolite tracking from land, behavior observations, and photographic surveys for individual identification were attempted. Vocalization recordings show that the dolphins searched sometimes a few meters ahead or 200 m ahead. Theodolite tracking surveys clarify a regular movement pattrn along the shore in the daytime. Behavior observations suggest that the dolphins take a rest in a limited areas during the heat of the day. Individual identification surveys give estimetes of population size of almost 200 individuals and mortality rate of 3.4% per year.