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Research article - Peer-reviewed, 2011

Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary

Gardmark, Anna; Nielsen, Anders; Floeter, Jens; Moellmann, Christian


Precautionary management for fish stocks in need of recovery requires that likely stock increases can be distinguished from model artefacts and that the uncertainty of stock status can be handled. Yet, ICES stock assessments are predominantly deterministic and many EC management plans are designed for deterministic advice. Using the eastern Baltic cod (Gadus morhua) stock as an example, we show how deterministic scientific advice can lead to illusive certainty of a rapid stock recovery and management decisions taken in unawareness of large uncertainties in stock status. By (i) performing sensitivity analyses of key assessment model assumptions, (ii) quantifying the uncertainty of the estimates due to data uncertainty, and (iii) developing alternative stock and ecosystem indicators, we demonstrate that estimates of recent fishing mortality and recruitment of this stock were highly uncertain and show that these uncertainties are crucial when combined with management plans based on fixed reference points of fishing mortality. We therefore call for fisheries management that does not neglect uncertainty. To this end, we outline a four-step approach to handle uncertainty of stock status in advice and management. We argue that it is time to use these four steps towards an ecosystem- based approach to fisheries management


advice; assessment; Baltic Sea; cod; ecosystem-based; ecosystem indicator; fisheries management; stock recovery; uncertainty

Published in

ICES Journal of Marine Science
2011, volume: 68, number: 1, pages: 212-220

Authors' information

Swedish Board of Fisheries
Nielsen, Anders
No organisation
Floeter, Jens
Möllmann, Christian

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Fish and Aquacultural Science

Publication Identifiers


URI (permanent link to this page)