Marine mammal predator-prey interactions in the North Sea ...

• Main Author: Ransijn, Janneke
• Format: Text
• Language: English
• Published: The University of St Andrews 2023
• Subjects: Marine mammal; Predator-prey interactions; Multi-species functional response; Sandeel; Harbour porpoise; Harbour seal; Grey seal; North Sea; Prey switching; Distribution; QL758.R2; Predation Biology; Marine mammals > North Sea; Porpoise Harbour; harbour seal; Phoca vitulina; Phocoena phocoena
• Online Access: https://dx.doi.org/10.17630/sta/346; https://research-repository.st-andrews.ac.uk/handle/10023/27182

Trophic levels within an ecosystem are linked by the functional response which describes how the consumption rate of a predator varies in relation to prey density. Knowledge of functional responses is key to understanding predator-prey interactions, population dynamics, predation pressure, prey preference, and the ecosystem. This thesis explores multi-species functional responses (MSFR) of key marine mammal predators in the North Sea, and the prey energy available to them. Spatiotemporal variation in prey energy available to harbour porpoises (Phocoena phocoena) was modelled, using species distribution models, and showed that large amounts of energy were available both within and outside the Southern North Sea (SAC). Sandeels are energy-rich, their patchy restricted distribution drove the observed patterns of the spatiotemporal distribution of all porpoise prey energy. The MSFR of three predator species (harbour porpoise, grey (Halichoerus grypus) and harbour seal (Phoca vitulina)) were modelled using ...