Integrated assessment of fishery systems

Fisheries play a key role in food security worldwide, but many aquatic food resources are fully exploited, overexploited, or depleted. This reflects the difficulties of addressing the competing demands on the services rendered by aquatic ecosystems, and when accounting for the multiple stressors they face.

© Igor Kiporuk | Dreamstime

© Igor Kiporuk | Dreamstime

The Evolution and Ecology Program (EEP) is developing general approaches for integrated assessments of fishery systems that help reconcile multiple objectives:

  • The success of a management system requires its objectives to be well defined. Different stakeholder groups, however, can hold very different views regarding which products and services are the most important. Some stakeholders may emphasize employment in the fishing sector, others profits or ecosystem conservation. Ultimately, managing aquatic systems requires reconciling the preferences of all stakeholders with legitimate interests in the resources and services these systems can provide. To facilitate identification of management options that are most likely to be agreeable to all stakeholders, EEP is developing a framework for the evaluation of joint stakeholder satisfaction based on multi-criteria utility functions [1].
  • The human dimensions of sustainability can manifest in unexpected ways: model analyses suggest that fleet dynamics—resulting from the collective responses of fishers to changing fishing conditions—can sometimes accelerate the pace of fisheries-induced evolution [2].
  • Traditionally, sustainability has been assessed mainly from an ecological perspective. Expanding this view, EEP’s research has drawn attention to the challenges of evolutionary sustainability, highlighting that fishing may favor adaptations that, in the long run, reduce the value of the provisioning services rendered by fish stocks. Addressing these challenges, the first comprehensive Evolutionary Impact Assessment (EvoIAs) was conducted on the North Sea plaice fishery [3] (Figure 1).
  • Thanks to steadily developing theoretical and model-based analyses, the main characteristics of evolutionarily sustainable harvesting strategies are now emerging [3][4][5].
  • Robust management systems need to consider emerging stressors proactively, such as rising temperatures resulting from climate change [6].
  • A related case study presents the first multitarget fisheries assessment for two coastal communities in Hokkaido, Japan. The assessments enable forecasting responses to changing climatic, economic, and biological conditions [7].

Figure 1. By changing the size-selectivity of fishing gear (left), managers can alter the selection pressures on the maturation size threshold from negative to neutral or even positive, leading to markedly different evolutionary impacts in the future (right) [3].







References

[1] Dankel DJ, Heino M & Dieckmann U. Can integrated assessments reconcile stakeholder conflicts in marine fisheries management? In preparation.

[2] Landi P, Hui C & Dieckmann U. Fleet dynamics can accelerate fisheries-induced evolution. In preparation.

[3] Mollet FM, Poos JJ, Dieckmann U & Rijnsdorp AD (2015). Evolutionary impact assessment of the North Sea plaice fishery. Canadian Journal of Fisheries and Aquatic Sciences, doi:10.1139/cjfas-2014-0568.

[4] Heino M, Díaz Pauli B & Dieckmann U (2015). Fisheries-induced evolution. Annual Review of Ecology, Evolution, and Systematics 46: 461–480.

[5] Heino M, Dunlop ES, Godø OR & Dieckmann U. Management implications of fisheries-induced evolution. In Dieckmann U, Godø OR & Heino M eds. Fisheries-induced Evolution, Cambridge University Press, UK, in press.

[6] Ficker H, Mazzucco R, Gassner H, Wanzenböck J & Dieckmann U (2016). Stocking strategies for a pre-alpine whitefish population under temperature stress. Ecological Modelling 320: 170–176.

[7] Sweke EA, Landi P, Kobayashi Y, Sakurai Y, Hui C, Brännström Å & Dieckmann U. Allocation of fishing effort among different target species in northeastern Hokkaido, Japan. In preparation. 


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Last edited: 20 April 2016

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