The contribution of quota to the discards problem

A case study on the complexity of common megrim Lepidorhombus whiffiagonis discarding in the northern North Sea

P. Macdonald*, I. R. Cleasby, C. H. Angus, C. T. Marshall

*Corresponding author for this work

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The common megrim Lepidorhombus whiffiagonis is a commercially important, high-value flatfish species. From the early 2000s, discarding of common megrim in the northern North Sea has been widespread. In this study, we investigated temporal variation in megrim discarding in the mixed demersal fishery in the northern North Sea before, and following recent quota increases. Furthermore, logistic regression models were applied to investigate the effects of a range of explanatory factors on the probability of individual fish being discarded. Results indicate that discarding on the vessels sampled has declined from an average of 54% of the total common megrim catch in 2009 to 20% in 2012. The decrease in total discards was primarily a result of a decrease in the proportions of discards categorized by the crew as small within the catches from 0.39 (±0.02 s.e.) in 2009 to 0.10 (±0.01 s.e.) in 2012. Model outputs also suggest that the likelihood of a fish being discarded decreases significantly (p < 0.001) with increasing quota. The current megrim total allowable catch serves only to regulate landings and does little to regulate fishing mortality. Additionally, the proposed reform of the CFP, including the move towards a discards ban and the implementation of maximum sustainable yield, raises a number of concerns that need to be addressed if the northern North Sea mixed demersal fishery is to be managed sustainably and remain economically viable in the future.

Original languageEnglish
Pages (from-to)1256-1265
Number of pages10
JournalICES Journal of Marine Science
Volume71
Issue number5
Early online date9 Feb 2014
DOIs
Publication statusPublished - Jul 2014

Fingerprint

demersal fishery
North Sea
case studies
maximum sustainable yield
flatfish
fishing mortality
fish
logistics
temporal variation
vessel
fisheries
Pleuronectiformes
sea
Lepidorhombus whiffiagonis

Keywords

  • common megrim
  • discards
  • highgrading
  • Lepidorhombus whiffiagonis
  • North Sea
  • quota

ASJC Scopus subject areas

  • Oceanography
  • Aquatic Science
  • Ecology, Evolution, Behavior and Systematics
  • Ecology

Cite this

The contribution of quota to the discards problem : A case study on the complexity of common megrim Lepidorhombus whiffiagonis discarding in the northern North Sea. / Macdonald, P.; Cleasby, I. R.; Angus, C. H.; Marshall, C. T.

In: ICES Journal of Marine Science, Vol. 71, No. 5, 07.2014, p. 1256-1265.

Research output: Contribution to journalArticle

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title = "The contribution of quota to the discards problem: A case study on the complexity of common megrim Lepidorhombus whiffiagonis discarding in the northern North Sea",
abstract = "The common megrim Lepidorhombus whiffiagonis is a commercially important, high-value flatfish species. From the early 2000s, discarding of common megrim in the northern North Sea has been widespread. In this study, we investigated temporal variation in megrim discarding in the mixed demersal fishery in the northern North Sea before, and following recent quota increases. Furthermore, logistic regression models were applied to investigate the effects of a range of explanatory factors on the probability of individual fish being discarded. Results indicate that discarding on the vessels sampled has declined from an average of 54{\%} of the total common megrim catch in 2009 to 20{\%} in 2012. The decrease in total discards was primarily a result of a decrease in the proportions of discards categorized by the crew as small within the catches from 0.39 (±0.02 s.e.) in 2009 to 0.10 (±0.01 s.e.) in 2012. Model outputs also suggest that the likelihood of a fish being discarded decreases significantly (p < 0.001) with increasing quota. The current megrim total allowable catch serves only to regulate landings and does little to regulate fishing mortality. Additionally, the proposed reform of the CFP, including the move towards a discards ban and the implementation of maximum sustainable yield, raises a number of concerns that need to be addressed if the northern North Sea mixed demersal fishery is to be managed sustainably and remain economically viable in the future.",
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note = "Acknowledgements This study was carried out during a wider investigation into the biology, ecology, and fishery of megrim in the northern North Sea and was partly funded by the Seafish Industry Authority, Scottish Fishermen's Trust, and Shetland Islands Council. We are grateful to the Shetland Fishermen's Association and all the fishers who provided access to their vessels for sampling. We are also grateful to Sarah Kraak, Jordan P. Feekings, and two anonymous reviewers for insightful comments that have greatly improved the manuscript.",
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N1 - Acknowledgements This study was carried out during a wider investigation into the biology, ecology, and fishery of megrim in the northern North Sea and was partly funded by the Seafish Industry Authority, Scottish Fishermen's Trust, and Shetland Islands Council. We are grateful to the Shetland Fishermen's Association and all the fishers who provided access to their vessels for sampling. We are also grateful to Sarah Kraak, Jordan P. Feekings, and two anonymous reviewers for insightful comments that have greatly improved the manuscript.

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