Fish to Eat

Choose wisely… think local.

Seafood is a tasty treat. When buying seafood, consider when and where it was caught, how it was caught and what size it is (most species have a minimum landing size).

To help you make your seafood choice we have used a simple traffic light system to evaluate the top ten fish/shellfish species, in terms of value that were landed into ports in south Wales in recent years.

  • Green = recommend
  • Orange = eat with caution
  • Red = Avoid

Our Living Seas: Future Fisheries, Assessment of Welsh Fisheries report can be downloaded here

Mussels

Definitions:

Local means fish or shellfish caught in Welsh waters by welsh fishers/boats.

Low impact means fishing methods that have little or no environmental impact beyond the removal of the target species.


Fish advisor – types of fish to eat or avoid

Common whelk (Buccinum undatum)
European lobster (Homarus gammarus)
King scallop (Pecten maximus)
European Bass (Dicentrarchus labrax)
Brown (Edible) crab (Cancer pagurus)
Common prawn (Palaemon serratus)
Spider crabs (Maja sp.)
Common sole (Solea solea)
Crawfish (Palinurus elephas)
Thornback ray (Raja clavata)

Common whelk (Buccinum undatum)

Orange = Caution

WTSWW advise caution when buying whelk due to concern over species biology and methods of capture as well as high levels of concern over management of the stocks in Welsh waters.

Whelks are predators and scavengers found in water depths between 3-600m. Spawning occurs between November and January. The current minimum landing size (MLS) for common whelk is 45mm. Studies have shown that the current MLS does not protect brood stocks of whelks in Welsh waters and the persistent removal of immature whelks means that fewer animals are reaching maturity prior to being caught. The size of maturity for common whelks in Welsh waters varies greatly and technical measures do not take account of regional variations in size.

More than 99% of whelks are caught in pots; potting is a selective and low impact method of fishing although there are concerns over the use of crab species such as edible crab as bait in pots targeting whelks.

Concerns are that whelk fishing is comparatively cheap to enter into and with decreased landings and increased restrictions in other fishing sectors an increase in whelk effort is expected and therefore with no effort controls in place and unmanaged latent effort the future sustainability of whelk fishing is considered to be at risk.

Existing conservation/management measures

  • Current minimum landing sizes (MLS) is 45mm

Further information

  • Haig, J. A., Pantin, J., Salomonsen, H., Murray, L., Kaiser, M., 2015. The size at maturity for the common whelk, Buccinum undatum in Welsh waters, with an industry perspective on minimum landing sizes. Tech. Rep. 50, Fisheries & Conservation Report, Bangor University.
  • McIntyre, R., Lawler, A., Masefield, R., 2015. Size of maturity of the common whelk, Buccinum undatum: Is the minimum landing size in England too low? Fisheries Research 162, 53–57.
  • Robson, G., 2014. The distribution and movement of the adult whelk (Buccinum undatum) (L.1758) in South Wales, UK. Master’s thesis, Marine Biology, School of Ocean Sciences, Bangor University.

European lobster (Homarus gammarus)

Orange = Caution

WTSWW advise caution when buying European lobster due to concerns over management of the stock in Welsh waters. Regional variation in size at first maturity has been observed and there is little data for the Welsh inshore population of lobsters. due to minimal data available on Welsh stocks.

In Wales almost all (>99%) of species landings into south Wales are caught in pots known as parlour pots. Potting is a selective and low impact method of fishing.

European lobster can be found distributed within the continental shelf from the Arctic circle to the Mediterranean, more commonly found in shallower waters up to 50m depths although may be found in depths up to 150m. European lobsters favour rocky reef and rough ground, with rocks and boulders providing crevices for shelter. Lobsters are nocturnal, they are opportunistic feeders and will scavenge for food although they mainly feed on mussels and other crustaceans. Female lobsters will continue to feed when berried and are commonly caught in baited pots. Newly hatched larvae take between 4-8 years, depending on water temperature and conditions, to attain EU minimum landing size.

No stock management in terms of limits on the numbers taken just a Minimum landing size (MLS) in place which is currently different for north (87mm) and south Wales (90mm).

Existing conservation/management measures

  • A voluntary v-notch scheme is in place, allowing fishermen to tag berried females by removing a small v-shape from a tail paddle. It is illegal to land v-notched or mutilated individuals
  • Minimum landing size (MLS) different throughout Wales, 87mm (north Wales) and 90mm (south Wales).

Further information

  • Cook, W., Fish, J., Sankey, S., 1989. Lobster stock enhancement studies in Cardigan Bay. An interim report 1984-1988. North Western and North Wales Sea Fisheries Committee.
  • Smith, I., Jensen, A., Collins, K., Mattey, E., 2001. Movement of wild European lobsters Homarus gammarus in natural habitat. Marine Ecology Progress Series 222, 177–186.
  • Gunning, D., 2012. The importance of size-fecundity relationships in the management of the European lobster, Homarus gammarus. Master’s thesis, Sustainable Aqua- culture and Inshore Fisheries, Queens University Belfast.
  • Pantin, J.R., Murray, L.G., Cambiè, G., Le Vay, L. & Kaiser, M.J. 2015. Escape Gap Study in Cardigan Bay: consequences of using lobster escape gaps. A Preliminary Report. Fisheries & Conservation report No. 44, Bangor University. 43 pp.
  • Tully, O., Bell, M., OLeary, A., McCarthy, A., ODonovan, V., Nee, D., 2006. The lobster (Homarus gammarus L.) fishery: Analysis of the resource in 2004/2005. Tech. Rep. 6, Fisheries Resource Series, Bord Iascaigh Mhara (Irish Sea Fisheries Board), Dun Laoghaire, Ireland.
  • Tully, O., 2004. The Biology and Management of Clawed Lobster (Homarus gammarus L.) in Europe. Tech. Rep. 6, Fisheries Resource Series, Bord Iascaigh Mhara (Irish Sea Fisheries Board), Dun Laoghaire, Ireland.
  • Woolmer, A., Woo, J., Bayes, J., 2013. Review of evidence for best practice in crustacean fisheries management in Wales. Tech. rep., Report to Welsh Government Fisheries and Marine Unit.
  • Murray, L.G., Hinz, H & Kaiser, M.J. 2015.Lobster Escape Gap Trials. Fisheries & Conservation report No. 09, Bangor University. 11 pp.

King scallop (Pecten maximus)

Orange = Caution

WTSWW advise caution when buying scallops due to concerns over management of the stock in Welsh waters and high levels of concern over methods of capture.

Small quantities (0.5%) are caught in pots as bycatch. Most >99% of species landings into south Wales are dredge caught. Scallop dredges are considered to be the most damaging to non-target benthic communities and seafloor habitats (Collie et al. 2000; Kaiser et al. 2006).

In UK waters king scallops become sexually mature at approximately 2-3 years old and 80-90mm in shell length (Stewart, B. D & Stewart, J. S. 2009; Howarth, L. M. & Stewart, B. D. 2014), >60mm (Bangor University website, 2015). King scallops can live for up to 20 years and they reach sexual maturity between 3 and 5 years. King scallops have both male and female reproductive organs (hermaphrodites) and fertilization takes place externally. Their larvae develop in the water column and are dispersed in the currents often over considerable distances (Howarth, L. M. & Stewart, B. D. 2014).

After approximately 30 days they settle to the sea floor and attach to a suitable surface using their byssal threads (strong, silky fibres). Young scallops usually remain attached by byssal threads until they are between 4 and 13 mm in length and then settle on the seabed. After 30 days they settle to the sea floor and attach to a suitable surface using their byssal threads (strong, silky fibres) where they develop into free-swimming adult form. The reproductive success and recruitment of scallops is influenced by a number of factors including spawning stock biomass, the availability of suitable settlement habitat, environmental conditions and ecological interactions such as predator density. As adults king scallops are relatively static, not moving much further than 30m in 18 months

Existing conservation/management measures

  • There is an annual seasonal closure when scalloping is prohibited in Welsh waters from 1st May to 31st October. Scalloping is prevented in all but one area of Cardigan Bay Special Area of Conservation (SAC).
  • Bangor University are working with local scallop fishermen to test the use of steel skids attached to the underside of the bag it is lifted clear of the ground, reducing damaging effects.
  • The maximum permissible engine power for scallopers in Welsh waters is 221 kw. The number of dredges a vessel can tow is restricted depending on the distance from shore. Limits on the number of dredges towed is also restricted by the size of the fishing vessel.
  • In welsh waters there is also a total ban on fishing with dredges between the shore and 1 nm
  • In Welsh waters there are restrictions on the number of dredges a vessel can tow per side. Between 1 and 3 nm the number of dredges is restricted to 3 per side, provided the vessel is less than 10 metres; 4 a side between 3 and 6 nm; and outside 6 nm a maximum of 7 dredges per side.

Further information

  • Howarth, L., Stewart, B., 2014. The dredge fishery for scallops in the United Kingdom (UK): effects on marine ecosystems and proposals for future management. Report to the Sustainable Inshore Fisheries Trust. Marine Ecosystem Management. Tech. Rep. 5, University of York.
  • Beukers-Stewart, B., Beukers-Stewart, J., 2009. Principles for the management of in-shore scallop fisheries around the UK. Tech. Rep. 5, University of York.
  • Albrecht, J., 2013. Taxonomic and functional recovery of epifauna after the permanent closure of an area of the Cardigan Bay Special Area of Conservation (SAC), Wales, to a scallop dredge fishery. MSc thesis. Marine Environmental Protection, School of Ocean Sciences, Bangor University.
  • J. S. Collie, J. M. Hall-Spencer, M. J. Kaiser, and I. R. Poiner. (2000) A quantitative analysis of fishing impacts on shelf-sea benthos. Journal of Animal Ecology 69:785-798
  • M.J. Kaiser, M. J., K. Clarke, H. Hinz, M. Austen, P. Somerfield, and I. Karakassis. (2006) Global analysis of response and recovery of benthic biota to fishing. Marine Ecology Progress Series 311:1-14.

European Bass (Dicentrarchus labrax)

Orange = Caution

WTSWW advise caution when buying bass due to concerns over management of species biology and high levels of concern of stock management.

Bass is currently a non quota stock. ICES Advice June 2014 5.3.32. Eco-region Celtic Sea and West of Scotland. Divisions IVbc, VIIa, and VIId-h. Advice for catches in 2015 – Total landings from commercial and recreational sectors should be no more than 1155 tonnes. The European Commission recognise that there is an urgent need to protect sea bass stocks due to a rapid decline in their numbers. Additional proposals, including minimum landing size to protect stocks is still being considered by the European Commission.

The minimum length at which sea bass mature is 35cm TL in males and has recently been suggested to be around 40cm TL in females. This means that the current MLS for sea bass in the UK and more specifically Wales, (36 cm in the North and 37.5cm in the South) allows the removal of immature bass from the stock, reducing potential spawning stock biomass.

The spawning season of bass around Welsh waters has been estimated to be between January and May. There are features specific to the bass stock around Wales which include a sex ratio highly skewed towards females across all seasons in north Wales.

Sea bass are slow growing and do not reach maturity between 4 and 7 years of age for females and size at maturity is around 40cm, whilst in males maturation occurs between 3 and 6 years at around 35cm. Bass may continue to reproduce for up to 20 years. Bass may continue to reproduce for up to 20 years.

The juvenile stage occurs approximately 2 months after spawning, larval bass remain in the plankton and are moved around by inshore currents into estuaries and shallow coastal waters (10-15mm), bass spend much of the juvenile stage in these brackish waters. Bass are long lived and slow growing, female bass mature at a greater size and age than males and fully mature bass undertake seasonal migrations from summer coastal grounds to winter offshore spawning grounds, concentrating their populations in specific areas at particular times of year, making them easier to catch.

Previous conservation/management measures (2015)

  • Minimum landing size (MLS), 36 cm in the north and 37.5cm in the south
  • The European commission introduced technical conservation measures to help preserve bass stocks. These include a ban on pelagic trawling for sea bass during its spawning season – effective until 30 April 2015; a limit on recreational sea anglers of three fish per day per angler and a proposed maximum catch per month by gear type aimed at limiting the targeting of vulnerable stock.

New conservation/management measures for 2016

For commercial fisheries:

  • a continued closure throughout 2016 to all commercial bass fishing in ICES Areas VIIb, VIIc, VIIj, VIIk and outside the UK 12nm in areas VIIa and VIIg
    • Demersal trawls and seines which are permitted a 1% bass by-catch; and
    • Hooks and lines and fixed gill nets which are permitted 1,300kg per vessel in January, April, May and June (NB: this does not include drift net fisheries). The fishery is closed in February and March.
    • from 1st July to 31st December 2016 monthly catch limits apply to all vessels in ICES Areas IVb, IVc, VIIa, VIId, VIIe, VIIf, VIIg, VIIh:
      – 1,300kg per vessel per month for hooks and lines and fixed gill nets (NB: this does not include drift net fisheries)
      – 1,000kg per vessel per month for all other gearsFrom 1st January to 30th June 2016 a prohibition on commercial vessels fishing for bass in ICES Areas IVb, IVc, VIIa, VIId, VIIe, VIIf, VIIg, VIIh except for:

For recreational fisheries (including fishing from the shore):

In ICES Areas IVb, IVc, VIIa, VIId, VIIe, VIIf, VIIg, VIIh

  • from 1st January to 30th June 2016 catch and release only permitted
  • from 1st July to 31st December 2016 one bass per fisherman per day

In ICES areas VIIj and VIIk

  • from 1st January to 31st December 2016 one bass per fisherman per day

From the 1 September 2016 the European Commission introduced a regulation applying a minimum conservation reference size of 42cm for bass, thus fishermen and angles are prevented from catching juvenile bass under 42cm in size in order to give female bass the chance to grow to an age where they can spawn.  (Commission Implementing Regulation (EU) 2015/1316 applies a minimum conservation reference size of 42cm for bass as a derogation from annex XII of the “technical conservation” regulation (Council Regulation (EC) 850/98).

Further information

  • Carroll, A., 2014. Population dynamics of the European Sea Bass (Dicentrarchus labrax) in Welsh waters. Master’s thesis, MSc thesis, Marine Environmental Protection, School of Ocean Sciences, Bangor University.
  • Hirst, D., 2015. UK and European sea bass conservation measures. Tech. rep., House of Commons Briefing Paper Number 00745, 26 May 2015.
  • Cambie. G, Kaiser. M.J. Hiddink. J.G, Salomonsen. H, Pantin. J.R, McCarthy. I. 2015. Population dynamics of the European sea bass (Dicentrarchus labrax) in Welsh waters and management implications. Fisheries & Conservation report No. 56, Bangor University. 73 pp.

Brown (Edible) crab (Cancer pagurus)

Orange = Caution

WTSWW advise caution when buying brown (edible) crab caught in pots in Wales due to concerns over the current management of the stock in Welsh waters. The current minimum landing size for brown crab is different between north (130mm) and south Wales (140mm).

In Wales brown (edible) crab is mainly (>99%) caught in pots known as parlour pots. Potting is a selective and low impact method of fishing.

We recommend that you buy crab outside of the spawning season (December – February).

Edible crabs are commonly found on rocky, inshore ground. Mating occurs from December to February and egg laying occurs from January to June but can be delayed for 15 months. Berried (egg bearing) females are unlikely to feed during this phase. Juveniles are found in high abundance in the intertidal zone and as adults up to a depth of 100m.

Studies have shown that crab stocks in Wales are maturing smaller than the minimum landings size and therefore although the current minimum landing sizes do allow stocks in Wales to mature and that both males and females have an opportunity to reproduce at least once prior to capture. However, there is a chance that fishing mortality may be driving down the size at maturity as all the lager crabs have been fished out. Further research into this is required and therefore we advise caution when considering brown crab.

Existing conservation/management measures

  • Current minimum landing sizes (MLS) of 130mm in North Wales and 140mm in South Wales
  • There is a restriction on the number of shellfish licenses available, ban on landing of berried hens (egg bearing females) and soft shelled individuals.

Further information

  • http://www.seafish.org/rass/index.php/profiles/edible-crab-in-the-celtic-sea-pots/
  • Haig, J. A., Pantin, J., Salomonsen, H., Kaiser, M., 2015. Size at maturity of Cancer pagurus in Welsh waters. Tech. Rep. 53, Fisheries & Conservation Report, Bangor University.
  • Haig, J. A., Rayner, G., Akritopoulou, E., Kaiser, M., 2015c. Fecundity of Cancer pagurus in Welsh waters, a comparison with published literature. Tech. Rep. 49, Fisheries & Conservation Report, Bangor University.

Common prawn (Palaemon serratus)

Orange = Caution

WTSWW advise caution when buying common prawns caught in Wales due to concerns over the management of the stocks including lack of information on the species and species biology.

Prawn fishery in Wales is the largest of its kind in the UK, the species is fished throughout Britain for live export to Europe where it commands a premium price. It is caught in pots which is a selective and low impact method of fishing.

In Wales it is a seasonal fishery (October to May). At present the fishery is unregulated with little management in place to protect stocks from over-exploitation. A closed season is imposed from May to August in Ireland. Stock status of P. serratus is unknown and fishery is considered “data poor”. Stock fluctuations have been observed through landings data. Fishers in Cardigan Bay have adopted voluntary measures to ensure small prawns are returned to the sea. Measures include riddling catch and increasing pot mesh size.

Common prawns are decapod crustaceans that are widely distributed within inshore waters of Europe, the temperate waters around the UK form the northern limit of the geographical range of the species. This species has a relatively short lifespan, thought to survive no longer then two and five years.

Prawns are sexually dimorphic in catches, on average males are smaller than females. Females mature at a size of around 60 mm total length, therefore many of the berried females caught would be of a land-able size. Bangor University study found that that berried females can be found throughout the year and so the seasonal nature of the fishery may be allowing females to carry broods to term in months outside the winter fishery. Males mature faster than females and reach sexual maturity at six to seven months old whilst females at nine to ten months. Egg development is slower in colder inshore waters during winter. Majority of common prawns caught in UK waters are exported to markets in southern Europe, little retained for local markets due to smaller size.

No enforceable minimum landing size in place, size landed is dictated by the market demand (larger individuals); currently there is a market pressure for a certain sized prawn and this length corresponds to a 10 mm carapace width (the riddle size usually). This market demand is driving the fishery to select for mostly females. As females mature at a size of around 60 mm total length, therefore many of the berried females caught would be of a land-able size. The market driven selection for larger prawns protects the immature stocks, though would preferentially take females over males. Prawns are the highest seafood import into UK in 2012. Larger species (Penaeus monodon) are imported. Palaemon serratus is smaller species, and not available year around – exported live and commands a premium price in Europe.

Existing conservation/management measures

  • A closed season is imposed from May to August in Ireland.
  • Voluntary measures in place in Cardigan Bay include: 1) Increasing the mesh size on the prawn pots from 8 to between 10-14 mm, either on the pot-end or main-body as preferred by the fisher.
  • 2) Grading the catch by hand on a “Minimum Landing Size” dictated by market preference.
  • 3) Grading the catch using a 10 mm riddle to a MLS dictated by market preference.

Further information

  • Emmerson, J., Haig, J., Robson, G., Kaiser, M., 2014. Palaemon serratus Fishery Report: 2013 / 14. Tech. Rep. 39, Fisheries & Conservation Report, Bangor University.
  • Haig, J. A., Ryan, N., Williams, K., Kaiser, M., 2014. A review of the Palaemon serratus fishery: biology, ecology management. Tech. Rep. 38, Fisheries & Conservation Report, Bangor University.
  • Haig. J., 2014. Prawn: December (2014). Tech. rep., Fisheries & Conservation Science Update, Bangor University.

Spider crabs (Maja sp.)

Orange = Caution

WTSWW advise caution when buying Spider crabs caught in Wales due to concerns over the management of the stocks and species biology.

Almost all (99.4% ) of species landed into south Wales are caught using pots, a selective low impact method of fishing. However, more recently reports suggest that the majority of spider crab fishing areas identified are fished using tangle nets or gill nets, less selective forms of fishing. Welsh specific studies required to determine suitability of MLS in the local fishery (as well as species determination) and need for further conservation measures. Morphological studies and genetic research have determined that spider crabs found around British coasts and along the Atlantic coast of western Europe to be a distinct species (Maja brachydactyla).

Common spider crab has patchy distribution within its range, they inhabit a broad depth range from intertidal areas to down to 120m, more commonly found on flat seabed and soft substrate in coastal waters, moving further offshore in winter months. Spider crabs feed on seaweeds and benthic invertebrates, particularly species that are sessile or have low mobility, feeding rate decreases prior to and just after moult. Spider crabs grow quickly and mature crabs can live for a number of years. Spider crabs stop growing once they reach sexual maturity and are therefore able to reproduce, once per year, when hard-shelled. It is thought that this occurs between May to July, when berried females are observed. Spider crabs are not able to regenerate lost limbs unlike other crab species (Cancer pagurus).

Existing conservation/management measures

  • Existing legislation for spider crabs in Wales includes minimum landings size of 130mm for males and 120mm and a prohibition of landing detached parts of spider crabs in south Wales.

Further information

  • Woolmer, A., Woo, J., Bayes, J., 2013. Review of evidence for best practice in crustacean fisheries management in Wales. Tech. rep., Report to Welsh Government Fisheries and Marine Unit.
  • Pantin, J.R., Murray, L. G., Hinz, H., Le Vay, L. and Kaiser, M. J. (2015) The Inshore Fisheries of Wales: a study based on fishers’ ecological knowledge. Fisheries & Conservation report No. 42, Bangor University. Pp.60

Common sole (Solea solea)

Red = Avoid

WTSWW do not recommend buying common sole caught in Welsh waters due to concerns over management of the stocks, high levels of concern over species biology and the fishing methods.

ICES advice June 2014, Celtic Sea – ICES advices catches in 2015 should be no more than 652 tonnes to ensure a long term optimal use of this resource (35% less than 2014 TAC). ICES Advice June 2014, Irish Sea – ICES advices that there should be no directed fishery for Irish Sea Sole in 2015 to avoid catches that could lead to a reduction of the production of offspring. The Irish Sea population there is reduced reproductive capacity.

There is a discrepancy between the minimum landing size (MLS) and the size at first maturity. MLS in Wales is 240 mm and size at first maturity is recorded as 303mm

Sole is a flatfish which mainly occurs in the temperate waters of the eastern Atlantic, with a preference for sandy and muddy bottoms down to depths of 150m. Sole are known to live for up to 40 years, but currently fish over the age of 15 years are rarely caught. Females grow larger than males and can reach lengths of 50-60cm. They are sexually mature at age two to three but do not achieve full reproductive potential until age four or five.

Sole undergo seasonal migrations between spawning and feeding grounds but don’t move great distances and once recruited to a spawning ground they appear to continue to spawn on that ground. Planktonic larvae move inshore into estuaries, tidal inlets and sandy bays and at 15-18mm in length the left eye moves to the right side of the head. Juveniles are found in coastal nurseries and remain there for around two years before moving to deeper offshore waters where adults are found. Sole are nocturnal predators feeding on worms, molluscs, and small crustaceans.

Existing conservation/management measures

  • MLS for sole in Wales is 240 mm

Further information

  • Seafish, 2013. Seafish responsible sourcing guide: Dover sole, 2013.
  • ICES Advice, Sole in Division VIIa (Irish Sea) June 2014
  • Fishbase

Crawfish (Palinurus elephas)

Orange = Caution

WTSWW advice caution when buying Welsh crawfish (if available) due to concerns over the species biology and the current management of the stocks.

Crawfish caught in pots in Welsh waters are commonly a bycatch of fisheries for lobsters and crabs. Nets were historically used to target Crawfish.

Crawfish are a lobster-like marine crustacean that have small claws and spiny body that is bright red/orange in colour. Around the British Isles they mainly occur along the south and west coast. They prefer areas of reef with strong currents and steep topography with crevices, in 5-70m but have been recorded as deep as 200m. There is no known published information on the depth distribution and habitat preference of crawfish in Welsh although records show they are found around the Llyn Peninsula and Pembrokeshire, in low numbers.

Crawfish hatch from the egg into planktonic larval stage and from there they go through various stages before becoming an adult. There are no free-swimming larval stages, they are transported via currents. Growth of no more than 4mm carapace length has been recorded at moult for crawfish, in some cases change in length was non-existence but weight increases were observed.

Males are larger than females throughout their geographic distribution. In UK waters females moult in summer months (July to September), mating observed to take place within two weeks of the female moult with egg laying occurring five to ten days after. The female carries the eggs throughout the winter before they hatch in the following spring.

In the Atlantic, catch rates from the Welsh fishery showed a decline of 92% between 1980 and 1997 (Hunter 1999). This species is harvested throughout its range by recreational and commercial fisheries. Over-exploitation by fisheries is a major threat to this species.

Existing conservation/management measures

  • Prohibition of landing berried females
  • Minimum landing size (MLS) – south Wales is 110mm, north Wales is 95mm
  • Restrictions on gear type and number of nets and pots per boat
  • Closed seasons in certain areas
  • Species is on the UK Biodiversity action Plan species list and is protected under schedule 5 of the Wildlife & Countryside Act 1981

Further information

  • Hunter, E., Shackley, S., Bennett, D., 1996. Recent studies on the crawfish Palinurus elephas in south Wales and Cornwall: A quantitative analysis of fishing impacts on shelf-sea benthos. Journal of Animal Ecology 69, 785–798.
  • Leslie, B., Shelmerdine, R., 2012. Management measures for self-propagated future recovery of crawfish, Palinurus elephas in welsh waters. Tech. Rep. 989, CCW Contract Science Report.

Thornback ray (Raja clavata)

Red = Avoid

WTSWW advice caution when buying Thornback ray caught in Welsh waters due to high levels of concern over the species biology, current management of the stocks and methods of capture.

Raja clavata is a coastal and inner shelf species that is a by-catch species of trawl and gillnet fisheries, mainly caught close to the eastern side of the Irish Sea by beam and otter trawlers, and in the Bristol Channel. As one of the larger species of skate they may be targeted in some local, seasonal fisheries.

Most of this species landings in south Wales are caught in gillnets (18.8%), otter trawls (46%) or beam trawls (29.6%) which are non-selective methods of fishing.

The minimum landing size (MLS) in south Wales is 45cm which is possibly greater than size at first maturity depending on length information used, particularly for females. There is no minimum landing size for this species in north Wales.

Thornback rays are actually a species of skate. They prefer soft substrates such as mud and sand and can also be found over gravel and rock beds. Thornbacks are seasonally migratory, spending the winter in deeper water and coming into shallower areas in the late spring and summer to breed. Juveniles are more likely to be found in shallower, coastal waters than adults as these areas are used as nursery grounds. They can reach 12 years of age, they mature around 6 years and length 65–71 cm. Thornback ray are slow growing, late maturing and have low fecundity (reproductive) rates.

Existing conservation/management measures

  • Minimum landing size (MLS) – south Wales is 45cm, there is no minimum landing size in north Wales

Further information

  • McCully, S., Burt, G., Silva, J., Ellis, J., 2013. Monitoring thornback ray movements and assessing stock levels. Tech. Rep. 35, Centre for Environment, Fisheries and Aquaculture Science (Lowestoft), Fishery Science Partnership, Programme
  • Ryland, J., Ajayi, T., 1984. Growth and population dynamics of three Raja species (Batoidei) in Carmarthen Bay, British Isles. Journal du Conseil International pour l’Exploration de la Mer 41, 111120.
  • Gallagher, M., Nolan, C., Jeal, F., 2005. Age, growth and maturity of the commercial ray species from the Irish Sea. Journal of Northwest Atlantic Fishery Science 35, 47–66.
  • Holden, M., 1975. The fecundity of Raja clavata in British waters. Journal du Conseil International pour l’Exploration de la Mer 36, 110118.
  • Ellis, J., Cruz-Martinez, A., Rackham, B., Rogers, S., 2005. The distribution of chondrichthyan fishes around the British Isles and implications for conservation. Journal of Northwest Atlantic Fishery Science 35, 195–213
  • ICES Advice, October 2014