Program rensefisk: Kunstig lys og rensefisk - Sluttrapport FHF prosjekt 901146

In this review, we have systematized current knowledge about the effect of stocking lumpfish (Cyclopterus lumpus) as cleaner fish to control Lepeophtheirus salmonis infestations on farmed Atlantic salmon (Salmo salar L.). The review was prompted by recent reports in which the usefulness of lumpfish has been doubted, and the urgent need to investigate whether common lumpfish can be used to reduce L. salmonis numbers on farmed Atlantic salmon by active grazing on this species. Available published data clearly indicate that lumpfish graze on L. salmonis, and can significantly lower the lice burden in Atlantic salmon farming. It is possible to enhance the lice grazing behavior of lumpfish with the assistance of live feed conditioning prior to sea pen transfer, and with selective breeding. Data indicate that lice grazing of lumpfish is size dependent, and grazing effect is low for lumpfish larger than 200–250 g. Observations from large-scale rearing of Atlantic salmon in open sea cages in Norway, Iceland, the Faroe Islands, and Scotland also indicate that lumpfish can be effective in lowering infestations of L. salmonis on salmon. Overall, this present review reveals that lumpfish can actively contribute to lower numbers of L. salmonis on farmed Atlantic salmon.

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In lumpfish We Trust? The Efficacy of Lumpfish Cyclopterus lumpus to Control Lepeophtheirus salmonis Infestations on Farmed Atlantic Salmon: A Review

Chronic allostatic overload on the hypothalamic-pituitary-interrenal axis of lumpfish (Cyclopterus lumpus). Effect of size

Personality profiling may help select better cleaner fish for sea-lice control in salmon farming

Investigation and comparative analysis of ecological risk for heavy metals in sediment and surface water in east coast estuaries of India

Output Status: Forthcoming/Available Online Additional authors: P.T.J. Deacon, B.T. Jennings, A. Deakin, A.I. Moore, D. Phillips, G. Bardera, M.F. Castanheira, M. Scolamacchia, N. Clarke, O. Parker, J. Avizienius, M. Johnstone & M. Pavlidis

https://dspace.stir.ac.uk/bitstream/1893/32848/1/raq.12589.pdf

Addressing the welfare needs of farmed lumpfish: knowledge gaps, challenges and solutions

Lumpfish (Cyclopterus lumpus L.) are commercially important species used world-wide since 2008 as cleaner fish to control sea lice (Lepeophtheirus salmonis), one of the most significant parasites affecting Atlantic salmon (Salmo salar L.) and costing the industry over 500M € annually. However, lumpfish mortalities in sea cages can be as high as 100%, raising welfare concerns on whether their use continue to be acceptable. The industry is under scrutiny by both government agencies and non-governmental organisations to improve lumpfish welfare, but they do not provide much direction as welfare standards are not developed yet for this species. This thesis examined novel ways to monitor welfare in farmed lumpfish in order to increase the sustainability and ethical use of lumpfish in aquaculture. Chapter 1 reviewed the bases of fish welfare as well as lumpfish biology, use as cleaner fish and main challenges within the aquaculture industry. Chapter 2 developed and tested a practical, easy-to-use, validated and highly repeatable (ICC=0.83) scoring index combining six Operational Welfare Indicators to measure lumpfish welfare under farm conditions. Chapter 3 found welfare deterioration in sea cages to be dependent on time spent at sea and to be worse in smaller fish. Welfare monitoring should be particularly regular during the first months post-transfer at sea. Chapter 4 found differences in welfare, growth, feeding preferences and gut microbiota between different genetic stocks of lumpfish, with Icelandic lumpfish growing faster, showing better welfare and ingesting more formulated pellets than Scottish lumpfish. Significant associations in the gut microbiota were identified between compromised welfare and Candidatus branchiomonas and high plasma cortisol and Clostridium, suggesting these could be used as potential biomarkers. Chapter 5 investigated the effect of sea lice ingestion in lumpfish welfare and gut health and found that sea lice ingestion did not have any influence and is not detrimental for lumpfish welfare. Welfare investigations under commercial conditions proved that lumpfish welfare status (measured by using individual morphological indicators) deteriorates in time when stocked in salmon net pens, resulting in an increase of these scores, which also differ between commercial sites and populations under the same conditions. The ability of monitoring welfare in regular basis serves as an early warning for health and welfare issues and the application of the index along the knowledge withdrawn from this thesis will help farmers to identify critical periods where lumpfish welfare starts deteriorating, as well as provide scientific reference to policy developers, welfare organisations and NGOs and quality assurance schemes. In this sense, welfare standards for these novel species can be developed, and corrective actions can be taken before any issues progress into mortalities. This will enhance the sustainability of the lumpfish industry and will reduce economic costs of sea lice management, mitigating environmental impacts for not using chemotherapeutants at sea and improving salmon welfare overall. 

Carolina Gutierrez Rabadan

Papers

Addressing the welfare needs of farmed lumpfish: knowledge gaps, challenges and solutions

Welfare investigations in farmed lumpfish (Cyclopterus lumpus L.) used for sea lice control in the salmon industry