Lumpfish stress response characterization, health and welfare improvement through nutritional management and selective breeding

CYCLOIMPROVE aims to improve the welfare status of lumpfish used in Atlantic salmon aquaculture by mitigating health disorders through nutritional management. The project will also contribute to health robustness of the farmed lumpfish by assisting a selective breeding program with key immunology studies. In the last years, there has been an incredible growth of the deployment of lumpfish in Atlantic salmon pens to assist in biological control of sea-lice. This tremendous growth led to a lagging understanding of the biological needs and physiological processes of lumpfish, which often poses a serious welfare risk. As with any novel aquaculture species, it is paramount to increase our knowledge on the species requirements to sustain and support the growth of the industry while safeguarding fish welfare. To achieve CYCLOIMPROVE?s goals, a series of planned studies will be conducted to ascertain the relation between nutritional status, stress response and health disorders in lumpfish under aquaculture conditions. A greater understanding of the lumpfish stress response and its relation to reported health disorders can assist farmers in the interpretation and detection of early signs of health and welfare worsening. For this purpose, a series of stress-related studies will be conducted, studying the acute and chronic stress physiology of this species, as well as the associated health disorders. In addition, an understanding of the relation between nutritional requirements, the stress response and health disorders will allow the formulation of customized nutritional strategies that counter nutritional-related health disorders while promoting health.

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Lumpfish use in biological control of sea-lice is growing exponentially, with a growing concern over the welfare of these animals, as they undergo several acute and chronic stress events throughout their life in aquaculture operations. Our knowledge about possible suppressive effects of chronic stress in the lumpfish immune system and overall health is very limited. It is therefore, essential to understand how to accurately assess stress status with robust biomarkers, and how stress relates to several health impairments, such as high cataract incidence and disease outbreaks reported in this species. Aquaculture of lumpfish is still in its infancy, and as such, customized aquafeeds are still sub-optimal. These dietary imbalances become aggravated with stress, since the latter increases demand for energy. Thus, studying the relation of several health disorders to the nutritional and stress status of lumpfish is of utmost importance to improve the welfare of these animals. This project will assess differences in stress response and immune status between lumpfish families in net pens with Atlantic salmon, contributing to breeding programs, which are paramount for optimized performance of a cultured species. The overall aim of this doctoral thesis is to improve lumpfish welfare by characterizing the stress response, identifying nutritional imbalances and stress suppressive effects in health, and designing a nutritional strategy to counter identified health impairments.