1
Ecosystem-based resource assessments for sustainable
fisheries
Chang Chang IkIk ZhangZhang
Pukyong National University, Koreay g y,
PICES Summer School, Hakodate, Japan, August 23, 2008
Contents
Review of world fisheries and their resources
Resource assessment and fisheries management
Ecosystem-based fisheries assessment approaches
1. ERAEF by Australia2. MSC’s FAM3. EBFA approach
2
Total catch (in 2006) = 83.1 million tons
Catch by FAO marine fishing area
22. 1
11.34.5
5. 8 12. 3
1. 61. 8
2. 23. 1
3.3
9.3
2 40.61.4 2.4
11.2% / 4.8%(0.55)
Proportion of catch to area by FAO area
( ) : catch per unit area (mt/km2)
26.6% / 6.0%(1.08)
1.9% / 13.8%(0.03)
14 8% / 8 5%
3.7% / 2.1%(0.41)
13.6% / 9.4%(0.33)
5.4% /8.5%(0.15)
1.8% / 4.1%(0.25)
4.0% / 3.9%(0.23)
2.7% / 1.4%(0.42)
0.8% / 8.0%(0.03)
14.8% / 8.5%(0.41)
7.0% / 8.4%(0.18)
1.7% / 5.2%(0.08)
2.9% / 4.9%(0.13)
0.01% / 3.5%(0.001)
3
Reductions in traditional fishing grounds due to the EEZ
Status of World Fisheries
Reductions in traditional fishing grounds due to the EEZ regime
Depletion of fisheries resources in quantity and quality
Deterioration of coastal ecosystems due to pollution
-> Necessary to develop tools and system for managing
fisheries resources by a environmentally sound and y y
sustainable way : Ecosystem-based fisheries management
EcosystemEnvironment
Typical Population-based Approach
StockGrowth(G)
Fishing mortality(F)
Recruitment(R)
Environment(E)
Natural mortality(M)
Population parameters1. Recruitment (R)2. Growth (G)3. Natural mortality (M)4. Fishing mortality (F)
4
Typical Fisheries Management Typical Fisheries Management
Mostly indirect control devicesMostly indirect control devices
TAC-based management
Community-based self-management
Enhancement by artificial reefs, releasing fries and juveniles, and seaweed bedsj
Marine ranching
Buy-back program to reduce fishing vessels
* Operated separately, not systematically
Interactions of Organisms with Biotic and Abiotic Environments in a Marine Ecosystem
R denotes recruitment, G, growth, M, natural mortality, and F, fishing mortality.
5
6
Shortcomings of a single species management
Why ecosystem-based fisheries management?
Shortcomings of a single species management
- Limited management: only focus on sustainability explicitly
Reykjavik Declaration (2002), FAO (2003): stressed implementation
of ecosystem approach to fisheries (EAF)
WSSD (2002): encouraged the application of the ecosystem-based
approach of fisheries by 2010
Traditional fishery
Ecosystem-based fishery
Ecosystem-based multi-
Spectrum of Ecosystem-based Management Approaches (Modified from Sainsbury)
Ecosystem-based fishery
Traditional fishery
Traditional fishery
target species
single species or multi-species
ymanagement
ymanagement sector
management
integrated management
multiple use
ymanagement
ymanagement
ymanagement
start with the target species
add issues of t i t
start with the target species
add issues of t i tp
management
EBFA approach
ecosystem impact on fishery resourcesecosystem impact on fishery resources
JJ Vollenweider
7
Definitions of Ecosystem and Ecosystem-based Management
‘Ecosystem’ is ‘the spatial unit and its organisms and natural
processes that is being studied or managed.’
‘Ecosystem-based management’ is ‘a strategic approach to
based Management
Ecosystem-based management is a strategic approach to
managing human activities that seeks to ensure the
coexistence of healthy, fully functioning ecosystems and
human communities’
1. The ability to predict ecosystem behavior is limited.
Principles of Ecosystem (NMFS EPAP 1999)
1. The ability to predict ecosystem behavior is limited.
2. Ecosystems have real thresholds and limits which, whenexceeded, can affect major system restructuring.
3. Once thresholds and limits have been exceeded,changes can be irreversible.
4. Diversity is important to ecosystem functioning.
5. Multiple time scales interact within and amongecosystems.
6. Components of ecosystems are linked.
7. Ecosystem boundaries are open.
8. Ecosystems change with time.
8
It is becoming clear that we cannot manage entire
Steele and Collie in THE SEA (2004)
It is becoming clear that we cannot manage entireecosystems; we can only regulate first-order impactswithout being able to predict second-orderconsequences…
Ecosystem-based Management Goals
Maintain system sustainability
Maintain biodiversity consistent with natural processes
Protect and restore habitats of fish andProtect and restore habitats of fish and prey
Maintain social and economic benefits
9
Ecosystem-based Fisheries Assessment Approaches
- ERAEF by AustraliaMSC’ FAM- MSC’s FAM
- EBFA approach
Ecological Risk Assessment for the Effects of Fishing (ERAEF)
Risk assessment is one way of evaluating sustainability
10
ERAEF Approach
5 ecological “components” evaluated (= t )ecosystem)
Target speciesByproduct and Bycatch speciesThreatened, Endangered and ProtectedThreatened, Endangered and Protected species (TEP)HabitatsCommunities (including food chains)
Outline of approach: ERAEF
Hierarchical approach:Hierarchical approach: Levels allow screening & elimination of low risk
Initial scoping (whole fishery, all issues)Level 1 – qualitative risk assessmentLevel 2 – semi-quantitative risk assessmentLevel 3 – full quantitative risk assessment
Proceed to subsequent level depending on estimated risk at current level
11
ERAEF Method Development
Level 1; SICA
Level 2: PSA
Level 3; Stock assessment, Eco-family
e.g. stock assessment e.g. Ecosim
e.g. stock assessment
Leve
l 3
ERA-EF OUTLINE
14
16
89
10
161820
14
16
P
S
LHL
H
P
S
LHL
H
P
S
LHL
H
161820
Leve
l 2
X X
0
2
4
6
8
10
12
1 2 3 4 5 6
Consequence score
Freq
uenc
y
012345678
1 2 3 4 5 6
Consequence score
02468
10121416
1 2 3 4 5 6
Consequence score
0
2
4
6
8
10
12
1 2 3 4 5 6
Consequence score
Fishing Activities (e.g. Longlining)
02468
10121416
1 2 3 4 5 6
Consequence score
Target CommunitiesHabitatsTEPBycatch
Leve
l 1Sc
opin
g
12
Level 1 – All componentsSBT Fishery. Target Species Component
16
SBT Fishery. Bycatch/Byproduct Species
14
SBT Fishery. TEP Species Component
10
02468
101214
1 2 3 4 5 6
Consequence score
Freq
uenc
y
0
2
4
6
8
10
12
1 2 3 4 5 6
Consequence score
Freq
uenc
y0
2
4
6
8
1 2 3 4 5 6
Consequence score
Freq
uenc
y
SBT Fishery. Habitat Component SBT Fishery. Community Component
02468
1012141618
1 2 3 4 5 6
Consequence score
Freq
uenc
y
02468
10121416
1 2 3 4 5 6
Consequence score
Freq
uenc
y
Confidence•Low•High
Level 1 – All componentsSBT Fishery. Target Species Component
16
SBT Fishery. Bycatch/Byproduct Species
14
SBT Fishery. TEP Species Component
10
02468
101214
1 2 3 4 5 6
Consequence score
Freq
uenc
y
0
2
4
6
8
10
12
1 2 3 4 5 6
Consequence score
Freq
uenc
y
0
2
4
6
8
1 2 3 4 5 6
Consequence score
Freq
uenc
y
SBT Fishery. Habitat Component SBT Fishery. Community Component
02468
1012141618
1 2 3 4 5 6
Consequence score
Freq
uenc
y
02468
10121416
1 2 3 4 5 6
Consequence score
Freq
uenc
y
Confidence•Low•High
13
Level 2 (PSA) Progress
Axis 1: Productivity Attributes (additive)Axis 1: Productivity Attributes (additive)Axis 2: Susceptibility Attributes (multiplicative)
Level 2 PSA is “semi-quantitative”BdB
Level 3 would solve this equation…e.g. stock assessmentCannot do this for all species time and $
qEBKBrB
dtdB
−−= )1(
Cannot do this for all species…time and $
PSA estimates the “r” and the “q”B=species, habitats, communities
14
The Marine Stewardship Council
The MSC Standard* (Principles and Criteria for Sustainable
Fishing)
Sustainability of th t kthe stock
Impact on ecosystem
Management systems
* based on international guides for standard setting and founded on theFAO Code of Conduct for Responsible Fisheries
15
Assessment Hierarchy
Principle 1 Principle 2 Principle 3 Scores obtained For each Principle
Fishery passes with or without conditions or failsPrinciples & Criteria for Sustainable Fishing
Criterion 1.1 Criterion 1.2 Criterion 1.3
Sub criterion 1.2.1 Sub criterion 1.2.2 Sub criterion 1.2.3 Scores aggregated
Scores obtained For each Criterion
Performance Indicator1.2.2.1
Performance Indicator1.2.2.2
Scoring occurs at this level
100
80
60
Each performance indicator must score > 60
Passing the StandardPassing the Standard
Each performance indicator must score > 60 (minimum pass, sustainable performance)Each Principle must achieve an aggregate score of > 80 (best practice)For any indicator scoring from > 60 to < 80, fishery client must agree to meet conditions to achieve client must agree to meet conditions to achieve specified outcomes over a defined period of time
16
Certifications and Assessmentsaround the world WWF partnerships
The best environmental choice in seafood www.msc.org
17
E t b d Fi h iEcosystem-based Fisheries Assessment (EBFA) approach
(Zhang et al. in prep)
Considerations for EBFA approach (Zhang et al. in prep)
Not revolutionary but evolutionary approachNot revolutionary, but evolutionary approach
Capable of being applied w/ available information
Precautionary, and environmentally sound
Simple and pragmatic
18
Elements of the EBFA approach
Two-tier assessment system
Management objectives, indicators and reference points
Risk indices and management status indices
2 tier assessment system
Tier Method Level of information
Tier 1 Quantitative analysis High
Tier 2Semi-quantitative or
qualitative analysis
Low
19
Management Objectives of EBFAA
Maintain system sustainability
Maintain biodiversity consistent with natural processes
Protect and restore habitats of fish andProtect and restore habitats of fish and prey
Selecting Indicators
1. Ease of understanding by users
2. Susceptibility to influence thru management of human activities
3. Measurability using existing data or currently monitored information
• Selection of indicators was based on FAO (2000),MSC (Marine Stewardship Council, 2005 ) method,and ERA (Ecological Risk Assessment) from Australia (2005)
20
Attribute IndicatorTier 1 (8) Tier 2 (12)
Biomass- Biomass
- CPUECPUE
Identification of indicators : Sustainability
or CPUE
Fishing intensity- Fishing mortality or Catch
- Restricted access- Fishery monitoring and sampling- Fishing method- Precautionary approach and sensitivity of stock assessment
Size at first capture - Size at first capture - Size at entryHabitat size - Habitat size
Community structure - FIB index
Reproductive potential - FRP indexReproductive potential FRP index
Productivity - Total production of ecosystem
Life history characteristics - Maximum age or age at maturity- Adult habitat overlap with juvenile
Management - Management plan for fishery - Management of IUU fishery
Recovery - Recovery plan and period for depleted stocks
Genetic structure - No. of spawning populations - Population structure
Attribute IndicatorReference points
Target (0) Between (0 - 2) Limit (2)
BiomassBiomass (B) B≥ B40% B40% >B≥B35% B <B35%
or CPUE (U) U≥ UABC UABC >U≥Ulimit1 U <Ulimit
Sustainability
Tier 1 (Quantitative analysis)
Fishing intensity
Fishing mortality (F) F ≤ F40%(or F0.1) F40% (or F0.1) < F ≤ FMSY F>FMSY
or Catch (C) C ≤ ABC ABC < C ≤ MSY C>MSY
Size at first capture Age at first capture (t) t≥ ttarget ttarget >t≥tlimit
2 t <tlimit
Habitat size Habitat size (H) H≥ Htarget Htarget >H≥Hlimit3 H <Hlimit
Community structure FIB index FIB≥ FIBtarget FIBtarget >FIB≥FIBlimit
4 FIB <FIBlimit
Reproductive potential FRP index FRP≥ FRPtarget FRPtarget >FRP≥FRPlimit
5 FRP<FRPlimitp
Productivity Total production of ecosystem (P) P≥ Ptarget Ptarget >P≥Plimit
6 P<Plimit
Genetic structure
No. of spawning populations (SP) SP≥ SPtarget SPtarget >SP≥SPlimit
7 SP<SPlimit
1 Ulimit : UABC – SD, UABC was estimated from stock assessment.2 tlimit : 0.5ttarget , ttarget was optimal age at first capture from Beverton-Holt yield per recruit analysis.3 Hlimit : Htarget – 2SD, Htarget was mean plus one standard deviation of habitat size from 1990 to 2006.4 FIBlimit : FIBtarget – 2SD, FIBtarget was mean plus one standard deviation of FIB indices from 1990 to 2006.5 FRPlimit : FRPtarget – 2SD, FRPtarget was mean plus one standard deviation of FRP indices from 1990 to 2006.6 Plimit : 0.5Ptarget,7 SPlimit : 0.5SPtarget,
21
Reference Points (RP) and Risks
Increased anthropogenic impactIncreased anthropogenic impact
Limit RPTarget RPUndisturbed
Green zone Yellow zone Red zone
Improvement by proper management
Risk 0 2
Nested risk indices of EBFA
I S f i di t i
∑
∑
=
== n
ii
n
iii
W
WIORI
1
1
Ii : Score of indicator i Wi : Weighting factor of indicator in : Number of indicators
: Weighting value for objectives : Sustainability risk index: Biodiversity risk index: Habitat risk index
∑= iiSRIBFRI
HHBBSS ORIORIORISRI λλλ ++=
SORI
BORI
HORI
HλSλ
Bλ
0.1=∑ λ
∑∑=
i
ii
BSRIBFRI
∑∑=
i
ii
CFRICERI
Ci : Catch of fishery
Bi : Biomass or biomass index of species i
∑ iBFRI
22
Risk Assessment Diagram: examining indices to determine areas in needs of management action
Each ORI has score from 0 to 2Sustainability
Diagonal bisecting line shows SRI value
Each colored zone with boundary values of
1.16 and 1.63
- has same area --> same probability for
points to be in each zone
Habitat Biodiversity
- represents degree of safety in ecosystem
Red and yellow zones require corrective
management plans to move to green zone
Biodiversity
Management status indices
100×−
= +
t
ittF FRI
FRIFRIMI 100×−
= +
t
ittE ERI
ERIERIMI
100×−
= +
t
ittS SRI
SRISRIMI100×−
= +
t
ittO ORI
ORIORIMI
Management improvement can be examined by Wilcoxon non-parametic
test for differences in risk indices.
23
1 Identifying ecosystem and fisheries
Steps for EBFA approach
1. Identifying ecosystem and fisheries
eg., EBS, trawl fishery and longline fishery
2. Identifying species based on tier system
Tier 1 : 9 species such as walleye pollockp y p
Tier 2 : 28 species such as POP
3. Identifying indicators
Indicators for each management objectives
Steps for EBFA approach (cont.)
4. Setting reference points
5. Scoring risks
Using continuous and discrete methods
6 Calc lating ORI SRI and FRI and plotting risk6. Calculating ORI, SRI and FRI, and plotting risk
diagrams
7. Calculating MIs to compare
24
Assessing indicators using reference points
Reference points
Example _ Sustainability_Biomass (Tier 1)
Objectives Attribute Indicator WeightTarget (0) Limit (1) Beyond
Limit (2)
Sustainability Biomass Biomass (B) B≥B40% B40% >B≥ B35% B<B35% ***
In Tongyeong marine ranch
Jacopever rockfish : B40% : 527.6mt
B35% : 461.62mt
Biomass in 1998 : 110mt-Beyond limit, Risk score: 2
Biomass in 2006 : 833mt-Target, Risk score: 0
Result of tier 1 assessment
Jacopever rockfish
ObjectivesORI (Zone)
MI Significance1998 2006
Sustainability 1.333(Yellow) 0.583(Green) 56.25 *
Biodiversity 1.571(Yellow) 0.857(Green) 45.45 **
Habitat 1.375(Yellow) 0.375(Green) 72.73 *( ) ( )
SRI 1.407(Yellow) 0.593(Green) 57.89 **
* : denotes a significant difference at α = 0.05 level
** : denotes a significant difference at α = 0.01 level
NS : denotes non-significant
25
ORI diagram for Jacopever rockfish by Tier 1 assessment
Sustainability Sustainability
SRI =0.593
Habitat Biodiversity Habitat Biodiversity
1998 2006
SRI =1.047
Biodiversity Biodiversity
ORI diagram for by-catch species by Tier 2 assessment
Sustainability Sustainability
Habitat Biodiversity Habitat Biodiversity
1.4781.522
1.543
0.3480.5220.6300.696
0.7390.804
1998 2006
Black rockfish Red sea bream Common seabass
Black seabream Yellow tail Rock bream
Biodiversity Biodiversity
1.5651.630
1.543
1.652
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EBS Pollock Biomass Risk Scores
2
2007Xtarget
BMSY
2007Xlimit
0.5BMSY
1997Xtarget
BMSY
1997Xlimit
0.5BMSY
1
Ris
k Sc
ore
00 1000 2000 3000 4000
Biomass (1000s mt)
2007
1997
EBS Pollock Catch Risk Scores
2
Xtarget
ABC2007
Xlimit
OFL1997
Xlimit
OFL2007
Xtarget
ABC1997
1
Ris
k Sc
ore
0980,000 1,180,000 1,380,000 1,580,000 1,780,000 1,980,000 2,180,000
Catch (mt)
20071997
27
Discussion and Conclusion
• Integrated holistic approaches such as ERAEF, MSC
Approach, EBFA, are useful to assess species and
fisheries concerned
• Further comprehensive studies on indicators andFurther comprehensive studies on indicators and
reference points required
• Socio-economic status should be explicitly included
Thank you!
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