RSS 1.0Nephrops Under Water TV Surveys
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Nephrops Under Water TV Surveys
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The Labadie, Jones and Cockburn Banks Nephrops Grounds (FU2021) 2022 UWTV Survey Report and catch scenarios for 2023This report provides the main results of the 2022 underwater television survey on the ‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 2021. The 2022 annual survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A total of 92 UWTV stations were completed at 6 nm intervals over a randomised isometric grid design. The mean burrow density was 0.10 burrows/m2 compared with 0.12 burrows/m2 in the year 2021. The 2022 geostatistical abundance estimate was 1032 million, a 14% decrease on the abundance from 2021, with a CV of 5%, which is well below the upper limit of 20% recommended by SGNEPS 2012. Low to medium densities were observed throughout the ground. Using the 2022 estimate of abundance and updated stock data implies catch in 2023 that correspond to the ICES MSY approach of 1803 tonnes assuming that discard rates and fishery selection patterns do not change from the average of 2019–2021. One species of sea-pen (Virgularia mirabilis) was recorded as present at the stations surveyed. Trawl marks were observed at 20% of the stations surveyed.
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The “Smalls” Nephrops Grounds (FU22) 2022 UWTV Survey Report and catch scenarios for 2023This report provides the main results and findings of the seventeenth annual underwater television survey on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A total of 42 UWTV stations were surveyed successfully (high quality image data), carried out over an isometric grid at 4.5nmi or 8.3km intervals. The precision, with a CV of 7%, was well below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2022 abundance estimate was 36% higher than in 2022 and at 895 million is below the MSY Btrigger reference point (990 million). Using the 2022 estimate of abundance and updated stock data implies catch in 2023 that correspond to the ICES MSY approach of 2548 tonnes, assuming that discard rates and fishery selection patterns do not change from the average of 2019 - 2021. One species of sea pen was recorded as present at the stations surveyed: Virgularia mirabilis. Trawl marks were observed at 29% of the stations surveyed.
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FU19 Nephrops Grounds 2022 UWTV Survey Report and catch scenarios for 2023This report provides the main results of the twelfth underwater television survey of the various Nephrops patches in Functional Unit 19. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. In 2022 a total 42 UWTV stations were successfully completed. The mean density estimates varied considerably across the different patches. The 2022 raised abundance estimate showed a 4% decrease from the 2021 estimate and at 259 million burrows is below the MSY Btrigger reference point (430 million). Using the 2022 estimate of abundance and updated stock data implies catch in 2023 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 302 and 338 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2019–2021). One species of sea pen was observed; Virgularia mirabilis which has been observed on previous surveys of FU19. Trawl marks were observed at 12% of the stations surveyed.
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Porcupine Bank Nephrops Grounds (FU16) 2022 UWTV Survey Report and catch scenarios for 2023This report provides the results of the tenth underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. In total 58 UWTV stations were successfully completed out of the 68 stations planned in a randomised 6 nautical mile isometric grid covering the full spatial extent of the stock. The mean burrow density observed in 2022, adjusted for edge effect, was 0.19 burrows/m². The final krigged abundance estimate was 1363 million burrows with a CV of 3% and an estimated stock area of 7,124 km2. The 2022 abundance estimate was 34% higher than in 2021. Using the 2022 estimate of abundance and updated stock data imply that catches in 2023 should be between 3054 and 3787 tonnes, according to the EU MAP and ICES MSY approach (assuming that all catch is landed). Three species of sea-pen (Virgularia mirabilis, Funiculina quadrangularis and the deepwater sea-pen Kophobelemnon stelliferum) were observed during the survey. Trawl marks were also observed on 52% of the stations surveyed.
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Aran, Galway Bay and Slyne Head Nephrops Grounds (FU17) 2022 UWTV Survey Report and catch scenarios for 2023This report provides the main results and findings of the 21st annual underwater television survey on the Aran, Galway Bay and Slyne head Nephrops grounds, ICES assessment area; Functional Unit 17. In 2022, due to disruption to the survey schedule caused by weather downtime, the UWTV survey could not complete the Aran Grounds and Slyne Head stations, and was only able to complete successfully the 5 Galway Bay stations. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. The mean burrow density observed in Galway Bay, adjusted for edge effect, was 0.19 burrows/m2; and the final abundance estimate for this ground was 15 million burrows with a CV (Coefficient of Variance; relative standard error) of 3%. There were no sea-pen species nor trawl marks observed in the footage from Galway Bay. The 2022 UWTV survey was not deemed robust enough to derive fishing advice for 2023 owing to the reduced number of stations. As such, the stock size is considered unknown for 2022. Therefore, the assessment and catch advice for 2023 is based on the 2021 UWTV survey. The 2021 combined abundance estimate (331 million burrows) was below the MSY Btrigger reference (540 million burrows). Using the 2021 estimate of abundance and updated stock data imply that catches in 2023 should be no more than 363 tonnes, according to the EU MAP and ICES MSY approach and assuming that discard rates and fishery selection patterns do not change from the average of 2019–2021.
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The Labadie, Jones and Cockburn Banks Nephrops Grounds (FU2021) 2021 UWTV Survey Report and catch scenarios for 2022.This report provides the main results of the 2021 underwater television survey on the ‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 2021. The 2021 survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A total of 97 UWTV stations were completed at 6 nm intervals over a randomised isometric grid design. The mean burrow density was 0.12 burrows/m2 compared with 0.102 burrows/m2 in 2020. The 2021 geostatistical abundance estimate was 1202 million, a 18% increase on the abundance from 2020, with a CV of 5%, which is well below the upper limit of 20% recommended by SGNEPS 2012. Low to medium densities were observed throughout the ground. Using the 2021 estimate of abundance and updated stock data implies catch in 2022 that correspond to the ICES MSY approach of 1978 tonnes assuming that discard rates and fishery selection patterns do not change from the average of 2018–2020. One species of sea-pen (Virgularia mirabilis) were recorded as present at the stations surveyed. Trawl marks were observed at 21% of the stations surveyed.
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The “Smalls” Nephrops Grounds (FU22) 2021 UWTV Survey Report and catch scenarios for 2022This report provides the main results and findings of the sixteenth annual underwater television survey on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A total of 42 UWTV stations were surveyed successfully (high quality image data), carried out over an isometric grid at 4.5nmi or 8.3km intervals. The precision, with a CV of 7%, was well below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2021 abundance estimate was 13% lower than in 2020 and at 656 million is below the MSY Btrigger reference point (990 million). Using the 2021 estimate of abundance and updated stock data implies catch in 2022 that correspond to the ICES MSY approach of 1257 tonnes assuming that discard rates and fishery selection patterns do not change from the average of 2018–2020. One species of sea pen was recorded as present at the stations surveyed: Virgularia mirabilis. Trawl marks were observed at 24% of the stations surveyed.
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FU19 Nephrops Grounds 2021 UWTV Survey Report and catch scenarios for 2022This report provides the main results of the twelfth underwater television survey of the various Nephrops patches in Functional Unit 19. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. In 2021 a total 42 UWTV stations were successfully completed. The mean density estimates varied considerably across the different patches. The 2021 raised abundance estimate was a 16% decrease from the 2020 estimate and at 270 million burrows is below the MSY Btrigger reference point (430 million). Using the 2021 estimate of abundance and updated stock data implies catch in 2022 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 363 and 407 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2018–2020). One species of sea pen were observed; Virgularia mirabilis which has been observed on previous surveys of FU19. Trawl marks were observed at 19% of the stations surveyed.
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Aran, Galway Bay and Slyne Head Nephrops Grounds (FU17) 2021UWTV Survey Report and catch scenarios for 2022This report provides the main results and findings of the twentieth annual underwater television survey on the Aran, Galway Bay and Slyne head Nephrops grounds, ICES assessment area; Functional Unit 17. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In 2021 a total of 44 UWTV stations were successfully completed, 34 on the Aran Grounds, 5 on Galway Bay and 5 on Slyne Head patches. The mean burrow density observed in 2021, adjusted for edge effect, was medium at 0.26 burrows/m². The final krigged burrow abundance estimate for the Aran Grounds was 311 million burrows with a CV (Coefficient of Variance; relative standard error) of 4%. The final abundance estimate for Galway Bay was 12 million and for Slyne Head was 9 million, with CVs of 2% and 2% respectively. The total abundance estimates have fluctuated considerably over the time series. The 2021 combined abundance estimate (331 million burrows) is 16% lower than in 2020, the MSY Btrigger reference and it is below point (540 million burrows). Using the 2021 estimate of abundance and updated stock data imply that catches in 2022 should be no more than 360 tonnes, according to the EU MAP and ICES MSY approach and assuming that discard rates and fishery selection patterns do not change from the average of 2018–2020. Virgularia mirabilis was the only sea-pen species observed on the UWTV footage. Trawl marks were present at 5% of the Aran stations surveyed.
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Porcupine Bank Nephrops Grounds (FU16) 2021 UWTV Survey Report and catch scenarios for 2022This report provides the results of the ninth underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. In total 71 UWTV stations were successfully completed in a randomised 6 nautical mile isometric grid covering the full spatial extent of the stock. The mean burrow density observed in 2021, adjusted for edge effect, was 0.14 burrows/m². The final krigged abundance estimate was 1018 million burrows with a CV of 5% and an estimated stock area of 7,130 km2. The 2021 abundance estimate was 19% lower than in 2020. Using the 2021 estimate of abundance and updated stock data imply that catches in 2022 should be no more than 2804 tonnes, according to the EU MAP and ICES MSY approach (assuming that all catch is landed). Four species of sea-pen (Virgularia mirabilis, Funiculina quadrangularis, Pennatula phosphorea and the deepwater sea-pen Kophobelemnon stelliferum) were observed during the survey. Trawl marks were also observed on 38% of the stations surveyed.
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The “Smalls” Nephrops Grounds (FU22) 2020 UWTV Survey Report and catch scenarios for 2021This report provides the main results and findings of the fifteenth annual underwater television survey on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A total of 40 UWTV stations were surveyed successfully (high quality image data), carried out over an isometric grid at 4.5nmi or 8.3km intervals. The precision, with a CV of 8%, was well below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2020 abundance estimate was 33% lower than in 2019 and at 750 million is below the MSY Btrigger reference point (990 million). Using the 2020 estimate of abundance and updated stock data implies catch in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 1238 and 1560 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019). One species of sea pens was recorded as present at the stations surveyed: Virgularia mirabilis. Trawl marks were observed at 48% of the stations surveyed.
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The Labadie, Jones and Cockburn Banks Nephrops Grounds (FU2021) 2020 UWTV Survey Report and catch scenarios for 2021.This report provides the main results of the 2020 underwater television survey on the ‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 2021. The 2020 survey was multi-disciplinary in nature collecting UWTV, and other ecosystem data. A total of 97 UWTV stations were completed at 6nm intervals over a randomised isometric grid design. The mean burrow density was 0.102 burrows/m2 compared with 0.06 burrows/m2 in 2019. The 2020 geostatistical abundance estimate was 1020 million, a 65% increase on the abundance from 2019, with a CV of 5%, which is well below the upper limit of 20% recommended by SGNEPS 2012. Low to medium densities were observed throughout the ground. Using the 2020 estimate of abundance and updated stock data implies catch in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 1682 and 1710 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019). One species of sea-pen (Virgularia mirabilis) were recorded as present at the stations surveyed. Trawl marks were observed at 36% of the stations surveyed.
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Aran, Galway Bay and Slyne Head Nephrops Grounds (FU17) 2020 UWTV Survey Report and catch scenarios for 2021This report provides the main results and findings of the nineteenth annual underwater television survey on the Aran, Galway Bay and Slyne head Nephrops grounds, ICES assessment area; Functional Unit 17. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In 2020 a total of 44 UWTV stations were successfully completed, 34 on the Aran Grounds, 5 on Galway Bay and 5 on Slyne Head patches. The mean burrow density observed in 2020, adjusted for edge effect, was medium at 0.29 burrows/m². The final krigged burrow abundance estimate for the Aran Grounds was 359 million burrows with a CV (Coefficient of Variance; relative standard error) of 4%. The final abundance estimate for Galway Bay was 27 million and for Slyne Head was 7 million, with CVs of 13% and 4% respectively. The total abundance estimates have fluctuated considerably over the time series. The 2020 combined abundance estimate (394 million burrows) is 20% lower than in 2019, and it is below the MSY Btrigger reference point (540 million burrows). Using the 2020 estimate of abundance and updated stock data implies catches between 443 and 508 tonnes in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters, assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019. Virgularia mirabilis was the only sea-pen species observed on the UWTV footage. Trawl marks were present at 7% of the Aran stations surveyed.
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Porcupine Bank Nephrops Grounds (FU16) 2020 UWTV Survey Report and catch scenarios for 2021This report provides the results of the eighth underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. In total 65 UWTV stations were successfully completed in a randomised 6 nautical mile isometric grid covering the full spatial extent of the stock. The mean burrow density observed in 2020, adjusted for edge effect, was 0.17 burrows/m². The final krigged abundance estimate was 1264 million burrows with a CV of 4% and an estimated stock area of 7,130 km2. The 2020 abundance estimate was 25% higher than in 2019. Using the 2020 estimate of abundance and updated stock data implies catches between 2653 and 3290 tonnes in 2021 that correspond to the F ranges in the EU multiannual plan for Western Waters (assuming that all catch is landed). Four species of sea-pen; Virgularia mirabilis, Funiculina quadrangularis, Pennatula phosphorea and the deepwater sea-pen Kophobelemnon stelliferum were observed during the survey. Trawl marks were also observed on 22% of the stations surveyed.
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FU19 Nephrops grounds 2020 UWTV survey report and catch scenarios for 2021This report provides the main results of the eleventh underwater television survey of the various Nephrops patches in Functional Unit 19. The survey was multi-disciplinary in nature collecting UWTV, multi-beam and other ecosystem data. In 2020 a total 42 UWTV stations were successfully completed. The mean density estimates varied considerably across the different patches. The 2020 raised abundance estimate was a 20% decrease from the 2019 estimate and at 320 million burrows is below the MSY Btrigger reference point (430 million). Using the 2020 estimate of abundance and updated stock data implies catch in 2021 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 531 and 595 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2017–2019). Two species of sea pen were observed; Virgularia mirabilis and Pennatula phosphorea which have been observed on previous surveys of FU19. Trawl marks were observed at 26% of the stations surveyed.
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Western Irish Sea Nephrops Grounds (FU15) 2019 UWTV Survey Report and catch options for 2020This report provides the main results and findings of the 17th annual underwater television survey on the ‘Irish sea west Nephrops grounds’ ICES assessment area, Functional Unit 15. The survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. The 2019 design consisted of a randomised isometric grid of 100 stations at 4.5 nautical mile intervals out over the full known extent the stock. The resulting krigged burrow abundance estimate was 4.4 billion burrows. This was a similar result of that obtained in 2015, but a 10% lower than the abundance in 2018. In contrast to 2017 the spatial distribution of burrows shows a high density band on the central western area of the survey ground. The abundance remains within previously observed ranges and is above MSY Btrigger. The CV (or relative standard error) of 3% is in line with previous estimates and well below the upper limit of 20% recommended by SGNEPS 2012. Total catches and landings options at various different fishing mortalities were calculated and fishing at Fmsy in 2020 implies a total catch option at Fmsy (=Fmax) of 10,377 tonnes estimated to result in landings of no more than 8,546 tonnes. Sea-pens were observed at 21% of stations with high densities observed in the south-west of the ground. Trawl marks were noted at 15% of the UWTV stations.
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Porcupine Bank Nephrops Grounds (FU16) 2019 UWTV Survey Report and catch scenarios for 2020This report provides the results of the seventh underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In total 65 UWTV stations were successfully completed in a randomised 6 nautical mile isometric grid covering the full spatial extent of the stock. The mean burrow density observed in 2019, adjusted for edge effect, was 0.14 burrows/m². The final krigged abundance estimate was 1010 million burrows with a relative standard error of 5% and an estimated stock area of 7,130 km2. The 2019 abundance estimate was 9.5% lower than in 2018. Using the 2019 estimate of abundance and updated stock data implies catches between 2127 and 2637 tonnes in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters (assuming that all catch is landed). Four species of sea-pen; Virgularia mirabilis, Funiculina quadrangularis, Pennatula phosphorea and the deepwater sea-pen Kophobelemnon stelliferum were observed during the survey. Trawl marks were also observed on 31% of the stations surveyed.
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The Labadie, Jones and Cockburn Banks Nephrops Grounds (FU20-21) 2019 UWTV Survey Report and catch scenarios for 2020.This report provides the main results of the 2019 underwater television survey on the ‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 20-21. The 2019 survey was multi-disciplinary in nature collecting UWTV, and other ecosystem data. A total of 95 UWTV stations were completed at 6 nm intervals over a randomised isometric grid design. The mean burrow density was 0.06 burrows/m2 compared with 0.27 burrows/m2 in 2018. The 2019 geostatistical abundance estimate was 617 million, a 77% decrease on the abundance for 2018, with a CV of 5% which is well below the upper limit of 20% recommended by SGNEPS 2012. Low densities were observed throughout the ground. Using the 2019 estimate of abundance and updated stock data implies catch in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 1131 and 1150 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2016–2018). One species of sea-pen (Virgularia mirabilis) were recorded as present at the stations surveyed. Trawl marks were observed at 32% of the stations surveyed.
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FU19 Nephrops grounds 2019 UWTV survey report and catch scenarios for 2020.This report provides the main results of the tenth underwater television survey of the various Nephrops patches in Functional Unit 19. The survey was multidisciplinary in nature collecting UWTV, multi-beam and other ecosystem data. In 2019 a total 44 UWTV stations were successfully completed. The mean density estimates varied considerably across the different patches. The 2019 raised abundance estimate was a 220% increase from the 2018 estimate and at 386 million burrows is below the MSY Btrigger (430 million). Using the 2019 estimate of abundance and updated stock data implies catch in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 749 and 839 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2016–2018). Two species of sea pen were observed; Virgularia mirabilis and Pennatula phosphorea which have been observed on previous surveys of FU19. Trawl marks were observed at 12 % of the stations surveyed.
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The “Smalls” Nephrops Grounds (FU22) 2019 UWTV Survey Report and catch scenarios for 2020.This report provides the main results and findings of the fourteenth annual underwater television survey on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. A total of 41 UWTV stations were surveyed successfully (high quality image data), carried out over an isometric grid at 4.5nmi or 8.3km intervals. The precision, with a CV of 9%, was well below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2019 abundance estimate was 30% higher than in 2018 and at 1121 million is below the MSY Btrigger reference point (990 million). Using the 2019 estimate of abundance and updated stock data implies catch in 2020 that correspond to the F ranges in the EU multi annual plan for Western Waters are between 2247 and 2820 tonnes (assuming that discard rates and fishery selection patterns do not change from the average of 2016–2018). One species of sea pens were recorded as present at the stations surveyed: Virgularia mirabilis. Trawl marks were observed at 57% of the stations surveyed.
