Red mullet

The striped red mullet population (or stock) in this region is buoyant in size but fishing pressure is just above sustainable levels.The stock size indicator shows the population to largely fluctuate throughout the time series but has remained above the maximum sustainable yield trigger point (MSY Itrigger 117.38 kg/km2 - below this level, F should be reduced to allow the stock to increase) since 2017. In 2022, the stock size increased to 306.13 kg/km2, from 238.12 kg/km2 the previous year (2021).Fishing pressure (F) on the stock has remained just above Maximum Sustainable Yield (FMSY proxy 1) since 2019 and been at or around FMSY proxy from the early 2000’s. In 2022, F was 1.072, a slight increase from the year previous (1.048 in 2021) but almost equal to F in 2019 and 2020.ICES advises that when the MSY approach is applied, catches should be no more than 1,985 tonnes in each of the years 2024 and 2025. All catches are assumed to be landed.Stock structure remains an issue and a source of uncertainty.

There are some management measures in place, but the striped red mullet population is fished without limit and significantly above advised levels, whilst being caught before having had the chance to reproduce.The EU multiannual plan (MAP) for stocks in the North Sea and adjacent waters applies to bycatches of this stock. It aims to ensure that stocks are exploited sustainably and that the decisions on fishing opportunities are based on the most up-to-date scientific information. UK and Norway have not requested ICES to provide advice based on the EU MAP.Striped red mullet is not subject to Total Allowable Catch (TAC) and quotas. Total catches have been markedly above advised annual catch levels every year catch advice has been provided, since 2012 (except in 2013). Between 2014 and 2019, the average total catch was 573% (ranging 373-975%) of advice. In 2022, total catch again exceeded advice, at 147% of the advised limit.There is no minimum landing size for striped red mullet and there is a market for small fish. Recent catches of this stock mainly consist of fish ages 0 and 1. Striped red mullet start maturing at age 1 but are not fully matured before age 3. The stock status would therefore benefit from improved technical measures, such as sorting grids, increased mesh size, and spatial and temporal closures. These measures could reduce the catches of small fish and contribute to more stable yields.However, a Minimum Conservation Reference Size (MCRS) does apply to striped red mullet fished within some Inshore Fisheries Conservation Authorities (i.e., Southern, Cornwall, and North Western IFCAs: 15 cm), providing some protection to immature fish within English inshore waters. Striped red mullet reaches sexual maturity at an average of 16.1 cm (ranging 15-26 cm).Discards are assumed negligible.In the EU, compliance with regulations has been variable, and there are ongoing challenges with implementing some of them.In the UK, the Fisheries Act only came into force in January 2021. The Act requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans). FMPs have the potential to be very important tools for managing UK fisheries. They will set out the policies to secure the long-term sustainability of our fish stocks for current and future generations and can include (data allowing):Targets for fishing pressure and biomass, with effective management to meet them;Timeframes for stock recovery;Use of technologies such as Remote Electronic Monitoring (REM) to support data collection, improve transparency and accountability;Consideration of wider environmental impacts of the fishery.

Gillnets in this area can encounter bycatch of non-target fish, mammals and birds. This includes the harbour porpoise which is vulnerable in Europe.The striped red mullet is a benthic fish found mostly on sandy bottoms. Young fish are distributed in coastal areas, while adults have a more offshore distribution. In 2022, 71% of the total catch was taken by Danish seine (also known as fly shooters), 19.7% by otter trawlers, and a further 9.3% by other fishing gears (likely fixed nets).Fixed gillnets consist of a single vertical netting wall hanging between a float line and a weighted ground line which have little to no impact on the habitat, and very low levels of disturbance to the seabed. They are, however, recognised as the highest risk type of fishery for cetaceans globally, especially for small cetaceans in coastal areas. In the UK, the species most affected is the harbour porpoise, but a number of other species have been reported, and it should be assumed that most cetaceans are vulnerable to gill net bycatch. Gillnets pose serious risk to harbour porpoise wherever they are used around the UK and other cetaceans where their distribution overlaps with gill net use.Harbour porpoises:Listed as Vulnerable in Europe by IUCN.Are on OSPAR’s List of Threatened and/or Declining Species and Habitats for the Greater North Sea and Celtic Seas (owing to evidence of a decline in populations, their sensitivity and the threat of incidental capture and drowning in fishing nets).A priority species in UK and EU law (under which there are explicit bycatch requirements).Consequently, the UK designated seven Special Areas for Conservation for harbour porpoises, but these areas are not yet managed.The UK Dolphin and Porpoise Conservation Strategy lists harbour porpoise as having medium vulnerability to gillnetting for the UK as a whole. This is based on the species having a high sensitivity to gillnetting and medium exposure. The area of most concern is in the Celtic Seas, southwest of the UK, where most of the seabass gillnetting activity takes place. Exposure to gillnetting is high. A review of activities in the Bristol Channel Approaches Harbour Porpoise SAC lists commercial fisheries with bycatch (predominantly static nets) as a high risk, and a strandings report by Cornwall Wildlife Trust also shows that common dolphin bycatch is very high in this area. There is also bycatch of elasmobranch species which may be threatened or endangered. Porbeagle sharks are being caught as bycatch in gillnets but as they are a prohibited species, there is no official data on the numbers being caught and discarded. Spurdog bycatch is also thought to be of concern. The National Evaluation of Populations of Threatened and Uncertain Elasmobranchs (NEPTUNE) highlighted continued problems of spurdog bycatch and despite a supposed real time avoidance programme being implemented, 50 tonnes were still landed in Cornish ports in 2019.Acoustic deterrent devices (ADDs), such as ‘pingers’, have been shown to be effective at reducing harbour porpoise bycatch in gillnets, but the reduction achieved so far has been small (<15% of the total number of cetaceans killed in UK fisheries), they may cause unwanted disturbance or displacement, and they may not be effective for other species.Larger mesh sizes used (100mm, south Wales) and the banning of fishing in inshore bass nursery areas in England and Wales, will reduce bycatch of small species and undersized seabass.Increasing evidence over the last decade has shown that seabirds are suffering mortality from bycatch, particularly in gillnets. Bycatch of seabirds in gillnet fisheries is estimated to kill ~400,000 birds globally, each year. Diving seabirds are generally more vulnerable than surface feeding seabirds. Most of the UK’s gillnetting takes place in southwest UK and therefore there is concern for seabird populations here (i.e., razorbill (Near Threatened, Europe: IUCN), puffin (Endangered, Europe: IUCN) and the herring gull, arctic skua and roseate tern (Red - Birds of Conservation Concern 4: the Red List for Birds (UK)).If lost, gillnets can continue to fish for several weeks before becoming tangled and bundled up, a phenomenon known as ghost fishing. Fishing gears represent an investment by fishermen, thus there are incentives to avoid losing or damaging gear.UK regulations to reduce the impacts of fishing on marine habitats and wider species are under development, in the meantime most EU regulation have been adopted. Under EU legislation, bycatch species should be managed within scientifically defined or, where data isn’t available, suitability precautionary sustainable exploration limits. If stocks fall below a certain threshold, measures can be brought in such as gear limitations (e.g., mesh size or depth of use), time and/or areas closures, and Minimum Conservation Reference Sizes (MCRS).

Angling Trust, 2023. Minimum Conservation Reference Sizes. Available at https://anglingtrust.net/minimum-conservation-reference-sizes-mcrss/ [Accessed 24.07.2023]Bradbury, G., Shackshaft, M., Scott-Hayward, L., Rexstad, E., Miller, D., and Edwards, D., 2017. Risk assessment of seabird bycatch in UK waters. Produced by Wildfowl & Wetlands Trust (Consulting) Ltd for Defra project MB0126. Available at: http://sciencesearch.defra.gov.uk/Document.aspx?Document=14620_MB0126RiskassessmentofseabirdbycatchinUKwaters_updated21Oct2019.pdf [Accessed on 04.10.2021].Calderan, S. and Leaper, R., 2019. Review of harbour porpoise bycatch in UK waters and recommendations for management. January 2019, WWF. Available at https://www.wwf.org.uk/sites/default/files/2019-04/Review_of_harbour_porpoise_in_UK_waters_2019.pdf [Accessed on 06.07.2021].Chadwick, H., Clear, N., Crosby, A., Hawtrey-Collier, A. and Williams, R. Marine Strandings in Cornwall and the Isles of Scilly: 2019 Annual Report. Report by Cornwall Wildlife Trust and Marine Strandings Network. Available at https://www.cornwallwildlifetrust.org.uk/sites/default/files/2020-12/2019%20Summary%20Report%20-%20Marine%20Strandings%20in%20Cornwall%20and%20the%20Isles%20of%20Scilly.pdf [Accessed on 06.07.2021].Cornwall IFCA, 2023. Cornwall IFCA byelaws, other regulations and codes of practise: Specified fish sizes (as amended). Available at https://www.cornwall-ifca.gov.uk/Byelaws_Regulations [Accessed 24.07.23]Ellis, J. R., Bendall, V. A., Hetherington, S. J., Silva, J. F. and McCully Phillips, S. R. 2016. National Evaluation of Populations of Threatened and Uncertain Elasmobranchs (NEPTUNE). Project Report (Cefas) V1.4. Available at: http://randd.defra.gov.uk/Document.aspx?Document=13513_MB5201NEPTUNEFinalReportv1.4.pdf [Accessed on 04.10.2021]Froese R. and Pauly D. (Editors), 2023. Mullus surmuletus, Red mullet. Available at: https://www.fishbase.se/Summary/SpeciesSummary.php?ID=1327&AT=red+mullet [Accessed 24.07.2023]Glemarec, G., Kindt-Larse, L., Scherffenberg Lundgaard, L. and Larsen, F. 2020. Assessing seabird bycatch in gillnet fisheries using electronic monitoring. Biological Conservation. 243. 108461. Available at https://doi.org/10.1016/j.biocon.2020.108461 [Accessed on 30.09.2021]ICES, 2018. ICES Advice: Bycatch of small cetaceans and other marine animals - review of national reports under Council Regulation (EC) No. 812/2004 and other information. Published 11 September 2018. Available at https://www.ices.dk/sites/pub/Publication%20Reports/Advice/2018/2018/byc.eu.pdf [Accessed on 06.07.2021]ICES. 2022c. Greater North Sea ecoregion – fisheries overview. ICES Advice: Fisheries Overviews. Report. https://doi.org/10.17895/ices.advice.21641360.v1 [Accessed 03.07.2023]ICES. 2022d. Greater North Sea ecoregion – Ecosystem Overview. ICES Advice: Ecosystem Overviews. Report. https://doi.org/10.17895/ices.advice.21731912.v1 [Accessed 03.07.2023]ICES. 2023a. Striped red mullet (Mullus surmuletus) in Subarea 4 and divisions 7.d and 3.a (North Sea, eastern English Channel, Skagerrak and Kattegat). In Report of the ICES Advisory Committee, 2023. ICES Advice 2023, mur.27.3a47d. https://doi.org/10.17895/ices.advice.21840957 [Accessed 20.07.2023]ICES. 2023b. Stock Annex: Striped red mullet (Mullus surmuletus) in Subarea 4 and divisions 7.d and 3.a (North Sea, eastern English Channel, Skagerrak and Kattegat). ICES Stock Annexes. 29 pp. https://doi.org/10.17895/ices.pub.23578803 [Accessed 20.07.2023]ICES. 2023c. Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK). ICES Scientific Reports. 5:39. 1072 pp. https://doi.org/10.17895/ices.pub.22643143 [Accessed 20.07.2023]JNCC. 2022. Harbour porpoise (Phocoena phocoena) Special Area of Conservation: Bristol Channel Approaches / Dynesfeydd Môr Hafren. Conservation Objectives and Advice on Operations. Available at https://sac.jncc.gov.uk/species/S1351/ [Accessed on 22.7.2022].Leaper, R. 2021. An evaluation of cetacean bycatch in UK fisheries: problems and solutions. Available at https://uk.whales.org/wp-content/uploads/sites/6/2021/02/cetacean-bycatch-uk-fisheries-problems-solutions.pdf [Accessed 17.07.2023]Leeney, R. H., Amies, R., Broderick, A.C., Witt, M. J., Loveridge, J., Doyle, J. and Godley, B. J. 2008. Spatio-temporal analysis of cetacean strandings and bycatch in a UK fisheries hotspot. Biodiversity and Conservation. 17, 2323. Available at https://link.springer.com/article/10.1007/s10531-008-9377-5#citeas [Accessed on 06.07.2021].Leeney, R. H., Witt, M. J., Broderick, A. C., Buchanan, J., Jarvis, D. S., Richardson, P. B. and Godley, B. J. 2011. Marine megavertebrates of Cornwall and the Isles of Scilly: relative abundance and distribution. Journal of the Marine Biological Association of the United Kingdom, 92(8), 1823-1833. Available at https://www.cambridge.org/core/journals/journal-of-the-marine-biological-association-of-the-united-kingdom/article/marine-megavertebrates-of-cornwall-and-the-isles-of-scilly-relative-abundance-and-distribution/7981AA197C2320B6A9E2C01BD7A1F7B7 [Accessed on 06.07.2021].MCS. 2023. MPA Reality Check. Available at https://mpa-reality-check.org/ [Accessed 03.07.2023]Moan, A., Skern-Mauritzen, M., Vølstad, J. H., Bjørge, A. 2020. Assessing the impact of fisheries-related mortality of harbour porpoise (Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries, ICES Journal of Marine Science, Volume 77, Issue 7-8, Pages 3039–3049. Available at https://doi.org/10.1093/icesjms/fsaa186 [Accessed on 06.07.2021]Monterey Bay Aquarium Seafood Watch. 2023. Red mullet. Available at https://www.seafoodwatch.org/globalassets/sfw-data-blocks/reports/M/seafood-watch-red-mullet-uk-27937.pdf [Accessed 24.07.2023]North Western IFCA, 2023. Minimum sizes. Available at https://www.nw-ifca.gov.uk/minimum-sizes/ [Accessed 24.07.23]Omeyer, L.C.M., Doherty, P.D., Dolman, S., Enever, R., Reese, A., Tregenza, N., Williams, R. and Godley, B.J. 2020. Assessing the Effects of Banana Pingers as a Bycatch Mitigation Device for Harbour Porpoises (Phocoena phocoena). Frontiers in Marine Science. Front. Mar. Sci. https://doi.org/10.3389/fmars.2020.00285.OSPAR, 2017. Intermediate Assessment 2017: Harbour Porpoise Bycatch. Available at https://oap.ospar.org/en/ospar-assessments/intermediate-assessment-2017/biodiversity-status/marine-mammals/harbour-porpoise-bycatch/ [Accessed 18.07.2023]Peltier, H., Authier, M., Deaville, R., Dabin, W., Jepson, P. D., van Canneyt, O., Daniel, P. and Ridoux, V. (2016). Small cetacean bycatch as estimated from stranding schemes: The common dolphin case in the northeast Atlantic. Environmental Science and Policy, 63: 7-18. doi: 10.1016/j.envsci.2016.05.004. Available at https://www.sciencedirect.com/science/article/abs/pii/S1462901116301514 [Accessed 23.07.2020]Scottish Government, 2021. UK Dolphin and Porpoise Conservation Strategy: Technical Report. Published 22 March 2021. ISBN: 9781800048522. Available at https://www.gov.scot/publications/uk-dolphin-porpoise-conservation-strategy-technical-report/documents/ [Accessed on 26.07.2021]. Seafish, 2022. Gill Nets. Available at: https://www.seafish.org/responsible-sourcing/fishing-gear-database/gear/gill-nets/ [Accessed on 12.8.22]Seafish, 2023. Gill nets. Available at https://www.seafish.org/responsible-sourcing/fishing-gear-database/gear/gill-nets/ [Accessed 27.07.2023]Southern IFCA, 2023. Minimum sizes. Available at https://www.southern-ifca.gov.uk/da/164147 [Accessed 24.07.23]Species account by IUCN SSC Cetacean Specialist Group; regional assessment by European Mammal Assessment team. 2007. Phocoena phocoena. The IUCN Red List of Threatened Species 2007: e.T17027A6734714. Available at https://www.iucnredlist.org/species/17027/6734714 [Accessed on 04.10.2021]