title: Somatic Growth Dilution of a toxicant in a predator-prey model under stoichiometric constraints.
abstract: The development of aquatic food chain models that incorporate both the effects of nutrient availability, as well as, track toxicants through trophic levels will shed light on ecotoxicological processes and ultimately help improve risk assessment efforts. Here we develop a stoichiometric aquatic food chain model of two trophic levels that investigates concurrent nutrient and toxic stressors in order to improve our understanding of the processes governing the trophic transfer for nutrients, energy, and toxicants. Analytical analysis of positive invariance, local stability of boundary equilibria, numerical simulations, and bifurcation analysis are presented. The model captures and explores a phenomenon called the Somatic Growth Dilution (SGD) effect recently observed empirically, where organisms experience a greater than proportional gain in biomass relative to toxicant concentrations when consuming food with high nutritional content vs. low quality food.
authors.affiliation: Department of Mathematics and Statistics, Texas Tech University, Lubbock, USA; National Institute for Mathematical and Biological Synthesis, University of Tennessee, USA. Electronic address: a.peace@ttu.edu.
authors.forename: Angela
authors.initials: A
authors.lastname: Peace
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Monica D
authors.initials: MD
authors.lastname: Poteat
authors.affiliation: Centre for Mathematical Biology, Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada T6G 2G1.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D018533:Biomass; D003198:Computer Simulation; D008954:Models, Biological; D009716:Numerical Analysis, Computer-Assisted; D011156:Population Density; D011235:Predatory Behavior / Q000187:drug effects / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Ecological stoichiometry; Ecotoxicology; Methylmercury; Predator–prey model