Developing a bioeconomic model to foster discussions among stakeholders. An application to Indonesian Blue Swimming Crab fisheries

Abstract

Blue swimming crab fisheries in Indonesia have been under high pressure for several years: quasi- open access, weak management and weak enforcement are some of the key reasons explaining the recent a stark increase in catch jeopardizing the sustainability of the resource. In January 2015, a multi stakeholder workshop was organized in Semarang to discuss potential management measures. A bioeconomic model was developed specifically for the workshop to be used during discussions, allowing direct feedback on the potential effect of various management measure mixes proposed by stakeholders. This paper presents the model developed for the workshop and how it was used to inform the discussions among stakeholders. The model describes a crab fishery in the Demak area (central Java) targeted by three gear-types (net, trap, trawl) and includes seven types of management measures that can be combined to create a pool of rules. The principal management measure mixes that were discussed during the workshop are presented and compared, notably in terms of potential short-term losses, which in the Indonesian context are strong drivers for weak compliance with new rules. Measure mixes need to be carefully phased to exert maximum effect. Since this workshop, several regulatory changes have been introduced by the Indonesian administration, notably the introduction of a minimum landing size, a ban on landing berried female and a ban on trawling. This paper also explores the potential need for further regulatory changes to reach a sustainable level of exploitation, notably the added value of a spatial approach.

Full text

Developing*a*bioeconomic model*to*foster*
discussions*among*stakeholders.*
An*application*to*Indonesian*
Blue*Swimming*Crab*fisheries
Sébastien*Metz1,*Dessy Anggraeni2,*Geoff*Tingley2,*Jack*Whalen2,*Juan*Manuel*
Garcia-Caudillo2,* Jim*Cannon2
Affiliations:*
1*Sakana*Consultants*
2*Sustainable Fisheries Partnership Foundation
With the*financial support*of*the*The*Rockefeller*Foundation

Objective*of*this*work
•Supporting*transition*work*in*Indonesia*by*
providing*a*tool*to*foster*discussion*among*
stakeholders
•for*expert*led*meetings
•to*implement*“serious”*games
•This*presentation*is*about*how*we’ve*built*a*
bieconomic model*for*a*meeting*held*in*
Semarang*at*the*beginning*of*2015

Context:
Blue*Swimming*Crab*(BSC)*in*Indonesia
•~65,000*fishermen
•~13,000*pickers*working*in*
miniplantsand*cooking*stations
•Production*in*2009:*35,000*
tonnes of,*more*than*7*times*the*
landings*in*1990
•Mainly*exported,*representing*
8%*of*fishery*product*export*
value*in*2011
•Main*market*=*USA*(more*than*
50%*of*exports)
•Weak*management*framework
•FIP*initiated*in*2008

Our*case*study*is*
based*on*the*
Betahwalang
village*(central*
Java)

Supply*chain*structure
Fishing*boats
Cooking stations
Miniplants
Processors
Exporters
•Artisanal*fleet:*wooden*boat,*
from*6*to*12-13*meters
•Three*gear*type:*Net*–Trap*–
Trawl
•Crew:*from*1*to*3
•Day*boat,*except*for*large*trap*
vessels*(cook*crab*onboard)
•Crab*cooked*few*hours*after*the*
catch
•Crab*peeled*in*miniplants
•Main*issue:*no*effective*
management

Model*Structure:*the*fishery
Biological*Box
Blue*Swimming*Crab*Stock
Age*structured
Male*&* Female
Quick*growth*=>*not*annual*
but* monthly* step
Economic*Box
3*gear*segments
(trap,*gillnet,* minitrawl)
Va ri abl e* & *fix ed* c os ts
Market*(different* price*for*
different* gear)
Production*Box
Harvest*(catch/landing)
Discards
Regulation*Box
Minimum* size
Season/area*closure
Fishing* gear*restriction
Quota*and*effort* restrictions
Stock*enhancement

The*usual*suspects
𝑁"#∆" = 𝑁"& 𝑒()&∆"
𝐶𝑎𝑡𝑐ℎ"= 𝑊
"& 𝑁"& 𝑒(0&∆"
𝑃𝑟𝑜𝑓𝑖𝑡"=𝐶𝑎𝑡𝑐ℎ"&𝑃𝑟𝑖𝑐𝑒"− 𝐸𝑓𝑓𝑜𝑟𝑡"& 𝑉𝑐𝑜𝑠𝑡𝑠 + 𝐹𝑐𝑜𝑠𝑡𝑠

Key*assumptions
•Simulation*model*over*15*years*(180*periods)
•36*age*classes
•Monospecific*fishery
•Fishery*is*isolated:*no*other*fleet*segment*involved
•2*areas*onshore*(small*crab)*/*offshore*(large*crab)
•Fishermen*=*price*takers:*the*local*supply*has*little*to*no*
effect*on*ex-vessel*price
•Fishermen*are*owning*their*vessels*–in*reality,*this*may*be*
slightly*different*as*there*might*be*some*vertical*
integration*(miniplant owners*partly/fully*owning*boats)

Management*Options
1. Minimum*Legal*Size
2. Forbid*the*landing*of*berried*females
3. Impose*the*closing*of*inshore*zone
4. Impose*seasonal*closure
5. Catch*limitation*(quota)
6. Effort*restriction*(less*fishing*days)*
7. Modify*the*gears*(selectivity)
8. Stock*enhancement

The*workshop*setting
All*types*of*stakeholders*
represented:
•Fishermen*(the*3*gear*
groups)
•Head*of*the*local*village
•Local*scientists
•Local*and*central*
administration
•Exporters
•Model*projected*on*
screen*(excel*file)
•Depending*on*
discussion,*conditions*of*
the*model*are*adjusted*
to*show*potential*
outcome

Setting*a*minimum*landing*size*at*10*cm

Ban*on*mini*trawl

Mixed*approach:*gradual*increase*of*MLS,*seasonal*
closure,*gear*change*(trawl)

Next*steps
•Implementation*of*control*document,*to*force*
the*implementation*of*minimum*landing*size,*
ban*on*berried*female*landings*and*ban*of*trawls
•Project*started*on*three*areas*(East*Lampung,*
Madura,*South*East*Sulawesi)
•Aim:*evaluating*the*effect*of*the*control*document
•Data*collection*–biology*&*economy
•Data*Integration*in*model(s)*

Developing*a*bioeconomic model*to*foster*
discussions*among*stakeholders.*
An*application*to*Indonesian*
Blue*Swimming*Crab*fisheries
Sébastien*Metz1,*Dessy Anggraeni2,*Geoff*Tingley2,*Jack*Whalen2,*Juan*Manuel*
Garcia-Caudillo2,* Jim*Cannon2
Affiliations:*
1*Sakana*Consultants*
2*Sustainable Fisheries Partnership Foundation
With the*financial support*of*the*The*Rockefeller*Foundation