Download Kerim Aydin Alaska Fisheries Science Center

The evolution of ecosystem approaches:
notes from the front lines
Kerim Aydin
Alaska Fisheries Science Center
September 8, 2008
THE
THE ALASKAN
ALASKAN CONTEXT
CONTEXT
• Federally-managed groundfish populations
– Yield of 2.5M mt/year
• Conservative exploitation rates/productive stocks (unless you’re a crab).
• Some declining mammal and bird stocks (fisheries management with
Endangered Species Act considerations)
• Pro-active management: ecosystem committee, ecosystem considerations
chapter, but also pro-active lawsuits
• The Congress finds and declares the following
– A number of the Fishery Management Councils have demonstrated
significant progress in integrating ecosystem considerations in fisheries
management using the existing authorities provided under this [MSFCMA].
Annual Ecosystem Considerations chapter:
A wealth of information (Boldt et al. 2007)
http://access.afsc.noaa.gov/reem/ecoweb/index.cfm
• Ecosystem Status Indicators:
–
–
–
–
–
–
–
–
–
–
–
Habitat
Nutrients and Productivity
Zooplankton
Forage Fish
Herring
Salmon
Groundfish
Benthic and Non-target
Marine Mammals
Seabirds
Ecosystem/Community
–
–
–
–
Diversity
Habitat
Sustainability
Humans
• Ecosystem-Based Mgt Indices:
Ecosystem Considerations
• Ecosystem Assessment
– Summarize historical climate
and fishing in BSAI and GOA
and possible future effects on
ecosystems using multispecies and ecosystem models
• Ecosystem Status Indicators
– Historical and current status
and trends 60+ indicators
BS
250
12%
10%
200
8%
150
6%
100
4%
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
0%
1996
2%
0
1995
50
1994
– Early signals of direct human
effects 20+ indicators
14%
Discards (1000 t)
Discard rate
300
Dicards (1000t)
• Ecosystem-Based Mngt
Indices
16%
Discard rate
350
MSFCMA reauthorization (2007)
• (5) […] the fisheries can be conserved and maintained so as to
provide optimum yields on a continuing basis.
• (33) The term "optimum", with respect to the yield from a fishery,
means the amount of fish which—
– (A) will provide the greatest overall benefit to the Nation […]
– (B) is prescribed as such on the basis of the maximum
sustainable yield from the fishery […]
– (C) […] provides for rebuilding to a level consistent with
producing the maximum sustainable yield in such fishery.
Sustainability?
• (Oxford English Dictionary 1989): Sustainable (adj): 1.
Capable of being borne or endured; supportable,
bearable.
• “From a human point of view, maintaining yield at a
certain (maximal) rate or level over time implies that we
are getting everything we can, which we think is best for
society. From the resource viewpoint, however, this is
something that the resource has to “endure,” which
implies stress, and constant maximal stress at that.”
– (Gaichas 2008, Marine Policy)
• How reversible (renewable) is a system from the
continual endurance of maximum stress?
Does the primary goal of “maximum sustainable”
mesh with increased inclusion of “ecosystem
considerations?”
• Are we in for a revolutionary collision? If so, where?
• Can this we manage this “smoothly”? If so, how?
Currently: fisheries science and
management starts from a single
species
Ecology and statistics
• Lots of single-species ecology, lots of data
• Lots of statistics
Science, science review, and decisions –
North Pacific Council
Data collectors
Stock
assessment
authors
Plan
teams
SSC
Advisory
Panel
Council
– Annual cycle per stock (45+ species or
complexes)
• Science reviewed by Plan Teams
• Scientific and Statistical Committee (SSC) sets
maximum limit based on biology
• Advisory panel may set further limits
(economic, social, allocation)
• Council decides.
The primary
scorecard
Stock
assessment
authors
Plan
teams
SSC
(Time does exist for multi-year strategic actions: ecosystem committee,
non-target committee, working groups, research, etc.)
Along comes the ecosystem.
Complexity vs. management reality
Eastern
Bering
Sea
Gulf of Alaska
WHERE’S THE TEETH?
The “Programmatic Supplemental
Environmental Impact Statement”
• The National Environmental Protection Act requires EISs for changes
•
•
•
•
in management plans.
But also requires “Programmatic” EISs which report on the
cumulative effects of many changes and plans.
Punctuated the evolutionary equilibrium: Lawsuit from
environmental groups found we did not look at a wide enough
range of alternatives, management strategies, and potential
“cumulative” impacts.
Never been done in a fisheries management plan context.
1,000s of pages, multiple attempts, years of work and deadlines…
• We took a good hard look at our science, policy, and
procedures, and put forward (agreed-to) methods for
looking at and monitoring cumulative and ecosystemlevel effects.
One lasting
result:
Including
ecosystem
considerations
in each stock
assessment
(Lowe et al. 2007)
Plan team scorecard from summary of
assessments
• How does this help? Let’s look at a species…
Recent
declines in
the Eastern
Bering Sea
1.2
1996
1998
2000
2002
2004
2006
1998
2000
2002
2004
2006
1998
2000
2002
2004
2006
1992
1990
1988
1996
Capelin
1996
0.0
1994
0.2
1994
0.4
1994
0.6
1992
0.8
1992
1.0
1990
Eulachon
1990
1988
1.4
1988
1986
1984
1982
1.2
1986
1984
1982
1.4
1986
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1984
1982
Relative CPUE
Bottom-up production? Some indices
Sandlance
1.0
0.8
0.6
0.4
0.2
0.0
Assessment focus: Forage fish biomass
b
io
m
as
sd
en
s
ity(t/km
^
2)
30
EBS POLLOCK
25
Age 2+ pollock
(assessment)
20
15
10
5
20
05
20
04
20
03
20
02
20
01
20
00
19
99
19
98
19
97
19
96
19
95
19
94
19
92
(Aydin and Mueter 2007)
19
93
19
91
19
90
19
89
19
88
19
87
19
86
19
85
19
84
19
83
19
82
0
This continued low
level of forage was
(qualitative) reason
for caution for
pollock discussed
by BSAI Plan Team
20
05
04
03
2.5
20
3
02
01
00
99
98
96
97
95
94
93
92
91
90
89
88
87
86
85
84
83
82
3.5
20
20
20
20
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
The eastern
Bering Sea:
predators of
pollock.
b io m a s s d e n s ity (t/k m ^ 2 )
Stock assessment biomass
4
EBS COD
BS GT
Skates
EBS ATF
Lg Sculpins
2
1.5
1
0.5
0
Evolution of single-species assessments to include advice
frommultispecies models and indicators
From North Pacific Fisheries Management Council’s Scientific and Statistical
Committee minutes, December 2006:
•
“The [eastern Bering Sea walleye pollock] stock remains above the MSY level, having
declined … at a rate of about 19% per year….A series of 4 below-average
recruitments has contributed to the decline…the series of low recruitments will result
in an age-structure that is dominated by only a few year-classes which could increase
fluctuations in the population.”
Result from single-species assessment
•
“Other issues raised in the stock assessment suggest a need for further caution.”
– a northward shift … with some portion of the population into Russian waters.
Assessment + ecosystem indicators
– a large decline in zooplankton, which is important in providing forage for juvenile
pollock.
Ecosystem indicators
– increasing predation by arrowtooth flounder on juvenile pollock, which could
contribute to further declines in adult pollock biomass. A multispecies model
•
“Consequently, the SSC agrees with the Plan Team that a reduction in
Allowable Biological Catch from the maximum permissible is justified.”
Conclusion I: Incorporating ecosystem
concerns needs hand-in-hand work
between ecosystem researchers and stock
assessment authors at many stages.
• Mandate + resources in assessment
and reporting/Council process.
• (Not every species will need this level of scrutiny)
Where’s the teeth II ?
• Ecosystem -> Stock assessment works in the
•
previous context, but:
– Stock assessment -> other stock assessment
– Stock assessment -> unassessed component
What then?
Solution I: more integrated monitoring
• Ecosystem Assessment: Combine trends
and model results into ecosystem thresholds
to:
– Maintain predator-prey relationships
– Maintain diversity
– Maintain energy flow and balance
Solution II: decision support tools
Sustainability and current tools?
• “Maximum Sustainable Yield is fine, close, reasonable.”
• “Sustainable (adj): 1. Capable of being borne or
endured; supportable, bearable.”
• Reconciliation between two views:
– How recoverable is a system from the continual endurance of
maximum stress? Risk of irreversibility is a key criterion.
– Are we accurately reporting expectations? Are we misleading
with our ability to predict irreversible thresholds?
– Simulation with adequately broad models of potential
interactions and uncertainty.
– Time-based risk management, long-term risk reporting.
Aleutian Islands Fishery Ecosystem Plan
Decision Support Tools and long-term Risk Assessment
Communication of strategic ecosystem alternatives must:
•
Specify policy risk based on uncertainty versus reward.
Number of "droughts" over 1000 years
35
Low F
High F
30
25
“Pollock drought”:
length of time during
which pollock catch
remains below a reference
level.
20
15
10
5
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Duration of "drought"
CONCLUSION II: We must include time
and events – and improve our use of
this language of risk and uncertainty:
state-based indicators may miss this.
Acknowledgements
Jennifer Boldt
Shannon Bartkiw
Jennifer Boldt
Nick Bond
David Carlile
Kristin Cieciel
Amy Childers
Cathy Coon
Dean Courtney
Ken Coyle
Braxton Dew
Miriam Doyle
Don Dragoo
Sherri Dressel
Doug Eggers
Lisa Eisner
Lowell Fair
Ed Farley
Angela Feldman
Ron Felthoven
Shannon Fitzgerald
Lowell Fritz
Jeff Fujioka
Sarah Gaichas
Jessica Gharrett
John J. Goering
Gary Greene
C. E. Grosch
Steven Hare
Pat Harris
Alan Haynie
Kyle Hebert
Jon Heifetz
Jack Helle
Terry Hiatt
Jerry Hoff
Jim Ianelli
Jim Ingraham
JISAO
Jesus Jurado-Molina
Tom Kline
Kathy Kuletz
Carol Ladd
Bob Lauth
Heather Lazrus
Mike Litzow
Pat Livingston
Mitch Lorenz
S. Allen Macklin
Michael Martin
Bob McConnaughey
Kathryn Mier
Steve Moffitt
Jim Murphy
Jeff Napp
Ivonne Ortiz
Bob Otto
James Overland
Fisheries And The
Environment
Julie Pearce
Mike Perez
Amanda Poole
Franz Mueter
Alexei Pinchuk
Susan Picquelle
Marc Pritchett
Jennifer Reynolds
TaeKeun Rho
Dylan Righi
Kim Rivera
Sergei Rodionov
Chris Rooper
Tom Royer
Lou Rugolo
Sigrid Salo
Nandita Sarkar
Jennifer Sepez
Naonobu Shiga
Kalei Shotwell
Elizabeth Sinclair
Paul Spencer
Mick Spillane
Phyllis Stabeno
Dean Stockwell
Robert Stone
Allan Stoner
Steve Syrjala
Ward Testa
Jack Turnock
Dan Urban
Gary Walters
Muyin Wang
Fred West
Terry Whitledge
Tom Wilderbuer
Doug Woodby
Cynthia Yeung
Harold Zenger
Jie Zheng
Mark Zimmermann