Spatio‐temporal analyses of marine predator diets from data‐rich and data‐limited systems

• DOI: 10.1111/faf.12457
• Publication Date: 2020-03-16T05:22:01Z
• Authors: Arnaud Grüss; James T. Thorson; Gemma Carroll; Elizabeth L. Ng; Kirstin K. Holsman; Kerim Aydin; Stan Kotwicki; Hem N. Morzaria‐Luna; Cameron H. Ainsworth; Kevin A. Thompson
• Keywords: Pollock; Gadidae; Bloom

Abstract Accounting for variation in prey mortality and predator metabolic potential arising from spatial consumption is an important task ecology resource management. However, there no statistical method processing stomach content data that accounts fine‐scale spatio‐temporal structure while expanding individual samples to population‐level estimates of predation. Therefore, we developed approach fits a model both prey‐biomass‐per‐predator‐biomass (i.e. the ratio biomass stomachs weight) survey data, predict “predator‐expanded‐stomach‐contents” (PESCs). PESC can be used visualize either annual landscape PESCs (spatio‐temporal variation), or aggregated across space calculate diet proportions (variation among items years). We demonstrated our two contrasting scenarios: data‐rich situation involving eastern Bering Sea (EBS) large‐size walleye pollock ( Gadus chalcogrammus , Gadidae) 1992–2015; data‐limited West Florida Shelf red grouper Epinephelus morio Epinephelidae) 2011–2015. Large was predicted higher very warm years on Middle EBS, where food abundant. Red variable north‐western waters, presumably due harmful algal bloom severity. Our employed parameterize validate diverse ecosystem models, serve address many fundamental ecological questions, such as providing improved understanding how climate‐driven changes overlap between distributions might influence predation pressure.