Working Group for the Assessment of Nephrops Stocks (WGNEPH)

Working Group for the Assessment of Nephrops Stocks (WGNEPH) was established in 2025, gathering all Nephrops stocks from several ecoregional groups into one working group. The objective of WGNEPH was to perform stock assessments on Nephrops stocks in all relevant ICES ecoregions (Bay of Biscay and Iberian Coast, Celtic Seas, and the Greater North Sea). The work followed the generic Terms of Reference for stock assessment working groups, focusing on conducting stocks assessments and producing advice, carrying out audits and preparing drafts of report chapters.An increase in stock size (abundance or biomass) in the majority of the assessed Nephrops stocks characterized 2025; this pertains to all the North Sea stocks, half of the stocks in the Celtic Sea ecoregion (stocks in FUs 11, 12, 13, 2021 and 22), and 4 out of 6 stocks in the Bay of Biscay ecoregion (stocks in FUs 2324, 25, 2627 and 31). For stocks with UWTV surveys, increase in abundance varied between 1 and 221%. Eight Category 1 stocks with agreed reference points have stock size greater than MSY Btrigger (stocks in FUs 6, 7, 8, 9, 11, 12, 13 and 2021), while 5 stocks have stock size below MSY Btrigger (stocks in FUs 14, 15, 17, 19 and 22). Three Category 1 stocks have no agreed stock size reference point (stocks in FUs 3-4, 16 and 2324). For Category 2 stocks for which both MSY Btrigger and Blim reference points are defined, all 3 stocks are below Blim (stocks in FUs 25, 2627 and 32). Two Category 3 stocks are above Itrigger (stocks in FUs 2829 and 31) while 1 is below Itrigger (FU 30). The majority of the assessed Nephrops stocks are exploited at or below Fmsy levels (stocks in FUs 3-4, 7, 8, 9, 11, 12, 13, 14, 15, 17, 19, 22, 25 and 2627) while 8 stocks are exploited above Fmsy/Fmsy proxy (stocks in FUs 6, 16, 2021, 2324, 2829, 30, 31 and 32). Fishing pressure has decreased or remained at a stable level in recent years in the majority of the stocks (stocks in FUs 6, 8, 9, 12, 13, 14, 17, 19, 25, 2627, 2829, 30 and 32) but is increasing in several stocks (stocks in FUs 3-4, 7, 11, 15, 16, 2021, 22, 2324 and 31). Recruitment is not estimated for Nephrops stocks, but high discard rates and/or high prevalence of undersized Nephrops in length distributions from scientific surveys and commercial catches are used as proxies for recruitment.WGNEPH is also responsible for the assessment of several Category 4 and 5 stocks, which include 4 stocks in defined functional units (stocks in FUs 5, 10, 33 and 34), and 3 stocks outside the defined functional units (nep.27.4outfu, nep.27.6aoutfu, nep.27.7outfu). These stocks have biennial or triannual advice and are all due for advice in 2026.The summary of the stock status is as follows:Category 1:· Nephrops FU 3–4 (nep.fu.3-4): Fishing pressure has been slowly increasing since 2017 but is still below Fmsy. Stock size decreased over the same period (until 2024) but increased substantially in 2025. No reference point for stock size has been defined for this stock.· Nephrops FU 6 (nep.fu.6): Fishing pressure has been fluctuating above Fmsy (except in 2008). Stock size has been fluctuating around MSY Btrigger, was below the reference point in 2025, but increased to above MSY Btrigger in 2025.· Nephrops FU 7 (nep.fu.7): Since 2011, fishing pressure has been well below Fmsy. Since 2016, stock size has been well above MSY Btrigger and showed an increase from 2024 to 2025.· Nephrops FU 8 (nep.fu.8): Fishing pressure has been fluctuating around or been below Fmsy since 2015. Fishing pressure was below the reference point in 2024. Stock size has been above MSY Btrigger for the entire time-series and showed a substantial increase from 2024 to 2025.· Nephrops FU 9 (nep.fu.9): Fishing pressure has been fluctuating around Fmsy and has been below the reference point since 2020. Stock size was estimated to be at or above MSY Btrigger for the whole time series and showed a substantial increase from 2024 to 2025.· Nephrops FU 11 (nep.fu.11): Fishing pressure decreased from 2012 to 2020, but has since increased, to just below Fmsy in 2024. Stock size has fluctuated above MSY Btrigger since 2015 and showed a substantial increase from 2024 to 2025.· Nephrops FU 12 (nep.fu.12): Fishing pressure has been decreasing since 2007, to well below Fmsy in 2024. Stock size has fluctuated above MSY Btrigger for the whole time series (except in 2012) and showed a substantial increase from 2024 to 2025.· Nephrops FU 13 (nep.fu.13): The combined fishing pressure for Clyde and Jura has been fluctuating around Fmsy since 2009 and has been below the reference point the last 3 years. In both areas, stock size has fluctuated above MSY Btrigger for the whole time series and showed a substantial increase from 2024 to 2025.· Nephrops FU 14 (nep.fu.14): Fishing pressure has been fluctuating well below Fmsy for the whole time series. Stock size has decreased since 2020 and fell below MSY Btrigger in 2023.· Nephrops FU 15 (nep.fu.15): Fishing pressure has been below Fmsy since 2016. Stock size has been well above MSY Btrigger for the whole time series except the last 3 years and showed a substantial decrease from 2024 to 2025.· Nephrops FU 16 (nep.fu.16): Fishing pressure has increased since 2020, to above Fmsy in 2024. Stock size has been slowly increasing since 2012 but has decreased the last 2 years. No reference point for stock size has been defined for this stock.· Nephrops FU 17 (nep.fu.17): Fishing pressure has decreased since 2022, to below Fmsy in 2024. Stock size has been decreasing since 2004 to the lowest level in the time series in 2025 (below MSY Btrigger).· Nephrops FU 19 (nep.fu.19): Fishing pressure has fluctuated without trend below Fmsy since 2014. Stock size decreased from 2011 to 2023, then increased slightly in 2024 and 2024 but is still below MSY Btrigger.· Nephrops FU 20-21 (nep.fu.2021): Fishing pressure has increased since 2020, to above Fmsy in 2024. Stock size has been above MSY Btrigger for the whole time series and has been increasing since 2019.· Nephrops FU 22 (nep.fu.22): Fishing pressure has increased the last 2 years, to just above Fmsy in 2024. Stock size has shown a decreasing trend since 2017, but increased in 2025, although it is still below MSY Btrigger.· Nephrops FU 23-24 (nep.fu.2324): Fishing pressure has been below or at Fmsy for the whole time series but increased to above the reference point in 2024. Stock size has shown a decreasing trend since 2016 but increased from 2024 to 2025. No reference point for stock size has been defined for this stock.Category 2:· Nephrops FU 25 (nep.fu.25): Relative fishing pressure F/Fmsy has been basically zero since 2017 (no landings). Relative biomass B/Bmsy has been below Blim since 1995 but has increased slightly in recent years.· Nephrops FU 26-27 (nep.fu.2627): Relative fishing pressure F/Fmsy has been below Fmsy since 2013. Relative biomass B/Bmsy has been below Blim since 1994.· Nephrops FU 32 (nep.fu.32): Relative fishing pressure F/Fmsy has been above Fmsy since 1999. Relative biomass B/Bmsy has been below Blim since 2009 but showed a slight increase in 2025. Category 3:· Nephrops FU 28-29 (nep.fu.2829): Relative fishing pressure has been above Fmsy proxy for most of the time series, also in 2024. Relative biomass (commercial CPUE) has been above Itrigger since 2001 but has shown a decreasing trend from 2018 to 2024.· Nephrops FU 30 (nep.fu.30): Fishing pressure has been fluctuating around Fmsy proxy for the whole time series and is currently above the reference point. Stock size (UWTV survey index) has been around Itrigger since 2021 and is in 2025 just below the reference point.· Nephrops FU 31 (nep.fu.31): Relative fishing pressure has shown an increasing trend since 2013, but decreased slightly in 2024, although it is still above Fmsy proxy. Relative biomass (bottom trawl survey index) increased substantially in 2023 and 2024 and is well above Itrigger.