Whale sightings during POLARSTERN cruise PS124

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 PS124 (Port Stanley – Port Stanley) 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.

极地海洋鲸类分布与丰度相关数据较为匮乏，因标准调查方法——样线法调查（line-transect surveys）的实施难度大、成本高昂。为解决这一难题，我们启动了一项计划，通过当班值班驾驶员，在所有极星号（Polarstern）科考航次中，以电子方式记录所有偶遇鲸类目击记录。在极星号PS124航次（斯坦利港—斯坦利港）期间，当班值班驾驶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套件WALOG（WhAleLOGger），以裸眼目视方式记录了偶遇鲸类目击事件。科研人员通过裸眼或手持7×50规格双筒望远镜，尽可能将物种鉴定至最低分类学层级，并为物种鉴定赋予"确定性"等级。若条件允许则统计动物个体数量，对于大型群体则进行估算；若无法鉴定至物种层级，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。所有已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，研究人员会核查目击时间、位置的合理性，物种名称的标准化，目击时添加的附带注释，以及照片（若有）等额外信息，以验证或优化物种鉴定结果。该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。