Ecosystem based management

Ecosystem based management

Fish 513A

Logistics

• Find time for alternative meetings• Class activities• Readings• Student Responsibility• Web site• Finding discussion times

Wikipedia definitions

Ecosystem-based management is an environmental management approach that recognizes the full array of interactions within an ecosystem, including humans, rather than considering single issues, species, or ecosystem services in isolation

An ecosystem

An ecosystem is a biological system consisting of all the living organisms or biotic components in a particular area and the nonliving or abiotic component with which the organisms interact, such as air, mineral soil, water and sunlight.

ManagementManagement is the act of getting people together to accomplish desired goals and objectives using available resources efficiently and effectively. Management comprises planning, organizing, staffing, leading or directing, and controlling an organization (a group of one or more people or entities) or effort for the purpose of accomplishing a goal.

Elements of marine management

• Fisheries– Input controls # vessels, size, gear, effort– Output controls: total allowable catches, size limits– Area controls – closed areas seasonal or permanent

• Land use affecting run off• Tidal and Wind Power• Communications Cables• Transportation• Oil and Gas• Mining

The Litany of Disaster

• Plundering of sea otters and fur seals• Sequential depletion of whales• Collapse of cod• Overfishing estuaries and coral reefs

It isn’t single species management that failed

• It was the failure to do single species management well

• I contend that if we did single species management well, keeping populations at or above BMSY, we wouldn’t have nearly the problems we now have

However, there are obvious deficiencies in single species management that mean we do want to move to considering

ecosystem effects

• By catch of birds, mammals and fish needing protection• Impacts of fishing gear on fragile environments• Impacts of removals on other species often at higher

trophic levels such as marine birds and mammals• We are trying to maintain human communities

EBFM in the Bering Sea and Aleutian Islands

• Annual allowable catches on the major species, pollock, cod, flatfish, crabs, herring

• 2 million ton cap• By-catch limits for halibut, salmon, birds• Closed areas to protect spawning grounds• Closed areas to protect sea lions• Closed areas to protect sensitive habitats from

trawl contact

The framework for managing the BSAI

• Magnuson-Stevens FMC Act• The Marine Mammal Protection Act• The Endangered Species Act• The National Environmental Policy Act• Migratory Bird Treaty• FAO agreements – straddling stocks etc.• Alaskan State legislation

Garcia et al 2003 Ecosystem approach to fisheries: key issues

• Human and Ecosystem well being

• Resource scarcity• Maximum acceptable fishing

level• Maximum biological

productivity• Impact reversibility• Impact minimization• Rebuilding resources• Ecosystem integrity• Species interdependence

• Institutional integrity• Uncertainty, risk, precaution• Compatibility of

management measures• Polluter pays principle• User pays principle• Precautionary approach• Subsidiarity, decentralization

and participation• Equity

Pikitch et al 2004 EBFM should

• (i) avoid degradation of ecosystems, as measured by indicators of environmental quality and system status;

• (ii) minimize the risk of irreversible change to natural assemblages of species and ecosystem processes;

• (iii) obtain and maintain long-term socioeconomic benefits without compromising the ecosystem; and

• (iv) generate knowledge of ecosystem processes sufficient to understand the likely consequences of human actions.

Francis et al 2007 10 commandments

1. Keep a perspective that at is holistic, risk-averse and adaptive.2. Question key assumptions, no matter how basic.3. Maintain old-growth age structure in fish populations.4. Characterize and maintain the natural spatial structure of fish

stocks.5. Characterize and maintain viable fish habitats.6. Characterize and maintain ecosystem resilience.7. Identify and maintain critical food web connections.8. Account for ecosystem change through time.9. Account for evolutionary change caused by fishing.10. Implement an approach that is integrated, interdisciplinary and

inclusive

The two stages of EBFM

• The easy stuff– Reducing by-catch by technical measures, incentives

and closing “hot spots”– Protecting sensitive ecosystems by closing them to

specific gears or all fishing• The hard stuff

– Understanding the ecosystem trade-offs, perhaps through models

– Finding social agreement on the appropriate objectives (e.g. Human food vs seals), setting reference points

EBM tools

• Ecosystem models• Fleet models• MPA models: spatial planning in general

Single species modelsFishing FleetsAnd communities

Managers

Other species

Physical environment

The tradeoffs

• Worm et al 2009• Walters• Smith et al forage fish

Tradeoffs in sustainable management of marine ecosystems

Carl WaltersMote 2002 Symposium

Fisheries managers regularly face three main kinds of tradeoffs

• Immediate fisher well-being versus long term fishery value

• Existence values (biodiversity, mammals, birds, etc.) versus consumptive values

• Expected consumptive value versus risk of collapse (increasing risk and variability with increased harvesting)

Alternative visions of future marine ecosystems

• Restoration and protection of non-consumptive values, regardless of economic impact

• Maximization of consumptive (fishery) values, without regard to collateral damage

• Ecosystem “cultivation”: use of fisheries to control ecosystem structure as well as to produce direct economic value

We have been slow to admit that these visions may be deeply incompatible

The “convex tradeoff”hypothesis (belief, pretense,hope, wishful thinking)

The “concave tradeoff”hypothesis (better supportby data, models)

Non

-con

sum

ptive

Valu

e

Fishery Value

Lots of both values

Achievable states

Non

-con

sum

ptive

Valu

e

Fishery Value

Compromisesacrifices much of both values

It is easy to trade off among values/stakeholders when the tradeoff relationship is convex

• Each stakeholder can get most of the maximum possible, without the other stakeholder(s) having to give up much.

• There is a compromise policy that gives each stakeholder a “fair share” of whichever ecosystem value that person might care about.

It is very difficult to make “fair” choices when tradeoff relationships are concave

• Simple, economic weighting of alternative values generally leads to conclusion that overall value would be greatest by choosing one or other extreme option (ignore existence values, or stop fishing)

• There is no public standard or ethical principle that tells us what minimum value is tolerable for whichever value measure is seen as “less important”

The convex tradeoff assumption is hidden in some intuitive management prescriptions

• Good single species management would be adequate to insure protection of other values

• Fisheries take is acceptable provided it does not reduce stocks enough to make them incapable of meeting current “demand” by other species that they support“Because consumption of herring by marine mammals may exceed the natural mortality rate used in the stock assessment, there is reason to be concerned about the future availability of herring for growing populations of marine mammals.”

• Species that compete with fisheries for particular prey can switch to other, unharvested prey types to meet their needs (the food web will save them).

Shrimp response to cod overfishing off Newfoundland

Newfoundland Cod and Shrimp

0

500000

1000000

1500000

2000000

2500000

3000000

60 70 80 90

Year

Cod

Sto

ck s

ize

(age

3+

biom

ass)

0

50000

100000

150000

200000

250000

Shrim

p ca

tch

Cod age 3+ biomassShrimp Catch

SeeWorm andMyers 2002

The cod-shrimp tradeoff is apparently concave

Shrimp Catch--Cod biomass tradeoff

0

50000

100000

150000

200000

250000

0 1000000 2000000 3000000Cod Biomass

Shrim

p C

atch

(Cod-shrimp interaction is not restricted to Newfoundland area)

(Source: Figure 3, Worm and Myers 2002)

Has fishing down the food chain off Newfoundland been bad?

Landings, Value, and Jobs Atlantic Canada

0

200

400

600

800

1000

1200

1400

1600

1986 1988 1990 1992 1994 1996 1998

Year

Tons

, Dol

lars

0100002000030000400005000060000700008000090000100000

Jobs

Catch (t)Value ($)Jobs

MSA SECTION 406 ECOSYSTEM WORKSHOP

J A N U A R Y 9 - 1 0 , 2 0 0 8

M I K E B U R N E R

• E X I S T I N G E C O S Y S T E M - B A S E D M A N A G E M E N T

• E C O S Y S T E M F I S H E R Y M A N A G E M E N T P L A N C O N C E P T

• L E S S O N S L E A R N E D

EXISTING ECOSYSTEM-BASED MANAGEMENT APPROACHES

•Harvest Ban on All Species of Euphausiids•Harvest Control Rules for Coastal Pelagics•Marine Protected Areas•Oregon Coastal Coho Harvest Control Rule•Sablefish Assessment


Harvest Ban on All Species of Krill (Euphausiids)• Initiated by the Monterey Bay National Marine

Sanctuary.• Broadened to Entire EEZ by Pacific Council• Recognizes Importance of Krill in Marine Food Web• Enhances Recovery and Protection of Overfished

Rockfish and Salmon Species Listed under the ESA.


Harvest Control Rules for Coastal Pelagics

HGyear+1 = (Biomassyear – Cutoff) * Fraction(0.05-0.15) * Distribution

0%

5%

10%

15%

20%

16.0 16.5 17.0 17.5 18.0 18.5 19.0Sea Surface Temperature (°C)

3-Year Moving Average

Expl

oita

tion

Frac

tion

2001 2000 1999 1998

•Pacific Sardine-150,000mt•Buffer Against Overfishing•Ecological Role as Forage


Marine Protected Areas


Oregon Coastal Natural Coho Harvest Matrix

4 Fish per Mile

12% of Full Seeding

19% of Full Seeding

50% of Full Seeding

75% of full Seeding

899 21,700 3,596 NA 4,123 10,850 16,275

1,163 55,000 4,652 NA 10,450 27,500 41,250

1,685 50,000 6,740 NA 9,500 25,000 37,500

450 5,400 NA 648 1,026 2,700 4,050

4,197 132,100 25,099 66,050 99,075

(based on return of jacks per hatchery smolt)

HighMediumLowExtremely Low(>0.0040 )(>0.0014 to 0.0040)

M H

Marine Survival Index

Parent Spawner Status 1/

0 - 8% 0 - 8% 0 - 8% 0 - 8%

< 15%

< 15%

< 15%

< 11%

15,636Coastwide Total

(<0.0008 ) (0.0008 to 0.0014 )

Sub-aggregate and Basin Specific Spawner Criteria Data

Northern

North - Central

South - Central

Southern

< 8% < 11%

< 15% < 25%

L

< 11%

Q

E

D

C

B

< 8%

< 8%

< 8%

J

I

H

G

K P

J

< 45%

I

< 38%

O

< 30%

N

< 20%

Sub-aggregate

1/ Parental spawner abundance status for the OCN aggergate assumes the status of the weakest sub-aggregate.

2/ "Critical" parental spawner status is defined as 4 fish per mile for the Northern, North-Central, and South-Central subaggergates. Because the ratio of high quality spawning habitat to total spawning habitat in the Rogue River Basin differs significantly from the rest of the basins on the coast, the spawner density of 4 fish per mile does not represent "Critical" status for that basin. Instead. "Critical" status for the Rogue Basin (Southern Sub-aggergate) is estimated as 12% of full seeding of high quality habitat.

HighParent Spawners > 75% of full seeding

Miles of Available Spawning Habitat

100% of Full Seeding

"Critical" Very Low, Low, Medium & High

A

Parent Spawners > 4 fish per mile & < 19% of full seeding

Critical 2/

Parental Spawners < 4 fish per mile

MediumParent Spawners > 50% & < 75% of full seeding

LowParent Spawners > 19% & < 50% of full seeding

Very Low

F

EXISTING ECOSYSTEM-BASED MANAGEMENT APPROACHESSablefish Assessment

• Utilizes Environmental Indicator (sea surface height) as a Predictor of Larval Survival and Year-Class Strength.

• This Environmental Parameter is only One of Several Abundance Indices.

Conclusions

• EBM can encompass a wide range of concepts• We have a range of tools• We are a long way from agreeing on

objectives

Documents

Ecosystem based management