WCPFC Harvest Strategy and Reference Points

Harvest Strategy CMM - 2014-06  

WCPFC11 agreed to Conservation and Management Measures to develop and implement a harvest strategy approach for key fisheries and stocks in the WCPO (326.23 KB)  The objective of CMM 2014-06 is "To agree that the Commission shall develop and implement a harvest strategy approach for each of the key fisheries or stocks under the purview of the Commission according to the process set out in CMM 2014-06."

Pursuant to paragraph 13 of CMM 2014-06, WCPFC12 agreed a workplan for adoption of Harvest Strategies under CMM 2014-06 Workplan for the adoption of Harvest Strategies under CMM 2014-06 (506.05 KB) An updated workplan was agreed at WCPFC13 and records as an annex the Harvest Strategy-related outcomes from WCPFC13 Updated workplan on Harvest Strategies 2016 - 2019 and record of outcomes from WCPFC13 (240.6 KB)

Limit reference points (LRPs)

WCPFC8 approved a number of SC7 recommendations related to limit reference points

1. The agreed working definition for LRPs is to be based on the following principles:

  • they define a state of the fishery that is considered to be undesirable and which management action should avoid;
  • the probability of breaching an LRP should be very low;
  • management actions should be taken before the fishery falls below or is at risk of falling below an LRP.

 

2. The hierarchical approach (as outlined in SC7-MI-WP-03) to identify key LRPs for key target species in the WCPFC is as follows:

Level

Condition

LRPs

Level 1

A reliable estimate of steepness is available

FMSY and BMSY

Level 2

Steepness is not known well, if at all, but the key biological  (natural mortality, maturity) and fishery (selectivity) variables  are reasonably well estimated.

FX%SPRo and either

X%SBo or

X%SBcurrent,F=0

Level 3

The key biological and fishery variables are not well estimated or understood.

X%SBo or

X%SBcurrent,F=0

Bigeye: the LRP set at Level 2 with regard to the biomass-based LRP of 20%SBrecent,F=0, with deferral of a recommendation on the value of X% in the Level 2 fishing mortality-based LRP of Fx%SPR to SC9 (SC8 recommendation)

Yellowfin: the LRP set at Level 2 with regard to the biomass-based LRP of 20%SBrecent,F=0, with deferral of a recommendation on the value of X% in the Level 2 fishing mortality-based LRP of Fx%SPR to SC9 (SC8 recommendation)

South Pacific albacore: the LRP set at Level 2 with regard to the biomass-based LRP of 20%SBrecent,F=0, with deferral of a recommendation on the value of X% in the Level 2 fishing mortality-based LRP of Fx%SPR to SC9 (SC8 recommendation)

Skipjack: the LRP for skipjack is set at Level 3, 20%SBrecent,F=0.  (SC8 recommendation)

(note that SPR refers to the spawning-potential-per-recruit and SBrecent,F=0 refers to the estimated average spawning biomass over a recent period in the absence of fishing). 

WCPFC10 endorsed that the time window to be used in the LRP 20%SBF=0,t1-t2 satisfy the following criteria:

  1. have a length of 10 years;
  2. be based on the years t1=ylast-10 to t2=ylast-1 where ylast is the last year used in the assessment; and
  3. the approach used for calculating the unfished biomass levels be based on scaled estimates of recruitment according to the stock recruitment relationship.

Acceptable Risk Level of exceeding LRP

At WCPFC12, the Commission noted that SC10 had considered levels of risk associated with breaching the LRP within the range 5-20% and that the identification of acceptable risk is a management issue.  The Commission agreed to identify the level of acceptable risk which should be applied to breaching a LRP for the key target species, noting that the UN Fish Stocks Agreement states that the risk of exceeding LRPs should be very low.

At WCPFC13, the Commission agreed to:

i)         not specify, at this time, acceptable levels of risk of breaching the limit reference point for each stock;

ii)         consider any risk level greater than 20 percent to be inconsistent with the LRP related principle in UNFSA  (as referenced in Article 6 of the Convention) including that the risk of breaching limit reference points be very low; and

iii)        determine the acceptability of potential HCRs where the estimated risk of breaching the limit reference point is between 0 and 20%.

(Ref: WCPFC13 Summary Report, paragraph 296)

Target Reference Point for Skipjack

WCPFC12 agreed to CMM 2015-06 (363.05 KB) which establishes a target reference point for the WCPO skipjack tuna stock shall initially be 50 per cent of the estimated recent average spawning biomass in the absence of fishing, (SBF=0, t1-t2) calculated in a manner consistent with that detailed above for the LRP. This target reference point shall be an interim target reference point until it is reviewed in accordance with paragraph 8 of CMM 2015-06.  

Rebuilding timelines for Bigeye to [or above] its LRP

At WCPFC13, the Commission agreed to an interim timeframe of up to ten years for rebuilding the bigeye tuna stock to the agreed Limit Reference Point of 0.2SBF=0.  The Commission shall use this timeframe in its development and evaluation of strategies and conservation and management measures relevant to the rebuilding of bigeye tuna. Amongst other matters, the Commission will consider the probability of the bigeye stock being at or above the limit reference point at the end of the rebuilding timeframe.  (Ref: WCPFC13 Summary Report, paragraphs 304 – 306)

Agreed interim performance indicators to evaluate Harvest Control Rules

At WCPFC13, the Commission accepted the suggested initial list of performance indicators for tropical purse-seine fisheries as developed by the Small Working Group on Management Objectives at WCPFC13 for the purpose of the evaluation of harvest control rules (This list is attached at WCPFC13 Summary Report Attachment M: WCPFC13 Att M (109.82 KB) )  (Ref: WCPFC13 Summary Report, paragraph 286)

Links to WCPFC MOW and HSW workshop materials and outcomes

Four WCPFC workshops have been held on Management Objectives and Harvest Strategies from 2012 - 2014.  These workshops were held as informal meetings of stakeholders with an interest in WCPO tuna fisheries, that were convened by the Commission to facilitate and support the development of harvest strategies by Commission Members.  Links to the relevant meeting pages and reports: 

 

Page Updated 23 Mar, 2017
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