Ecological perspectives from an end-to-end representation of the Baltic Sea using Ecopath with Ecosim in Fortran (EwE-F) coupled to the Baltic Sea Long-Term Large Scale Eutrophication Model

Akoğlu, Ekin
Tomczak, Maciej
Gustaffson, Bo
Ecosystem-based marine management can be considered to be most effective through establishingend-to-end representations of marine ecosystems from physical processes to fish using ecosystemmodels. Yet no single model includes sophisticated delineations of physical, biogeochemical and foodweb processes altogether to form a realistic picture of marine environment. Therefore, coupling models ofdifferent realms, i.e., physical, biogeochemical and trophodynamic, is required to set up holisticecosystem representations. When first released in 2015, the Fortran version of the widely-adopted foodweb model Ecopath with Ecosim (EwE-F) opened up new possibilities to form such representations byintegrating oceanographic models of physics and biogeochemistry with the sophistication of EwE’strophodynamic modelling framework. In this work we form such a representation of the Baltic Seaecosystem using the Baltic Sea Long-Term Large Scale Eutrophication Model (BALTSEM) with an EwE-Fmodel of the Baltic Sea food web to delineate the interactions between food web dynamics andbiogeochemical processes to quantify the impacts of; i) higher-trophic-level (HTL) dynamics on thebiogeochemical processes, and ii) bottom-up propagation of the effects of biogeochemical processes inthe HTL food web. This is the first study that attempts to build a validated end-to-end representation of alarge marine ecosystem, i.e., Baltic Sea, by integrating EwE-F and a sophisticated biogeochemical modelin a two-way and online coupled framework. Results of the simulations showed that HTL processesmodified the production of primary producers through changes in nutrient cyclings that, in turn, impactedplanktivorous species in the food web model. This cascaded up to the planktivorous fish throughzooplankton and then to top predators in the food web. Consequently, in the coupled model monthlyaverage zooplankton standing stock was simulated to be lower than the standalone BALTSEM modelsimulation. These results indicated that a more realistic representation of the ecosystem is possible byintegrating trophodynamic and biogeochemical models of the Baltic Sea.


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Citation Formats
E. Akoğlu, M. Tomczak, and B. Gustaffson, “Ecological perspectives from an end-to-end representation of the Baltic Sea using Ecopath with Ecosim in Fortran (EwE-F) coupled to the Baltic Sea Long-Term Large Scale Eutrophication Model,” presented at the Ecopath 35 years – Making Ecosystem-Based Management Operational, Florida, Amerika Birleşik Devletleri, 2019, Accessed: 00, 2021. [Online]. Available: