Sea lice on Salmon
Funded by: Biotechnology and Biological Sciences Research Council, and the Chilean government (CONICYT)
Project partners: Universidad de Chile, University of Aberdeen, University of Glasgow, BioMar, Lallemand, Veterquimica
Principal Investigator: Dr Daniel Merrifield
Co-investigators: Dr Vikram Sharma, Professor Sam Martin, Dr Martin Llewellyn, Dr Ted Henry, Dr Jaime Romero

Developing strategies to control sea lice infections

Dr Daniel Merrifield and a team of experts across biotechnology, microbiology, immunology and pathology addressed the immunological responses to sea lice infections in the commercially important species, Atlantic salmon (Salmo salar).
Sea lice (Lepeophtheirus salmonis and Caligus spp) infections are the most economically important causes of disease in marine-farmed salmon worldwide. Sea lice infestation costs the UK aquaculture sector alone more than £20 million annually and the Chilean aquaculture industry more than $120 million every year and poses a major risk for global food security.
Aerial photo of aquaculture of salmon in Atlantic ocean

Fish mucosal surfaces, microbiomes and pathogens

A better understanding of the relationship between sea lice (host-microbiome-parasite) and the mucosal surfaces (skin, intestine and gills) of salmon and other fish is an essential prerequisite for improved treatment strategies. 
The mucosal surfaces of fish are constantly interacting with a wide range of pathogens and alongside the mucosal microbiota are the first line of defence for fish against pathogens. Several immune factors can affect this line of defence and lead to bacterial or microbial imbalances that may lead to secondary infections. Sea lice infections damage the external surface of the fish, which provides a portal of entry for secondary infections and, alongside the stress of infections, can suppress the immune response.

Evaluating the influence of sea lice infection on salmon health and immune responses

The research explored the relationship between mucosal health, diet, and microbiota in salmon, developing the understanding of both lice and salmon responses to infection – determining epidermal mucus proteomic responses, microbiota changes and mucosal transcriptomic changes.
Researchers looked at the effect of dietary supplements on the fish's immune systems and its ability to develop resistance to sea life infestation in order to develop new strategies for antigens for vaccines, targets for RNAi, probiotics, prebiotics and imminomodulants for sea lice control.

Aquaculture: Fish Health and Nutrition

The University of Plymouth has a strong research track record in the fields of fish health and nutrition dating back more than three decades. 
Led by Dr Daniel Merrifield, the Fish Health and Nutrition research team actively engages with hatcheries, aquaculture farms and various other organisations, nationally and internationally, to support and conduct research and development at fundamental and applied levels contributing to United Nations Sustainable Development Goals, 2 (Zero Hunger), 12 (Sustainable Consumption and Production) and 14 (Life Below Water).
Fish tanks in the facilities for animal studies

Centre of Research excellence in Intelligent and Sustainable Productive Systems (CRISPS)

CRISPS brings together a vibrant community of transdisciplinary researchers, working towards addressing the challenge of sustainably feeding a global population of 9 billion. Founded upon research excellence in aquaculture, agricultural technology and soil health, and underpinned by investment in cutting-edge facilities, the Centre will create the critical mass required to ensure impactful research and real-world deployment in the UK and beyond.
Centre of Research Excellence in Intelligent and Sustainable Productive Systems (CRISPS) lead image showing a hand holding soil and a plant.