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Gaydos JK, St Leger J, Raverty S, Nollens H, Haulena M, Ward EJ, Emmons CK, Hanson MB, Balcomb K, Ellifrit D, Weiss MN, Giles D. Epidemiology of skin changes in endangered Southern Resident killer whales (Orcinus orca). PLoS One 2023; 18:e0286551. [PMID: 37379317 DOI: 10.1371/journal.pone.0286551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/18/2023] [Indexed: 06/30/2023] Open
Abstract
Photographic identification catalogs of individual killer whales (Orcinus orca) over time provide a tool for remote health assessment. We retrospectively examined digital photographs of Southern Resident killer whales in the Salish Sea to characterize skin changes and to determine if they could be an indicator of individual, pod, or population health. Using photographs collected from 2004 through 2016 from 18,697 individual whale sightings, we identified six lesions (cephalopod, erosions, gray patches, gray targets, orange on gray, and pinpoint black discoloration). Of 141 whales that were alive at some point during the study, 99% had photographic evidence of skin lesions. Using a multivariate model including age, sex, pod, and matriline across time, the point prevalence of the two most prevalent lesions, gray patches and gray targets, varied between pods and between years and showed small differences between stage classes. Despite minor differences, we document a strong increase in point prevalence of both lesion types in all three pods from 2004 through 2016. The health significance of this is not clear, but the possible relationship between these lesions and decreasing body condition and immunocompetence in an endangered, non-recovering population is a concern. Understanding the etiology and pathogenesis of these lesions is important to better understand the health significance of these skin changes that are increasing in prevalence.
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Affiliation(s)
- Joseph K Gaydos
- The SeaDoc Society, Karen C. Drayer Wildlife Health Center - Orcas Island Office, UC Davis School of Veterinary Medicine, Eastsound, Washington, United States of America
| | - Judy St Leger
- SeaWorld Parks and Entertainment, San Diego, California, United States of America
| | - Stephen Raverty
- Animal Health Center, Ministry of Agriculture, Abbotsford, British Columbia, Canada
| | - Hendrik Nollens
- SeaWorld Parks and Entertainment, San Diego, California, United States of America
| | | | - Eric J Ward
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
| | - Candice K Emmons
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
| | - M Bradley Hanson
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
| | - Ken Balcomb
- Center for Whale Research, Friday Harbor, Washington, United States of America
| | - Dave Ellifrit
- Center for Whale Research, Friday Harbor, Washington, United States of America
| | - Michael N Weiss
- Center for Whale Research, Friday Harbor, Washington, United States of America
| | - Deborah Giles
- Center for Whale Research, Friday Harbor, Washington, United States of America
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Van Bressem MF, Van Waerebeek K, Duignan PJ. Tattoo Skin Disease in Cetacea: A Review, with New Cases for the Northeast Pacific. Animals (Basel) 2022; 12:ani12243581. [PMID: 36552501 PMCID: PMC9774126 DOI: 10.3390/ani12243581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Tattoo skin disease (TSD) is a poxviral dermatopathy diagnosed in cetaceans. We review the literature on TSD aetiology, clinical characteristics, pathology and epidemiology and evaluate immune responses against the virus. In addition, necropsy reports for fifty-five harbour porpoises (Phocoena phocoena), twenty-two Delphinidae and four Kogiidae stranded in northern California in 2018-2021 were checked for diagnostic tattoo lesions. TSD occurs in the Mediterranean, North and Barents Seas, as well as in the Atlantic, eastern Pacific and Indian Oceans in at least 21 cetacean species, with varying prevalence. Two cetacean poxvirus (CePV) clades are recognised: CePV-1 in odontocetes and CePV-2 in mysticetes. CePV-1 isolates were recovered from six Delphinidae and one Phocoenidae in the Americas, Europe and Hong Kong. Strains from Delphinidae are closely related. Among Phocoenidae, poxviruses were sampled only in harbour porpoises around the British Isles. CePV-2 isolates were obtained from southern right whales (Eubalaena australis) and a bowhead whale (Balaena mysticetus). In healthy animals, an immune response develops over time, with young calves protected by maternal immunity. Salinity and sea surface temperature do not seem to influence TSD prevalence in free-ranging cetaceans. High concentrations of immunotoxic halogenated organochlorines may cause a more severe clinical disease. Substitution and loss of genes involved in anti-viral immunity may favour CePV entry, replication and persistence in the epidermis. Off California, Delphinidae were less often (26.3%) affected by TSD than harbour porpoises (43.6%). Male porpoises were significantly more prone (58.1%) to show clinical disease than females (25%). Among males, TSD affected a high proportion of juveniles and subadults. TSD was not detected in the Kogiidae.
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Affiliation(s)
- Marie-Françoise Van Bressem
- Cetacean Conservation Medicine Group, Peruvian Centre for Cetacean Research, Museo de Delfines, Lima 20, Peru
- Correspondence:
| | - Koen Van Waerebeek
- Cetacean Conservation Medicine Group, Peruvian Centre for Cetacean Research, Museo de Delfines, Lima 20, Peru
- ProDelphinus, Miraflores, Lima 18, Peru
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