A Framework for Ecosystem A Framework for Ecosystem Impacts Assessment Using an Impacts Assessment Using an

Indicator ApproachIndicator Approach

Patricia A. LivingstonPatricia A. Livingston11, K. Aydin, K. Aydin11, J. Boldt, J. Boldt22, J. Ianelli, J. Ianelli11, , and J. Juradoand J. Jurado--MolinaMolina22

11Alaska Fisheries Science Center Seattle, WA, USAAlaska Fisheries Science Center Seattle, WA, USA22JISAO, University of Washington, Seattle, WA USAJISAO, University of Washington, Seattle, WA USA

OverviewOverview

•• Alaskan contextAlaskan context•• Evolution and Description of the Evolution and Description of the

FrameworkFramework–– Documentation of status and trendsDocumentation of status and trends–– Evaluation of past and present impactsEvaluation of past and present impacts–– Prediction of future trends and management Prediction of future trends and management

optionsoptions

Magnuson-Stevens FisheryConservation andManagement Act

1976

Marine Mammal Protection Act

1972

Endangered Species Act

1973Clean Water

Act1972

National Environmental

ProtectionAct

1969

US Legislation on Environmental ProtectionUS Legislation on US Legislation on Environmental ProtectionEnvironmental Protection

Ecosystem-based Management Actions EcosystemEcosystem--based Management Actions based Management Actions

•• TAC less than ABC for individual stocksTAC less than ABC for individual stocks

•• OY cap on total OY cap on total groundfishgroundfish yieldyield

•• No target fisheries on forageNo target fisheries on forage

•• ShortShort--tailed albatross take tailed albatross take restrictions, Seabird restrictions, Seabird bycatchbycatchmitigation devicesmitigation devices

•• No fishing in No fishing in StellerSteller sea lion foraging sea lion foraging area and minimum biomass threshold area and minimum biomass threshold for sea lion preyfor sea lion prey

•• Trawl closures, bottom trawling Trawl closures, bottom trawling restrictionsrestrictions

•• BycatchBycatch and discard controlsand discard controls

ABCTAC≤ ≤Catch OFL<ABCTAC≤ ≤Catch OFL<

Conservative single species targets

CAP on TOTAL TARGET CATCHTotal yield < 2 million tonnes

Gather information Historical status

and trendsEcosystem components

and stressors

Establish assessmentFramework, objectives,Thresholds, indicators

Generate managementAlternatives,

Future scenariosMODELS for Prediction

Expert judgmentto analyze impactsAnd provide advice

DECISION

Key Pieces of the FrameworkKey Pieces of the FrameworkKey Pieces of the Framework

Closed Areas

CatchLevels

Effort

Physical Forcing

Management

Status

Ecosystem Measures and InfluencesEcosystem Measures and Influences

Gear

Ecosystem Impacts Assessment Framework: Objectives, sub-objectives, ecosystem indicators

Ecosystem Impacts Assessment Ecosystem Impacts Assessment Framework: Framework: Objectives, subObjectives, sub--objectives, ecosystem indicatorsobjectives, ecosystem indicators

SUBOBJECTIVESSUBOBJECTIVES•• More focused, tangibleMore focused, tangible

•• Relate to key areas/issues Relate to key areas/issues for protectionfor protection

•• May vary across May vary across ecosystems depending on ecosystems depending on differences in threats, differences in threats, stressors, ecosystem stressors, ecosystem characteristicscharacteristics

•• Thresholds relate to legal Thresholds relate to legal mandates under various mandates under various lawslaws

INDICATORSINDICATORS

•• Measures of particular Measures of particular ecosystem attributesecosystem attributes

•• Qualitative analysis of Qualitative analysis of change used when change used when targets/thresholds are not targets/thresholds are not defineddefined

•• Requires expert judgmentRequires expert judgment

Ecosystem ProcessesEcosystem ProcessesEcosystem Processes

OBJECTIVES FOR ECOSYSTEM OBJECTIVES FOR ECOSYSTEM PROTECTIONPROTECTION

•• Maintain Predator/prey Maintain Predator/prey relationshipsrelationships

•• Maintain Energy/flow Maintain Energy/flow balancebalance

•• Maintain Habitat and Maintain Habitat and DiversityDiversity

ECOSYSTEM DEFINITIONECOSYSTEM DEFINITION

•• PopulationsPopulations and and communitiescommunities of of interactinginteracting organisms organisms and and physical physical environmentenvironment with with characteristic characteristic trophictrophicstructurestructure and material and material ((energy) cyclesenergy) cycles

Objectives for Ecosystem Protection:Objectives for Ecosystem Protection:

Maintain predatorMaintain predator--prey relationships prey relationships pelagic forage availabilitypelagic forage availabilityspatial/temporal conc. of fishery impact on forage spatial/temporal conc. of fishery impact on forage fishfishremovals of top predatorsremovals of top predatorsintroduction of nonintroduction of non--native speciesnative species

Maintain diversityMaintain diversityspecies diversityspecies diversityfunctional (functional (trophictrophic, structural habitat) diversity, structural habitat) diversitygenetic diversitygenetic diversity

Maintain energy flow and balanceMaintain energy flow and balancehumanhuman--induced energy redirectioninduced energy redirectionsystem impacts attributable to energy removalsystem impacts attributable to energy removal

CLIMATE and FISHING

Ecosystem Impacts Assessment Framework: Objectives, sub-objectives, ecosystem indicators

Ecosystem Impacts Assessment Ecosystem Impacts Assessment Framework: Framework: Objectives, subObjectives, sub--objectives, ecosystem indicatorsobjectives, ecosystem indicators

OBJECTIVE: OBJECTIVE: MAINTAIN PREDATOR/PREY RELATIONSHIPSMAINTAIN PREDATOR/PREY RELATIONSHIPS

SUBOBJECTIVE1: Sustain top predator populations SUBOBJECTIVE1: Sustain top predator populations

THRESHOLD: THRESHOLD: Catch levels high enough to cause the biomass of Catch levels high enough to cause the biomass of one or more top level predator species to fall below minimum one or more top level predator species to fall below minimum biologically acceptable limitsbiologically acceptable limits

INDICATORS: INDICATORS: •• Population status of top predator speciesPopulation status of top predator species•• BycatchBycatch levels of sensitive top predators that lack population levels of sensitive top predators that lack population

estimates (sharks, birds)estimates (sharks, birds)•• TrophicTrophic level of the catchlevel of the catch

Effects AnalysisEffects Analysis

ObjectiveObjective SubobjectiveSubobjective Significance ThresholdSignificance Threshold IndicatorsIndicatorsPredatorPredator--prey prey relationshipsrelationships

Pelagic forage Pelagic forage availabilityavailability

Fishery induced changes outside the Fishery induced changes outside the natural level of abundance or natural level of abundance or variability for a prey species relative variability for a prey species relative to predator demandsto predator demands

Population trends in pelagic forage Population trends in pelagic forage biomass (quantitative biomass (quantitative -- pollockpollock, Atka , Atka mackerel, catch/mackerel, catch/bycatchbycatch trends of trends of forage species, squid and herring)forage species, squid and herring)

Spatial and Spatial and temporal temporal concentration of concentration of fishery impact fishery impact on forageon forage

Fishery concentration levels high Fishery concentration levels high enough to impair the long term enough to impair the long term viability of ecologically important, viability of ecologically important, nonresourcenonresource species such as marine species such as marine mammals and birdsmammals and birds

Degree of spatial/temporal concentration Degree of spatial/temporal concentration of fishery on of fishery on pollockpollock, Atka mackerel, , Atka mackerel, herring, squid and forage species herring, squid and forage species (qualitative)(qualitative)

Removal of top Removal of top predatorspredators

Catch levels high enough to cause Catch levels high enough to cause the biomass of one or more top level the biomass of one or more top level predator species to fall below predator species to fall below minimum biologically acceptable minimum biologically acceptable limits limits

TrophicTrophic level of the catchlevel of the catchSensitive top predator Sensitive top predator bycatchbycatch levels levels (quantitative: sharks, birds; qualitative: (quantitative: sharks, birds; qualitative: pinnipedspinnipeds))Population status of top predator species Population status of top predator species (whales, (whales, pinnipedspinnipeds, seabirds) relative to , seabirds) relative to minimum biologically acceptable limitsminimum biologically acceptable limits

Introduction of Introduction of nonnative nonnative speciesspecies

Fishery vessel ballast water and hull Fishery vessel ballast water and hull fouling organism exchange levels fouling organism exchange levels high enough to cause viable high enough to cause viable introduction of one or more nonnative introduction of one or more nonnative species, invasive speciesspecies, invasive species

Total catch levelsTotal catch levels

Effects Analysis (cont.)Effects Analysis (cont.)

ObjectiveObjective SubobjectiveSubobjective Significance ThresholdSignificance Threshold IndicatorsIndicators

Energy Energy flow and flow and balancebalance

Energy reEnergy re--directiondirection

LongLong--term changes in system term changes in system biomass, respiration, biomass, respiration, production or energy cycling production or energy cycling that are outside the range of that are outside the range of natural variability due to natural variability due to fishery discarding and offal fishery discarding and offal production practicesproduction practices

Trends in discard and offal Trends in discard and offal production levelsproduction levels(quantitative for discards)(quantitative for discards)Scavenger population trends relative Scavenger population trends relative to discard and offal production levels to discard and offal production levels (qualitative)(qualitative)Bottom gear effort (qualitative Bottom gear effort (qualitative measure of unobserved gear measure of unobserved gear mortality particularly on bottom mortality particularly on bottom organisms)organisms)

Energy Energy removalremoval

LongLong--term changes in term changes in systemsystem--level biomass, level biomass, respiration, production or respiration, production or energy cycling that are energy cycling that are outside the range of natural outside the range of natural variability due to fishery variability due to fishery removals of energy removals of energy

Trends in total retained catch levels Trends in total retained catch levels (quantitative)(quantitative)

Effects Analysis (cont.)Effects Analysis (cont.)

ObjectiveObjective SubobjectiveSubobjective Significance ThresholdSignificance Threshold IndicatorsIndicators

DiversityDiversity Species Species diversitydiversity

Catch removals high enough to cause Catch removals high enough to cause the biomass of one or more species the biomass of one or more species (target, (target, nontargetnontarget) to fall below or to ) to fall below or to be kept from recovering from levels be kept from recovering from levels below minimum biologically below minimum biologically acceptable limits acceptable limits

Population levels of target, Population levels of target, nontargetnontarget species species relative to MSST or ESA listing thresholds, relative to MSST or ESA listing thresholds, linked to fishing removals (qualitative)linked to fishing removals (qualitative)BycatchBycatch amounts of sensitive (low potential amounts of sensitive (low potential population turnover rates) species that lack population turnover rates) species that lack population estimates (quantitative: sharks, population estimates (quantitative: sharks, birds, HAPC biota)birds, HAPC biota)Number of ESA listed marine speciesNumber of ESA listed marine speciesArea closuresArea closures

Functional Functional ((trophictrophic, , structural structural habitat) habitat) diversity diversity

Catch removals high enough to cause Catch removals high enough to cause a change in functional diversity a change in functional diversity outside the range of natural variability outside the range of natural variability observed for the systemobserved for the system

Guild diversity or size diversity changes linked Guild diversity or size diversity changes linked to fishing removals (qualitative)to fishing removals (qualitative)Bottom gear effort (measure of benthic guild Bottom gear effort (measure of benthic guild disturbance)disturbance)HAPC biota HAPC biota bycatchbycatch

Genetic Genetic diversitydiversity

Catch removals high enough to cause Catch removals high enough to cause a loss or change in one or more a loss or change in one or more genetic components of a stock that genetic components of a stock that would cause the stock biomass to fall would cause the stock biomass to fall below minimum biologically below minimum biologically acceptable limitsacceptable limits

Degree of fishing on spawning aggregations or Degree of fishing on spawning aggregations or larger fish (qualitative)larger fish (qualitative)Older age group abundances of target Older age group abundances of target groundfishgroundfish stocksstocks

MANAGEMENT INDICATORSMANAGEMENT INDICATORSEastern Bering Sea

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

1954 1959 1964 1969 1974 1979 1984 1989 1994 1999

Tota

l cat

ch (t

)

1

2

3

4

Trop

hic

leve

l (ca

tch)

Total catch

Trophic level ofcatch

0

500

1000

1500

2000

2500

3000

3500

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Year

Obs

erve

d bo

ttom

traw

l dur

atio

n (2

4hr d

ays)

GOAAIBS

0

50,000

100,000

150,000

200,000

250,000

1993 1994 1995 1996 1997 1998 1999 2000 2001

Year

Long

line

effo

rt (1

,000

hoo

ks)

0

5,000

10,000

15,000

20,000

25,000

30,000

Inci

dent

al ta

ke o

f sea

bird

s

Effort (1000 hooks)Number of seabirds

BSAI Non-target

0

10000

20000

30000

40000

50000

60000

70000

1997 1998 1999 2000 2001 2002

Tota

l Cat

ch (t

ons)

Time trends in bottom trawl effort

Total catch and trophic level of catch

Amount and composition of non-target fish species in catch

Seabird bycatch and fishing effort

ECOSYSTEM STATUS INDICATORSECOSYSTEM STATUS INDICATORS

3.16

3.65

3.98

4.23

4.42

1982 19

85 1988 19

91 1994 19

97 20000

123456789

101112

ln (N +1)

ln (length midpoint +1)

Year

Size frequency distribution all fish

11.000-12.00010.000-11.0009.000-10.0008.000-9.0007.000-8.0006.000-7.0005.000-6.0004.000-5.0003.000-4.000

Seabird Population Trends

0

2

4

6

8

10

12

14

16

N.Bering/Chukchi

SE Bering SW Bering Gulf of Alaska Southeast

Freq

uenc

y

Negative trend No discernable trend Positive trend

Fish community size spectrum

Status of structural habitat biota

SEAPENS/W HIPS

0

500

1000

1500

2000

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

Bio

mas

s (t

Pa c ific De c a d a l O sc illa tion

- 4.00

- 3.00

- 2.00

- 1.00

0.00

1.00

2.00

3.00

4.00

19

00

19

05

19

10

19

15

19

20

19

25

19

30

19

35

19

40

19

45

19

50

19

55

19

60

19

65

19

70

19

75

19

80

19

85

19

90

19

95

20

00

Ye a r

Ind

ex

PD O5-m o n th ru n n in g m e a n15-m o n th ru n n in g m e a n

Seabird population trends

Environmental fluctuations

YE AR1982 1984 1986 1988 1990 1992 1994 1996 1998

00.20.40.60.8

11.21.41.61.8

Population trends of non-target fish species

•• Accompanies single species stock assessment advice to Accompanies single species stock assessment advice to North Pacific Fishery Management Council since 1995North Pacific Fishery Management Council since 1995

•• Provides status and historical trend information of Provides status and historical trend information of ecosystem components using scientific information from a ecosystem components using scientific information from a variety of experts and agencies: Assess Present Statusvariety of experts and agencies: Assess Present Status

•• Contains species, community, and ecosystemContains species, community, and ecosystem--level level indicators and indicators of environmental and human indicators and indicators of environmental and human impactsimpacts

•• Track efficacy of ecosystemTrack efficacy of ecosystem--based management efforts based management efforts

•• Meets the national fishery management scientific Meets the national fishery management scientific information requirement (National Standard 2) to include information requirement (National Standard 2) to include information on past, present, and possible future condition information on past, present, and possible future condition of the stocks, marine ecosystems, and fisheries being of the stocks, marine ecosystems, and fisheries being managed in the stock assessment and fishery evaluation managed in the stock assessment and fishery evaluation reports provided to managers.reports provided to managers.

The Framework: Part 1 Evaluate Present StatusEcosystem Considerations Section

The Framework: Part 1 The Framework: Part 1 Evaluate Present StatusEvaluate Present StatusEcosystem Considerations SectionEcosystem Considerations Section

Need for Ecosystem AssessmentNeed for Ecosystem Assessment

•• Requires an Requires an ecosystem impacts assessment frameworkecosystem impacts assessment framework

•• Prediction of possible future trends under various Prediction of possible future trends under various management strategies: management strategies: MODELSMODELS

•• Provide guidance on possible Provide guidance on possible aggregate effectsaggregate effects of fishing of fishing and climate that are not captured under single species and climate that are not captured under single species assessmentsassessments

•• Uses Uses NEPANEPA as the umbrella legislation for providing an as the umbrella legislation for providing an ecosystemecosystem--based management framework that considers based management framework that considers the ecosystem first the ecosystem first

The Framework Part 2:The Framework Part 2:Moving Beyond Status and Trends Moving Beyond Status and Trends

Ecosystem Impacts Assessment Framework: PREDICTIONEcosystem Impacts Assessment Ecosystem Impacts Assessment Framework: Framework: PREDICTIONPREDICTION

KEY CONSIDERATIONS

1. MODELS that incorporate processes of interest

2. MANAGEMENT ALTERNATIVES to evaluate• Annual quota-setting• Management strategy evaluation of

policies

3. SCENARIOS of future environmental state

Impacts AnalysisImpacts Analysis

Elements:Elements:•• Predefined thresholds Predefined thresholds

or amounts of or amounts of acceptable change in acceptable change in an indicatoran indicator

•• Expert judgmentExpert judgment•• Falling below Falling below

threshold or too much threshold or too much change in indicator change in indicator triggers action or triggers action or eliminates eliminates management management alternativealternative

•• Performed at Performed at ecosystem and ecosystem and individual fishery levelindividual fishery level

Fishing Mortality

Oldoverfishing

level

Catch

Stock

0 Fmsy

Bmsy

B0 (unfished)

Spaw

ning

Biomas

s

Newoverfishing

level

Fishing Mortality

Oldoverfishing

level

Catch

Stock

0 Fmsy

Bmsy

B0 (unfished)

Spaw

ning

Biomas

s

Newoverfishing

level

Change in Discards by Management Alternative

-80.0

-60.0

-40.0

-20.0

0.0

20.0

40.0

60.0

1 2 3 4 5 6 7 8 9

Management Alternative

Perc

ent c

hang

e fr

om

base

line

Discards

Threshold

Future ChallengesFuture ChallengesFuture Challenges

• Improve predictive capability with regard to climate and human impacts on ecosystems: model refinement and regime shift analysis to drive recruitment scenarios

• More explicit definition of ecosystem-based management objectives: may require public involvement in defining specific regional objectives for management

• Developing objective criteria and sensitive indicators to measure the success in achieving desired ecosystem state or condition (or avoidance of undesirable states)

• More formalized decision-making framework

• Improve predictive capability with regard to climate and human impacts on ecosystems: model refinement and regime shift analysis to drive recruitment scenarios

• More explicit definition of ecosystem-based management objectives: may require public involvement in defining specific regional objectives for management

• Developing objective criteria and sensitive indicators to measure the success in achieving desired ecosystem state or condition (or avoidance of undesirable states)

• More formalized decision-making framework