Transcript – Harvest control rules in context limits, possibilities and the ICES experience

Harvest control rules in context –
limits, possibilities and the ICES
experience
Poul Degnbol
IFM, Denmark & ICES
Workshop on Harvest Control Rules for
Sustainable Fisheries Management
13-15 September 2004, Bergen, Norway
Trailer
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The context of Harvest control rules
Harvest control rules and reference points
Evaluation criteria
Evaluation approach
How to get there
The context of Harvest control rules
Why harvest control rules?
• Harvest control rules is a fix to avoid the
annual dealing and wheeling during
fisheries negotiations
• Harvest control rules is an element in a
policy to move the focus in fisheries
management from tactical (annual)
decisions to decisions regarding longer
term goals
• Harvest control rules is the tactical element of a
management strategy
• Management strategies include
– Decision (explicit or implicit) on longer term
management objectives and performance criteria
– Decision on the relevant knowledge base for tactical
management decisions
– Decision on implementation framework (mainly input
or output control etc.)
– Implementation modes such as a management plan
including
• Sanctions
• Rules for tactical management decisions regarding the
fisheries in the current or coming fishing season (harvest
control rules)
• Monitoring requirements
The fisheries management system
Adaptation system
Fishing decision and fishing
Fishery
Resource system
Social system
Monitoring,
surveillance,
control
Perceived system
Management
measures
Management decision system
Management decision
Fishery system
Nature:
Variation within regime
Regime shifts
Society:
Fleet adaptation
Strategic decision system
/Management strategy
Objectives
Performance criteria
Relevant
Knowledge
Implementation
framework
Management plan
Sanctions
Monitoring
requirements
Tactical decision
system
Corrections to
objectives
(‘flexibility’)
Accept of
knowledge
Harvest
control
rule
If state=xx then do yy
Fishery system
Nature:
Variation within regime
Regime shifts
Society:
Fleet adaptation
Strategic decision system
/Management strategy
Objectives
Performance criteria
Relevant
Knowledge
Implementation
framework
Management plan
Sanctions
Monitoring
requirements
Tactical decision
system
Corrections to
objectives
(‘flexibility’)
Accept of
knowledge
Harvest
control
rule
If state=xx then do yy
The normative string - Objectives
and performance
• Achievement of explicit and implicit objectives
– Sustainability
• Maintenance of reproductive capacity
• Delivery of ecosystem services
– Societal benefits
• High long term yields
• Social and economic objectives?
– Justice/Equity
• Performance criteria
– Robustness
– Cost efficiency
– Transparancy and legitimacy
The regulatory string –
implementation means
• Implementation means – basic choice of main
instruments
– Output - TACs
– Input – effort
– Technical incl closed areas
• The choice of implementation means defines
options for distributions of benefits
• Once implementation means have been chosen
this may become a nearly irreversible choice
due to the distributional implications (Example –
CFP)
The cognitive string –
Predictive- Adaptive balance?
• Uncertainty is here to stay!
• Predict or learn by experience from implementation
• Passive adaptivity: predict and correct through next years prediction
– Requires either that relevant reference points can be estimated and that
predictions make sense technically and operationally
• Active adaptivity: explore a range of exploitation ranges and adapt
– Stocks for which data series short or only one state known: explore
production dynamics
– Target reference points for stocks where biological interactions are
important or only low productivity seen
– Regime shifts?
– Stocks where we are uncertain about present state or stock dynamics
• Adaptive elements should be considered for several stocks in the
NE Atlantic where dynamics is poorly known
• Dont hardwire HCR parameters if it can be avoided
– identify conceptual basis
– identify processes to modify
The cognitive string – what is
relevant, valid and sufficient
knowledge?
• The relevance of knowledge relates to
objectives
• The validity of knowledge relates to
acceptance by stakeholders
• Sufficency of knowledge relates to the
desired robustness of the management
strategy
Harvest control rules cannot be developed
or evaluated independently of their
normative, cognitive and regulatory context.
HCRs must always be seen as one element
in a management institution which is
subject to external constraints and includes
a range of decisions and assumptions
regarding objectives, knowledge and
implementation
Distortions in the normative,
cognitive or regulatory
embeddedness of HCRs in the
management institution will lead
to failure to achieve objectives
and ultimately to conflict
If harvest control rules ar used as a fix to solve
problems in the decision making process they will
fail – HCRs will only work if the existing problems
are addressed simultaneously.
Harvest control rules should only be considered
as elements in a management strategy which
simultaneously addresses the cognitive,
normative and regulatory issues which are
external to the HCR but conditional for its
operation
Fishery system
Nature:
Variation within regime
Regime shifts
Society:
Fleet adaptation
Strategic decision system
/Management strategy
Objectives
Performance criteria
Relevant
Knowledge
Implementation
framework
Management plan
Sanctions
Monitoring
requirements
Tactical decision
system
Corrections to
objectives
(‘flexibility’)
Accept of
knowledge
Harvest
control
rule
If state=xx then do yy
HCR parameters
HCR parameters
• Limit points
– Relates to conservation (reproductive
capacity, ecosystem services)
• Target points
– Relates to societal benefits
• Trigger points
– Technical signpost for decisions
Default current HCR
• TAC decision based on two-year catch
forecast based on stock size one year
prior to fishing season
• Limits: Blim and derived from this Flim
• Trigger points: PA reference points
• No target reference points
• PA reference points are only relevant as
trigger points within current default HCR
• In other management strategies present
PA reference points may be irrelevant
• With the introduction of an extended range
of management strategies we will need to
change the advice framework to link to
management plans beyond present default
option
• The present pa advisory
framework is just a special
case for one strategy variant
HCR evaluation criteria
Management strategy evaluation
criteria
• Achievement of explicit and implicit objectives
– Sustainability
• Maintenance of reproductive capacity
• Delivery of ecosystem services
– Societal benefits
• High long term yields
• Social and economic objectives?
– Justice/equity
• Performance criteria
– Robustness
– Cost efficiency
– Transparanecy and legitimacy
The PA and HCR evaluation
• The precautionary approach:
– Robustness of management regime to uncertainties
regarding achievement of sustainability
– Sustainability: reproductive capacity and ecosystem
services
• Robustness to
– Data uncertainty
• May be estimated but...
– Model uncertainty
• Sensitivity to model choice
– Implementation uncertainty
• Sensitivity – historical performance
• Bias – nonreporting and discards
– Uncertainty about future state of nature
• Sensitivity – S/R parameters, growth, M, maturity
Performance evaluation
• Robustness
• Cost efficiency
– Data requirements
– Assessment costs – complexity, updates
– Implementation requirements (MCS)
• Transparency
– Methods acceptance – complex, intuitive?
– Process open to public scrutiny
Evaluation approach
HCR evaluation from objectives
Objectives
Performance criteria
Evaluation
Management regime
Harvest control rule and its
parameters such as trigger
and target points
HCR evaluation by trial and error
Harvest control rule and its
parameters such as trigger
and target points
Evaluation
Management regime
Objective achievement
Performance
Uncertainty in HCR evaluations
•
Robustness to
– Data uncertainty
• May be estimated but...
– Model uncertainty
• Sensitivity to model choice
– Implementation uncertainty
• Sensitivity – historical performance
• Bias – nonreporting and discards
– Uncertainty about future state of nature
• Sensitivity – S/R parameters, growth, M, maturity
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All these should be included in a HCR evaluation
Two approaches:
– stochastic modelling when uncertanties can be estimated
– Sensitivity analysis when uncertainties cannot be estimated or modelled
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Stochastic modelling on basis of estimates of uncertainty:
– Data uncertainty
•
Sensitivity analysis
– model uncertainty
– implementation uncertainty
– uncertainty about future state of nature
How to get there
ICES transition
• Develop conceptual base for management strategy
evaluations incl HCR evaluations, include in form of
advice framework (2005)
• SG to provide tools for WGs for HCR and target ref point
candidates in 2005 – initially based on trial-and-error
framework
• 2005 forward
– Dialogue with clients about management strategies – to develop
HCRs in context
– modify advisory framework to relate to management strategies –
from pa reference points to management strategies
– Develop appropriate management strategy evaluation tools
Short term problem in
implementation
• The present pa framework is percieved as
universally applicaple independently of
management strategies
• Communication issue: develop and accept
management plans which are
precautionary relative to sustainability
concerns but do not relate to the present
pa reference point framework except for
Blim.
Longer term – changed advice
delivery mechanisms
• We need to move from ’Vatican’ model (smoke
out of chimney after closed non-transparent
process)
– To
• ’Socratic’ model - exploratory, dialogue based
search evaluation of options
• Requires that advice is presented as a wider
range of options with implications and that
stakeholders & advisors spend considerable
time exploring these
• Handling unceratinties and risks should be a
shared responsibility
Fishery system
Nature:
Variation within regime
Regime shifts
Society:
Fleet adaptation
Strategic decision system
/Management strategy
Objectives
Performance criteria
Relevant
Knowledge
Implementation
framework
Management plan
Sanctions
Monitoring
requirements
Tactical decision
system
Corrections to
objectives
(‘flexibility’)
Accept of
knowledge
Harvest
control
rule
If state=xx then do yy