Nephrops Under Water TV Surveys
http://hdl.handle.net/10793/59
2024-03-29T05:45:53ZFU19 Nephrops Grounds 2023 UWTV Survey Report and catch scenarios for 2024
http://hdl.handle.net/10793/1879
FU19 Nephrops Grounds 2023 UWTV Survey Report and catch scenarios for 2024
Doyle, Jennifer; Aristegui, M.; Ryan, Gráinne; Bentley, K.; Sullivan, Mairead; Opanowski, Artur; Sugrue, S.; Farrell, Ellen; Domingos, Marta; McCorriston, P.; Hehir, Imelda; Ni Chonchuir, G.; Fahy, James; Manning, Laurence; McCann, Neve; O’Connor, Sean; Woodcock, Kirsty; Course, Grant; Meireles de Castro, Rita; Joyce, Haleigh; Moloney, Sarah; Dower, Ciara; White, Jonathan
This report provides the main results of the fourteenth 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 2023 a total 42
UWTV stations were successfully completed. The mean density estimates varied
considerably across the different patches. The 2023 raised abundance estimate
showed a 15% decrease from the 2022 estimate and at 220 million burrows is below
the MSY Btrigger reference point (430 million). Using the 2023 estimate of abundance
and updated stock data implies catch in 2024 that correspond to the F ranges in the
EU multi annual plan for Western Waters are between 224 and 248 tonnes
(assuming that discard rates and fishery selection patterns do not change from the
average of 2020–2022). One species of sea pen was observed; Virgularia mirabilis
which has been observed on previous surveys of FU19. Trawl marks were observed
at 10% of the stations surveyed.
2023-01-01T00:00:00ZThe “Smalls” Nephrops Grounds (FU22) 2023 UWTV Survey Report and catch scenarios for 2024
http://hdl.handle.net/10793/1878
The “Smalls” Nephrops Grounds (FU22) 2023 UWTV Survey Report and catch scenarios for 2024
Doyle, Jennifer; Bentley, K.; Sullivan, Mairead; Opanowski, Artur; Sugrue, S.; Farrell, Ellen; Domingos, Marta; Hehir, Imelda; Ryan, Gráinne; McCorriston, P.
This report provides the main results and findings of the eighteenth 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 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 < 7%, was well
below the upper limit of 20% recommended by SGNEPS (ICES, 2012). The 2023 abundance
estimate was 13% lower than in 2022 and at 776 million is below the MSY Btrigger reference
point (990 million). Using the 2023 estimate of abundance and updated stock data implies
catch in 2024 that correspond to the ICES MSY approach of 1912 tonnes, assuming that
discard rates and fishery selection patterns do not change from the average of 2020 - 2022.
One species of sea pen was recorded as present at the stations surveyed: Virgularia
mirabilis. Trawl marks were observed at 37% of the stations surveyed.
2023-01-01T00:00:00ZThe Labadie, Jones and Cockburn Banks Nephrops Grounds (FU2021) 2023 UWTV Survey Report and catch scenarios for 2024
http://hdl.handle.net/10793/1877
The Labadie, Jones and Cockburn Banks Nephrops Grounds (FU2021) 2023 UWTV Survey Report and catch scenarios for 2024
Doyle, Jennifer; Bentley, K.; Sullivan, Mairead; Opanowski, Artur; Sugrue, S.; Farrell, Ellen; Domingos, Marta; McCorriston, P.
This report provides the main results of the 2023 underwater television survey on the
‘Labadie, Jones and Cockburn Banks’ ICES assessment area; Functional Unit 2021. The 2023
annual survey was multi-disciplinary in nature collecting UWTV and other ecosystem data. A
total of 100 UWTV stations were completed at 6 nm intervals over a randomised isometric
grid design. The 2023 mean burrow density was 0.104 burrows/m2
compared with 0.101
burrows/m2
in the year 2022. The 2023 geostatistical abundance estimate was 1026 million,
a 0.6% decrease on the abundance from 2022, with a CV of 4%, which is well below the
upper limit of 20% recommended by SGNEPS 2012. Low to medium densities were observed
throughout the ground. Using the 2023 estimate of abundance and updated stock data
implies catch in 2024 that correspond to the ICES MSY approach of 1865 tonnes assuming
that discard rates and fishery selection patterns do not change from the average of 2020–
2022. Two species of sea-pen (Virgularia mirabilis and Pennatula phosphorea) were
recorded as present at the stations surveyed. Trawl marks were observed at 20% of the
stations surveyed.
2023-01-01T00:00:00ZAran, Galway Bay and Slyne Head Nephrops Grounds (FU17) 2023 UWTV Survey Report and catch scenarios for 2024
http://hdl.handle.net/10793/1876
Aran, Galway Bay and Slyne Head Nephrops Grounds (FU17) 2023 UWTV Survey Report and catch scenarios for 2024
Aristegui, M.; Ryan, Gráinne; Fahy, James; Manning, Laurence; McCann, Neve; Woodcock, Kirsty; Course, Grant; Meireles de Castro, Rita; Murphy, Natasha; White, Jonathan; O’Connor, Sean
This 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. The survey was multi-disciplinary in nature collecting UWTV, CTD and
other ecosystem data. In 2023 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 2023, adjusted for edge effect, was medium at 0.29 burrows/m². The
final krigged burrow abundance estimate for the Aran Grounds was 356 million burrows
with a CV (Coefficient of Variance; relative standard error) of 3%. The final abundance
estimate for Galway Bay was 15 million and for Slyne Head was 5 million, with CVs of 7%
and 4% respectively. The total abundance estimates have fluctuated considerably over the
time series. The 2023 combined abundance estimate (375 million burrows) is 13% higher
than in 2021, and it is below MSY Btrigger (540 million burrows). Using the 2023 estimate of
abundance and updated stock data imply that catches in 2024 should be no more than 454
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 2020–2022. Virgularia
mirabilis was the only sea-pen species observed on the UWTV footage. Trawl marks were
present at 5% of the Aran stations surveyed.
2023-01-01T00:00:00Z