Modelling the dynamical interactions between seals and their prey: The example of steller sea lions

• Main Authors: Matthiopoulos, Jason, Thompson, David, Boyd, Ian Lamont
• Format: Book
• Language: English
• Published: Unknown Publisher 2005
• Subjects: Kodiak; Alaska
• Online Access: https://research-portal.st-andrews.ac.uk/en/publications/9659aa59-98e9-4432-91ea-4698ce2db516

The model outlined here synthesizes most of the avilable information (energetics, reproductive rates, mortality/survival rates, growth and life-history variables) about Steller sea lions. We parameterised this model partly by using published values and partly by fitting it to the contrasting trajectories of pup production from sites in SE Alaska and on Kodiak Island. Predictions of this fully parameterized model compared favourably with a validation data set of non-pup data. The model was then used to investigate the effects of changing prey density and quality on past and projected populations, the effects of changing levels of background mortality and the effects of changing the depth of prey in the water column. Although preliminary, the results suggest that sea lions are likely to be most sensitive to changes in the quality and depth distribution of prey. This study has shown that models with such wide biological scope can nevertheless make useful contributions to management and conservation. Therefore there are plans to use the same general approach for human/wildlife conflicts in UK populations of grey and common seals.