Report of the Working Group on the Assessment of Southern Shelf Stocks of Hake, Monk and Megrim (WGHMM). 10 - 16 May 2013. ICES Headquarters, Copenhagen
|Ref.||ICES CM 2013/ACOM:11A|
|Copyright||2013 International Council for the Exploration of the Sea|
|Contributor(s)||Bertignac Michel, Biais Gerard, Lissardy Muriel|
|Sponsor||CIEM / ICES|
|Note||ICES WGHMM REPORT 2013 ICES ADVISORY COMMITTEE|
|Abstract||The ICES Working Group on the Assessment of Southern Shelf Stocks of Hake, Monk and Megrim (WGHMM) met in ICES Headquarters during May 10-16 2013. There were 24 stocks in its remit distributed from ICES Divisions IIIa to IXa though mostly distributed in Sub Areas VII, VIII and IX. There were 17 participants (of whom 2 participated part time and 2 by correspondence). The group was tasked with carrying out stock assessments and catch forecasts and providing a first draft of the ICES advice for 2013 for 11 stocks. Several stocks, nine functional units for Nephrops and some of the new stocks from last year’s WG were listed as “biennial 2nd year”. For those stocks, catch and abundance indices information was updated. In addition, three new stocks were also added to the terms of reference in 2013 (two stocks of sea bass and one stock of striped red mullet).
Analytical assessments using age-structured models were conducted for the southern stocks of megrim and the Bay of Biscay sole, whereas the two hake stocks and one southern stock of anglerfish were assessed using models that allow the use of only length-structured data (no age data). A surplus-production model, without age or length structure, was used to assess the second southern stocks of anglerfish. No analytical assessments have been provided for the northern stocks of anglerfish or megrim after 2006. For anglerfish this is mostly due to ageing problems and to an increase in discards in recent years, for which there is no reliable data at the stock level. For megrim, there have been severe deficiencies in the input data, of which several still remain. The state of stocks for which no analytical assessment could be performed was inferred from examination of commercial LPUE or CPUE data and from survey information.
Both hake stocks and both southern megrim stocks are scheduled for benchmark assessments at the start of 2014. The WGHMM meeting spent some time planning this benchmark (see Annex N) together with longer term benchmarks (2015 and after, see section 1.).
A recurrent issue significantly constrained the group’s ability to address the terms of reference this year. Despite a deadline of 4 weeks before the meeting, data for several stocks were still not available at the start of the meeting which lead to increase in workload during the working group, as in that case, the assessments could not be carried out in National Laboratories prior to the meeting as mentioned in the ToRs. This is an important matter of concerns for the group members.
Section 1 of the report presents a summary by stock and discusses general issues. Section 2 provides descriptions of the relevant fishing fleets and surveys used in the assessment of the stocks. Sections 3 to 13 contain the single stock assessments. This year a new section has been created for the new stocks. Several annexes follow. Additionally, the WG ToRs this year included a reconsideration of the reference points for northern hake (see Annex T) and an assessment of the progress on the interssessional work made on the use of SS3 to the anglerfish stocks (Lophius budegassa and L. piscatorius) in Divisions VIIb-k and VIIIa,b (see Annex R).