1. Integrating biological components into a spatially explicit, complex economic model for fisheries management evaluations: The North Sea saithe fishery as a case study
Sarah Simons, Alexander Kempf, Ralf Döring, Heleen Bartelings, Katell Hamon, Axel Temming
ICES ASC 2015
Session M:05
Copenhagen, 22nd Sept. 2015

2. Fisheries management failures
Introduction
Model development
Model application
Results & Discussion
Summary
Page 2
ICES ASC 2015 M:05
Disputation
Sarah Simons
Titel der Veranstaltung

3. What can we do?
Introduction
Model development
Model application
Results & Discussion
Summary
Improving methods and tools that are used to evaluate management strategies
How, when and where do people fish?
What is the economic impact of management measures on fishers?
How much of their income will be affected and what alternatives could be offered?
In the face of management contraints what are the strategies fishers develop? Do they fit the management objective?
What spatio-temporal interplay exists between fleet and fish stocks?
Page 3
ICES ASC 2015 M:05
Disputation
Sarah Simons
Titel der Veranstaltung

4. Integrating age-structured population dynamics into FishRent
Introduction
Model development
Model application
Results & Discussion
Summary
Model development
Integrating age-structured population dynamics into FishRent
Considering the spatio-temporal interplay between fleets and fish stocks
Model application
Identifying major drivers and their impact
Evaluating current and alternative management strategies
ICES ASC 2015 M:05
Disputation
Sarah Simons
Titel der Veranstaltung

5. The basic version of FishRent
Introduction
Model development
Model application
Results & Discussion
Summary
Fuel
price
Capital Cost
Fixed Cost
Fuel
Cost
Crew Cost
Variable Cost
Effort allocation
Profit maximization
Biomass
Cobb-Douglas
Catch
Catch
Revenue
Fleet size
Stock biomass
Fish Price
Landings
Discards
Fishing effort
Disputation
Sarah Simons
Disputation
ICES ASC 2015 M:05
(Salz et al., 2011)
Titel der Veranstaltung

6. Step 1: Integrating a dynamic population model
Introduction
Model development
Model application
Results & Discussion
Summary
Step 1: Integrating a dynamic population model
Fuel
price
Capital Cost
Fixed Cost
Fuel
Cost
Crew Cost
Variable Cost
Change of effort allocation pattern
Profit maximization
Cobb-Douglas
Biomass production function
Population model
Catch
Revenue
Fleet size
Fish Price
Landings
Discards
ICES ASC 2015 M:05
Disputation
Sarah Simons
(Simons et al., 2014a)
Titel der Veranstaltung

7. Step 2: Integrating the spatio-temporal component
Introduction
Model development
Model application
Results & Discussion
Summary
Seasonal migrations
Q 1
Q 2
Quarter 4
Quarter 3
Quarter 1
Quarter 2
Q 3
Q 4
XXII EAFE CONFERENCE
Sarah Simons
ICES ASC 2015 M:05
Titel der Veranstaltung
(Simons et al., 2014a)

8. North Sea Saithe Fishery
Introduction
Model development
Model application
Results & Discussion
Summary
SSB has declined below Bpa
Recruitment is below average
Mean weight-at-age is reduced
Decline in stock productivity
ICES Advice 2014
ICES ASC 2015 M:05
Disputation
Sarah Simons

9. The spatio-temporal interplay between fleet and stock
Introduction
Model development
Model application
Results & Discussion
Summary
CPUEs reflect not just fish abundance they also depend on steaming costs
ICES ASC 2015 M:05
ICES ASC 2015 M:07
Sarah Simons
(Simons et al., 2014b)

10. The impact of a discard ban
Introduction
Model development
Model application
Results & Discussion
Summary
TAC saithe is 3x higher than TAC cod
Source: ICES advice 2014
Spatial overlap of high cod and saithe stock biomass
(Simons et al., 2014)
XXII EAFE CONFERENCE
Sarah Simons
ICES ASC 2015 M:05
Titel der Veranstaltung

11. The impact of a discard ban
Introduction
Model development
Model application
Results & Discussion
Summary
Benefical for cod but negative for saithe
Cod
Saithe
Spatial overlap cod-saithe 8%
41% 6% 4%
Economic cosequences depend on cod quota availability
Disputation
Sarah Simons
ICES ASC 2015 M:05
ICES ASC 2015 M:07
(Simons et al., 2014c)
Titel der Veranstaltung

12. In summary… Extension of the biological part of FishRent
Introduction
Model development
Model application
Results & Discussion
Summary
Extension of the biological part of FishRent
Same indicators as ICES
Includes fishers behaviour
Economic performance of multiple fleet segments
Multi-species effects of landing obligation
Species distribution in stock assessment & quota advice
CPUEs also depend on steaming costs
Inclusion of economic variables in stock assessment
ICES ASC 2015 M:05
Disputation
Sarah Simons
Titel der Veranstaltung

13. Many thanks to … ICES ASC 2015 M:05 XXII EAFE CONFERENCE
Sarah Simons

14. Thanks for your attention !
ICES ASC 2015 M:05
XXII EAFE CONFERENCE
Sarah Simons

15. References
ICES Report of the Working Group on Mixed Fisheries Advice for the North Sea (WGMIXFISH-NS). Book 6. ICES Document, CM 2014/ACOM:22.
Salz, P., Buisman, E., Frost, H., Accadia, P., Prellezo, R., and Soma, K Fishrent:bio-economic simulation and optimization model for fisheries. LEI Report, 2011: 024.
Simons, S. L., Bartelings, H., Hamon, K. G., Kempf, A. J., Döring, R., and Temming, A. 2014a. Integrating stochastic age-structured population dynamics into complex fisheries economic models for management evaluations: the North Sea saithe fishery as a case study. ICES Journal of Marine Science: Journal du Conseil, 71:
Simons, S. L., Döring, R., and Temming, A. 2014b. Modelling the spatio-temporal interplay between North Sea saithe (Pollachius virens) and multiple fleet segments for management evaluation. Aquatic Living Resources, 27: 1-16.
Simons, S. L., Döring, R., and Temming, A. 2014c. Modelling fisher's response to discard prevention strategies: the case of the North Sea saithe fishery. ICES Journal of Marine Science: Journal du Conseil.
Simons, S. L., Döring, R., and Temming, A Combining area closures with catch regulations in fisheries with spatio-temporal variation: Bio-economic implications for the North Sea saithe fishery. Marine Policy, 51:
ICES ASC 2015 M:05
Disputation
Sarah Simons
Titel der Veranstaltung