Coupling planktonic ecosystem and fisheries food web models for a pelagic ecosystem: Description and validation for the subarctic Pacific

Kearney, Kelly A. and Stock, Charles and Aydin, Kerim and Sarmiento, Jorge L.

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We provide a modeling framework that fully couples a one-dimensional physical mixed layer model, a biogeochemical model, and an upper trophic level fisheries model. For validation purposes, the model has been parameterized for the pelagic Eastern Pacific Subarctic Gyre ecosystem. This paper presents a thorough description of the model itself, as well as an ensemble-based parameterization process that allows the model to incorporate the high level of uncertainty associated with many upper trophic level predator-prey processes. Through a series of model architecture experiments, we demonstrate that the use of a consistent functional response for all predator-prey interactions, as well as the use of density-dependent mortality rates for planktonic functional groups, are important factors in reproducing annual and seasonal observations. We present the results of a 50-year climatological simulation, which demonstrates that under contemporary physical forcing, the model is capable of reproducing long-term seasonal dynamics in primary production and biogeochemical cycling, while maintaining steady-state coexistence of upper trophic level functional groups at levels consistent with observations.