INTERNATIONAL INSTITUTE OF FISHERIES ECONOMICS AND TRADE
CONFERENCE 2014
Considering the Costs of Enforcement:
Improving Marine Spatial Planning
Katrina Davis
David Pannell, Marit Kragt, Stefan Gelcich, & Steven Schilizzi
Restricted-use management zones
• No-take
• Use rights
Spatial optimisation
• Terrestrial
− National parks
• Marine
− Minimize losses to
fishers
The University of Western Australia
Aim
•
Determine impact of including management
and opportunity costs on spatially optimal
marine zoning
Management costs = costs of preventing poaching and
enforcing catch restrictions, i.e. enforcement costs
The University of Western Australia
Chile
Chile
• 1989-1991 Fisheries law
• 4,200 km of coastline
− Territorial user rights for
• Rich marine resources
fisheries
• One of top 10 countries for
fisheries landings
The University of Western Australia
Central marine region of Chile
Management zones
Open access
TURF
Enforced-TURF
No-take
Enforced no-take
Algarrobo
The University of Western Australia
Enforcement costs
Deterring poachers and
enforcing catch restrictions:
− Costs vary spatially
El Quisco A
El Quisco B
The University of Western Australia
Spatial optimisation model
• Allocate cells (Ci=1,..,96) to management zones
Open access, TURF, Enforced-TURF, No-take, Enforced-no-take
• Objective: Maximize fisher revenue from fish
caught
RevenueCi = (Number of fish which can be caught x
Price) – Enforcement costs
• Subject to minimum abundance targets
The University of Western Australia
Abundance targets
• Targets based on maximum potential
abundance
The University of Western Australia
Spatial optimisation model
• Multiple scenarios – impact of enforcement
•
No enforcement:
A → O, T, N
•
Enforcement, no cost:
B → O, T, ET, N, EN
•
Enforcement, cost:
C → O, T, ET, N, EN → $$
The University of Western Australia
Results - Fisher revenue
Benefits of
enforcement
=
Revenue scenario B
(Enforcement, no cost)
-
Revenue scenario A
(No enforcement)
Revenue
(US$1,000)
1,200
Benefits
1,000
800
600
400
200
0
0%
4%
8%
12%
Abundance target
The University of Western Australia
Fisher revenue
Costs of
enforcement
=
Revenue scenario B
(Enforcement, no cost)
-
Revenue scenario C
(Enforcement and cost)
Revenue
(US$1,000)
1,200
Benefits
1,000
800
600
400
200
0
0%
4%
8%
12%
Abundance target
The University of Western Australia
Fisher revenue
Costs of
enforcement
=
Revenue scenario B
(Enforcement, no cost)
-
Revenue scenario C
(Enforcement and cost)
Revenue
(US$1,000)
1,200
Benefits
Costs
1,000
800
600
400
200
0
0%
4%
8%
12%
Abundance target
The University of Western Australia
Fisher revenue
1. Enforcement costs negligible compared to benefits
2. Benefit Cost Ratios (BCRs) > 1
Revenue
(US$1,000)
1,200
Benefits
Costs
1,000
BCR: 7
800
600
BCR: 9
BCR: 5
BCR: 5
400
200
0
0%
4%
8%
12%
Abundance target
The University of Western Australia
Optimal spatial allocation – scenario C
Abundance
target:
0%
10%
20%
30%
40%
The University of Western Australia
Sensitivity analysis - Enforcement costs
Allocation of study
area %
100
90
80
70
60
100
50
90
40
80
30
70
20
60
10
50
0
Base case
5
Enforced-TURF
Open access
BCR
3
1
40
4
2
3
Enforcement cost multiplier
30
11
2
20
10
Scenario
C, no abundance target
0
1
2
3
Enforcement cost multiplier
1
11
The University of Western Australia
Sensitivity analysis - Enforcement costs
Allocation of study
area %
100
90
80
70
60
100
50
90
40
80
30
70
20
60
10
50
0
Base case
5
Enforced-TURF
Open access
BCR
3
1
40
4
2
3
Enforcement cost multiplier
30
11
2
20
10
Scenario
C, no abundance target
0
1
2
3
Enforcement cost multiplier
1
11
The University of Western Australia
Sensitivity analysis - Enforcement costs
Allocation of study
area %
BCR
100
5
90
80
4
70
60
100
50
90
40
80
30
70
20
60
10
50
0
Base case
Enforced-TURF
3
4
2
Open access
BCR
1
3
1
40
5
2
3
Enforcement cost multiplier
30
11
2
20
10
Scenario
C, no abundance target
0
1
2
3
Enforcement cost multiplier
1
11
The University of Western Australia
Sensitivity analysis - Enforcement costs
Allocation of study
area %
BCR
100
5
90
80
4
70
60
Base case
50
3
40
30
20
10
Enforced-TURF
2
Open access
BCR
0
1
1
2
3
Enforcement cost multiplier
11
Scenario C, no abundance target
The University of Western Australia
Net benefits from enforcement
• Enforcement of TURF zones has net benefits
for fisher revenue
• Mixture of enforced TURF and no-take zones
was optimal for conservation
The University of Western Australia
Why are fishers not enforcing?
• Fishers in the study area don’t enforce
TURFs that are far away
− Fishers may under-estimate the benefits of
enforcement
− Fisher associations may lack capacity or authority
− Other biological forces at work
− Transaction costs of enforcement may be higher
than we have modelled
Currently investigating this further
The University of Western Australia
Accounting for enforcement can
improve marine management
1. Large benefits from enforcement,
negligible costs
2. Costs have a spatial component and can
be minimized
Davis, K. J., M. E. Kragt, S. Gelcich, S. Schilizzi, and D. J. Pannell.
In press. Accounting for enforcement costs in the spatial allocation
of marine zones, Conservation Biology.
katrina.davis@research.uwa.edu.au, School of Agricultural and Resource Economics, University of
Western Australia
The University of Western Australia