Minimum Conservation Reference Sizes (MCRSs)

Minimum landing sizes are used all over the World to manage fish stocks. As a common-sense approach to conservation, and an easy concept to understand (protecting immature fish) and apply when fishing, they have become particularly recognised by recreational anglers as important conservation method for fish.

Historically, UK anglers have been required to adhere to legally enforceable minimum sizes for a variety of fin-fish. Those sizes have become known as Minimum Conservation Reference Sizes (MCRS) 

The legal basis for the MCRSs used to include EU legislation but now that the UK has left the EU, the legal basis has become a combination of UK national legislation (“statutory instruments”) and local legislation such as byelaws introduced by Inshore Fisheries and Conservation Authorities (IFCAs). Some species are subject to total protection including not targeting them. 

Unfortunately, not all IFCAs have adopted the same MCRS for particular species and some do not even have MCRSs for all the species that some other IFCAs have included. 

We appreciate that a good proportion of recreational sea anglers may well have little inclination to research the websites of IFCAs to find what legal MCRSs apply in the area in which they fish and, instead, they rely on various sources such as lists of voluntary minimum sizes published by their clubs. 

The Angling Trust has investigated the websites of all IFCAs and has collated all the MCRSs published on them. From that data we have selected the highest MCRS we found for each species. By referring to that column in our chart below, an angler fishing in any IFCA area can be reasonably assured that should they choose to retain a fish and that fish is not below the relevant listed MCRS, then they would not be committing an illegal act. The situation with IFCAs regarding MCRSs is currently somewhat fluid with some IFCA reviews underway so our list is for initial guidance only. In the event of any dispute, the byelaws in force for the particular IFCA in whose area the fish was caught take precedence. They can be found by following these links:- 

Northumberland IFCA
North East IFCA
Eastern IFCA
Kent and Essex IFCA
Sussex IFCA
Southern IFCA
Devon and Severn IFCA
Cornwall IFCA
Isles of Scilly
North West IFCA


The Angling Trust believes that many anglers, whilst enjoying their sport and occasionally retaining fish for consumption, are keen to adopt a conservation-minded approach as well as supporting campaigns aimed at ensuring commercial exploitation of stocks is also done at a sustainable level. To that end, the Angling Trust believes in allowing all species of fish the chance to have spawned at least once before being taken. 

On that basis, we have reviewed available scientific data regarding maturity sizes and we have selected the point at which 50% of the population of a particular species is reported to be mature and hence capable of having bred at least once. We have listed those sizes in the column-headed Maturity. In addition, the Angling Trust recognises that stocks of some species are at a level where we feel it reasonable to suggest that those species are not retained (in instances where safe release is achievable) but with catch and release remaining acceptable. 

Species Max National or IFCA legal MCRS MATURITY or restriction
Anglerfish (Lophius piscatorius) (Sold as Monk) None 70cm
Bass (Dicentrarchus labrax) 42cm 48cm
Bream – Black (Spondyliosoma cantharus) 23cm 24cm
Bream – Gilthead (Sparus aurata) None 40cm
Bream- Rays (Brama brama) None 40cm


Bream- Red (Pagellus bogaraveo)  33cm  35cm 
Brill (Scophthalmus rhombus)  30cm  41cm 
Coalfish (Pollachius virens)  35cm  70cm 
Cod (Gadus morhua)  35cm  60cm 
Common skate (Dipturus batis)  45cm across wings  Return 
Conger eel (Conger conger)  58cm  100cm 
Dab (Limanda limanda)  23cm  25cm 
European Eel (Anguila anguila)  None (See note 2)  Return 
Flounder (Platichthys flesus)  27cm  30cm 
Garfish (Belone belone)  None  45cm 
Gurnard – Grey (Eutrigla gurnardus)  None  25cm 
Gurnard – Red (Chelidonichthys cuculus)  None  28cm 
Gurnard – Tub (Chelidonichthys lucerna)  None  30cm 
Haddock (Melanogrammus aeglefinus)  30cm  40cm 
Hake (Merluccius merluccius)  30cm  43cm 
Halibut (Hippoglossus hippoglossus)  None  135cm 
Herring (Clupea harengus)  20cm  23cm 
Horse mackerel /Scad (Trachurus trachurus)  15cm  30cm 
John Dory (Zeus faber)  None  35cm 
Lesser Spotted Dogfish (Scyliorhinus canicula)  None  60cm 
Ling (Molva molva)  63cm  100cm 
Mackerel (Scomber scombrus)  30cm  34cm 
Megrim (Lepidorhombus whiffiagonis)  25cm  25cm 
Monkfish AKA Angel Shark (Squatina squatina)  Protected (see Note 5)  Return 
Mullet – Grey, thick-lipped (Chelon labrosus)  42cm  47cm 
Mullet – Grey, thin-lipped (Liza ramada)  42cm  47cm 
Mullet – Golden Grey (Chelon aurata)  36cm  47cm 
Mullet – Red  15cm  24cm 
Plaice (Pleuronectes platessa)  27cm  35cm 
Pollack (Pollachius pollachius)  30cm  50cm 
Poor Cod (Trisopterus minutus)  None  25cm 
Pouting (Trisopterus luscus)  None  25cm 
Ray – Blonde (Raja brachyuran)  45cm across wings  100cm (Note 10) 
Ray – Cuckoo (Raja naevus)  45cm across wings  60cm (Note 10) 
Ray –Shagreen (Leucoraja circularis)  45cm across wings  85cm (Note 10) 
Ray – Small-eyed (Raja microocellata)  45cm across wings  77cm (Note 10) 
Ray – Spotted (Raja montagui)  45cm across wings  55cm (Note 10) 
Ray – Starry (Amblyraja radiata)  45cm across wings  87cm (Note 10) 
Ray – Stingray (Dasyatis pastinaca)  45cm across wings  63cm (Note 10) 
Ray – Thornback (Raja clavata)  45cm across wings  85cm (Note 10) 
Ray – Undulate (Raja undulate)  78cm nose to tail  Return (Note 3) 
Rockling – Five Bearded (Ciliata mustela)  None  20cm 
Rockling – Shore (Gaidropsarus mediterraneus)  None  20cm 
Rockling – Three-bearded (Gaidropsarus vulgaris)  None  20cm 
Shad- Allis (Alosa alosa)  None (see note 4)  Return 
Shad- Twait (Alosa fallax)  None (see note 4)  Return 
Shark – Blue (Prionace glauca)  None  Return (Note 6) 
Shark – Bull Huss (Scyliorhinus stellaris)  None  80cm 
Shark – Mako (Isurus oxyrinchus)  None  Return (Note 6) 
Shark – Porbeagle (Lamna nasus)  None  Return (Note 6) 
Shark – Smoothhound (Mustelus asterias)  None  85cm 
Shark – Spurdog (Squalus acanthias)  None  Return (Note 7) 
Shark – Thresher (Alopias vulpinus)  None  Return (Note 6) 
Shark – Tope (Galeorhinus galeus)  None (See note 8)  Return 
Sole – Dover (Solea solea)  24cm  35cm 
Sole – Lemon (Microstomus kitt)  25cm  30cm 
Swordfish  Prohibited (NWIFCA)  Return 
Trigger fish (Balistes capriscus)  None  20cm 
Turbot (Scophthalmus maximus)  30cm  46cm 
Tuna – Bluefin (Tunnus thynnus)  Banned (See Note 9)  Return 
Whiting (Merlangius merlangus)  27cm  30cm 
Witch (Glyptocephalus cynoglossus)  28cm  30cm 
Wrasse – Ballan (Labrus bergylta)  18cm  30cm 
Wrasse – Corkwing  14cm  14cm 
Wrasse – Cuckoo (Labrus mixtus)  None  25 cm 
Wrasse -Goldsinny (Ctenolabrus rupestris)  12cm  14cm 
Wrasse – Rock cook. (Centrolabrus exoletus)  12cm  14cm 
  1. The size of sexual maturity for species from the Gadidae family including cod, whiting, haddock, pollack and coalfish (saithe) can vary wildly depending on a number of factors. The figures quoted represent the size at which 50 per cent of fish of these species have reached sexual maturity. 
  2. An Environment Agency byelaw prevent anglers from retaining the European eel (Anguilla anguilla). However, they can be retained for weighing or measuring but must be returned alive to the water they were taken from on completion of fishing. For the Angling Trust’s policy on retaining European eels click here
  3. Undulate Ray in our waters are classified as near threatened (IUCN). We suggest that all fish are returned alive (in instances where safe release is achievable).
  4. Shad are protected under the Wildlife and Countryside Act and all fish must be returned.
  5. Monkfish (also called Angel Shark) are listed under UK Wildlife and Countryside Act and will be protected against killing, injuring or taking (section 9(1)) on land and up to 3 nautical miles (nm) from English coastal baselines. These are not to be confused with the unprotected Anglerfish (Lophius piscatorius) whose tails are marketed as Monkfish.
  6. We recommend that all large sharks are released unharmed at the side of the boat rather than being brought on board. We publish a separate handling guide for them.
  7. Spurdog are classified as critically endangered in the Northeast Atlantic and we suggest that all fish are returned alive (in instances where safe release is achievable).
  8. Anglers should be aware that there is a national restriction on landing tope caught from a boat, which includes kayaks, by rod and line. Any boat-caught tope are legally required to be released as soon as possible after capture. Details of the Tope (Prohibition of Fishing Order) 2008 can be found here.
  9. Atlantic Bluefin Tuna may only be directly targeted by recreational anglers taking part in a licensed recreational catch and release fishery applicable to the home nation in whose waters they are fishing. Therefore, recreational sea anglers who are not part of such programmes are obliged to do everything they can to ensure any by-catch is returned to the sea alive.
  10. IFCAs define the MCRS for most skate/ray species by way of the measurement between wing tips for whole fish or wing base to wing tip for detached wings. All Angling Trust sizes refer to the overall length (nose to tail).

The maturity sizes shown here have been formulated from the best available evidence at the time. If you have more information and can provide referenced studies to update this information then we would love to hear from you. Please email us at [email protected] 



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