Spatial fisheries management for
conservation and profitability
Christopher Costello*
University of California and
National Bureau of Economic Research
September, 2010
* Costello@bren.ucsb.edu
Motivation & introduction
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Fisheries collapsing due to open access
Marine protected areas for conservation
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Moving towards property-based mgt.
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ITQs (property rights over catch)
TURFs (property rights over space)
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Incentives for stewardship of stocks?
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Seemingly contradictory approaches
Connectivity in marine systems
A human action in one place affects:
1. Ecosystem service provision
2. Level of service in future
3. Services in other places
4. Other services of value
Movies: “Flow Fish and Fishing” UC Santa Barbara
Marine spatial planning
• MSP considers
– Services & values
– Ecological interactions
– Is an Obama priority
• How far will MSP go?
– Where, who, how much
– Devolve decisions
locally?
Spatial planning in Lesser Sunda, Indonesia
Courtesy of The Nature Conservancy
• Transboundary stocks
Marine protected areas vs.
fisheries management
• MPAs:
– Habitat
– Diversity
– Conservation
• Fishery Management:
– Economics
– Sustainability
Inside MPA
Outside MPA
Questions for this talk
1. Do MPAs increase or decrease fisheries
profits?
2. Can TURFs be economically efficient? For
which species?
3. With spatial externalities, are TURFs any
better than open access?
4. Will coordinated private TURF owners create
MPAs?
Fishermen and MPAs
• Traditionally:
– Fish win
– Fishermen lose
• Emerging Science:
– Enhance productivity
– “Spillover”
– Couple with fisheries management
• Requires careful design
Bioeconomic models for conservation
and economics
• Inputs: Habitat, species,
ocean currents,
management, MPAs,
fisherman behavior
• Outputs: Spatial
distribution of fish,
profit, fishermen
“Flow, Fish, and Fishing” Biocomplexity
How to choose an MPA network?
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Many Uses of Model Outputs
• Optimize network
design
• Evaluate stakeholder
proposals
• Inform monitoring
Models for California
Insights from MPA models
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Spatial management improves value of fishery
Must conserve stocks to profit from them
MPAs often part of profit-maximizing solution
Informed placement of MPAs can lead to winwin
• Fishery management outside MPAs has huge
effect on MPA conservation
TURFs instead of MPAs?
Spatial externality: One
owner’s harvest affects
other owners
Result: Excessive catch
For TURFs to be efficient,
must overcome spatial
externality
One method: coordination
mechanism called
“unitization”
Numerical application
• Use spatial data on biology/economics
• Hypothesize spatial property rights
• Predict private property owners’ actions and
ecosystem outcomes
• Consider effects of coordination
• What is effect of MPAs?
Numerical Model
• Parameterization
– Kelp Bass ecology (White and Caselle, 2008)
• Patch specific carrying capacity (kelp cover)
– Oceanographic dispersal kernel (Oda et al. 1993,
Cordes and Allen, 1997)
• Dispersal Dij from TURF i to TURF j
– Larval dispersal (Mitarai et al. 2008, Watson et al.
2009)
• pelagic larval duration of 30 days
Coordination across TURFs
• “Unitization” as coordination mechanism
– First best harvesting behavior AND
– Voluntary participation
• Coordination has the following effects:
– System-wide profits increase by 350%
– Fish abundance increases
– Private owners voluntarily create MPAs
Uncoordinated TURFs: profitability
Profits rise when MPAs imposed on TURFs
Uncoordinated TURFs: conservation
MPAs create conservation
Coordinated TURFs
• Coordination implies that TURF owners
internalize spillovers to connected TURFs
• With large enough spillovers, may be privately
optimal not to harvest at all
– Effectively creates a network of private MPAs
– 37.5% of TURF owners find it optimal to create
private reserves
“Private” closures in unitized TURFs
Impact of MPAs on TURFs
• Uncoordinated TURFs:
– Profits and abundance typically increase (win-win
in a majority of cases)
– Optimal MPA network with no coordination
outside gets 97% of sole-owner profits
• Coordinated TURFs
– TURF owners voluntarily create MPAs
– Additional closures typically increase abundance,
but at the cost of profits
Overall conclusions
• Spatial externalities common in fisheries and
other renewable resources
• MPAs may be part of “optimal” fisheries
management
– Conservation & profitability consistent
• TURFs may be no better than open access
– But: coordination leads to first-best, private MPAs
– Without coordination, MPAs close to efficient
• Same models for trans-boundary stocks