Scallop, King, scallops

Pecten maximus

Method of production — Caught at sea
Capture method — Dive caught
Capture area — North East Atlantic (FAO 27)
Stock area — Scotland
Stock detail — 6a (0-3nm)
Picture of Scallop, King, scallops

Sustainability rating two info

Sustainability overview

Scallops are the second most valuable shellfish fishery in Scotland and represent shortly half of the value of all the scallops landed in the UK. The scallop stocks which provide the highest landings (which comprise over 75% of landings into Scotland) are the Irish Sea, West of Kintyre, the North West, North East and East Coast.

Four stocks were assessed for this region (ICES area 6a), two of which (Clyde and part of the Orkney stock) have not been assessed here because they represent a very small proportion of landings and there isn’t enough information to evaluate if they are healthy. The other two stocks (North West and West of Kintyre) have both have experienced increases in recruitment and spawning stock biomass (SSB), with stable or low levels of fishing mortality. However, Marine Scotland advise that there should be no increase in fishing effort in these two areas.

New management has been implemented into the fishery that follows scientific advice, however, it is too soon to tell how effective these are.

Scallops are almost exclusively fished by dredges but some (around 5%) are removed by commercial divers.

Diving has a very low impact on bycatch as it is a very selective fishing method and generally a low impact on the seabed.

There are Marine Protected Areas (MPAs) to protect seabed features within the area of this assessment and some components of this fishery may be fishing in these areas. If appropriate management measures are not in place to protect these features, or, an appropriate impact or risk assessment of the activity has not been undertaken to indicate the commercial fishing activity does not damage the integrity of the site, MCS considers these fishing activities as default red rated.

Biology

King scallops are bivalve molluscs found in a range of depths from shallow waters in sea lochs to over 100m. They inhabit sandy-gravel and gravel seabeds. They have 2 shells or valves, the upper being flat, and the under or right valve, cup shaped. They are hermaphrodites (i.e. both male and female) and become fully mature at about 3 years old (80 to 90mm in length). Spawning occurs in the warmer months, from April to September. The species can grow to more than 20cm in length and live for more than 20 years, although average sizes are in the range of 10-16cm.

Stock information

Criterion score: 0.25 info

Stock Area

Scotland

Stock information

Summary
Four stocks were assessed for this region (ICES area 6a), two of which (Clyde and part of the Orkney stock) have not been assessed here because they represent a very small proportion of landings and there isn’t enough information to evaluate if they are healthy. The other two stocks are discussed in detail below but their health has been improving over time.

In the North West area, estimated recruitment has increased and has been above the long-term average since 2010. Estimated Spawning Stock Biomass (SSB) has also increased. Landings have been moderate and fishing mortality has been fairly stable, around the long-term average. Catches mostly consist of four six year olds.

In the West of Kintyre area, recruitment is estimated to have increased substantially and estimated SSB at record highs. The stock is considered to be stable, at a high level. Landings have increased since 2011, but fishing mortality remains relatively low. Marine Scotland advise that there should be no increase in fishing effort in both these areas. King Scallops are deemed to have a medium resilience to fishing pressure.

Management

Criterion score: 0.5 info

Summary
Generally the management required in scallop fisheries are needed to reduce the level of fishing mortality on the stock and the impact of dredging on the environment. However, the dive fishery only lands around 5% of the total landings in the Scottish scallop fishery and it is a highly selective fishing method and therefore, limited management is required to reduce the effect of the dive fishery on the scallop stock and environment.

However, new management has been implemented into the Scottish fishery in 2017 however, it is too soon to tell how effective these are.

Justification
Marine Scotland manages Scottish stocks in its territorial waters. There are six Regional Inshore Fishing Groups (RIFGs) that help define management measures within their districts. Scallops are managed under a harvest strategy in Scottish waters which is based on stock trends.

Scottish scallop fisheries are not subject to EU or national Total Allowable Catches. However, in June 2017, new management measures were enacted in Scottish waters (Regulation of Scallop Fishing (Scotland) Order 2017). Management measures included an increased minimum landing size of 105mm, regulations relating to the dredge fleets, some spatial closures. Under EU Western Waters effort regime, all UK vessels over 15 m in length are restricted to 1,974,425 kW days for Subarea 6 (Council Regulation (EC) No. 1415/2004).The Clyde fisheries also receive weekend closures. In the West of Kintyre, management measures are applied to Northern Irish, Scottish and Dutch fleets.

There are Special Areas of Conservation (SAC) under the European Natura 2000 and proposed Marine Conservation Zones (MCZs) under the UK Marine Act. The Marine Strategy Framework Directive (MSFD) have committed to Good Environmental Statusa for the seafloor habitat by year 2020. The EU habitats directive and OSPAR defines priority habitat e.g. for biogenic reefs, maerl beds, horse mussel beds and other reef habitats) can be protected or are going through this process.

Monitoring
Scottish regional scallop stock assessments are conducted by Marine Scotland Science (MSS) using fishery dependent (e.g. surveys in processoras factories) and fishery-independent (e.g. research vessel surveys) survey data. Trends are deduced on fishing mortality, biomass, abundance (pre-recruits and adults) and recruitment. Vessel Monitoring Systemas data are collected only every two hours which significantly reduces the ability to monitor fishing in relation to Marine Protected Areas (MPAs). However, Electronic Monitoring System (EMS) may help advise management regarding bycatch, the stock status and will help enforce management measures in the fishery.

Capture Information

Criterion score: 0 info

Diving has a very low impact on bycatch as it is a very selective fishing method and generally a low impact on the seabed.

References

Dobby, H., Fryer, R., Gibson, T., Kinnear, S., Turriff, J. and McLay, A. (2017) Scottish Scallop Stocks: Results of 2016 Stock Assessments. Scottish Marine and Freshwater Science Vol 8 No 21, 178pp. DOI: 10.7489/2005-1

ICES. 2016. Report of the Scallop Assessment Working Group (WGScallop), 5-9 October 2015, Trinity, Jersey, UK. ICES CM 2015/ACOM:23. 42 pp.

The Regulation of Scallop Fishing (Scotland) Order 2017. Available at: http://www.legislation.gov.uk/en/ssi/2017/127/made.

Fisheries Research Services. 2008. Scottish Scallop Stocks Biology and Assessment. Available at: https://www.gov.scot/Uploads/Documents/FM20Scallopbiology08.pdf

Lambert, G.I., Murray, L.G., Hiddink, J.G., Hinz, H., Lincoln, H., Hold, N., Cambia, G., Kaiser, M.J., 2017. Defining thresholds of sustainable impact on benthic communities in relation to fishing disturbance. Sci. Rep. 7. https://doi.org/10.1038/s41598-017-04715-4

Hollyrood. 2017. The battle over Scotland's inshore fishing industry. 10th July 2017. Available at: https://www.holyrood.com/articles/inside-politics/battle-over-scotlands-inshore-fishing-industry

Howarth, L. M. & Stewart, B. D. 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 Report no. 5, University of York, 54 pp.

Hiddink, J., Jennings, S., Sciberras, M., Szostek, C.L., Hughes, K.M., Ellis, N., Rijnsdorp, A.D., McConnaughey, R.A., Mazor, T., Hilborn, R., Collie, J.S., Pitcher, C.R., Amoroso, R.O., Parma, A.M., Suuronen, P., and Kaiser, M.J. 2017. Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance. PNAS. 114: 8301-8306.

Howarth, L.M., Roberts, C.M., Steadman, D.J., Hawkins, J.P., Beukers-Stewart, B.D. 2015. Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve. MABI-D-14-00592R3 . Available at: https://pure.york.ac.uk/portal/files/49894421/MABI_D_14_00592R3.pdf

ndes, F., Kaiser, M.J. and Murray, L.G. 2016. Quantification of the indirect effects of scallop dredge fisheries on a brown crab fishery. Marine Environmental Research 119, 136-143.

Hervas, A., Nimmo, F., Southall, T., Macintyre, P., 2012. The SSMO Shetland inshore brown & velvet crab, lobster and scallop fishery Public Certification Report. Inverness, UK.

ICES. 2016. Report of the ICES Scallop Assessment Working Group (WGScallop), 3-7 October 2016,Aberdeen, UK.ICES CM 2016/ACOM: 24. 39 pp.

ICES. 2017. Interim Report of the Scallop Assessment Working Group (WGSCALLOP), 10-12 October 2017, Belfast, Northern Ireland, UK. ICES CM 2017/SSGEPD:25. 18 pp.

Curtis, H., Quintana, M.M., Motova, A. Witteveen, A. 2017. Seafish Economic Analysis: UK king scallop dredging sector 2008 2016 2nd Edition, final 2016 data. Report for Seafish. Seafish Report No. SR716. Available at: http://www.seafish.org/media/Publications/2nd_Edition_Scallop_report_11May2018.pdf

Poseidon. 2013. A review of the Scottish scallop fishery. Report for Marine Scotland. Lymington Hampshire. Available at: https://www.gov.scot/Resource/0045/00450683.pdf

Marine Scotland. 2014. Fish and Shellfish Stocks 2014 Edition. Available at: https://www.gov.scot/Resource/0045/00458803.pdf