COBECOS final meeting, 22-23 June 2009, ReykjavikCOBECOS final meeting, 22-23 June 2009, Reykjavik

Case Study: GSA 9 bottom trawling fishery

SimulationsSimulations

COBECOSCOBECOSCosts and Benefits of Control Costs and Benefits of Control

StrategiesStrategies

Paolo Accadia (accadia@irepa.org)

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Model dimensionsModel dimensions The demersal fleet is divided in three fleet segments:The demersal fleet is divided in three fleet segments:

Bottom trawlersBottom trawlersSmall scale (vessels Small scale (vessels under 12 m in length)under 12 m in length)Polyvalent (Polyvalent (vessels over 12 m in length)vessels over 12 m in length)

Target species are: Target species are: European hakeEuropean hakeStriped mulletStriped mulletDeepwater rose shrimpDeepwater rose shrimp

Management measures (illegal behaviours):Management measures (illegal behaviours):Fishing without holding a fishing licence (VFishing without holding a fishing licence (VEE): fishing activity ): fishing activity

regulated by a closed licence schemeregulated by a closed licence schemeUsing or keeping on board prohibited fishing gears (VUsing or keeping on board prohibited fishing gears (VSS): ):

minimum mesh size, minimum landing size for some target minimum mesh size, minimum landing size for some target speciesspecies

Unauthorized fishing (VUnauthorized fishing (Vqq): all temporal and spatial ): all temporal and spatial restrictions.restrictions.

Enforcement tools:Enforcement tools:Landings inspections (eLandings inspections (e11)) Inspections at sea (eInspections at sea (e22))

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Private Benefit FunctionPrivate Benefit Function

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Social Benefit FunctionSocial Benefit Function

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Penalty probability function Penalty probability function and enforcement cost and enforcement cost

functionfunction

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Simulation categoriesSimulation categories Enforcement intensityEnforcement intensity Enforcement toolsEnforcement tools PenaltiesPenalties Management measuresManagement measures Management toolsManagement tools Combinations of the above Combinations of the above

categoriescategories

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Simulations on Simulations on enforcement intensityenforcement intensity

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Simulations on Simulations on enforcement intensityenforcement intensity

Levels of compliance at different combinations of enforcement intensity

Optimal combinations of enforcement intensity to maximize compliance at lowest

cost of enforcement

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Optimal combinations of Optimal combinations of enforcement intensityenforcement intensity

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Maximizing Social Maximizing Social BenefitBenefit

Optimal combination of enforcement intensity to maximize social benefit

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Simulations on penaltiesSimulations on penalties

Optimal levels of penalties to maximize compliance (full compliance)

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Simulations on penaltiesSimulations on penalties

VVEE: Fishing without : Fishing without holding a fishing licenceholding a fishing licence

VVSS: Using or keeping on : Using or keeping on board prohibited fishing board prohibited fishing gearsgears

VVqq: Unauthorized fishing: Unauthorized fishing

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Maximizing Social Benefit Maximizing Social Benefit with changes in penaltieswith changes in penalties

The levels of compliance and biomass determining the optimal social benefit are independent on the amounts of penalty and the marginal costs of enforcement.

50% increase in penalties

100% increase in penalties

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ConclusionsConclusions Even if inspections at sea are more efficient in detecting illegal behaviours, Even if inspections at sea are more efficient in detecting illegal behaviours,

the cost-benefit analysis shows that operating on landings inspections can the cost-benefit analysis shows that operating on landings inspections can improve the level of compliance with fishery regulations at a lower cost. improve the level of compliance with fishery regulations at a lower cost. This is because of the higher marginal cost associated to the inspections at This is because of the higher marginal cost associated to the inspections at sea. sea.

Both full compliance with each of the regulations and the maximum social Both full compliance with each of the regulations and the maximum social benefit can be achieved by abolishing inspections at sea and increasing benefit can be achieved by abolishing inspections at sea and increasing significantly the percentage of fishing effort inspected by landings significantly the percentage of fishing effort inspected by landings inspections. This is because landings inspections and inspections at sea are inspections. This is because landings inspections and inspections at sea are assumed to be interchangeable. assumed to be interchangeable.

Imposing higher sanctions when violations are detected can be considered Imposing higher sanctions when violations are detected can be considered as an alternative to increasing enforcement effort. Both actions determine as an alternative to increasing enforcement effort. Both actions determine an improvement in the levels of compliance with regulations. However, a an improvement in the levels of compliance with regulations. However, a variation in the enforcement intensity affects the level of compliance with variation in the enforcement intensity affects the level of compliance with all regulations, while increasing the penalty associated to one category of all regulations, while increasing the penalty associated to one category of violation influences only that illegal behaviour, having no effect on the violation influences only that illegal behaviour, having no effect on the others.others.

Increasing penalties or reducing marginal costs produces an increase in the Increasing penalties or reducing marginal costs produces an increase in the optimal social benefit by a reduction in the enforcement costs.optimal social benefit by a reduction in the enforcement costs.

The optimal combination of enforcement tools maximizing social benefit The optimal combination of enforcement tools maximizing social benefit produces full compliance with only the regulation on unauthorized fishing, produces full compliance with only the regulation on unauthorized fishing, while a low level of violation with the other regulations seems to be while a low level of violation with the other regulations seems to be acceptable.acceptable.

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Thank you for the Thank you for the attention!attention!

Paolo Accadia (accadia@irepa.org)Paolo Accadia (accadia@irepa.org)