Biogeochemical processes and fish dynamics in food web models for end-to-end conceptualization of

marine ecosystems. Ecopath with Ecosim

6th European Conference on Ecological Modelling, ECEM’07

International Centre for Theoretical Physics

Trieste, Nov 26-27, 2007

Ecopath with Ecosim: the approach

Biogeochemical processes and fish dynamics in food web models

International Centre for Theoretical Physics

Trieste, Nov 26-27, 2007

Villy Christensen

UBC Fisheries Centre

Workshop introductions• EwE overview

– Ecotracer: persistent pollutant modeling

• Time-dynamic simulation

– Ecosim

• Spatial and time-dynamics simulation

– Ecospace

• EwE6

– Overview

– Making new modules

– Linking and coupling to other models3

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NOAA celebrates 200 yearhttp://celebrating200years.noaa.gov/breakthroughs/welcome.html

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and there are also activities on

the other side

Mote lab

Charles Darwin Research Station, Galapagos

Four Fish. Commissions

Prince William Sound

NMFS, Bering Sea, GoAlaska Greenland Fisheries Inst.Faroe Fisheries Inst

IMR, Bergen

DIFRES

CEFAS, Lowestoft

Santander

FL FWRI

S Atlantic MFC

NOAA, Chesapeake Bay

Fish. Inst, Lisboa

Six West African Countries

Concepcion, Chile

Namibia

Cape Town

DFO

Tongoy Gulf, Chile

Colombia

Venezuela

Argentina

Sao Paulo, Brazil

Abrolhos, Brazil

Trinidad, Tobago

Jamaica, BVI, …

La Paz, Mexico

Azores F.I.

G.o MexicoYucatan reefs

Trop. Tuna Comm.

Venice/Trieste

Virginia IMS

NCEAS

UoWisconsin

= training courses / workshops

UBC

Ecopath project activities

NMFS, Galveston

Angola

G.o.Guinea 19 countries

NMFS, Honolulu

Swedish Fisheries

PolandEstonia, Latvia, Lithuania

Thetis, Greece

Dominican Rep.

GoMexico FMC

>300 models>6000 reg. users155 countries

IFREMER

Stockholm Univ.FIMR, Helsinki

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Ecosystem model publications

Web of Science search(Ecosystem* + model* + fish*) or (multispecies

+ fish*)

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Toward ecosystem management

• Consider feeding interactions: fish eat fish, which causes trade-offs between fisheries

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Ecopath with Ecosim• Software system

• Open source-code

• Freely available

Ecopath: Mass-balance book-keeping

Ecosim: Time-dynamicsPolicy exploration modules

Ecospace: Spatial model

Ecotracer: Tracking persistent pollutants

Ecopath: Mass-balance model

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Mass balance: double-bookkeeping

Other

mortalit

y

Harvest

Predation

Predation

Predation

Predation

Other

mortali

ty

Other

mortality

Predation Respi-

ration

Harvest

Unassi-

milated

food

Respi-

ration

Unassi-

milated

food

Unassi-

milated

food

Respi-

ration

EwE: an overview

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Data Model Basic research Application

Biol.: B, P/B, Q/B, diet.

Fleet catches

Manual

Ecoranger

Automatic

Pedigree

M.Carlo

Vulnerability, mediation, …

Mass-balance (Ecopath)

Time-dynamic(Ecosim)

Spatial-dynamic(Ecospace)

Nutrient, O2, prim. prod. seagrass, …

Habitat preference,

dispersal, migration etc.

Spatial cost of fishing

Prim.prod.(SeaWiFS)

Runoff, nutri-ents, depth, …

Persistent pollutants

Tracer-dynamic

(Ecotracer)

Who eats whom?Network analysis

Biol. & fishing time series

Fisheries &.environment

Protectedarea dynamics. Spatial effort

allocation

Environmental time series

Policy exploration

Economics,social info.

Fisheriesmanage-

ment

Functionalresponse,

etc.

Ocean zoning

Academic (ecol. theory)

MPA zoning(Ecoseed)

Legend:

Facultative input

Optional input

Seaso-nality

Sensitivityanalysis

Hydrographic model

(external)

IBM model

Evaluating network analysis indicators of change in the Gulf of

Alaska

Sheila JJ Heymans, Sylvie Guénette

Villy Christensen, Andrew Trites

UBC

FISHERIES

CENTRE

Network Analysis

• Network analysis assumes that an ecosystem’s organization can be described by the structure of its flows

• EwE6 Network Analysis Plug-in

Ulanowicz, R.E. 1986. Growth and Development: Ecosystems Phenomenology. toExcel, San Jose.203 pp.

Redundancy

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Jan

-63

Jan

-66

Jan

-69

Jan

-72

Jan

-75

Jan

-78

Jan

-81

Jan

-84

Jan

-87

Jan

-90

Jan

-93

Jan

-96

Jan

-99

Jan

-02

44

45

46

47

48

49A

leu

tian

s

SEA

K

0

1

2

3

BAbs. diff. between value and 5 yr average

EwE Ecotracer

• See presentation

Ecosim

• Applications vary in complexity from simple ‘what-if’ scenario evaluations to data-intensive application for fisheries management

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EcosimIncreasingly

used for

management

Example:

• Gulf of Mexico FMC

• Stop to shrimp trawling?

• Impact of fitting procedure on policy outcome

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0

1

2

0

1

2

0

1

2

0

1

2

0

1

2

0

1

2

0

1

2

0

1

2

1950 1980

0

1

2

1950 1980 1950 1980 1950 1980 1950 1980 1950 1980 1950 1980

Number of forcing function parameters

0 5 10 20 30 40 54

Num

ber of vuln

era

bility p

ara

mete

rs

59

50

40

30

20

15

10

5

0

Bio

mass &

PP

A (re

lative)

Ecospace

• Designed to address spatial questions

– Notably related to protected areas

• Models have been rather exploratory up to now

• Data-driven models emerging

Management scenarios in the Catalan SeaTesting temporal and spatial management scenarios for the recovery of ecosystem

Area puesta

Area protegida

200 m

Anchovy spawning

areaProposed MPA for anchovy

“Don’t do anything” scenario

20% reduction of fishing effort for fleets fishing small pelagic fish

Establishment of MPA covering spawning area of small pelagic fish

20% reduction in fishing effort for trawl fleet

Banning trawling in 20% of the fishing area

Phytoplankton Zooplankton Macrzooplankton Jellyfish Suprabenthos Polychaetes Shrimps

Crabs Norway lobster Benthic invert. Benthic cephalop. Benthoph. cephalop. Red mullets Conger eel

Anglerfish Flatfish Poor cod Juvenile hake Adult hake Blue whiting Dem. fish 1

Dem. fish 2 Dem. fish 3 Dem. sharks Benthop. fish Anchovy Sardine Other small pel. fish

Horse Mackerel Mackerel Bonito Large pel. fish. Marine turtles Audouin’s gull Other seabirds

Dolphins Fin whales Discards By-catch Detritus

Vargiu, G. 2007. M.Sc. theses. IUSC Barcelona, Spain

What are EwE models used for?• Lyne Morisette contacted registered users:

325 models constructed or under construction

– 42% ecosystem structure;

– 30% fisheries management;

– 11% theoretical ecology;

– 6% protected area evaluations

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Fitting to time series: learning from ecosystem history

• Numerous ecosystem (EwE) models have in recent years produced credible fit to historical data, and made plausible policy predictions

–have clearly shown that this requires inclusion of environmental as well as fisheries impact

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Ecosystems where EwE models have been tested using historical trend data • E Bering Sea

• Aleutian Islands

• W&C GoAlaska

• E GoAlaska

• W Vancouver Island

• Hecate Strait

• British Columbia Shelf

• Strait of Georgia

• NE Pacific

• CN & ET Pacific

• NWHI, Hawaii

• Gulf of California

• Central Chile

• Bay of Quinte

• Oneida Lake

• Scotian Shelf

• Chesapeake Bay

• Tampa Bay

• US Gulf of Mexico

• S Brazil Bight

• Norwegian Sea

• North Sea

• Baltic

• S Benguela

• Gulf of Thailand

• South China Sea Christensen & Walters 2005

Use of EwE for fisheries management

• Evaluate impact of shrimp trawling, GoCalifornia;

• Evaluate impact of bycatch, GoCalifornia;

• Shrimp bycatch issues, Gulf of Mexico FMC

• Evaluate impact of predators on shrimp, GoMexico;

• Demonstrate ecological role of species, GoMexico;

• Impact of proposed fisheries interventions, Namibia

• South Africa pelagic fisheries

• EIA of proposed fisheries interventions, Bering Sea;

• EIA of alternative TAC’s, Bering Sea and GoAlaska;

• Target species response to TACs, Bering Sea

• Closed area sizing, Great Barrier Reef, Australia

• Valuation of cormorant impact, Ortobello, Italy

• Evaluation of cormorant impact, Ringkobing, Denmark

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So why aren’t ecosystem models used more for management?

• Lack of experience using ecosystem models for predictive purposes;

• Ecosystem modeling is for strategic management, and supplements the tactical single species assessment;

• Fisheries management process is focused on tactical management;

• Strategic decisions are virtually non-existing.

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Our empirical knowledge is limited

• Habitat and environmental changes (including those caused by fishing) and intensive fishery removals create novel situations

–We do not to understand the ‘mechanics’ of ecological response well enough to be able to predict all important responses to novel situations;

–Make models one can play with;

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Model runtime

• Ecopath– Normal run fractions of seconds

– Modifications seconds

• Ecosim– Normal run: seconds

– Fitting: minutes

– Optimization: minutes

– Modifications seconds

• Ecospace– Normal run: minutes

– Fitting: hours

– Optimizations: hours to days

– Modifications: seconds27

Predictive approaches are uncertain

• Lack of data

– Notably on mortality agents and density-dependence in the early life history

• Confounding effects

• Vampires in the basement

• Unpredictable pre-adaptations

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Ecosystem modeling & adaptive management

• Develop alternative models

– Environmental vs. fisheries vs. trophic effects;

• Develop management experiments

– Spatial closures

– Ecosystem modification

– Habitat modifications;

– Predator (or prey) exclusions/additions

29Walters, C. 1986. Adaptive Management