Controls on the Phenology of the Yellow Sea Lower Trophic Ecosystem: A Multi-faceted Modeling Approach

Abstract

This study aims to refine and evaluate an ecosystem model, specifically enhancing its capacity to simulate lower-trophic level ecosystems in the Yellow Sea. The research focused on four crucial dimensions: (1) the incorporation of attenuation by non-algal suspended particulate matter (aNAP), (2) the calibration of phytoplankton and zooplankton growth and mortality rates, (3) the expansion of zooplankton functional groups and their ecological roles, and (4) the integration of benthic-pelagic interactions into the model. Implementation of an aNAP parameterization scheme, predicated upon Chlorophyll-a (Chl-a) concentrations, demonstrably ameliorated the model's verisimilitude in characterizing the depth of the subsurface Chl-a maximum (SCM) layer. Calibrating growth and mortality rates, as informed by recent scholarly literature, better aligned the model with observed biomasses and revealed a more pronounced role of bottom-up controls on seasonal ecosystem variability. While the introduction of an additional functional group for macrozooplankton, specifically krill, and the adjustment for diel vertical migration (DVM) patterns based on zenith angles did not markedly affect lower-trophic level biomass, they contributed to greater ecosystem resilience and complexity. Noteworthy is the effect of an integrative benthic component, which significantly heightened the model's predictive acumen in forecasting pelagic biomass and its seasonal variations. Cumulatively, the findings underscore the exigency for nuanced parameterization and the judicious incorporation of benthic-pelagic interactions to enhance both the predictive veracity and ecological fidelity of marine ecosystem models, particularly within continental shelf contexts such as the Yellow Sea.