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:
A reliable estimate of steepness is available
FMSY and BMSY
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
The key biological and fishery variables are not well estimated or understood.
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:
- have a length of 10 years;
- be based on the years t1=ylast-10 to t2=ylast-1 where ylast is the last year used in the assessment; and
- 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:
- MOW1: 28 - 29 November 2012, Manila, Philippines: https://www.wcpfc.int/meetings/wcpfc-management-objectives-workshop
- MOW2: 28 November 2013, Cairns, Australia: https://www.wcpfc.int/meetings/wcpfc-management-objectives-workshop-2
- MOW3: 28 November 2014, Apia, Samoa: https://www.wcpfc.int/meetings/wcpfc-management-objectives-workshop-3
- MOW4/HSW: 30 November - 1 December, Bali, Indonesia: https://www.wcpfc.int/meetings/wcpfc-harvest-strategy-workshop
Precautionary Management Framework for North Pacific Albacore
At the Sixth Regular Session of the Northern Committee, and consistent with Article VI of the WCPFC Convention, Canada submitted a paper (WCPFC-NC6-DP02) on the development of a precautionary approach based fishery management regime for the northern stocks. Building on this paper, the Seventh Regular Session of the Northern Committee agreed to a three-year work programme to develop a precautionary approach based management framework for North Pacific albacore.
The Ninth Regular Session of the Northern Committee determined that it was best to delay discussions on the framework until the completion of the 2014 North Pacific albacore stock assessment. In July 2014, the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) concluded that the North Pacific albacore stock is “healthy and that current productivity is sufficient to sustain recent exploitation levels, assuming average historical recruitment in both the short and long term”. The ISC also provided further advice regarding candidate limit and target reference points.
Based on the advice from the ISC, the Northern Committee (NC) recommends the following precautionary management framework for NP albacore.
1. Management objective
The management objective for the North Pacific albacore fishery is to maintain the biomass, with reasonable variability, around its current level in order to allow recent exploitation levels to continue and with a low risk of breaching the limit reference point.
2. Biological reference points
Based on ISC’s 2014 stock assessment advice and following the hierarchical approach adopted by the Commission, North Pacific albacore is to be treated as a Level 2 stock. The following is based on an average recruitment scenario:
The limit reference point (LRP) for this stock is established at 20%SSBcurrent F=0. This LRP is consistent with the Annex II of the UN Fish Stocks Agreement (UNFSA) and recent WCPFC decisions on LRPs for the three tropical tuna species and South Pacific albacore, where 20%SSBcurrent F=0 was adopted. If this point is breached, management actions will be taken to return the stock to a predetermined level as outlined in the subsequent section on Decision Rules. This LRP replaces the current interim limit which was previously established by the NC as FSSB-ATHL.
The target reference point (TRP) for this stock will be determined following a comprehensive analysis, if appropriate, under a management strategy evaluation (MSE) approach as outlined in section 4 on “Future Work”. Historical fishing activity, anticipated fishing activity, and the source of increased fishing mortality will also be considered when evaluating a suitable TRP. Socioeconomic factors, as per UNFSA Article 6.3.c., will be further considered. The existing conservation and management measure (CMM) for the stock (WCPFC 2005-03) establishes through limits on current effort an overall management regime for the stock.
3. Decision rules
NC recommends a management strategy for the stock that ensures that the risk of the biomass decreasing below the LRP is low.
LRP rule: In the event that, based on information from ISC, the spawning stock size decreases below the LRP at any time, NC will, at its next regular session or intersessionally if warranted, adopt a reasonable timeline, but no longer than 10 years, for rebuilding the spawning stock to at least the LRP and recommend a CMM that can be expected to achieve such rebuilding within that timeline. NC will take into account historical fishing activity and the source of increased fishing mortality when developing management strategies to rebuild the stock, including in establishing effort reductions. NC will further consider socioeconomic factors, as per UNFSA Article 6.3.c., as well as which NC members, if any, contributed to exceeding the LRP.
4. Future work
This framework shall be reviewed following the 2017 ISC stock assessment of North Pacific albacore. In the interim, NC would support an MSE, if appropriate, for the stock to yield new information that would enhance the robustness of this framework. This framework shall be reviewed following the 2017 ISC stock assessment of North Pacific albacore.