Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany.
CIISA - Centre for Interdisciplinary Research in Animal Health, University of Lisbon, Lisbon, Portugal.
Sci Rep. 2020 Oct 1;10(1):16345. doi: 10.1038/s41598-020-73258-y.
As a follow-up on the data presented for seals, we herein report and discuss outcomes resulting from a retrospective evaluation of harbour porpoise stranding and necropsy data from Schleswig-Holstein, Germany (n = 4463) to enable an objective evaluation of potential ecological effects of grey seal predation on porpoises. Results are compared to a recent case of definite grey seal predation as well as to reports from other countries. Porpoise carcasses potentially subject to grey seal predation show severe lacerations, with large parts of skin and underlying tissue being detached from the body. Loss of blubber tissue is common. Based on the occurrence frequencies of encountered lesions, a list of parameters as well as a complementary decision tree are suggested to be used for future assessments. The results shown add to an increasingly standardised assessment protocol of suspected grey seal predation cases making respective results comparable between different areas and countries. The usage of a standardised protocol may increase the awareness of grey seal predation and the reporting of such cases. By this, differences in the predation and feeding patterns as well as the potential ecological relevance of this behaviour may be elucidated.
继有关海豹的数据报告之后，我们在此报告和讨论了对德国石勒苏益格-荷尔斯泰因州港湾鼠海豚搁浅和尸检数据（n=4463）进行回顾性评估的结果，以便能够客观评估灰海豹捕食对鼠海豚的潜在生态影响。结果与最近一起明确的灰海豹捕食案例以及来自其他国家的报告进行了比较。可能受到灰海豹捕食的海豚尸体有严重的撕裂伤，大量皮肤和下面的组织从身体上脱落。鲸脂组织的损失很常见。基于遇到的病变的发生频率，建议列出一组参数以及一个补充的决策树，以便在未来的评估中使用。所显示的结果增加了一个越来越标准化的疑似灰海豹捕食案例评估协议，使得不同地区和国家之间的结果具有可比性。使用标准化协议可能会提高对灰海豹捕食的认识，并增加对此类案例的报告。通过这种方式，可以阐明这种行为的捕食和喂养模式的差异，以及其潜在的生态相关性。
