Whale sightings during POLARSTERN cruise PS122/3 (MOSAiC)@en

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 PS122/3 (Arctic Ocean Drift) 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，因为实施标准调查方法线样带调查（line-transect surveys）难度大且成本高昂。为解决这一难题，我们启动了一项计划，通过值班航海官员，在所有极地号（Polarstern）科考航次期间，对所有偶遇鲸类目击事件进行电子记录。在极地号PS122/3航次（北极海洋漂移航次）期间，当班航海官员借助安装在船舶驾驶台触摸屏笔记本电脑上的定制化软件包WALOG（WhAleLOGger，鲸类目击记录仪），记录了裸眼目视的偶遇目击事件。研究人员通过裸眼或7×50手持式双筒望远镜对物种进行鉴定，尽可能细化至最低分类学层级，并为鉴定结果赋予“置信度”等级。若条件允许则统计动物个体数量，对于大种群落则进行数量估算。若无法将物种鉴定至具体物种层级，则将其归类至下一级可识别的分类学类别。目击位置、日期与时间信息会在记录生成时，自动从船舶DAVIS船舶系统（DAVIS-Ship System，https://dship.awi.de/）传输至WALOG软件。若条件允许，会拍摄照片用于后续回溯分析。所有获取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，我们将对目击时间、地点的合理性，物种名称的标准化处理，目击时添加的补充备注，以及照片（若有提供）等额外信息进行核查，以验证或优化物种鉴定结果。本数据集可应用于物种分布建模，并可为相关方提供鲸类目击事件的相关信息。