| one publication added to basket [405192] | Investigating the temporal biomass dynamics of the Southern Bight of the North Sea ecosystem through a food web model
Soroka, T. (2024). Investigating the temporal biomass dynamics of the Southern Bight of the North Sea ecosystem through a food web model. MSc Thesis. Universiteit Antwerpen/Ghent University/Vrije Universiteit Brussel: Antwerpen, Gent, Brussel. 39 pp.
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Document type: Dissertation
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Ecopath with Ecosim, food web model, Brexit, ecosystem-based management |
| Abstract |
The Southern Bight of the North Sea is an intensively fished area with many stressors placed upon it. An Ecopath with Ecosim food web model was created for this area for the period 1991- 2022 to analyze how the ecosystem has changed over time. Over this period, total biomass was reduced by 14.8%, commercial biomass was reduced by 13.7%, the trophic level of catch slightly decreased by 2.7%, the trophic level of community minimally increased by 1.7%, and total catch greatly decreased by 76.4%. With those parameters in mind, the health of the Southern Bight of the North Sea’s ecosystem is in jeopardy of worsening without proper management. The effects of Brexit fisheries policies on the EU and a tipping point scenario were tested through future management scenario based simulations until 2050. The simulations tested how a reduction in quota of cod by 3.0%, herring by 1.7%, mackerel by 2.5%, and sole by 10.2%, as set by the EU UK Trade and Cooperation Agreement, would affect the ecosystem. Additionally, a substitution of catch of herring, mackerel, cod, and sole with sprat, sea bass, whiting, and plaice respectively, was tested to convey a possible change in fishing behavior. The results of the Brexit simulations revealed that the quota losses coincide with maintaining constant fishing efforts from 2022-2050, while the substitution of catch did produce significantly different outputs. The Brexit policies alone were found to have minimal effects on the Southern Bight of the North Sea ecosystem, but the resulting fishermen’s behavior will influence the health of the ecosystem. The tipping point scenario revealed that a 30% annual increase in fishing efforts would cause all fished species to reach their tipping point by 2050. Future management of the area should implement ecosystem based management techniques that account for all influencing factors on the environment of the Southern Bight of the North Sea. |
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