Whale sightings during POLARSTERN cruise PS106/2 (ARK-XXXI/1.2)

Data on whale distribution and abundance in the polar oceans is rather sparse, as implementing the standard surveying method, line-transect surveys, is challenging and costly. To overcome this problem, we initiated a program to electronically log all opportunistic cetacean sightings during all Polarstern expeditions through the nautical officer on watch. Opportunistic (visual) sightings by naked eye were logged during Polarstern Cruise PS106/2 (Longyearbyen - Tromsø) by the nautical officer on duty using a customized Software package (WALOG, WhAleLOGger) installed on a touch screen laptop located on the ship's bridge. Species were identified by naked eye or handheld binoculars (7x50) to the lowest possible taxonomical level and assigned a “certainty” level of identification. The number of animals were counted if possible or estimated for larger groups. Whenever identification to species level was not possible, the next identifiable taxonomical category was assigned. Information on sighting position, date and time are automatically transferred from the ship's DAVIS-Ship System (https://dship.awi.de/) to the WALOG software at the time of logging. Photographs were taken if possible for retrospective analysis. All data of acquired sightings were retrospectively validated by a marine biologist and converted to a standard format. To this end, plausibility of sighting time, location, standardization of species names, eventual comments added at the time of sighting, as well as additional information such as photographs (if available) were checked either to verify or improve species identification. Datasets are used in species distribution modelling and to inform interested parties about occurrences.

极地海洋中鲸类的分布与丰度数据相当匮乏，因标准调查方法——线样带调查（line-transect surveys）——的实施既极具挑战性，又成本高昂。为破解这一难题，我们启动了一项计划，通过值班航海官，在所有极星号（Polarstern）科考航行中，对所有偶遇鲸类目击事件进行电子记录。在极星号PS106/2航次（朗伊尔城—特罗姆瑟航线）中，值班航海官借助安装于船舶驾驶台触摸屏笔记本电脑的定制化软件包WALOG（WhAleLOGger），记录了肉眼观测的偶遇目击事件。鲸类物种通过肉眼或手持双筒望远镜（7×50）鉴定至尽可能低的分类学层级，并赋予对应鉴定置信度等级。若条件允许，会统计动物个体数量；对于大型群体则予以估算。若无法鉴定至物种层级，则将其归类至可识别的次一级分类单元。目击位置、日期与时间信息会在记录时，自动从船舶DAVIS-Ship系统（https://dship.awi.de/）传输至WALOG软件。若条件允许，会拍摄照片用于回溯分析。所有采集到的目击数据均由海洋生物学家进行回溯验证，并转换为标准格式。为此，研究人员将核查目击时间、地点的合理性，物种名称的标准化处理，目击当时添加的备注信息，以及照片（若有）等额外信息，以确认或优化物种鉴定结果。本数据集可用于物种分布建模，并可为相关方提供鲸类出现情况的参考信息。