AbstractUsing ecosystem models, past and present dynamics of the northern North Sea were explored to estimate future impacts of the Landing Obligation (LO) and climate change. Building an Ecopath with Ecosim (EwE) model of northern North Sea (International Council for the Exploration of the Sea ICES division IVa) allowed for secondary consequences of how the LO may affect ecosystem dynamics and fisheries in the area; and how impacts may be exacerbated under ocean warming. The model focusses on catch, discards and diets within ICES area IVa to represent specific mixed fisheries surrounding the Shetland Isles. The model uses stock assessments and North Sea International Bottom Trawl Survey (NS IBTS) data, tailored discard estimations and fish stomach records (from Cefas DAPSTOM–supplemented by Shetland UHI: Shetland food web biodiversity and trophic interactions project 2017). Retrospective analysis of environmental drivers in terms of their significance in altering trophic dynamics of the food web and productivity of commercial stocks were also explored.
This research demonstrates how ecosystem models can highlight indirect impacts of changes to fisheries management: furthering our understanding of ecosystem dynamics and trophic cascades in the North Sea. By focussing on the regional level this ecosystem model has the potential to support tailored decision making for the fishers of Shetland and inform integrated advice on the journey towards Ecosystem-based fisheries management.
|Date of Award||26 May 2022|
|Supervisor||Clive Fox (Supervisor) & Sheila JJ Heymans (Supervisor)|