Causes of cetacean stranding and death on the Catalonian coast (western Mediterranean Sea), 2012-2019.

M Cuvertoret-Sanz,Ml Abarca,A Canturri,Ja Raga,A Cobos,A O’Byrne,Mf Van Bressem,L Ganges,C López-Figueroa,L Pérez,B Martí-Garcia,E Pintado,M Domingo

doi:10.3354/dao03550

Abstract

The causes of cetacean stranding and death along the Catalan coast between 2012 and 2019 were systematically investigated. Necropsies and detailed pathological investigations were performed on 89 well-preserved stranded cetaceans, including 72 striped dolphins Stenella coeruleoalba, 9 Risso's dolphins Grampus griseus, 5 bottlenose dolphins Tursiops truncatus, 1 common dolphin Delphinus delphis, 1 Cuvier's beaked whale Ziphius cavirostris and 1 fin whale Balaenoptera physalus. The cause of death was determined for 89.9% of the stranded cetaceans. Fisheries interaction was the most frequent cause of death in striped dolphins (27.8%) and bottlenose dolphins (60%). Cetacean morbillivirus (CeMV) was detected on the Catalan coast from 2016 to 2017, causing systemic disease and death in 8 of the 72 (11.1%) striped dolphins. Chronic CeMV infection of the central nervous system was observed from 2018-2019 in a further 5 striped dolphins. Thus, acute and chronic CeMV disease caused mortality in 18% of striped dolphins and 14.6% of all 89 cetaceans. Brucella ceti was isolated in 6 striped dolphins and 1 bottlenose dolphin with typical brucellosis lesions and in 1 striped dolphin with systemic CeMV. Sinusitis due to severe infestation by the nematode parasite Crassicauda grampicola caused the death of 4 out of 6 adult Risso's dolphins. Maternal separation, in some cases complicated with septicemia, was a frequent cause of death in 13 of 14 calves. Other less common causes of death were encephalomalacia of unknown origin, septicemia, peritonitis due to gastric perforation by parasites and hepatitis caused by Sarcocystis spp.

Highlights

Bressem et al 2009, Di Guardo et al 2011, Avila et al.Attribution Licence
Between January 2012 and December 2019, a total of 289 cetaceans from 7 species stranded along the coast of Catalonia
We report on the causes of stranding and death in cetaceans from the Catalonian coast

Summary

Introduction

Bressem et al 2009, Di Guardo et al 2011, Avila et al. Attribution Licence. Authors and original publication must be credited. Dis Aquat Org 142: 239–253, 2020 phis, common bottlenose dolphins Tursiops truncatus and striped dolphins Stenella coeruleoalba) and have severely reduced populations of these species (Silvani et al 1999, Tudela et al 2005, Hammond et al 2008, Bearzi et al 2012). Collision with vessels is another important cause of mortality, especially in large cetaceans such as fin whales Balaenoptera physalus and sperm whales Physeter macrocephalus (Panigada et al 2006, Notarbartolo-Di-Sciara 2014). High loads of chemical pollutants detected in the tissues of several species may reduce their immune response and impair reproduction

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Results

Conclusion