This is the publisher’s final pdf. The published article is copyrighted by Inter-Research and can be found at: http://www.int-res.com/journals/meps/meps-home/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.Marine and freshwater food webs are strongly structured by size-dependent predator−prey interactions. Predator−prey body mass ratios (PPMR) are important parameters in size-based food-web models, but studies evaluating the temporal stability of PPMR or its relationship to predator feeding modes are scant. Using a large data set of predator−prey pairs from a diverse fish community sampled in summer, fall, and winter, we showed that community-level PPMR varied with predator mass in a nonlinear (dome-shaped) manner. PPMR was higher in the summer relative to the fall and winter for all predator body size classes regardless of whether prey were fish or invertebrate. Further, the size dependency of PPMR was dome-shaped for invertebrate prey but positive and linear for fish prey. We empirically show that community-level PPMR is dynamic rather than fixed, which is in agreement with general expectations set by simulation studies of biomass spectra. However, we are presently unable to identify the specific processes underlying these patterns. Size-based models of marine ecosystems offer considerable promise over traditional taxa-based approaches, and our analyses provide insight into major patterns of variation in PPMR in a temperate marine system
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.