The development of high throughput diagnostic techniques to assess fish health and the impact of sea lice treatment in aquaculture

This industry led project uses a translational approach towards the re-purpose and validation of human medical diagnostic technologies to assess the health and impact of sea lice treatment on salmonid fish (rainbow trout and Atlantic salmon) in aquaculture in Scotland. There is currently no rapid, non-lethal method to assess fish health in aquaculture. This novel and innovative approach using automated and semi-automated technologies shall allow the rapid testing of various biomarkers of health (Table 1) from large numbers of fish, allowing for the first time the validation and establishment of background levels of these highly conserved endpoints commonly used in human and veterinary medicine.

This approach provides farmers with a means to assess the chronic impact of sea lice treatment, allowing the optimisation of the treatment method. The impact was assessed using clinical chemistry, haematology and histopathological methods.

Rainbow trout treated with azamethiphos (Salmosan) were assessed for 22 clinical chemistry endpoints. Creatinine, a biomarker of kidney damage was significantly elevated post treatment (Fig 1a). ALP, a typical marker of liver condition, was significantly elevated 10 days post treatment (Fig 1b). Increases in total bilirubin and haemoglobin indicate haemolysis occurred. These results were correlated with histopathology and shall be discussed for both salmon and rainbow trout.