Baldó, F. (Francisco)

Blanco, M. (Marian)

Fernández-Zapico, O. (Olaya)

Ruiz-Pico, S. (Susana)

Velasco, F. (Francisco)

English

Ruiz-Pico, Susana

Blanco, Marian

Fernández-Zapico, Olaya

Velasco, Francisco

Baldó, Francisco

Digital.CSIC

Results on Merluccius merluccius (hake), Lophius budegassa (black anglerfish) and Lophius piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) from the Spanish Ground Fish Survey on the Porcupine bank (NE Atlantic)

Repositorio Institucional Digital del IEO

 1Working Document to be presented to the Working Group for the Bay of Biscay and the Iberian Waters Ecoregion ICES WGBIE, 2th -9th May 2019, Lisbon, Portugal  Results on Merluccius merluccius (hake), Lophius budegassa (black anglerfish) and Lophius piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) from the Spanish Ground Fish Survey on the Porcupine bank (NE Atlantic)  S. Ruiz-Pico1, M. Blanco1, O. Fernández-Zapico1, F. Velasco1 & F. Baldó2    Instituto Español de Oceanografía  (1) (2)   Centro Oceanográfico de Santander Centro Oceanográfico de Cádiz   Promontorio San Martín s/n Muelle de Levante (Puerto Pesquero)  39004 Santander, Spain P.O. Box 2609    11006 Cádiz, Spain    Abstract This working document presents the results of Merluccius merluccius (hake), Lophius budegassa (black anglerfish), Lophius piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) caught on the Porcupine Spanish Groundfish Survey (SP-PORC-Q3) in 2018. Biomass, abundance, distribution and length frequency were analysed. Biomass indices of these target species decreased this last survey. However the abundance of L. budegassa and both species of megrims increased due to the increase of specimens from 18 to 28 cm and from 15 to 20 cm respectively.    Introduction The Spanish bottom trawl survey on the Porcupine Bank (ICES Divisions 7c and 7k) has been carried out annually in the third-quarter (September) since 2001 to study the distribution, relative abundance and biological parameters of commercial species in the area (ICES 2017).  The aim of this working document is to update the results (abundance indices, length frequency and geographic distributions) of the species Merluccius merluccius (hake), Lophius budegassa (black anglerfish) and L. piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and L. whiffiagonis (megrim) on Porcupine bottom trawl surveys after the results presented previously (Blanco et al. 2017; Ruiz-Pico et al 2018).  Material and methods The Spanish Ground Fish Survey on the Porcupine bank (SP-PORC-Q3) has been annually carried out since 2001 onboard the R/V Vizconde de Eza, a stern trawler of 53 m and 1800 Kw. The area covered extends from longitude 12° W to 15° W and from latitude 51° N to 54° N, following the standard IBTS methodology for the western and southern areas (ICES 2017). The sampling design was random stratified to the area (Velasco and Serrano, 2003) with two geographical sectors (Northern and Southern) and three depth strata (> 300 m, 300 – 450 m and 450 - 800 m) (Figure 1). Hauls allocation is proportional to the strata area following a buffered random sampling procedure (as proposed by Kingsley et al., 2004) to avoid the selection of adjacent 5×5 nm rectangles. More details on the survey design and methodology are presented in ICES (2017).   2The reduction in the tow duration (20 instead of 30 minutes) applied in the last three surveys worked successfully. Now the catches have been reduced and are easier to handle for the team who sort it, but they are still abundant enough to be representative samples. The biomass indices of the entire time series are not affected by this reduction because the results of these last surveys were extrapolated to 30 minutes of trawling time to keep up the time series.  Results In 2018, 85 standard hauls and 3 additional hauls were carried out (Figure 1).  The total mean catch per haul decreased slightly the last year (Figure 2). Fish represented 93% of the total stratified catch and the species analyzed in this report represented 8% of the total stratified fish catch, with the following percentages per species: hake (44%), anglerfishes (23%) and megrims (33%).  In 2018, the biomass of these species decreased. Species such as Merluccius merluccius, Lophius budegassa and Lepidorhombus boscii have been following a downward trend since the last three or two years. However, the biomass of L. piscatorius and L. whiffiagonis, which had been high for several years, decreased in this latest survey. The abundance of small specimens of these target species was lower than the previous year but the specimens of around 18 cm were more abundant, specifically in L. budegassa and both species of megrims.  Merluccius merluccius (hake) The biomass of M. merluccius has been decreasing since 2015 and this last year decreased even more (29.3 ± 1.9 kg haul-1) (Figure 3). The abundance that  increased in 2017, decreased in the last survey because the peak of specimens from 18 to 30 cm was weakened.  M. merluccius was widespread in the study area, but this last survey fewer and smaller spots of biomass were found than in previous years (Figure 4). Fewer spots of recruits (< 23 cm) were found but were concentrated in the Irish shelf and in the south of the bank as usual (Figure 5). The length distribution showed a smooth modes of specimens around 19 cm and another from 31 to 46 cm (Figure 6) where is clear the decrease of the importance of large individuals on the length density plot. Individuals larger than 50 cm were barely found in contrast to previous years.   Lophius budegassa (black anglerfish) and Lophius piscatorius (white anglerfish)  L. budegassa was scarcer than L. piscatorius in the area. In this last survey, the biomass of L. budegassa decreased while the abundance increased due the increment of specimens from 18 to 28 cm. The biomass and abundance of L. piscatorius were lower than the previous five years (Figure 7). In 2018, specimens of L. budegassa were found mainly on the Irish shelf and were almost not found in the south and around the bank as usual (Figure 8). L. piscatorius, although widespread, showed fewer spots of biomass around the bank than the previous years, which makes a difference in the depth distribution of both species even more than in previous years. Recruits of  L. budegassa  (< 20 cm) were on the Irish shelf and small specimens of L. piscatorius were around the bank and on the Irish shelf (Figure 9).  The abundance of small specimens (L. budegassa around 8 cm and L. piscatorius below 10 cm) was slightly lower than the previous year. However, the specimens of L. budegassa  from 18 to 28 cm were more abundant than previous years. Regarding adults, no mode was found in L. budegassa as usual, and the maximum size was 66 cm this last survey in contrast to specimens around 80 cm in  3the previous years. The mode of adults of L. piscatorius was around 65 cm and the maximum size was 122 cm this last year (Figure 10).  Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) L. boscii has been slightly scarcer than L. whiffiagonis in the area, although in this last survey their biomass were similar, around 11 kg haul-1. The biomass of both species decreased this last survey whereas the abundance increased due to the increase of specimens from 15 to 20 cm (Figure 11).  Both species were distributed as usual but with fewer spots of biomass in the north and western area, L. whiffiagonis around the bank and on the Irish shelf shallower than L. boscii (Figure 12). The recruits of both species were concentrated closer around the bank than the previous year, specifically in the east and the south of the bank, although some spots of biomass were found in the north (Figure 13 and Figure 14). Recruits of L. whiffiagonis that are usually distributed in the shallower waters of Irish shelf were not found this last survey (Figure 14). The length distribution of L. boscii showed that the recruits around 12 cm were hardly found this last survey, while the specimens around 17 cm increased. The usual adult mode around 22 cm was weakened this last survey. The length distribution of L. whiffiagonis showed that specimens around 17 cm also increased (Figure 15) while recruits of age 1 decreased this last survey (Figures 16, Figure 17 and Figure 18).   Acknowledgements		We would like to thank R/V Vizconde de Eza crew and the IEO scientific teams that made the Porcupine Spanish Groundfish Survey possible. They are included in the ERDEM project, which has been co-funded by the EU through the European Maritime and Fisheries Fund (EMFF) within the National Program of collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy.  References  Blanco M., Ruiz-Pico S., Fernández-Zapico O., Velasco F., Baldó F. 2017. Results on Merluccius merluccius (hake), Lophius budegassa (black anglerfish) and Lophius piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) from 2016 the Spanish Ground Fish Survey on the Porcupine bank (NE Atlantic). Working document presented to the WGBIE, Cádiz, Spain, 4 -11 May 2017. ICES, 2017. Manual of the IBTS North Eastern Atlantic Surveys. Series of ICES Survey Protocols SISP 15. 92 pp. http://doi.org/10.17895/ices.pub.35 Kingsley, M.C.S.; Kanneworff, P. and Carlsson, D.M., 2004. Buffered random sampling: a sequential inhibited spatial point process applied to sampling in a trawl survey for northern shrimp Pandalus borealis in West Greenland waters. ICES Journal of Marine Science, 61: 12-24. Ruiz-Pico S., Blanco M., Fernández-Zapico O., Velasco F., Baldó F. 2018. Results on Merluccius merluccius (hake), Lophius budegassa (black anglerfish) and Lophius piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) from the Spanish Ground Fish Survey on the Porcupine bank (NE Atlantic). Working document presented to the WGBIE, Copenhagen, Denmark, 3 May 2018. 18 pp Velasco, F. and Serrano, A., 2003. Distribution patterns of bottom trawl faunal assemblages in Porcupine Bank: implications for Porcupine surveys stratification design. WD presented to the ICES IBTSWG, Lorient, France 25-28 March 2003. 19 pp.  4Figures GalwayIRELANDSector 1: E, F & GSector 2: F & G15º 14º 13º 12º 11º 10º 9º51º52º53º54º15º 14º 13º 12º 11º 10º 9º51º52º53º54ºGalwayIRELAND15º 14º 13º 12º 11º 10º 9º51º52º53º54º15º 14º 13º 12º 11º 10º 9º51º52º53º54ºValid towsExtra tows Figure 1. Left: Stratification design used in Porcupine surveys from 2003, previous data were re-stratified. Depth strata are: E) shallower than 300 m, F) 301 – 450 m and G) 451 – 800 m. Grey area in the middle of Porcupine bank corresponds to a large non-trawlable area, not considered for area measurements and stratification. Right: distribution of hauls performed in 2018   Yearkghaul105001000150020012002200320042005200620072008200920102011201220132014201520162017201810 %90 % Figure 2. Evolution of the total catch in Porcupine surveys (2001-2018)     5Yearkghaul1Biomass02040608010020012002200320042005200620072008200920102011201220132014201520162017201810 %90 %YearIndhaul1Number02040608010012014020012002200320042005200620072008200920102011201220132014201520162017201810 %90 % Figure 3. Evolution of Merluccius merluccius biomass and abundance indices in Porcupine surveys (2001-2018). Boxes mark parametric standard error of the stratified abundance index. Lines mark bootstrap confidence intervals ( = 0.80, bootstrap iterations = 1000)     651525354300 kg2009300 kg2010300 kg2011300 kg2012300 kg20135152535415 14 13 12 11300 kg201415 14 13 12 11300 kg201515 14 13 12 11300 kg201615 14 13 12 11300 kg201715 14 13 12 11300 kg2018 Figure 4. Geographic distribution of Merluccius merluccius catches (kg/30 min haul) in Porcupine surveys (2009-2018)   M. merluccius <23 cm51525354700 ind.2011700 ind.2012700 ind.2013700 ind.20145152535415 14 13 12 11700 ind.201515 14 13 12 11700 ind.201615 14 13 12 11700 ind.201715 14 13 12 11700 ind.2018  Figure 5. Geographic distribution of Merluccius merluccius recruits (<23 cm) in Porcupine surveys (2011-2018)  7 Length (cm)Indhaul1246201024620112462012246201324620142462015246201624620172465 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 951001051102018Male Female UndetLength (cm)density0.000.020.040.060.0820100.000.020.040.060.0820110.000.020.040.060.0820120.000.020.040.060.0820130.000.020.040.060.0820140.000.020.040.060.0820150.000.020.040.060.0820160.000.020.040.060.0820170.000.020.040.060.0810 20 30 40 50 60 70 80 90 100 1102018 Figure 6. Mean stratified length distributions and length density plots of hake in Porcupine surveys (2010-2018)     8Yearkghaul1Lophius budegassa0.00.51.01.52.02.520012002200320042005200620072008200920102011201220132014201520162017201810 %90 %BiomassYearIndhaul10.00.51.01.52.020012002200320042005200620072008200920102011201220132014201520162017201810 %90 %NumberYearkghaul1Lophius piscatorius051015202520012002200320042005200620072008200920102011201220132014201520162017201810 %90 %BiomassYearIndhaul10246820012002200320042005200620072008200920102011201220132014201520162017201810 %90 %Number Figure 7. Evolution of Lophius budegassa and Lophius piscatorius biomass and abundance indices in Porcupine surveys (2001-2018). Boxes mark parametric standard error of the stratified abundance index. Lines mark bootstrap confidence intervals ( = 0.80, bootstrap iterations = 1000)   9 Lophius budegassa5152535430 kg201130 kg201230 kg201330 kg20145152535415 14 13 12 1130 kg201515 14 13 12 1130 kg201615 14 13 12 1130 kg201715 14 13 12 1130 kg2018  Lophius piscatorius51525354100 kg2011100 kg2012100 kg2013100 kg20145152535415 14 13 12 11100 kg201515 14 13 12 11100 kg201615 14 13 12 11100 kg201715 14 13 12 11100 kg2018  Figure 8. Geographic distribution of Lophius budegassa and Lophius piscatorius catches (kg×30 min haul-1) in Porcupine surveys (2011-2018)    10 L. budegassa <21 cm515253548 ind.2011 20128 ind.20138 ind.20145152535415 14 13 12 118 ind.201515 14 13 12 118 ind.201615 14 13 12 118 ind.201715 14 13 12 118 ind.2018 L. piscatorius <21 cm5152535420 ind.201120 ind.201220 ind.201320 ind.20145152535415 14 13 12 1120 ind.201515 14 13 12 1120 ind.201615 14 13 12 1120 ind.201715 14 13 12 1120 ind.2018 Figure 9. Geographic distribution of Lophius budegassa and Lophius piscatorius recruits in Porcupine surveys (2011-2018)   11Lophius budegassaLength (cm)Indhaul10.050.100.1520110.050.100.1520120.050.100.1520130.050.100.1520140.050.100.1520150.050.100.1520160.050.100.1520170.050.100.155 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1002018Male Female Undet Lophius piscatoriusLength (cm)Indhaul10.050.150.2520110.050.150.2520120.050.150.2520130.050.150.2520140.050.150.2520150.050.150.2520160.050.150.2520170.050.150.255 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 951001051101151201251301351402018Male Female Undet Figure 10. Mean stratified length distributions of Lophius budegassa and Lophius piscatorius in Porcupine surveys (2011-2018)      12Yearkghaul1Lepidorhombus boscii05101520012002200320042005200620072008200920102011201220132014201520162017201810 %90 %BiomassYearIndhaul105010015020020012002200320042005200620072008200920102011201220132014201520162017201810 %90 %NumberYearkghaul1Lepidorhombus whiffiagonis0510152020012002200320042005200620072008200920102011201220132014201520162017201810 %90 %BiomassYearIndhaul105010015020025030020012002200320042005200620072008200920102011201220132014201520162017201810 %90 %Number Figure 11. Evolution of Lepidorhombus boscii and Lepidorhombus whiffiagonis biomass and abundance indices in Porcupine surveys (2001-2018). Boxes mark parametric standard error of the stratified abundance index. Lines mark bootstrap confidence intervals ( = 0.80, bootstrap iterations = 1000)   13 Lepidorhombus boscii51525354100 kg2011100 kg2012100 kg2013100 kg20145152535415 14 13 12 11100 kg201515 14 13 12 11100 kg201615 14 13 12 11100 kg201715 14 13 12 11100 kg2018 Lepidorhombus whiffiagonis51525354100 kg2011100 kg2012100 kg2013100 kg20145152535415 14 13 12 11100 kg201515 14 13 12 11100 kg201615 14 13 12 11100 kg201715 14 13 12 11100 kg2018 Figure 12. Geographic distribution of Lepidorhombus boscii and Lepidorhombus whiffiagonis catches (kg×30 min haul-1) in Porcupine surveys (2011-2018)    14L. boscii <16 cm51525354200 ind.2011200 ind.2012200 ind.2013200 ind.20145152535415 14 13 12 11200 ind.201515 14 13 12 11200 ind.201615 14 13 12 11200 ind.201715 14 13 12 11200 ind.2018 Figure 13. Geographic distribution of Lepidorhombus boscii recruits (≤16 cm) in Porcupine surveys (2011-2018) Lepidorhombus whiffiagonisAge 151525354400 ind.2011400 ind.2012400 ind.2013400 ind.20145152535415 14 13 12 11400 ind.201515 14 13 12 11400 ind.201615 14 13 12 11400 ind.201715 14 13 12 11400 ind.2018 Figure 14. Geographic distribution of Lepidorhombus whiffiagonis recruits (age 1) in Porcupine surveys (2011-2018)   15  Lepidorhombus bosciiLength (cm)Indhaul15101520201151015202012510152020135101520201451015202015510152020165101520201751015205 10 15 20 25 30 35 40 45 50 55 602018Male Female Undet Lepidorhombus whiffiagonisLength (cm)Indhaul15101520201151015202012510152020135101520201451015202015510152020165101520201751015205 10 15 20 25 30 35 40 45 50 55 60 65 702018Male Female Undet Figure 15. Mean stratified length distributions of Lepidorhombus boscii and Lepidorhombus whiffiagonis in Porcupine surveys (2011-2018)   16Length (cm)Number05101520252009 201005101520252011 201205101520252013 201405101520252015 2016051015202510 20 30 40 50 60 70201710 20 30 40 50 60 702018012345678+ Figure 16. Mean stratified length distributions of Lepidorhombus whiffiagonis with the age classes in Porcupine surveys (2009-2018)   17Abundance at ageSurveyAge2005 2010 2015012345678+Proportion at ageSurveyAge2005 2010 2015012345678+Median-Standardized abundance at ageSurveyAge2005 2010 2015012345678+Median-Standardized proportion at ageSurveyAge2005 2010 2015012345678+Abundance at age 1SurveyInd./30 min haul 2005 2010 201501020304050 Figure 17. Bubble-plot of Lepidorhombus whiffiagonis abundances at age, proportion at age, median standardized abundances at age (year-median years) and median standardized proportion at age in Porcupine surveys time series. Blue bubbles are above the median value, red ones are below it and the cross marks the year with the median value.   18Abundance along age by cohortAgeLog(Abundance)-4-20240 1 2 3 4 5 6 7 8NA19930 1 2 3 4 5 6 7 8-0.9619940 1 2 3 4 5 6 7 8-0.919950 1 2 3 4 5 6 7 8-0.6219960 1 2 3 4 5 6 7 8-0.721997-4-2024 -0.61998-0.51999-0.42000-0.0120010.162002-4-2024 0.1620030.2220040.0720050.320060.342007-4-2024 0.3320080.3720090.2120100.4120110.622012-4-2024 1.0320130.920141.8920152.9320164.432017-4-2024 NA2018 Figure 18. Lepidorhombus whiffiagonis abundance (No./30 min haul) evolution in logarithmic scale along each cohort sampled in Porcupine surveys time series. Solid lines mark the linear regression fitted by cohort to the log(abundance)~age, the figure in the lower right corner of each panel corresponds to the slope. Dashed line marks the linear regression fitted to the overall time series.              

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Results on Merluccius merluccius (hake), Lophius budegassa (black anglerfish) and Lophius piscatorius (white anglerfish), Lepidorhombus boscii (four-spot megrim) and Lepidorhombus whiffiagonis (megrim) from the Spanish Ground Fish Survey on the Porcupine bank (NE Atlantic)

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