Sense and Sensibility:Hard choices and the future of

Chesapeake Bay

Ratana ChuenpagdeeSt. Francis Xavier University

Antigonish, Canada

Panel discussion, KUU 2003SIO, November 17, 2003

Chesapeake Bay is part of the US East Coast (North Carolina to Maine) itself part of FAO Area 21.

No break for Chesapeake Bay! 2000 BC - Assumed its current shape; 1000 BC - Native Americans fished the Bay with spears, traps, and hooks & lines

1607 – First permanent English settlement ; 1600s – Virginia enacted laws addressing fish wastes and blockage of fish migration by dams; 1750s – Colonists began using nets to catch fish

1800s to now – Forest clearing, infrastructure development, new agricultural techniques, population boom, creation of suburbs, modern fishing methods; 1813 – Oyster raking began.

1900s to 1950s – Water quality survey; aerial photographs for submerged aquatic vegetation; Water pollution agencies established in Maryland and Virginia; 1950s – diseases (MSX and DEMO) killing oysters

1967 to 1983 - Chesapeake Bay Foundation; Clean Water Act; Chesapeake Bay Program; 1983 – Bay resources identified as over-harvested; 1985 – Maryland Moratorium on striped bass fishing; 1989 – Virginia moratorium on striped bass fishing

1995 – Striped bass stock restored; 1997 – Pfiesteria found in the Bay.

2000 – Chesapeake Bay 2000 Agreement on habitat restoration and protection of marine living resources; 2002 – Report to Citizen on the state of the Bay; Ecosystem Management Plan.

Two analyses of the Chesapeake Bay ecosystem:

• Using ‘fishing down marine food web’ to put

Chesapeake Bay in the context of US east coast*;

• Evaluating stakeholders’ preferences for various

ecosystem scenarios, using ‘Ecopath with Ecosim’

and ‘damage schedule’ approach.

* Collaboration with D. Pauly

Landings* from Chesapeake Bay and adjacent shelf waters, 1950 to 2000, shown for major trophic groups. Note the important role of menhaden, which has increased since 1950 in both relative and absolute terms.

* Landings (commercial + recreational) from NMFS Annapolis Office, courtesy of D. Orner

The mean trophic levels* in Chesapeake Bay (blue), in US east coast (green), and in FAO Area 21 (purple) are converging toward the same low values. Chesapeake Bay led the way!

* TL values from Hagy (2002) and FishBase.

A food web (Ecopath) model of Chesapeake Bay was used to generate (using Ecosim) several ecosystem scenarios, based on various management options, structured around different abundances of four major species (striped bass, menhaden, blue crab and oyster)*

* Model and scenarios courtesy of V. Christensen and D. Priekshot

Striped bass Blue crabMenhaden Oyters

+ 25% + 100% + 25% + 900%

+ 25% + 200% n/c + 350%

- 25% + 200% n/c + 350%

-75% + 100% + 25% + 900%

-75% + 100% + 450%

+ 25% + 100% - 75% + 900%

-75% + 150% n/c + 250%

- 25% + 50% - 75% + 900%

n/c

Ecosystem scenarios (EwE based)% Biomass change from 2000 level

Biomass increase No changeBiomass decrease

Half blue crab fishing rate, double SAV*

Half total fishing rate, no change to SAV

Half menhaden fishing rate, no change to SAV

Half blue crab fishing rate, half SAV

Double menhaden fishing rate, half SAV

Double blue crab fishing rate, double SAV

Double blue crab fishing rate, no change to SAVDouble total fishing rate, no change to SAV

Ecosystem management options

* SAV = Submerged aquatic vegetations

The damage schedule approach employs the paired comparison method to present items (here ecosystem scenarios) in pairs (discrete choice model).

• A paired comparison questionnaire was sent to five stakeholder groups, i.e., watermen, seafood-related business people, conservation groups, scientists, and managers;

• Respondents were asked to select, for each pair, which ecosystem scenario they preferred;

• The responses were used to construct damage schedule (ranking) of the preferred scenarios, and thus preferred management options.

A B

Striped bass

Menhaden

Blue crab

Oysters

Population

25%

150%

No change

350%

Striped bass

Menhaden

Blue crab

Oysters

Population

200%

No change

350%

25%

The Chesapeake Bay contains many kinds of fish and marine life. In your opinion, what possible combination of striped bass, menhaden, blue crab and oyster populations, presented below as Ecosystem A and B, would you prefer to see in the Chesapeake Bay? The increases or decreases in

population are compared to current levels.

Please circle only ONE letter, A or B, to indicate your choice.

Stakeholders’ preference for various ecosystem scenarios of the Chesapeake Bay, based on 45 respondents (5 watermen, 6 seafood businesspersons, 11 scientists, 12 managers, and 11 NGOs). Rankings obtained from these group were significantly correlated at alpha 0.01, suggesting strong agreement between groups.

Preferencescore

84

62

56

51

31

29

17

18

Striped bass Blue crabMenhaden Oyters

+ 25% + 100% + 25% + 900%

+ 25% + 200% n/c + 350%

- 25% + 200% n/c + 350%

-75% + 100% + 25% + 900%

-75% + 100% + 450%

+ 25% + 100% - 75% + 900%

-75% + 150% n/c + 250%

- 25% + 50% - 75% + 900%

n/c

Ecosystem scenarios (EwE based)% Biomass change from 2000 level

Biomass increase No changeBiomass decrease

Half blue crab fishing rate, double SAV*

Half total fishing rate, no change to SAV

Half menhaden fishing rate, no change to SAV

Half blue crab fishing rate, half SAV

Double menhaden fishing rate, half SAV

Double blue crab fishing rate, double SAV

Double blue crab fishing rate, no change to SAVDouble total fishing rate, no change to SAV

Ecosystem management options

58%

2%

% Accept

70%

5%

5%

0%

* SAV = Submerged aquatic vegetations

What can the past inform the future of Chesapeake Bay?

• Chesapeake Bay is leading a whole region on its way down;

• High repair costs, low success;• Reactive policies are not sufficient;• Easy choices lead nowhere; • Hard policy options will have support from

stakeholders, if they make sense and are made available; and

• Implementing hard policy options requires courage.

Thank you for your attention.