Causes of Adult Mortality in Two Populations of New Zealand Sea Lions (Phocarctos Hookeri)

Overview

Journal Vet Anim Sci

Specialty Veterinary Medicine

Date 2020 Aug 1

PMID 32734078

Citations 1

Authors

B Lenting

B Gartrell

A Kokosinska

P J Duignan

S Michael

S Hunter

W D Roe

Affiliations

Soon will be listed here.

Abstract

The New Zealand sea lion is an endangered species endemic to New Zealand. While causes of death are well described for pups of this species, mortality in adults is poorly characterised. This study investigated causes of death in 136 New Zealand sea lions in two different populations: a major breeding site on remote, uninhabited Enderby Island in the sub-Antarctic, and a slowly increasing recolonising population on the inhabited mainland. For animals with at least a partial diagnostic investigation ( = 112), the most frequently diagnosed causes of mortality were infectious disease (41/112; 37%), particularly tuberculosis due to (20/112; 18%), and conspecific trauma (27/112; 24%). Anthropogenic trauma was an important cause of death in mainland sea lions (9/33; 26%). Deliberate anthropogenic mortality has previously been identified as the greatest potential threat to population recovery for mainland sea lions, and as human and pinniped populations increase, managing interactions between these species will become increasingly important.

Citing Articles

Pup mortality in New Zealand sea lions (Phocarctos hookeri) at Enderby Island, Auckland Islands, 2013-18.

Michael S, Hayman D, Gray R, Zhang J, Rogers L, Roe W PLoS One. 2019; 14(11):e0225461.

PMID: 31751414 PMC: 6874089. DOI: 10.1371/journal.pone.0225461.

References

Cousins D, Williams S, Reuter R, Forshaw D, Chadwick B, Coughran D . Tuberculosis in wild seals and characterisation of the seal bacillus. Aust Vet J. 1993; 70(3):92-7. DOI: 10.1111/j.1751-0813.1993.tb03284.x. View

Boardman W, Shephard L, Bastian I, Globan M, Fyfe J, Cousins D . Mycobacterium pinnipedii tuberculosis in a free-ranging Australian fur seal (Arctocephalus pusillus doriferus) in South Australia. J Zoo Wildl Med. 2015; 45(4):970-2. DOI: 10.1638/2014-0054.1. View

Cousins D, Bastida R, Cataldi A, Quse V, Redrobe S, Dow S . Tuberculosis in seals caused by a novel member of the Mycobacterium tuberculosis complex: Mycobacterium pinnipedii sp. nov. Int J Syst Evol Microbiol. 2003; 53(Pt 5):1305-1314. DOI: 10.1099/ijs.0.02401-0. View

Loeffler S, de Lisle G, Neill M, Collins D, Price-Carter M, Paterson B . The seal tuberculosis agent, Mycobacterium pinnipedii, infects domestic cattle in New Zealand: epidemiologic factors and DNA strain typing. J Wildl Dis. 2014; 50(2):180-7. DOI: 10.7589/2013-09-237. View

Woods R, Cousins D, Kirkwood R, Obendorf D . Tuberculosis in a wild Australian fur seal (Arctocephalus pusillus doriferus) from Tasmania. J Wildl Dis. 1995; 31(1):83-6. DOI: 10.7589/0090-3558-31.1.83. View

de Amorim D, Casagrande R, Alievi M, Wouters F, De Oliveira L, Driemeier D . Mycobacterium pinnipedii in a stranded South American sea lion (Otaria byronia) in Brazil. J Wildl Dis. 2014; 50(2):419-22. DOI: 10.7589/2013-05-124. View

de Paoli P . Bio-banking in microbiology: from sample collection to epidemiology, diagnosis and research. FEMS Microbiol Rev. 2005; 29(5):897-910. PMC: 7110355. DOI: 10.1016/j.femsre.2005.01.005. View

Roe W, Rogers L, Pinpimai K, Dittmer K, Marshall J, Chilvers B . Septicaemia and meningitis caused by infection of New Zealand sea lion pups with a hypermucoviscous strain of Klebsiella pneumoniae. Vet Microbiol. 2015; 176(3-4):301-8. DOI: 10.1016/j.vetmic.2015.01.019. View

Spraker T, Lander M . Causes of mortality in northern fur seals (Callorhinus ursinus), St. Paul Island, Pribilof Islands, Alaska, 1986-2006. J Wildl Dis. 2010; 46(2):450-73. DOI: 10.7589/0090-3558-46.2.450. View

10.

Gerber J, Roletto J, Morgan L, Smith D, Gage L . Findings in pinnipeds stranded along the central and northern California coast, 1984-1990. J Wildl Dis. 1993; 29(3):423-33. DOI: 10.7589/0090-3558-29.3.423. View

11.

Baker J, McCann T . Pathology and bacteriology of adult male Antarctic fur seals, Arctocephalus gazella, dying at Bird Island, South Georgia. Br Vet J. 1989; 145(3):263-75. DOI: 10.1016/0007-1935(89)90079-1. View

12.

Roe W, Michael S, Fyfe J, Burrows E, Hunter S, Howe L . First report of systemic toxoplasmosis in a New Zealand sea lion (Phocarctos hookeri). N Z Vet J. 2016; 65(1):46-50. DOI: 10.1080/00480169.2016.1230526. View

13.

Hunter J, Duignan P, Dupont C, Fray L, Fenwick S, Murray A . First report of potentially zoonotic tuberculosis in fur seals in New Zealand. N Z Med J. 1998; 111(1063):130-1. View

14.

Castinel A, Grinberg A, Pattison R, Duignan P, Pomroy B, Rogers L . Characterization of Klebsiella pneumoniae isolates from New Zealand sea lion (Phocarctos hookeri) pups during and after the epidemics on Enderby Island, Auckland Islands. Vet Microbiol. 2007; 122(1-2):178-84. DOI: 10.1016/j.vetmic.2006.12.024. View

15.

Castinel A, Duignan P, Pomroy W, Lopez-Villalobos N, Gibbs N, Chilvers B . Neonatal mortality in New Zealand sea lions (Phocarctos hookeri) at Sandy Bay, Enderby Island, Auckland Islands from 1998 to 2005. J Wildl Dis. 2007; 43(3):461-74. DOI: 10.7589/0090-3558-43.3.461. View