Cuttlefish

Sepia officinalis

Method of production — Caught at sea
Capture method — Trap
Capture area — North East Atlantic (FAO 27)
Stock area — UK
Stock detail — English Channel
Picture of Cuttlefish

Sustainability rating three info

Sustainability overview

In the UK the English Channel is the main fishing ground for this species, where their abundance is highly and seasonally variable. The main catching areas are off the coasts of Devon, Dorset and Sussex. Where available, look for cuttlefish taken in trap fisheries where measures have been adopted to protect cuttlefish eggs, e.g. Dorset (Poole, Christchurch) and Brittany. These measures include leaving egg encrusted cuttlefish traps in sheltered areas of the sea to allow the eggs to hatch, and providing a removable surface on the outside of the traps on which cuttlefish can lay their eggs.

Biology

Cuttlefish (family Sepiidae) belong to a specialised group of molluscs, known as cephalopods, which also includes octopus and squid. In the North East Atlantic and Mediterranean, the main commercial species is the common cuttlefish (Sepia officinalis), although other species (S. elegans and S. orbignyana) are fished in the Mediterranean. Cuttlefish have eight arms and two tentacles, like squid, but differ from other cephalopods by the presence of a significant internal skeletal/buoyancy structure, the cuttle bone, which is often found washed up on beaches. The common cuttlefish typically has a two year lifecycle, whilst in southern areas one year is normal. After overwintering in deeper waters, cuttlefish move into shallow coastal waters to breed in spring and summer. Females only breed once, and die soon after laying up to 4,000 eggs, which are around 8-10 mm in diameter and known as 'sea grapes'. They take up to two months to hatch. Males live longer, and breed more than once. Cuttlefish can attain body lengths of up to 45 cm and weigh up to 4 kg, although typically 20-30 cm and 1-2 kg is normal.

Stock information

Stock Area

UK

Stock information

There is currently no assessment of cuttlefish stocks by ICES in North East Atlantic. It is a non-pressure or unprotected species, i.e. not subject to quota restrictions. Although estimates of the total population size do not exist, attempts at stock assessment in the English Channel, the main UK fishery area, suggested they were probably fully fished. In spite of some overfishing, there was no indication that the species was at risk. Since 2006 landings from the English Channel have remained high, suggesting they are being exploited at sustainable levels. However,increases in market value and quota restrictions on other target species have increased fishing effort on cuttlefish. In recent years landings of cuttlefish have contributed substantially towards the income from mixed trawl fisheries in the southwest. There are two main components to the fishery, a mid-channel and an inshore fishery.The total value of the mid -channel fishery in 2011 was 8.8 million. Further research is recommended regarding population trends, distribution, life history traits and threats impacting the species. Ocean acidification caused by increased levels of carbon dioxide in the atmosphere is potentially a threat to all cuttlefish.

Management

There are no specific managment measures for cuttlefish. In 2006 the Sussex Sea Fisheries Committee (now Sussex Inshore Fishery Conservation Authority) investigated the feasibility of laying artificial substrates as receptors for cuttlefish eggs; the artificial substrate used was similar to a string of cuttlefish traps but without the traps, i.e. just the backline, weights and floats. The cuttlefish did use the alternative egg receptors provided in addition to the trap lines. The study recommended that further techniques should be developed in the form of 'removable receptors', which could be placed on the actual traps and once covered in eggs be removed and returned to the sea. Southern IFCA promote a voluntary Code of Practise (SIFCA Cuttlefish Traps Code of Practice) requesting fishers to minimise the removal or damage to cuttle eggs attached to gear when shooting, hauling or cleaning. Traps should also remain underwater until September. This allows any attached cuttle eggs to hatch.

Capture Information

The most predominent method of fishing cuttlefish is by trapping. Other commercial methods used to catch cuttlefish are trammel nets, commonly with a mesh size of 120 to 160 mm, and as bycatch in beam trawls and otter trawls.Taking cuttlefish in traps is generally a more selective fishing method and less damaging to marine benthos than trawl fishing. However, the trap fishery utilises the cuttlefishes' breeding behaviour in order to capture them when they come into inshore waters to lay their eggs. Instead of food, a female is used as 'bait'. As it is their breeding season this attracts the males and thus other females into the trap. On each haul the catch is emptied, the female is replaced and the gear is shot again in succession. The traps used in the fishery provide an ideal surface upon which eggs are laid, but unfortunately the eggs are destroyed when the traps are hauled and cleaned at the end of the fishing season. This could have negative consequences for cuttlefish reproduction. Similarly, eggs laid on ropes attached to shellfish pots may be removed from the sea before hatching, when the pots are hauled.

References

http://www.sussex-ifca.gov.uk/repository/Species_Guide_2011.pdf; http://www.southern-ifca.gov.uk/wp-content/uploads/2014/03/IFCA-Newsletter-Issue-4.pdf