Serum chemistry values for free-ranging ringed seals (Pusa hispida) in Svalbard

Background: Diseases and abnormal physiologic conditions can alter the concentrations of enzymes, metabolites, minerals, and hormones in the blood of animals. The ringed seal (Pusa hispida) has been selected as a key species for environmental monitoring, but information on disease and health parameters for this species is scarce. Objectives: The aim of the study reported here was to obtain serum chemistry reference intervals for free-ranging ringed seals in Svalbard, and then to evaluate serum chemistry values in relation to age, body condition, and sex. Methods: Blood samples were collected after death from ringed seals in Wijdefjorden and Billefjorden, Svalbard (2002-2003; n = 75). Serum was analyzed for 24 selected serum chemistry parameters (enzymes, protein, metabolites, minerals, and cortisol). Results: Compared with younger or older animals, seals between 7 and 16 years of age had larger variations in the activities of alanine transaminase, aspartate transaminase, lactate dehydrogenase, and creatine kinase (CK). Animals classified as having low body condition status had more variation in the serum activity of these enzymes, compared with that in animals with higher condition scores. Serum cortisol concentration was higher in young animals (1-5 years) than in older animals. Serum CK activity was higher in males than in females. Conclusion: The data reported here may be useful in monitoring the health of ringed seals and for tracking the impact of environmental changes in the Arctic.