Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761 Büsum, Germany; Marine Mammal Research, Institute of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
Prof. Krzysztof Skóra Hel Marine Station, Department of Oceanography and Geography, University of Gdansk, Morska 2, 84-150 Hel, Poland.
Environ Int. 2020 Oct;143:105904. doi: 10.1016/j.envint.2020.105904. Epub 2020 Jun 29.
Harbour porpoise (Phocoena phocoena), the only resident cetacean species of the Baltic Sea is formed of two subpopulations populations, occurring in the western Baltic, Belt Seas and Kattegat and the Baltic Proper, respectively. Harbour porpoises throughout these areas are exposed to a large number of human activities causing direct and indirect effects on individuals, that might also harm this species on a population level. From Latvia, Poland, Germany and Denmark 385 out of 1769 collected dead harbour porpoises were suitable for extensive necropsy. The animals were collected between 1990 and 2015 and were either by-caught or found dead on the coastline. Following necropsies, histopathological, microbiological, virological and parasitological investigations were conducted. Females and males were equally distributed among the 385 animals. Most animals from the different countries were juveniles between 3 months and 3 years old (varying between 46.5 and 100% of 385 animals per country). The respiratory tract had the highest number of morphological lesions, including lungworms in 25 to 58% and pneumonia in 21 to 58% of the investigated animals. Of those with pneumonia 8 to 33% were moderate or severe. The alimentary, hearing, and haematopoietic systems had inflammatory lesions and parasitic infections with limited health impact. 45.5 to 100% of the animals from the different countries were known by-caught individuals, of which 20 to 100% varying between countries had netmarks. Inflammatory lesions, especially in the respiratory tract were found in higher numbers when compared to control populations in areas with less human activities such as arctic waters. The high number of morphological changes in the respiratory tract and of bycatches especially among immature animals before reaching sexual maturity is of serious concern, as well as the low number of adult animals among the material. Data on health status and the causes of death are valuable for management. A next step in this regard will combine data from health and genetic investigations in order to detect differences between the two populations of the Baltic.
波罗的海的唯一常驻鲸目动物港湾鼠海豚（Phocoena phocoena）由两个亚种群组成，分别存在于西部波罗的海、边缘海和卡特加特以及波罗的海。这些地区的港湾鼠海豚暴露于大量人类活动中，这些活动直接或间接影响个体，也可能对该物种的种群水平造成危害。从拉脱维亚、波兰、德国和丹麦收集的 1769 头死亡的港湾鼠海豚中，有 385 头适合进行广泛的尸检。这些动物的收集时间从 1990 年至 2015 年不等，是被误捕或在海岸线发现死亡的。尸检后，进行了组织病理学、微生物学、病毒学和寄生虫学调查。在 385 头动物中，雌性和雄性的分布比例相当。来自不同国家的大多数动物都是 3 个月至 3 岁之间的幼崽（46.5%至 100%不等）。呼吸道的形态病变数量最多，包括 25%至 58%的肺线虫和 21%至 58%的肺炎。在肺炎动物中，有 8%至 33%的情况为中度或重度。消化道、听觉和造血系统存在炎症病变和寄生虫感染，但对健康的影响有限。不同国家的动物中，有 45.5%至 100%是已知的误捕个体，其中 20%至 100%的个体在不同国家之间存在网标。与人类活动较少的北极水域等地区的对照种群相比，呼吸道的炎症病变和形态病变的数量较多。在达到性成熟之前，特别是在不成熟的动物中，有大量的呼吸道形态变化和误捕现象，以及成年动物数量较少，这令人严重关切。关于健康状况和死亡原因的数据对于管理很有价值。在这方面的下一步将是结合健康和遗传调查的数据，以检测波罗的海两个种群之间的差异。
