Beached bachelors: an extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea

IJsseldijk, L. L. et al. (2018) Beached bachelors: an extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea. PLoS ONE, 13(8), e0201221. (doi: 10.1371/journal.pone.0201221) (PMID:30086178) (PMCID:PMC6080757)

Abstract

Between the 8th January and the 25th February 2016, the largest sperm whale Physeter macrocephalus mortality event ever recorded in the North Sea occurred with 30 sperm whales stranding in five countries within six weeks. All sperm whales were immature males. Groups were stratified by size, with the smaller animals stranding in the Netherlands, and the largest in England. The majority (n = 27) of the stranded animals were necropsied and/or sampled, allowing for an international and comprehensive investigation into this mortality event. The animals were in fair to good nutritional condition and, aside from the pathologies caused by stranding, did not exhibit significant evidence of disease or trauma. Infectious agents were found, including various parasite species, several bacterial and fungal pathogens and a novel alphaherpesvirus. In nine of the sperm whales a variety of marine litter was found. However, none of these findings were considered to have been the primary cause of the stranding event. Potential anthropogenic and environmental factors that may have caused the sperm whales to enter the North Sea were assessed. Once sperm whales enter the North Sea and head south, the water becomes progressively shallower (<40 m), making this region a global hotspot for sperm whale strandings. We conclude that the reasons for sperm whales to enter the southern North Sea are the result of complex interactions of extrinsic environmental factors. As such, these large mortality events seldom have a single ultimate cause and it is only through multidisciplinary, collaborative approaches that potentially multifactorial large-scale stranding events can be effectively investigated.

• Item Type: Articles
• Additional Information: Funding: Necropsies and stomach content analysis in the Netherlands were conducted through funding gained from the Dutch Ministry of Economic Affairs (grant number: HD3611/BO11018.02 065). UK necropsies and sampling were conducted by the UK Cetacean Strandings Investigation Programme, which is co-funded by Defra (Marine Biodiversity division) and the Devolved Governments of Scotland and Wales (contract number MB0111). The necropsy in France was funded by Agence Française pour la Biodiversité and Ministère de la Transition Ecologique et Solidaire. In addition, the Ministry of Energy, Agriculture, the Environment and Rural Areas of Schleswig-Holstein, the State Agency of Coastal Protection, National Parks and Ocean Protection of Schleswig-Holstein as well as the Federal Ministry of the Environment, Nature Conservation, Building and Nuclear Safety funded the work on the animals in Schleswig-Holstein.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: ten Doeschate, Mariel and Brownlow, Dr Andrew

Creator Roles

Brownlow, A.: Conceptualization, Data curation, Investigation, Writing – original draft
ten Doeschate, M.: Data curation, Investigation, Visualization, Writing – original draft

• Authors: IJsseldijk, L. L., van Neer, A., Deaville, R., Begeman, L., van de Bildt, M., van den Brand, J. M. A., Brownlow, A., Czeck, R., Dabin, W., ten Doeschate, M., Herder, V., Herr, H., IJzer, J., Jauniaux, T., Jensen, L. F., Jepson, P. D., Jo, W. K., Lakemeyer, J., Lehnert, K., Leopold, M. F., Osterhaus, A., Perkins, M. W., Piatkowski, U., Prenger-Berninghoff, E., Pund, R., Wohlsein, P., Gröne, A., and Siebert, U.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2018 IJsseldijk et al.
• First Published: First published in PLoS ONE 13(8): e0201221
• Publisher Policy: Reproduced under a Creative Commons License