Workshop on the assessment and management plan evaluation for Icelandic haddock and saithe (WKICEGAD)

On 10 December 2024, ICES received the following request from Iceland: The Government of Iceland requests ICES, in line with conditions stipulated in the MoU, to evaluate whether the proposed harvest control rule or rules are in accordance with its objectives, given current ICES definition of reference points or any re-evaluation of those points that may occur in the process. Additionally, the evaluation should also include review of input data and the applied assessment methodology for haddock and saithe. It is expected that the ICES advice for the 2025/2026 fishing year for Icelandic haddock and saithe be based on the above-mentioned HCRs. On further correspondence received by ICES on 23 January 2025, ICES was specifically requested to review six specified harvest control rules for Icelandic haddock (had.27.5a) and three specific harvest control rules for saithe (pok.27.5a). WKICEGAD – Workshop on the benchmark assessment and management plan evaluation for Icelandic haddock and saithe – was held in Hafnarfjörður, Iceland, on 24-28 February 2025. The participants to the WKICEGAD included the WK chair, two external reviewers and the incoming and outgoing stock assessors for each stock, as well as one participant from the industry. Haddock in 5a Benchmark assessment and evaluation of reference points The assessment method was updated during this benchmark. The previous assessment model was based on a statistical catch at age model (MUPPET). The new assessment model is based on the state space assessment model (SAM) using the two previously used survey series (the Icelandic spring and autumn groundfish surveys). The assessment results from the new model have similar characteristics as the previous assessments. The update of reference points resulted in Blim = 46.0 kt, based on the lowest observed biomass where large recruitment was observed (average of SSB in 1985 and 2000 as estimated in the benchmark assessment), and Bpa = Blim*1.4 = 64.5 kt. This is an increase in Blim from a previous value of 35.5 kt. The proposed harvest control rules (HCR) are either based on F at ages 6 to 10 or harvest rate (HR) relative to stock biomass of fish larger than 45 cm (45+ cm) in the assessment year. Given this the fishing pressure reference points were estimated for both harvest rate and fishing mortality, that resulted in HRpa = 0.35 and Fpa = 0.45. MSY reference points were also calculated and resulted in HRMSY = 0.35, FMSY = 0.45 and MSY Btrigger = 64.5 kt. Evaluation of candidate harvest control rules The proposed HCRs for the Icelandic haddock fishery, which sets a TAC for the fishing year y/y+1 (September 1 of year y to August 31 of year y+1) are based on target harvest rates or fishing mortalities, modified by the ratio SSBy/MGT Btrigger when SSBy < MGT Btrigger. Both reference biomass and SSB are estimated at spawning time April-May. Of the six harvest control rules proposed in the request four were found to be precautionary and three in accordance with the ICES MSY approach. Saithe in 5a Benchmark assessment and evaluation of reference points The assessment method was updated during this benchmark. The previous assessment model was based on a statistical catch at age model (MUPPET). The new assessment model is based on the state space assessment model (SAM) using the previously used survey series (the Icelandic spring groundfish surveys). The assessment results from the new model have similar characteristics as the previous assessments while between year consistency has improved. The update of reference points resulted in Blim being estimated to 48.0 kt, based on the lowest observed biomass (Bloss) (average of SSB in the years 1996 to 2000 as estimated in the benchmark assessment), and Bpa = Blim*1.4 = 67 kt. This is an increase in Blim from a previous value of 44 kt. The proposed harvest control rules (HCR) are either based on F at ages 4 to 9 or harvest rate (HR) (with and without stabilizer) relative to stock biomass of fish at age 4 and above (B4+). Given this the fishing pressure reference points were estimated for both harvest rate and fishing mortality. That resulted in HRpa = 0.23 when the reference biomass was based on catch weights in the assessment year but 0.25 when the reference biomass was based on stock weights. HRmsy was between 0.19 and 0.21 but 0.17 with the stabiliser and no trigger. For fishing mortality-based advice Fpa = 0.26. FMSY was estimated to 0.22. Evaluation of candidate harvest control rules The three proposed HCRs for the Icelandic saithe fishery, which sets a TAC for the fishing year y/y+1 (September 1 of year y to August 31 of year y+1) are based on target harvest rates or fishing mortalities, modified by the ratio SSBy/MGT Btrigger when SSBy < MGT Btrigger. All the three harvest control rules proposed in the request were found to be precautionary in accordance with the ICES MSY approach.