• FU19 Nephrops Grounds 2021 UWTV Survey Report and catch scenarios for 2022

      Doyle, Jennifer; Ryan, G; Aristegui, M.; Fitzgerald, Ross; Tully, D.; O’Brien, S.; White, Jonathan; Sullivan, M.; Lynch, Deirdre; McAuliffe, M (Marine Institute, 2021)
      This 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.
    • The Labadie, Jones and Cockburn Banks Nephrops Grounds (FU2021) 2021 UWTV Survey Report and catch scenarios for 2022.

      Doyle, Jennifer; Ryan, G.; Aristegui, M.; Fitzgerald, Ross; Tully, D.; O'Brien, S.; White, Jonathan; Sullivan, M.; Lynch, Deirdre; McAuliffe, M (Marine Institute, 2021)
      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.
    • The “Smalls” Nephrops Grounds (FU22) 2021 UWTV Survey Report and catch scenarios for 2022

      Aristegui, M.; Fitzgerald, Ross; Lynch, Deirdre; White, Jonathan; Doyle, Jennifer; McAuliffe, M (Marine Institute, 2021)
      This 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.