The WG did not have time at this year’s meeting to carry out a full evaluation of the western herring stocks (VIa (N), VIa (S), Irish Sea and Celtic Sea), as was suggested by ACFM. The current situation for these stocks is believed to be the following:
Only VIa (N) herring has a separate agreed assessment.
Currently fisheries in the four stock areas are rather distinct.
Stock development for Celtic Sea, Irish Sea is distinct but with mixing juveniles.
Demographically Celtic Sea, VIa (S) and VIa (N) herring have been believed to recruit inde-pendently. VIa (N) and VIa (S) were split into two stocks in 1982 based on demographics through a discriminant analysis of catch data.
Historically Irish Sea and VIa (N) appear to have similar historic stock productivity.
Currently there is an EU funded project evaluating the differences among the Western Stocks with a variety of methods, including genetics, life history traits and biological markers (WES-THER). This project is now in the data evaluation phase and will finish in December 2005. A full evaluation of all the data might not be available before by HAWG in 2006.
A combination of the catch data to provide a historic VPA would be relatively straightforward but would provide little benefit over combination of the individual VPAs.
The main benefits for combination of some or all of the area is where either fisheries overlap, as for juveniles in the southern Irish Sea for Celtic and Irish Sea herring, or where stock sepa-ration is less distinct for adults in areas VIa (N), Irish Sea and Clyde.
The current main problem for a combined area assessment is the lack of a single source of a comprehensive survey to act as a tuning index.
18 ICES HAWG Report 2005
The WG considers that it would be best to await the results from WESTHER before consider-ing what should be done. If combination of two or more stocks or areas in considered useful, this may require coordination of a suitable survey.
1.11 Recommendations
• HAWG recommends that the new ICES InterCatch database should provide an opportunity to clearly track changes or allocations of “official” landings made by WG members and to compensate for misreported or unallocated landings or dis-cards. This would, however, require means to keep some of the national disag-gregated data confidential in order to protect their sources. Further, a transparent and effective handling of information obtained from market sampling in foreign ports should be possible. The WG also encourages the ICES data centre to assure that access to InterCatch is platform-independent, if not using open source soft-ware. Action: C. Zimmermann. (from Sec 1.5)
• HAWG recommends that all metiers with substantial catch should be sampled (including by-catches in the small meshed fishery).
• HAWG recommends that similar arrangements, as the obligation implemented by the EU Member States on sampling of landings outside the flag country, to be implemented between all countries. Furthermore, agreements on when and how the sampling country provides sampled data to the flag country should be made in order to make data available for the HAWG
• HAWG recommends that the development of methods for estimating discards be based on a fleet based method, rather than on a national basis. The inclusion of discarded catch is considered to give more realistic values of fishing mortality and biomass. Action: PGCCDBS. (from Sec 1.7).
• To ensure the continuity of the North Sea herring larvae surveys they should be considered for priority 1 EU funding. This survey is providing value for money that is equivalent to the other sources of information used to assess North Sea herring. It should therefore be given the same priority of funding as the other sur-veys and market sampling data collection schemes.
• HAWG recommends that the existing surveys of herring in the southern North Sea and English Channel be maintained, and that the micro-increment analysis of otoliths (to determine spawning type) is carried out on samples collected during the annual acoustic survey.
• HAWG recommends that the possibility of separating the juveniles caught in the Irish Sea acoustic and ground fish surveys into autumn and winter spawning components based on otolith microstructure and/or length composition is investi-gated.
• The annual series of IBTS indices on North Sea herring 1-5+ ringers used by the HAWG is an accumulation of the indices retrieved during each years HAWG.
While there might have been additions and corrections to data after these retriev-als, and while there might be some differences between retrieval procedures throughout the series, HAWG recommends that updated, standardized retrievals are available to the WG at the 2006 meeting.
• HAWG recommends the following timetable for benchmark assessments:
2006 North Sea herring autumn spawners 2007 Western Baltic spring spawners 2008 Celtic Sea herring, VIa North herring
• HAWG notes the third year of weak recruitment in North Sea herring, and that series of poor recruitments have occurred in the past with major implications for the management of the North Sea herring stock. HAWG therefore recommends that studies be initiated into whether the tendency of periodicity in the level of re-cruitment of autumn spawned herring is linked to changes in the hydrography and/or the biology in the North Sea.
Table 1.5.1: Available disaggregated data for the HAWG per March 2005
X: Multiple spreadsheets (usually xls); W: WG-data national input spreadsheets (xls);
D: Disfad inputs and Alloc-outputs (ascii/txt)
Stock Ca tchyear Com ments
X W D
Baltic Sea: IIIa and SD 22-24
her_3a22 1991-2000 X raw data, provided by Jørgen Dals kov, Mar. 2001, s plitting revis ed 1998 X provided by Jørgen Dals kov, Mar. 2001, s plitting revis ed
1999 X provided by Jørgen Dals kov, Mar. 2001, s plitting revis ed, catch data revis ed 2000 X provided by Jørgen Dals kov, Mar. 2001
2001 X provided by Jørgen Dals kov, Mar. 2002 2002 X provided by Jørgen Dals kov, Mar. 2003 2003 X provided by Jørgen Dals kov, Mar. 2004 2004 X provided by Lotte Wors øe Claus en, Mar. 2005
Celtic Sea and VIIj
her_irls 1999 X provided by Ciarán Kelly, Mar. 2000
2000 X provided by Ciarán Kelly, Mar. 2001 2001 D provided by Ciarán Kelly, Mar. 2002 2002 D provided by Ciarán Kelly, Mar. 2003 2003 D provided by Maurice Clarke, Mar. 2004 2004 D provided by Maurice Clarke, Mar. 2005
Clyde
her_clyd 1999 X provided by Mark Dickey-Collas , Mar. 2000
2000-2003 included in VIaN
Irish Sea
her_nirs 1988-2003 X updated by SG HICS, March 2004 1998 X provided by Mark Dickey-Collas , Mar. 2000 1999 X provided by Mark Dickey-Collas , Mar. 2000 2000 X W provided by Mark Dickey-Collas , Mar. 2001 2001 X provided by Mark Dickey-Collas , Mar. 2002 2002 X provided by Richard Nas h, Mar. 2003 2003 X provided by Richard Nas h, Mar. 2004 2004 X provided by Beatriz Roel, Mar. 2005
North Sea
her_47d3, her_ns ea 1991 X provided by Yves Verin, Feb. 2001 1992 X provided by Yves Verin, Feb. 2001 1993 X provided by Yves Verin, Feb. 2001 1994 X provided by Yves Verin, Feb. 2001
1995 X W D provided by Yves Verin, Feb. 2001, updated by SG Rednos e, Oct 2003 1996 (X) W D provided by Yves Verin, Feb. 2001, updated by SG Rednos e, Oct 2003 1997 (X) W D provided by Yves Verin, Feb. 2001, updated by SG Rednos e, Oct 2003 1998 (X) W D provided by Yves Verin, Mar. 2000, updated by SG Rednos e, Oct 2003
1999 W D provided by Chris topher Zim m erm ann, Mar. 2000, updated by SG Rednos e, Oct 2003 2000 W D provided by Chris topher Zim m erm ann, Mar. 2001, updated by SG Rednos e, Oct 2003 2001 W D provided by Chris topher Zim m erm ann, Mar. 2002
2002 W D provided by Chris topher Zim m erm ann, Mar. 2003 2003 W D provided by Chris topher Zim m erm ann, Mar. 2004 2004 W D provided by Chris topher Zim m erm ann, Mar. 2005
West of Scotland (VIa(N))
her_vian 1957-1972 x provided by John Sim m onds , Mar. 2004 1997 X provided by Ken Patters on, Mar. 2002 1998 X provided by Ken Patters on, Mar. 2002
1999 W D provided by Paul Fernandes , Mar. 2000, W included in North Sea 2000 W D provided by Em m a Hatfield, Mar. 2001, W included in North Sea 2001 W D provided by Em m a Hatfield, Mar. 2002, W included in North Sea 2002 W D provided by Em m a Hatfield, Mar. 2003, W included in North Sea 2003 W D provided by Em m a Hatfield, Mar. 2004, W included in North Sea 2004 W D provided by John Sim m onds , Mar. 2005, W included in North Sea
West of Ireland
her_irlw 1999 X (W) provided by Ciaran Kelly, Mar. 2000 2000 X (W) provided by Ciaran Kelly, Mar. 2001 2001 D provided by Ciaran Kelly, Mar. 2002 2002 D provided by Ciaran Kelly, Mar. 2003 2003 D provided by Maurice Clarke, Mar. 2004 2004 D provided by Maurice Clarke, Mar. 2005
Sprat in IIIa
spr_kask 1999 X (W) provided by Els e Tors tens en, Mar. 2000 2000 X (W) provided by Els e Tors tens en, Mar. 2001 2001 X (W) provided by Lotte As kgaard Wors øe, Mar. 2002 2002 X (W) provided by Lotte Wors øe Claus en, Mar. 2003 2003 X (W) provided by Lotte Wors øe Claus en, Mar. 2004 2004 X (W) provided by Lotte Wors øe Claus en, Mar. 2005
Sprat in the North Sea
spr_nsea 1999 X (W) provided by Els e Tors tens en, Mar. 2000 2000 X (W) provided by Els e Tors tens en, Mar. 2001 2001 X (W) provided by Lotte As kgaard Wors øe, Mar. 2002 2002 X (W) provided by Lotte Wors øe Claus en, Mar. 2003 2003 X (W) provided by Lotte Wors øe Claus en, Mar. 2004 2004 X (W) provided by Lotte Wors øe Claus en, Mar. 2005
Sprat in VIId & e
spr_ech 1999 X (W) provided by Els e Tors tens en, Mar. 2000 2000 X (W) provided by Els e Tors tens en, Mar. 2001 2001 X (W) provided by Lotte As kgaard Wors øe, Mar. 2002 2002 X (W) provided by Lotte Wors øe Claus en, Mar. 2003 2003 X (W) provided by Lotte Wors øe Claus en, Mar. 2004 2004 X (W) provided by Lotte Wors øe Claus en, Mar. 2005
National Data
Germ any: Wes tern Baltic 1991-2000 X provided by Tom as Gröhs ler, Mar. 2001 (with s am pling) Germ any: North Sea 1995-1998 W provided by Chris topher Zim m erm ann, Mar 2001 (without s am pling) Norway: Sprat 1995-1998 W provided by Els e Tors tens en, Mar 2001 (without s am pling) Sweden 1990-2000 W provided by Johan Modin, Mar 2001 (without s am pling)
UK/England & Wales 1985-2000 X databas e output provided by Marinelle Bas s on, Mar. 2001 (without s am pling) UK/Scotland 1990-1998 W provided by Sandy Robb/Em m a Hatfield, Mar. 2002
Format
20 ICES HAWG Report 2005
Table 1.5.2 HAWG initial definitions for the new ICES InterCatch database. Note that definitions of fleets and fisheries are currently under development; the list provided here is not final.
1. General
Definitions should apply for all WGs and are therefore predefined (species, catchyear, date of submis-sion/resubmission, nation, contact details, national fleet descriptions, sampling level, catch,...) and gen-eral consistency checking should apply
2. WG/Species specific input 3. WG/Species specific validity check:
WGs should choose entry fields relevant for them from an initial range for acceptance exhaustive option list (to assure interWG operability)
spatial resol. res 1 ICES statistical rectangle (for CATON only) 20D2? 52G4?
res 2 HAWG (sub)-divisions (further defs with link to one of those listed
rectangles required):
22, 23, 24, IIIaN, IIIaS, IVaE, IVaW, IVb, IVb,
VIaN, VIaS, VIIaN, VIIaS, VIIb, VIIc, VIId, VIIe, check that sums VIIf, VIIg, VIIh, VIIj, VIIk, VIIIa rect-areas and also: IVa, IIIa, 22-24, IVcVIId, Blackwater, month-quarter
Norwegian fjords and shelf, Clyde match!
data required
catch unit 1 t 0.1 400000 if in t
unit 2 kg 100 400000000 if in kg
disaggregation type 1 fleet
fleet types directed all; freezer trawlers; trawlers and RSW trawlers;
RSW purse seiners; drift netters; set nets/traps one of those listed
(static gear); others; unknown
20.0 37.0 at age 7
Table 1.5.2 cont’d HAWG initial definitions for the new ICES InterCatch database.