Resource competition and fisher behaviour mediate the effect of effort reduction strategies in brown shrimp (Crangon crangon) fishery in the North Sea
van Kooten, T.; Hin, V.; Beier, U.; Melis, E.; van de Wolfshaar, K. (2026). Resource competition and fisher behaviour mediate the effect of effort reduction strategies in brown shrimp (Crangon crangon) fishery in the North Sea. ICES J. Mar. Sci./J. Cons. int. Explor. Mer 83(5): fsag084. https://dx.doi.org/10.1093/icesjms/fsag084
In: ICES Journal of Marine Science. Academic Press: London. ISSN 1054-3139; e-ISSN 1095-9289, more
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| Keywords |
Catching methods > Net fishing > Trawling > Bottom trawling
Fisheries management
Life history
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| Author keywords |
 physiologically structured population model, individual-based fleet model, density dependence, |
| Authors | | Top |
- van Kooten, T., more
- Hin, V.
- Beier, U.
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- Melis, E.
- van de Wolfshaar, K.
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| Abstract |
The fishery for brown shrimp (Crangon crangon) is one of the most valuable fisheries in the North Sea. There are concerns about the effects of this fishery on the ecosystem, especially since it takes place predominantly within Natura 2000 areas. The fishery potentially disturbs foraging seabirds and the seafloor ecosystem and produces substantial amounts of non-target bycatch. Furthermore, brown shrimp are an important food web component, both as predators and as food. There is societal pressure to reduce the shrimp fishing intensity. We study two qualitatively different approaches by which the maximum fishing effort can be limited: either by reducing the weekly allowed fishing time or by reducing the number of vessels. To do so, we combine an individual-based fleet model and a mechanistic, individual-based model of the shrimp stock. We show that a moderate fishing effort reduction can increase landings, but simultaneously yields higher bycatch of undersized shrimp. This is caused by stronger resource competition among shrimp at lower fishing mortality. The effort reduction also changes the seasonal pattern in shrimp growth as well as in the fishery. At fleet level, as well as for the shrimp stock, differences between the two scenarios are small. However, at vessel level, a reduced number of vessels leads to increased effort and landings for the remaining vessels. Our model accounts for both the ecological complexity of the stock as well as elements of the behaviour of the fishers The dynamic interplay between the two shapes the outcome of our study, and accounting for this level of complexity is essential when fishery management seeks to balance ecological and economic outcomes. |
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