Salmon, Atlantic (Farmed)

Salmo salar

Method of production — Farmed
Production country — UK
Production method — Open net pen
Picture of Salmon, Atlantic (Farmed)

Sustainability rating three info

Sustainability overview

Salmon are farmed in open net pens in the sea. Producing fish in open systems can cause environmental impacts such as: impacts of chemical and sea lice treatment usage; nutrient and organic waste deposition; outbreaks of disease; impacts on wild salmonids by transmission of sea lice, and escapes from farms. Salmon are carnivorous fish and rely on wild capture fisheries to produce their feed, MCS would like to see all these fish certified as sustainably managed. Due to the ongoing nature of as yet unresolved environmental impacts of salmon farming MCS is advocating a halt in industry expansion until these can be resolved.

Feed Resources

Criterion Score: 2

The ingredients that make up feed for Scottish farmed salmon are responsibly sourced. In recent years the amount of fish contained in the diets has reduced and been replaced with vegetable proteins and oils.

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Environmental Impacts

Criterion Score: -5

In un-certified farmed Scottish salmon there are concerns about the use of chemicals in terms of failed benthic sampling at some farms. These chemicals are sea lice treatments that can have an effect on crustacea species such as lobsters. Due to the elevated sea lice numbers at farms there is a risk of transfer to wild salmonid species - trout and salmon. Escapes are another issue of concern, there are periodic large escape events but regular trickle escapes of small number of fish. The interbreeding of farmed fish with wild fish and the intercompetition between them is of concern. Seals can be lethally controlled under license to protect farmed salmon from attacks. Wild wrasse species are caught to be used as cleaner fish to control sea lice, a percentage of these are coming from poorly managed wild stocks.

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Fish Health and Welfare

Criterion Score: 1

Welfare standards including humane slaughter are covered by Freedom Foods standards to which most of the industry in Scotland are certified

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Management

Criterion Score: 2

The National Marine Plan for Scotland is yet to be operational, this will hopefully integrate aquaculture into wider marine planning. Regulations are in place for all of the issues of environmental concerns, however given the failure of some farms in terms of chemical use this can only be classed as being partially effective. 90 % of the industry is certified to the industry’s own Code of Good Practice.

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Production method

Open net pen

Salmon are farmed in open net pens in the sea. These are floating cages suspended in the sea and held in place by moorings underneath the cages.

Biology

Salmon are termed “anadromous”, meaning during their lifecycle they move between fresh and marine waters; salmon farming attempts to mirror this lifecycle. Broodstock fish are moved to freshwater for spawning, where the eggs are also fertilised and hatched. The hatched fish (called fry) are also kept in freshwater and fed pellets manufactured from fish meal. At about 18 months the fish (now called smolts) are transferred to seawater cages where growth continues until market size is reached, usually at about 2 years.

References

Gillund, F. & Myhr, A.I., 2010. Perspectives on Salmon Feed: A Deliberative Assessment of Several Alternative Feed Resources. Journal of Agricultural and Environmental Ethics, 23 (6), pp.527-550

Shepherd, C.J., Monroig, O. & Tocher, D.R., 2017. Future availability of raw materials for salmon feeds and supply chain implications: The case of Scottish farmed salmon. Aquaculture, 467, pp.49-62. Available at: http://dx.doi.org/10.1016/j.aquaculture.2016.08.021 [accessed on 12-07-17]

Sprague, M., Dick, J.R. & Tocher, D.R., 2016. Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006-2015. Scientific reports, 6 (Nov 2015), p.21892. Available at: http://www.nature.com/srep/2016/160222/srep21892/full/srep21892.html, [accessed on 12-07-17]

SSPO, 2014. Efficient Use of Feed. Published on 27th March 2014. Available at: http://scottishsalmon.co.uk/efficient-use-of-feed/ [accessed on 12-07-17]

Munro, I.S. & Wallace, L.A., 2016. Scottish Fish Farm Production Survey 2015. Available at: http://www.gov.scot/Resource/0050/00505162.pdf [accessed on 13-07-17]

Ellis, T., Turnbull, J. F., Knowles, T. G., Lines, J. A., Auchterlonie, N. A., 2016. Trends during development of Scottish salmon farming: An example of sustainable intensification? Aquaculture, 458, pp.82-99. Available at: http://dx.doi.org/10.1016/j.aquaculture.2016.02.012. [accessed on 13-07-17]

FAO, 2004. Cultured Aquatic Species Information Programme. Salmo salar. FAO Fisheries and Aquaculture Department [online]. Rome., [accessed on 31-05-17])

Keeley N. B., Forrest B. M., Macleod CK 2015. Benthic recovery and re-impact responses from salmon farm enrichment: Implications for farm management. Aquaculture. Volume 435. Pages 412-423

Mayor, D. J., Zuur, A. F., Solan, M., Paton, G. I., Killham, K., 2010. Factors affecting benthic impacts at Scottish fish farms. Environmental Science and Technology, 44(6), pp.2079-2084

Wilding, T. A., Cromey, C. J., Nickell, T. D., Hughes, D. J. 2012. Salmon farm impacts on muddy-sediment megabenthic assemblages on the west coast of Scotland. Aquaculture Environment Interactions, 2(2), pp.145-156. Available at: http://www.int-res.com/abstracts/aei/v2/n2/p145-156/ [accessed on 27-10-14]

Aaen, S.M., Helgesen, K. O., Bakke, M. J., Kaur, K., Horsberg, T. E., 2015. Drug resistance in sea lice: A threat to salmonid aquaculture. Trends in Parasitology, 31(2), pp.72-81. Available at: https://www.researchgate.net/profile/Stian_Aaen/publication/271707505_Drug_resistance_in_sea_lice_A_threat_to_salmonid_aquaculture/links/5698d33b08ae1c42790676dc.pdf [accessed on 13-07-17]

Burridge, L., Weis, J S., Cabello, F., Pizarro, J., Bostick, K., 2010. Chemical use in salmon aquaculture: A review of current practices and possible environmental effects. Aquaculture 306(1-4): 7-23

Jones, P. G., Hammell, K. L., Gettinby, G., Revie, C. W., 2013. Detection of emamectin benzoate tolerance emergence in different life stages of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar L., Journal of Fish Diseases, 36(3): 209-220

Lillicrap, A., Macken, A. & Thomas, K. V, 2015. Recommendations for the inclusion of targeted testing to improve the regulatory environmental risk assessment of veterinary medicines used in aquaculture. Environment international, 85, pp.1-4

Murray, A.G., 2016. Increased frequency and changed methods in the treatment of sea lice (Lepeophtheirus salmonis) in Scottish salmon farms 2005-2011. Pest Management Science, 72(2), pp.322-326

SARF, 2017. SARF098: Towards Understanding of the Environmental Impact of a Sea Lice Medicine- the PAMP Suite. Available at: http://www.sarf.org.uk/cms-assets/documents/251503-644637.sarf098---whole-document-aug2016.pdf [accessed on 13-07-17]

Price, C., Black, K. D., Hargrave, B. T., Morris, J. A. Jr., 2015. Marine cage culture and the environment: effects on water quality and primary production. Aquaculture Environment Interactions, 6:151-174

Bjorn, P. A., Finstad, B., Kristoffersen, R., 2001. Salmon lice infection of wild sea trout and Arctic char in marine and freshwaters: the effects of salmon farms. Aquaculture Research 32: 947?962

Middlemas, S., Smith, G., Armstrong J. 2016. Using Catch Data to Examine the Potential Impact of Aquaculture on Salmon and Sea Trout. Marine Scotland. 2016

Butler, J., Cunningham, P., Starr, K., 2005. The prevalence of escaped farmed salmon, Salmo salar L., in the River Ewe, western Scotland, with notes on their ages, 21 weights and spawning distribution. Fisheries Management and Ecology 12: 149-159

Glover, K.. A., Pertoldi, C., Besnier, F., Wennevik, V., Kent, M., Skaala, O., 2013. Atlantic salmon populations invaded by farmed escapees: quantifying genetic introgression with a Bayesian approach and SNPs. BMC Genetics 14: 74. Available at: https://bmcgenet.biomedcentral.com/articles/10.1186/1471-2156-14-74 [accessed on 13-07-17]

ICES. 2016. Report of the Workshop to address the NASCO request for advice on possible effects of salmonid aquaculture on wild Atlantic salmon populations in the North Atlantic (WKCULEF), 1-3 March 2016, Charlottenlund, Denmark. ICES CM 2016/ACOM:42. 44 pp

Hansen, L. P. & Youngson, A. F., 2010. Dispersal of large farmed Atlantic salmon, Salmo salar, from simulated escapes at fish farms in Norway and Scotland. Fisheries Management and Ecology 17(1): 28-32

Walker A., Beveridge, C. M., Crozier W., O Maoileidigh, N., Milner N., 2006. Monitoring the incidence of escaped farmed Atlantic salmon, Salmo salar L., in rivers and fisheries of the United Kingdom and Ireland: current progress and recommendations for future programmes. ICES Journal 63: 1201-1210

Webb, J. H., Youngson, A. F., Thompson, C. E., Hay, D. W., Donaghy, M. J., McLaren, I. S., 1993. Spawning of escaped farmed Atlantic salmon, Salmo salar L., in western and northern Scottish rivers: egg deposition by females. Aquaculture Research 24(5): 663-670

SSPO, 2015. Code of Good Practice for Scottish Finfish Aquaculture. Available at:http://thecodeofgoodpractice.co.uk/ [accessed on 13-07-17]