FN Archimer Export Format
PT AVIS
TI Report of the Working Group on Biology and Assessment of Deep-sea Fisheries Resources (WGDEEP). 20–27 March 2015 Copenhagen, Denmark
BT 
AF ICES
SI NANTES
   LORIENT
SE PDG-RBE-EMH
   PDG-RBE-STH-LTBH
AC ICES
UR https://archimer.ifremer.fr/doc/00276/38705/37214.pdf
LA English
DT Expertises
CR EVHOE 2000
   EVHOE 2001
   EVHOE 2002
   EVHOE 2003
   EVHOE 2004
   EVHOE 2005
   EVHOE 2006
   EVHOE 2007
   EVHOE 2008
   EVHOE 2009
   EVHOE 2010
   EVHOE 2011
   EVHOE 2012
   EVHOE 2013
   EVHOE 2014
   EVHOE 2015
   EVHOE 871
   EVHOE 882
   EVHOE 883
   EVHOE 894
   EVHOE 905
   EVHOE 916
   EVHOE 927
   EVHOE 948
   EVHOE 959
   EVHOE 97
   EVHOE 98
   EVHOE 99
BO Thalassa
AB WGDEEP met at ICES Headquarters in Copenhagen, Denmark on 20–27 March 2015. The group was chaired by Pascal Lorance from France and Gudmundur Thordarson from Iceland. Terms of Reference of the Working Group are given in Section 2. WGDEEP gives advice according to an advice schedule where, in short, half of the stocks advice is given in year y and the other half has advice in year y+1. The excep-tion from this schedule is stocks from Va (Iceland) that have advice annually. Availa-ble time-series for international landings and discards, fishing effort, survey indices and biological information were updated and for all stocks and are presented in Sec-tions 4 to 14 of the report. Significant discrepancies found in previous years for some fisheries between official landings data supplied to ICES and scientific estimates of landings were lesser for 2014 landings. In order to maintain the consistency of time-series (which previously used only scientific estimates), some landings have been included in the data tables as “unallocated landing” (see Section 2.2). The assessment of ling in VA using GADGET, developed as exploratory assessment in recent years, is now benchmark as a fully analytical model. The spawning stock of ling in Va is estimated to have reached in 2013 a highest observed level in 30 years, three times above the 1982–2002 average. The state of other ling stocks is diverse and overall less favourable. Blue ling stocks also showed different status amongst stock units with strong varia-tions in catch, recruitment and biomass in Va, a sustained increased in biomass in relation to a decrease fishing mortality in Vb, VI and VII, and a persistent low level in other areas. The updated assessment for areas Vb, VI and VII suggested that the stock has recovered to BMSY level and the exploitation rate in 2014 was well below FMSY. There is no directed fishery for blue ling in other areas. The landings are now only bycatches. All Subareas within the assessment unit other areas show a declining trend in landings and the stock seems to be depleted in ICES Subarea II. Assessment of tusk was carried out as described in the stock annex, the main pro-gress being made is the standardization of cpue series for many of the stock units and a new estimate of FMSY for tusk in Va. Estimates of biomass for tusk in Va from the GADGET model were revised downward the main reason being a significant drop in the tuning series in 2014 (Icelandic March survey). Until 2014, ICES advised on two stock units of greater silver smelt, in Va and other areas. Following proposal form the group to split the other areas GSS into three advi-sory units; Area I and II, Vb and VIa and finally other areas, assessment were carried out and advice will be delivered for these three units. In areas I and II, data from Norwegian fisheries do not show any negative trends in recent years. Larger and older fish are caught from Norwegian surveys than from the fisheries in the same area. Acoustic biomass estimates in 2012 show some reduction compared to 2009, but marked upward trend again in 2014. Trawl cpue series show an upward trend since 2004. The advice for greater silver smelt in Vb and VIa is based on trends in cpue (kg/hour) from the Faroese summer survey on the Faroe Plateau, which show a slight decrease in the latest years. In 2014, the Faroese authorities set a law of species-specific management of greater silver smelt for Faroese waters. The TAC in 2014 was 16 000 tons and the TAC for 2015 was 14 400 tons. Six trawlers have licences to direct fishery of greater silver smelt. The regulation also includes limitations in e.g. bycatch, WGDEEP met at ICES Headquarters in Copenhagen, Denmark on 20–27 March 2015. The group was chaired by Pascal Lorance from France and Gudmundur Thordarson from Iceland. Terms of Reference of the Working Group are given in Section 2. WGDEEP gives advice according to an advice schedule where, in short, half of the stocks advice is given in year y and the other half has advice in year y+1. The excep-tion from this schedule is stocks from Va (Iceland) that have advice annually. Availa-ble time-series for international landings and discards, fishing effort, survey indices and biological information were updated and for all stocks and are presented in Sec-tions 4 to 14 of the report. Significant discrepancies found in previous years for some fisheries between official landings data supplied to ICES and scientific estimates of landings were lesser for 2014 landings. In order to maintain the consistency of time-series (which previously used only scientific estimates), some landings have been included in the data tables as “unallocated landing” (see Section 2.2). The assessment of ling in VA using GADGET, developed as exploratory assessment in recent years, is now benchmark as a fully analytical model. The spawning stock of ling in Va is estimated to have reached in 2013 a highest observed level in 30 years, three times above the 1982–2002 average. The state of other ling stocks is diverse and overall less favourable. Blue ling stocks also showed different status amongst stock units with strong varia-tions in catch, recruitment and biomass in Va, a sustained increased in biomass in relation to a decrease fishing mortality in Vb, VI and VII, and a persistent low level in other areas. The updated assessment for areas Vb, VI and VII suggested that the stock has recovered to BMSY level and the exploitation rate in 2014 was well below FMSY. There is no directed fishery for blue ling in other areas. The landings are now only bycatches. All Subareas within the assessment unit other areas show a declining trend in landings and the stock seems to be depleted in ICES Subarea II. Assessment of tusk was carried out as described in the stock annex, the main pro-gress being made is the standardization of cpue series for many of the stock units and a new estimate of FMSY for tusk in Va. Estimates of biomass for tusk in Va from the GADGET model were revised downward the main reason being a significant drop in the tuning series in 2014 (Icelandic March survey). Until 2014, ICES advised on two stock units of greater silver smelt, in Va and other areas. Following proposal form the group to split the other areas GSS into three advi-sory units; Area I and II, Vb and VIa and finally other areas, assessment were carried out and advice will be delivered for these three units. In areas I and II, data from Norwegian fisheries do not show any negative trends in recent years. Larger and older fish are caught from Norwegian surveys than from the fisheries in the same area. Acoustic biomass estimates in 2012 show some reduction compared to 2009, but marked upward trend again in 2014. Trawl cpue series show an upward trend since 2004. The advice for greater silver smelt in Vb and VIa is based on trends in cpue (kg/hour) from the Faroese summer survey on the Faroe Plateau, which show a slight decrease in the latest years. In 2014, the Faroese authorities set a law of species-specific management of greater silver smelt for Faroese waters. The TAC in 2014 was 16 000 tons and the TAC for 2015 was 14 400 tons. Six trawlers have licences to direct fishery of greater silver smelt. The regulation also includes limitations in e.g. bycatch,WGDEEP met at ICES Headquarters in Copenhagen, Denmark on 20–27 March 2015. The group was chaired by Pascal Lorance from France and Gudmundur Thordarson from Iceland. Terms of Reference of the Working Group are given in Section 2. WGDEEP gives advice according to an advice schedule where, in short, half of the stocks advice is given in year y and the other half has advice in year y+1. The excep-tion from this schedule is stocks from Va (Iceland) that have advice annually. Availa-ble time-series for international landings and discards, fishing effort, survey indices and biological information were updated and for all stocks and are presented in Sec-tions 4 to 14 of the report. Significant discrepancies found in previous years for some fisheries between official landings data supplied to ICES and scientific estimates of landings were lesser for 2014 landings. In order to maintain the consistency of time-series (which previously used only scientific estimates), some landings have been included in the data tables as “unallocated landing” (see Section 2.2). The assessment of ling in VA using GADGET, developed as exploratory assessment in recent years, is now benchmark as a fully analytical model. The spawning stock of ling in Va is estimated to have reached in 2013 a highest observed level in 30 years, three times above the 1982–2002 average. The state of other ling stocks is diverse and overall less favourable. Blue ling stocks also showed different status amongst stock units with strong varia-tions in catch, recruitment and biomass in Va, a sustained increased in biomass in relation to a decrease fishing mortality in Vb, VI and VII, and a persistent low level in other areas. The updated assessment for areas Vb, VI and VII suggested that the stock has recovered to BMSY level and the exploitation rate in 2014 was well below FMSY. There is no directed fishery for blue ling in other areas. The landings are now only bycatches. All Subareas within the assessment unit other areas show a declining trend in landings and the stock seems to be depleted in ICES Subarea II. Assessment of tusk was carried out as described in the stock annex, the main pro-gress being made is the standardization of cpue series for many of the stock units and a new estimate of FMSY for tusk in Va. Estimates of biomass for tusk in Va from the GADGET model were revised downward the main reason being a significant drop in the tuning series in 2014 (Icelandic March survey). Until 2014, ICES advised on two stock units of greater silver smelt, in Va and other areas. Following proposal form the group to split the other areas GSS into three advi-sory units; Area I and II, Vb and VIa and finally other areas, assessment were carried out and advice will be delivered for these three units. In areas I and II, data from Norwegian fisheries do not show any negative trends in recent years. Larger and older fish are caught from Norwegian surveys than from the fisheries in the same area. Acoustic biomass estimates in 2012 show some reduction compared to 2009, but marked upward trend again in 2014. Trawl cpue series show an upward trend since 2004. The advice for greater silver smelt in Vb and VIa is based on trends in cpue (kg/hour) from the Faroese summer survey on the Faroe Plateau, which show a slight decrease in the latest years. In 2014, the Faroese authorities set a law of species-specific management of greater silver smelt for Faroese waters. The TAC in 2014 was 16 000 tons and the TAC for 2015 was 14 400 tons. Six trawlers have licences to direct fishery of greater silver smelt. The regulation also includes limitations in e.g. bycatch, mesh size and fishing area. The EU introduced TAC management in 2003. For 2013 the EU TAC was set to 4316 tons in area V, VI, VII. For 2014 and 2016 the EU TAC was set to the same as in 2013 (V, VI, VII = 4316 tons). Most, if not all, of theEU TAC is caught in ICES Division VIa, therefore from the Vb–VIa stock unit. The fishery is smaller in other areas where the species is also discarded by various fisheries in quantities that could not be estimated. Little new data and no new assessment were presented for orange roughy in 2015. The species appears is very small amount in discards of some fleets in EU waters. There is a Faroese fishery on the Mid-Atlantic Ridge.For this particularly long-lived species, the results Productivity Susceptibility Analysis (PSA) presented in 2013 re-main appropriate and do no need yearly updating. The status of the roundnose grenadier stocks are varied. Roundnose grenadier in Vb, VI, VII and XIIb is assessed using a Bayesian surplus production model since 2010. The fishing pressure in recent years is estimated low, the biomass is slowly rebuild-ing after two decades of overexploitation.No advice is required in 2015. Exploratory assessments were carried out using the abundance indices from the Marine Scotland Deepwater Science Survey instead of the usual French tallybook indices (which was also run for comparison between models). Estimated trends in stock biomass using the survey of the tallybook indices are consistent. However, the stock biomass in re-cent years is estimated to increase at a substantially higher rate when the model is fit to the survey index. The survey covers the main distribution range of thee stock and the main fishing grounds. It is therefore most likely to provide a realistic index of the stock abundance. It may further be conservative as it does not cover the fully area of distribution part of which has not been fished in recent years. WGDEEP proposed the stock for benchmarking in 2017, in order to review the use of biomass indices and investigate alternative to the current assessment model. The fishery for roundnose grenadier in Division IIIa has been stopped since 2006 and landings are now insignificant. The bycatch from other fisheries is also low. The only information to assess this stock is now a Norwegian survey index from the same area. This index has shown a declining trend since 2006 and is now at the lowest level rec-orded during the time-series from 1984. The state of roundnose grenadier stocks on the Mid-Atlantic Ridge is unclear owing to limited data. This stock was intensively exploited in the 1970s and 1980s, the fishery declined in the 1990s and was insignifi-cant in the 2000s and resumed in 2011. In other areas, roundnose grenadier is only a bycatch and catch are insignificant. An assessment and advice was requested for the roughhead grenadier (Macrourus berglax) in the Northeast Atlantic owing to landings reported in previous years. Data were compiled and a catch based advice was prepared. This species is caught and subject to TAC management in the NAFO area. In the ICES area, it occurs at a much lower level, it is however known to occur at east Greenland (Division XIVb, Iceland (Va), Faroe Islands (Vb), Northern North Sea (IVa), Norwegian and Barents Sea (I and II). The landings level reported in some previous years were not plausible as high densities are not known to occur in reported catch areas. An advice reflecting possi-ble level of sustainable catch was prepared. Similarly, an assessment and advice was requested for the roundsnout grenadier (Trachyrincus scabrus) in the Northeast Atlantic (see chapter 15). This species is con-sidered to have none or only minor commercial interest. The request for an advice came from landings reported in previous years. These landings were considered to be either minor bycatch or species misreporting. The advice is that the possible small landings of the species are counted against existing roundnose and roughhead gren-adiers TACs. The assessment of black scabbardfish was benchmarked at WKDEEP 2014. This spe-cies was formerly assessed in three units in the ICES area. Although no final conclu-sion is reached all available evidence suggest that a single stock does a large clockwise migrations in the Northeast Atlantic and further south in the CECAF areas where spawning occurs. Whether fish in Azorean waters and on the Mid-Atlantic Ridge (ICES Subareas X and XII) belongs to the same widely distributed stock is un-certain and the picture in Subarea X is further blurred by the mixing with the closely related intermediate scabbardfish (Aphanopus intermedius). Greater forkbeard is caught mostly as a bycatch. Adults are a landed bycatch in slope fisheries for hake, monkfish, megrims and deep-water species and juveniles are a discarded bycatch in numerous fisheries. The assessment is based upon indices from four surveys. The increasing trend in abundance and biomass in recent years seems to be reverting. Time-series of survey indices display pluri-annual fluctuations, prob-ably related to recruitment variability. Alfonsinos are a mixture of two species (Beryx splendens and Beryx decadactylus. These species are oceanic demersal species occurring at the top of seamounts and along slopes, where they form local aggregations. They are widespread in the Northeast Atlantic from Iceland to the Azores and along the continental slope, in particular to the west of Iberia and Bay of Biscay. The stock structure is uncertain and data very limited. Although a longline survey is carried out in the Azores, where most of the catch occur, the reliably of survey indices is uncertain for these species owing to their large and patchy spatial distributions. As a consequence, the perception of the status of these stocks relies primarily on catch trends. Three stocks of blackspot sea bream are assessed by WGDEEP. In ICES Subarea IX Target fishery only take places in the Strait of Gibraltar, while the species is taken as a bycatch of artisanal fleets which uses mainly longlines. In 2014, landings and lpue from the Spanish “voracera” target fishery seemed increasing and the mean length in the catchwas slightly larger. However, the VMS-based lpue developed in recent years could not be updated and the assessment this stock is undermined by the lack of data from the Mediterranean and CECAF area as the same stockstraddles over ICES, CE-CAF and GFCM areas, where management regimes are different. Although no advice is given in 2015 for blackspot sea bream stocks, the WGDEEP report reminds that a recovery plan involving all parties is necessary for this stock. The stock of the same species in the Azores (ICES Subarea X) also showed signs of overexploitation. Ex-ploratory analyses of the natural and fishing mortalities were conducted using catch curves in order to investigate optimal exploitation reference points (yield-per-recruit analysis). Results show that modelling the fraction of population that change sex is a key issue to better estimating the trajectory of the spawning biomass. Data collection on sex ratio, maturity and sex change has been updated and analysed. Traditional models should be extended to incorporate the sex change issue. The third blackspot sea bream stock in ICES Subareas VI, VII and VIII remains at a low level, since it col-lapsed in the 1980s. In response to a request from the NEAFC, the working group update descriptions of deep-water fisheries in the NEAFC and ICES areas by compiling data on catch/landings, fishing effort and known spawning areas and areas of local deple-tionat the finest spatial resolution possible by ICES subarea and division (Chapter 15).
PY 2015
ID 38705
ER

EF