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

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SBT Fishery. Habitat Component SBT Fishery. Community Component

02468

1012141618

1 2 3 4 5 6

Consequence score

Freq

uenc

y

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10121416

1 2 3 4 5 6

Consequence score

Freq

uenc

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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

26

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!