Evaluating ecosystem impacts of gear regulations in a data-limited fishery—comparing approaches to estimate predator–prey interactions in Ecopath with Ecosim

• DOI: 10.1093/icesjms/fsac077
• Publication Date: 2022-04-19T03:14:20Z
• Authors: Jennifer Rehren; Marta Coll; Narriman Jiddawi; Lotta Clara Kluger; Omar Omar; Villy Christensen; Maria Grazia Pennino; Matthias Wolff
• Keywords: Discards; Ecosystem model

Abstract Ecosystem models, such as Ecopath with Ecosim (EwE), are useful tools for developing ecosystem-based management strategies. Model development, however, requires data the estimation of input parameters including time series calibration. Most small-scale fisheries lack information, making it difficult to reliably use ecosystem models strategy exploration. This is case Chwaka Bay fishery (Zanzibar), where an increase in dragnets has led concerns unsustainable development. While EwE could help explore impacts gear regulations bay, this hampered by estimate predator–prey interactions (vulnerabilities) model. Here, we available approaches estimating vulnerabilities simulate effects a dragnet prohibition and without reallocation fishing effort. Simulations suggest that banning would be beneficial community judged biomass functional groups fishers’ profits, but not if fishers were continue bay reallocating other gears, indicated reduced fish profits. The overall trend (decreasing or increasing) changes groups, indicators, profits relatively consistent across vulnerability settings, illustrating unfitted model can used qualitative