Predator-prey overlap induced Holling type III functionalresponse in the North Sea fish assemblage ...

• Main Authors: Kempf, Alexander, Floeter, Jens, Temming, Axel
• Format: Conference Object
• Language: unknown
• Published: ASC 2009 - Theme session P 2024
• Subjects: Fisheries and aquaculture; Pressures, impacts, conservation, and management; Gam; Gadus morhua
• Online Access: https://dx.doi.org/10.17895/ices.pub.25074407.v1; https://ices-library.figshare.com/articles/conference_contribution/Predator-prey_overlap_induced_Holling_type_III_functionalresponse_in_the_North_Sea_fish_assemblage/25074407/1

No abstracts are to be cited without prior reference to the author.Understanding the response of predator populations to varying prey fields is a prerequisite to understand prey population dynamics and to correctly parameterise multi species stock assessment or ecosystem models. Previous analyses on the large scale feeding response of predator populations, however, came to unrealistic results for the North Sea. The observed feeding response types (e.g., negative prey switching) would lead to the extinction of prey populations when becoming scarce. We analysed the large scale response of North Sea cod (Gadus morhua) and whiting (Merlangius merlangus) populations to varying prey fields using Generalised Additive Models (GAMs). Thereby, we took changes in predator-prey overlap explicitly into account in contrast to previous analyses. The composition of the prey field and changes in predator prey overlap had significant effects on the diet composition in the final GAM explaining 65.0% of the variance. The ...