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

• Fisheries collapsing due to open access• Marine protected areas for conservation

• Moving towards property-based mgt.– ITQs (property rights over catch)– TURFs (property rights over space)

• Incentives for stewardship of stocks?

• Seemingly contradictory approaches

Connectivity in marine systemsA human action in one place affects:

1. Ecosystem service provision2. Level of service in future3. Services in other places4. 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?

• Transboundary stocksSpatial planning in Lesser Sunda, IndonesiaCourtesy of The Nature Conservancy

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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“Efficiency Frontier”

Many Uses of Model Outputs

• Optimize network design

• Evaluate stakeholder proposals

• Inform monitoring

Models for California

Insights from MPA models

• 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 win-

win• 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