Date of Award

Spring 2011

Project Type


Program or Major

Natural Resources: Environmental Conservation

Degree Name

Master of Science

First Advisor

Andrew Rosenberg


In fisheries management, single-species stock assessment models use fisheries-dependent catch and landings data along with fishery-independent estimates of relative or absolute abundance to make estimates of species biomass for a given area. This output is used by the Atlantis marine ecosystem model as input. Atlantis uses an array of physical, biological, and anthropogenic factors to predict biomass for individual species or functional groups of species. Nonlinear analysis was used to assess the output for both the stock assessment, and Atlantis models for the marine ecosystem off the California coast. The number of time series displaying nonlinear characteristics decreases from raw (landings) data to model output, which suggests that models may not be conserving underlying data signals. Relationships between species in Atlantis functional groups (determined by the Atlantis modelers) were also analyzed using the nonlinear analysis, and relationships assumed by the Atlantis modelers were in disagreement with relationships that appeared out of the nonlinear analysis.