Proximate Aspects of Starvation-Related Morbidity and Mortality Among Young California Sea Lions (Zalophus californianus)
Lawler, D., Tangredi, B., Matassa, K., Hunter, M., Evans,, R. (2021). Proximate Aspects of Starvation-Related Morbidity and Mortality Among Young California Sea Lions (Zalophus californianus). EKB Journal Management System, 14(2), 39-56. doi: 10.21608/jva.2021.197200
Dennis F Lawler; Basil Tangredi; Keith Matassa; Michele Hunter; Richard H. Evans,. "Proximate Aspects of Starvation-Related Morbidity and Mortality Among Young California Sea Lions (Zalophus californianus)". EKB Journal Management System, 14, 2, 2021, 39-56. doi: 10.21608/jva.2021.197200
Lawler, D., Tangredi, B., Matassa, K., Hunter, M., Evans,, R. (2021). 'Proximate Aspects of Starvation-Related Morbidity and Mortality Among Young California Sea Lions (Zalophus californianus)', EKB Journal Management System, 14(2), pp. 39-56. doi: 10.21608/jva.2021.197200
Lawler, D., Tangredi, B., Matassa, K., Hunter, M., Evans,, R. Proximate Aspects of Starvation-Related Morbidity and Mortality Among Young California Sea Lions (Zalophus californianus). EKB Journal Management System, 2021; 14(2): 39-56. doi: 10.21608/jva.2021.197200

Proximate Aspects of Starvation-Related Morbidity and Mortality Among Young California Sea Lions (Zalophus californianus)

Journal of Veterinary Anatomy
Article 4, Volume 14, Issue 2, October 2021, Page 39-56  XML PDF (1.96 MB)
Document Type: Original Article
DOI: 10.21608/jva.2021.197200
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Authors
Dennis F Lawler email orcid 1; Basil Tangredi2; Keith Matassa3; Michele Hunter3; Richard H. Evans,3
1Center for American Archaeology, Rt. 100, Kampsville IL 62053 USA
2Consulting Veterinarian, Vermont Institute of Natural Sciences, Quechee VT 05059 USA
3Pacific Marine Mammal Center 20612 Laguna Canyon Rd Laguna Beach CA USA
Abstract
Dramatic fluctuations of west coast (USA) California sea lion (CSL) population sizes are well-known historical events. More recently, the episodes have involved extensive losses from pup starvation. However, beyond dams’ lactation failure that results from loss of preferred prey, proximate causes of malnutrition-related death among youngest CSL remain somewhat speculative. We hypothesized that age-related differences in presentation status and postmortem pathology would clarify elements of death trajectories. Records of 494 California sea lions included young pups to late adolescents, all present in the same environment and ecology. We identified differential starvation-related im-pacts among young CSL populations. Rapid and extreme loss of muscle and fat body mass, and resulting emaciation, were the primary overall features of morbidity. More specifically, the death trajectory among young pups was associated more proximately with contributing fluid deficit, hypovolemia, hypoglycemia, and loss of respiratory capacity. The death trajectory among non-pups was associated more proximately with negative effects of forced diet change that resulted in severe-to-overwhelming chronic parasitism. The vast majority of death trajectories appeared to be non-reversible, either in short term or over longer term. The sentinel status of marine mammals such as CSL forewarns of potential threats to local or regional ecology. It is especially concerning if recurring similar events appear to differ causally from historical patterns. We suggest that starvation events occurring in seemingly new patterns can signal new influences on a marine ecology.
Keywords
Starvation; Morbidity; California Sea Lions
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