Theoretical Ecology

, Volume 4, Issue 4, pp 513–526

The role of discounting and dynamics in determining the economic efficiency of time-area closures for managing fishery bycatch

  • Paul R. Armsworth
  • Barbara A. Block
  • Josh Eagle
  • Joan E. Roughgarden
Original Paper


Time-area closures are commonly used to manage fisheries bycatch and involve temporarily closing an area of the ocean to particular fishing gears. We examine conditions in which implementing a time-area closure would increase the economic value of fisheries, focusing on a case study application in the Gulf of Mexico. Pelagic longline fishermen catch the highly valued Atlantic bluefin tuna (Thunnus thynnus, Scombridae) on their Gulf of Mexico spawning grounds while fishing for Atlantic yellowfin tuna (Thunnus albacares). We analyze a multispecies, multifishery bioeconomic model that includes information on migratory patterns from electronic tagged bluefin tuna. We use dynamic optimization to identify management strategies that would maximize the net present value of tuna fisheries, allowing for discounting of future benefits and costs relative to the present. If past fishing mortality rates continue in Atlantic bluefin tuna fisheries, implementing a time-area closure in the Gulf of Mexico incurs economic costs. However, the net present value of the fisheries is increased by implementing a time-area closure as part of a broader commitment to rebuild the heavily depleted bluefin population, provided the discount rate and the costs of such a closure in forgone fishing opportunities are not too large. The increase in economic value offered by a time-area closure is small relative to the overall economic value of rebuilding itself and it may be economically optimal only to implement a closure once sufficient rebuilding has already taken place.


Fisheries Economics Time-area closure Longline Bluefin tuna Yellowfin tuna Thunnus thynnus Thunnus albacares Gulf of Mexico Discounting Marine protected area 

Supplementary material

12080_2010_93_MOESM1_ESM.pdf (103 kb)
(PDF 102 kb)

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Paul R. Armsworth
    • 1
    • 2
  • Barbara A. Block
    • 3
  • Josh Eagle
    • 4
  • Joan E. Roughgarden
    • 5
  1. 1.Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
  2. 2.Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleUSA
  3. 3.Hopkins Marine StationStanford UniversityPacific GroveUSA
  4. 4.School of LawUniversity of South CarolinaColumbiaUSA
  5. 5.Department of Biological SciencesStanford UniversityStanfordUSA

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