HR: 0800h
AN: H51D-1180    [Abstracts]
TI: A Dose-Structured Population Dynamics Model for Outmigrant Salmon
AU: * Ginn, T R
EM: trginn@ucdavis.edu
AF: Civil and Environmental Engineering, 1 Shields Avenue, UC Davis, Davis, CA 95616 United States
AU: Loge, F J
EM: fjloge@ucdavis.edu
AF: Civil and Environmental Engineering, 1 Shields Avenue, UC Davis, Davis, CA 95616 United States
AB: The response of fish populations to differing levels of exposure to stressor chemical is commonly characterized using canonical dose-response models that are calibrated in laboratory (e.g., toxicological) studies. Use of such information in the study of migrating populations is difficult because dose received in the environment can vary greatly within a population due to the heterogeneity of the mixing between population members and stressor chemicals. Thus direct use of dose-response models is often predicated on assumptions of complete mixing in the environment. To relax this assumption it is required to devise an approach that keeps track of dose as a distributed quantity over a population. Here such a method is described that uses an added dimension of exposure-time to keep track of the mixing time, or dose, between outmigrant Fall Chinook Salmon and stressor organic contaminants. A mathematical model for the fish population dynamics is developed in the form of a first-order partial differential equation in multiple structural dimensions of dose, size, and age, in addition to space and time. A method-of-characteristics solution to the model under some simplifying conditions is presented and described. The results shed light on the nature of the distribution of outmigrant salmon over structural variables on arrival at the ocean.
DE: 4815 Ecosystems, structure and dynamics
DE: 1803 Anthropogenic effects
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting