Movement and seasonal energetics mediate vulnerability to disturbance in marine mammal populations

In marine environments noise from human activities is increasing dramatically, causing animals to alter their behavior and forage less efficiently. These alterations incur energetic costs that can result in reproductive failure, death, and may ultimately influence population viability; yet the link...

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Bibliographic Details
Published in:The American Naturalist
Main Authors: Gallagher, Cara Alyse, Grimm, Volker, Kyhn, Line Anker, Kinze, Carl Christian, Nabe-Nielsen, Jacob
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
Online Access:https://pure.au.dk/portal/da/publications/movement-and-seasonal-energetics-mediate-vulnerability-to-disturbance-in-marine-mammal-populations(f8e28fcb-9332-4ecf-b379-02d618c17a09).html
https://doi.org/10.1086/712798
https://pure.au.dk/ws/files/273779448/Gallagheretal2021.pdf
http://www.scopus.com/inward/record.url?scp=85098988662&partnerID=8YFLogxK
Description
Summary:In marine environments noise from human activities is increasing dramatically, causing animals to alter their behavior and forage less efficiently. These alterations incur energetic costs that can result in reproductive failure, death, and may ultimately influence population viability; yet the link between population dynamics and individual energetics is poorly understood. We present an energy budget model for simulating effects of acoustic disturbance on populations. It accounts for environmental variability and individual state, while incorporating realistic animal movements. Using harbor porpoises (Phocoena phocoena) as a case study, we evaluated population consequences of disturbance from seismic surveys and investigated underlying drivers of vulnerability. The framework reproduced empirical estimates of population structure and seasonal variations in energetics. The largest effects predicted for seismic surveys were in late summer and fall, and were unrelated to local abundance, but instead to lactation costs, water temperature, and body fat. Our results demonstrate that consideration of temporal variation in individual energetics and their link to costs associated with disturbances is imperative when predicting disturbance impacts. These mechanisms are general to animal species, and the framework presented here can be used for gaining new insights into the spatiotemporal variability of animal movements and energetics that control population dynamics.