Cuttlefish

Sepia officinalis

Method of production — Caught at sea
Capture method — Trap
Capture area — North East Atlantic (FAO 27)
Stock area — English Channel Inshore: UK Waters (0-6nm) (excluding Cornwall IFCA district)
Stock detail — 7d, 7e, 7f, 7g, 7h
Picture of Cuttlefish

Sustainability rating four info

Sustainability overview

Updated: January 2020.

This stock is data limited. Cuttlefish are a migratory species, and there are no defined stock areas or formal stock assessments available. From 2008 to 2017, landings of cuttlefish to UK ports nearly doubled and a number of studies are in agreement that the English Channel cuttlefish population is either fully or over exploited. At present, there is limited management measures and there is no total allowable catch (TAC) quota or minimum conservation reference size (MCRS). In the UK, inshore fisheries are managed by one of ten Inshore Fisheries Conservation Authorities (IFCAs). In some IFCAs, permits exist that restrict the number of traps or pots that can be deployed by each vessel. The impact of cuttlefish trapping on the seabed is low, and this method is generally selective. In Southern IFCA, there is a voluntary code of best practice to encourage fishers to leave pots in the water at the end of the season, to allow any eggs that have attached to spawn, however, this is not enforced across the assessment area.

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

Criterion score: 1 info

Stock Area

English Channel Inshore: UK Waters (0-6nm) (excluding Cornwall IFCA district)

Stock information

This stock is data limited. Cuttlefish are a migratory species, and there are no defined stock areas or formal stock assessments available. Cuttlefish in the English Channel are fished mainly by France and the UK. Whilst originally dominated by France, in 2017, UK landings represented 55% of the total catch. Inshore exploitation is managed by local rules, however, no EU regulations apply to the whole stock.

From 2008 to 2017, landings of cuttlefish to UK ports nearly doubled and a number of studies are in agreement that the English Channel cuttlefish population is either fully or over exploited. Surveys suggest that the biomass is decreasing in the eastern English Channel with the ICES WGCEPH Report 2018 stating that the 2017 biomass index is the lowest on record. Beam and otter trawl fisheries have experienced a large increase in the amount of cuttlefish landed per vessel over the last 10 years. However, the inshore trap fisheries are experiencing large reductions in catch rate by over 50%. Landings in the northwest English Channel in summer 2017 were particularly high - likely owing to overfishing rather than high abundance. Overall, biomass is declining and fishing pressure is increasing so there is concern for both biomass and fishing pressure.

Management

Criterion score: 0.75 info

At present, there is limited management for cuttlefish in the English Channel. There is no total allowable catch (TAC) quota or minimum conservation reference size (MCRS). This means that fishers can land any amount of cuttlefish at any size. The lack of management is particularly problematic as cuttlefish are targeted both in their coastal spawning grounds in their pre-adult stage and in offshore deep-waters, where they have not had the chance to spawn.

In the UK, inshore fisheries (within 6 nautical miles of the coast) are managed by one of ten Inshore Fisheries Conservation Authorities (IFCAs). Six IFCAs are situated along the English Channel: Kent and Essex, Sussex, Southern, Devon and Severn, Cornwall, and the Isles of Scilly. All of these IFCAs restrict the maximum length of fishing vessel that can operate in the management area can this varies from 12 to 14 metres between IFCAs. In some IFCAs, permits exist that restrict the number of traps or pots that can be deployed by each vessel when targeting cuttlefish. In Sussex IFCA, this is set at 300.

As all cuttlefish reproduction occurs at the end of their lifecycle, almost all fisheries target cuttlefish before they have had the chance to reproduce. Inshore trap fisheries instead target cuttlefish at the end of their lives, during the breeding season. This often means that the cuttlefish will have had the chance to lay eggs before being caught. However, this also means that the traps used to target cuttlefish are often the last sites of egg laying for captured cuttlefish. If these eggs can be removed easily from the pots and returned to sea then this would reduce the ecological impact of the trap fishery.

However, while some fishers may try and remove and return the eggs, frequently it is not always possible to remove all the eggs while at sea and the removal of eggs sometimes requires aggressive scrubbing with the use of a stiff brush or jet wash which reduces the survival rate of the eggs. In some areas, it is considered best practice to leave pots in the water at the end of the season to allow eggs to hatch. In Southern IFCA, there is voluntary code of conduct which states that it is best practice for fishers to leave their traps or pots in the sea at the end of the season to allow deposited eggs to hatch. However, this is not enforced across the whole unit of assessment and there is no evidence that any management measures in place are resulting in an improvement in the stock.

Capture Information

Criterion score: 0 info

Like most other taps and pots, the impact of cuttlefish trapping on the seabed is low, and this method is generally selective. Cuttlefish traps are larger than most other traps and made of lightweight material. Most have two entrances which are designed to let the cuttlefish enter the trap easily but make it difficult for them to escape.

There is not much evidence of ghost fishing and as the fishery is seasonal, it usually occurs in the summer and autumn where traps are not usually lost due to stormy weather. Traps are hauled everyday which also reduces the chances of losses. In general, bycatch is minimal but may include invertebrates and some fish.

References

Gras, M., Roel, B.A., Coppin, F., Foucher, E. and Robin, J-P. 2014. A two-stage biomass model to assess the English Channel cuttlefish (Sepia officinalis L.) stock. ICES Journal of Marine Science, 71(9), pp.2457-2468. Available at https://academic.oup.com/icesjms/article/71/9/2457/594946 [Accessed on 05.02.2020].

ICES. 2019. Interim Report of the Working Group on Cephalopod Fisheries and Life History (WGCEPH), 5-8 June 2018, Pasaia, San Sebastian, Spain. ICES CM 2018/EPDSG:12. 194 pp. Available at https://www.ices.dk/sites/pub/Publication%20Reports/Expert%20Group%20Report/EPDSG/2018/WGCEPH%20-%20Report%20of%20the%20Working%20Group%20on%20Cephalopod%20Fisheries%20and%20Life%20History.pdf [Accessed on 05.02.2020].

ICES. 2016. Report of the Working Group on Cephalopod Fisheries and Life History (WGCEPH),14-17 June 2016, ICES Headquarters, Copenhagen, Denmark. ICES CM 2016/SSGEPD:03. Available at https://archimer.ifremer.fr/doc/00377/48775/49173.pdf [Accessed on 05.02.2020].

Davies, D. and Nelson, K. 2018. Supporting Sustainable Sepia Stocks. Report 1: The biology and ecology of the common cuttlefish (Sepia officinalis). Sussex IFCA. Available at https://secure.toolkitfiles.co.uk/clients/34087/sitedata/files/Research/1-Cuttlefish-biology-and-ecology.pdf [Accessed on 05.02.2020].

Davies, D. and Nelson, K. 2018. Supporting Sustainable Sepia Stocks. Report 2: The English Channel fishery for common cuttlefish (Sepia officinalis). Sussex IFCA. Available at https://secure.toolkitfiles.co.uk/clients/34087/sitedata/files/Research/2-English-Channel-fishery-for-cuttlefish.pdf [Accessed on 05.02.2020].

Davies, D. and Nelson, K. 2018. Supporting Sustainable Sepia Stocks. Report 3: Assessing the efficacy of egg receptors within fishing traps used to target common cuttlefish (Sepia officinalis). Sussex IFCA. Available at https://secure.toolkitfiles.co.uk/clients/34087/sitedata/files/Research/3-Efficacy-of-egg-receptors.pdf [Accessed on 05.02.2020].

Seafish. 2019. Pots and traps - Cuttlefish. Available at https://seafish.org/gear-database/gear/pots-and-traps-cuttlefish/ [Accessed on 05.02.2020].