Report of the Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA). 24–29 June 2017 Bilbao, Spain

Type Expertise
Date 2017
Language English
Ref. ICES CM 2017/ACOM:17
Other localization http://ices.dk/sites/pub/Publication%20Reports/Expert%20Group%20Report/acom/2017/WGHANSA/01%20Report%20of%20the%20WG%20on%20Southern%20Horse%20Mackerel,%20Anchovy%20and%20Sardine%20-%20WGHANSA%202017.pdf
Author(s) ICES
Sponsor ICES / CIEM - International Council for the Exploration of the Sea/Conseil International pour l’Exploration de la Mer
Abstract

The Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA) met in Bilbao (Spain), 24–29 June 2017, and was chaired by Lionel Pawlowski (France). There were 15 participants from France, Portugal, Spain and UK by correspondence. The main task was to assess the status and to provide short-term predictions for the stocks of anchovy in Division 9.a, for sardine in divisions 8.c and 9.a, and in divisions 8.abd and Subarea 7, and for horse mackerel (T. trachurus) in Division 9.a and blue jack Mackerel (T. picturatus) in 10 (Azores). Assessments were updated according to the stock annexes. Four stocks have been benchmarked in 2017. Some leftover work from the benchmark was carried out prior and completed during the meeting. Some unexpected technical issues with the PELAGO survey prevented the group to provide an assessment for the Iberian sardine stock. The assessment will be carried out in October 2017 (when the delayed data PELAGO will be processed and validated and made available for the group) and subsequent advice will be drafted and released later. As anchovy in Subarea 8 is scheduled for assessment and short-term forecast in November 2017, no preliminary or exploratory assessment was carried out in this meeting. Information from the new spring surveys 2017, provide point estimates of anchovy biomass of 85 500 t (CV=15%) and 134 500 t (CV=15%) for the DEPM and acoustic surveys respectively. Catches in 2016 were 20 670 t. As in previous years, the WG collected the few available data on the fisheries of anchovy in northern areas (subareas 4,5,6), although no assessment is so far required for the anchovy in those regions. Anchovy in Division 9.a is a Category 3 stock for which a trend-based assessment from surveys is provided. The current status of the stock is informed by the spring PELACUS (Subdivision 9.a North) and PELAGO surveys (subdivisions 9.a Central- North, Central-South and South). The only available 2017 survey estimates for the working group were those provided by the PELACUS survey (3566 t, a historical maximum within its series) and by the PELAGO survey, but for the Subdivision 9.a South only (13 797 t, below the average of the time-series). The abovementioned technical issues with the PELAGO survey also prevented the working group from providing stock size indicators of anchovy for the whole division and for the western component of the stock (subdivisions 9.a North, Central-North and Central-South). In the western areas, catches are generally low (several hundred tonnes), but sometimes exceeds a thousand tones, such as in 2016 (7140 t), which was one of the highest year records of the time-series. The bulk of the population is usually concentrated in the Subdivision 9.a South, where the stock supports a fishery whose catches were 6599 t in 2016 (against 13 740 t for the whole Division 9.a). Neither the fishery nor the population indices (assessed by surveys) show any long-term trend for the anchovy in 9.a South, although the 2017 value of the biomass stock size indicator is low. Exploratory evaluations of current harvest rates (10–50%) in the context of Yield-perrecruit analysis suggest that current exploitation levels in the 9.a South (until 2016) are sustainable, since these result in 50–90% of the potential spawning biomass being allowed to spawn. The European Commission has requested to ICES to give advice on whether catches of 15 000 t in 2017 are deemed sustainable (current TAC agreed in 12 500 t). Since the working group does not have a biomass index for the whole Division 9.a, it is not possible to determine if catches of 15 000 t in 2017 in the entire Division 9.a would be sustainable. Such an increase in catches cannot be considered sustainable if they are taken entirely in the Subdivision 9.a South because they would imply a harvest rate in this area far above the ones observed in the past and an SPR value below 50%. No catch option for this stock can be given for 2018 because there is no information on recruitment that will constitute the bulk of the biomass and catches. The WG assessed the sardine in divisions 8.a,b,d and Subarea 7, now as separate stocks following the conclusions from the (WKPELA 2017). There are no international TACs for those two regions. In divisions 8.a,b,d, the stock is assessed based upon trends in SSB, fishing mortality and recruitment estimates from a SS3 model relying on catch and survey data (acoustic PELGAS, eggs BIOMAN and triennial DEPM survey). The last two years have been marked by a good recruitment in 2016 leading to a high SSB in 2017. Fishing mortality estimates reflects the increase of landings in the early 2010s. Landings in 2016 in divisions 8.a.b.d were 30 181 t. Overall, the stock is in good status. There is no clear trend in biomass indices since 2000, though marked fluctuations are recorded. The last big cycle peaked in 2009–2010. Biomass estimates during the following years were lower due to an increase in the fishing mortality. Biomass estimated by PELGAS is 465 022 t in 2017 which is almost the double of the estimated biomass last year. 2017 has one of the highest age 1 group of the PELGAS survey series. As in previous years, there is little information from Subarea 7. The survey data from Peltic are for now too short and cover only a part of the stock to be considered as an index of the biomass of this region, but the development of this survey is promising. Catches are not monitored for biological sampling, so little can be done in terms of assessing the population and the fishery in this subarea. Catch are mainly taken by France, the Netherlands and the United Kingdom in 7 with occurrences in other countries such as Germany, Denmark. Landings for the whole stock area accounted for 19 408 t in 2016, twice the amount of landings of 2015. For the southern horse mackerel (Division 9.a) an updated analytical assessment was carried out following the stock annex. This stock has been benchmarked this year. Catches were around 40 730 tonnes in 2016. The estimated SSB in 2016 from the assessment is 487 950 t. The SSB decreased gradually from 2007 to 2011, increasing in 2012 and 2013 to around the long-term average and is since then well above it. Fishing mortality (0.077) has been increasing in the last two years. Recruitment is estimated to be well above long-term average in 2015. Catch options were provided under the assumption of historical geometric mean recruitment. For the blue jack Mackerel (Trachurus picturatus) in the waters of the Azores, the biennial advice was not updated this year. The WG continued with the collation of data. The assessment is currently based on commercial abundance indices from the purse-seiners and tuna bait boat, used as an indicator of stock trends. In addition the WG had an update about the preparation of the benchmark for anchovy in Subarea 9.a which is still recommended for 2018. The WG also had three presentations from members of WGEAWESS presenting the activity of this working group dealing with ecosystem integrated assessment. The possibility of collaborations was discussed and it was concluded that both groups could benefit from the mutual expertise of each other.

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ICES (2017). Report of the Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA). 24–29 June 2017 Bilbao, Spain. ICES / CIEM - International Council for the Exploration of the Sea/Conseil International pour l’Exploration de la Mer, Ref. ICES CM 2017/ACOM:17, 684p.https://archimer.ifremer.fr/doc/00415/52665/