Counting the true cost of combatting sea lice

21 August 2019, at 4:34am

How the recent proliferation of sea lice, and new methods for ensuing salmon are not infested with them, is driving up the cost of Norwegian salmon production was the subject of a compelling talk at Aqua Nor yesterday.

Part of Benchmark’s “Aquaculture fit for the future” seminar, the talk by Audun Iversen of Nofima gave a detailed breakdown of why sea lice were costing Norway's salmon sector 5 billion kroner (£460 million) – a figure higher than many people imagined - a year.

Iversen noted that production costs are increasing and, given that little of this is due to feed cost, "much of this is increase is related to lice, more or less directly".

Lice costs per kilo of salmon produced in Norway
Lice costs per kilo of salmon produced in Norway

© Nofima

In order to illustrate his point he looked at the most popular novel methods for combatting the ectoparasites, noting that the use of cleaner fish added an average of 1.2 kroner per kg of salmon produced, with this cost being accounted for by not only purchasing the fish, but also by feeding, transporting and providing hides for the cleaner fish.

He calculated that another novel method the louse laser – of which around 200 are currently being used in the sector - could be tallied up to around 0.34 kroner per kilo of salmon; bath treatments added an average of 0.5-1 kroner per kilo; while the new generation of mechanical treatments, such as hydrolicers and thermolicers, added 0.55 kroner per kilo.

Moreover, although conceded that there has been a dramatic reduction in the use of medicinal methods for treating lice, he pointed to a number of “indirect costs” that need to be factored in but are harder to quantify.

Lice have been partially to blame for the increase in FCRs in Norway over the last 15 years
Lice have been partially to blame for the increase in FCRs in Norway over the last 15 years

© Nofima

These include the drive to produce larger smolts before putting them out to sea (the average size has increased from 80g in 2000 to nearly 140g in 2018), the lower smolt yields, the higher labour costs per kilo, the increase in both mortality rates and higher feed conversion ratios (FCRs).

Moreover, he noted the problems are not unique to Norway and are broadly mirrored in Scotland, Chile, Canada and the Faroes.

Senior editor at The Fish Site

Rob Fletcher has been writing about aquaculture since 2007, as editor of Fish Farmer, Fish Farming Expert and The Fish Site. He has an MA in history from the University of Edinburgh and an MSc in sustainable aquaculture from the University of St Andrews. He currently lives and works in Scotland.

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