WP5: Reference points and harvest
control rules
Richard Hillary and Polina Levontin, Imperial
College London, Division of Biology
Deliverables
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D5.1: Global review of ref. points/HCRs used
for deep-water species
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D5.2: Strengths/weaknesses of current ref.
points/HCRs as applied to case-study stocks

D5.3: Report on suitable ref. points/HCRs for
EU-related deep water fisheries – present and
future
Interaction with other WPs
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WP2 – certain review deliverables should
provide background/motivation for some of
WP5
WP3 – Bioeconomic ref. pts./HCRs
WP4 – clearest linkage: “follows” much of WP4
work (SW analysis, ref. pt./HCR development)
WP7 – Clear link from WP4/5 but also from
WP7 to WP5 – MSE informs candidate HCRs
Review: D5.1
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Brief review complementary to those in WP2/4
Aim to identify EU applicable/”successful”
bio(economic) reference points from wider field
Case study RPs/HCRs: D5.2

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Identification of appropriate
indicators/RPs/HCRs for case study stocks
Also identify potential MPs (given objectives) to
be tested in WP7
Problems with current (if relevant) RPs/HCRs
will be identified
Designing HCRs for CS: D5.3

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Strong linkage with WP4 work – clear that
relevant RP/HCR for CS conditional on relevant
assessment method/outputs/uncertainty
Feedback with WP7 – candidate HCRs from
WP5 but MSE process can inform HCR
construction/selection...
Reference points
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Biological/bioeconomic values from which we
can measure stock status/targets/objectives
Data hungry: MSY paradigm, “absolute” targets
(F/biomass limit/reference points)
Data diet-friendly: abundance depletion (current
to unfished/”good” conditions), indicator-based
RPs derived directly from observations
Harvest Control Rules
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(I) Automatic changes to exploitation
level/pattern given stock status relative to RPs
(II) Agreed exploitation level – status quo or
agreed changes in fishing pressure/pattern at
agreed rate until target is reached
Future harvest “actions” given RPs, indicators,
auxiliary information and historic harvest
“actions”
Utility of RPs/HCRs
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Achieve management objectives specified
Use agreed (and tested) MPs to reduce conflict
and delays in action
Increase transparency in management process
Uncertainty and precautionary
approach
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From WP4 selection of assessment methods
will incorporate uncertainty in stock dynamics
Preferable to have “probabilistic” RPs
HCRs designed according to prec. appr. as a
rule require “probabilistic” information on both
stock status and reference points
Requirements for RP/HCR/MP
design

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Clear and specific management objectives: time
horizons, constraints, targets, some
quantification of risk of key events
Reference points/assessment models that are
estimable from the data available now and in
the future
Ecosystem approach

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Probably the most challenging aspect of
designing RPs/HCRs
Likely to be qualitative/semi-quantitative given
data and trophic dependence/spatial
understanding

“Simple” multi-species ideas possible

Data poor: composite indices of fishery impact