Final Report Summary - WEALTH (Welfare and health in sustainable aquaculture)
The health and welfare of European farmed fish remains a major concern due to environmental conditions and husbandry practices and in spite of the progress in diagnoses, sanitary control and proactive treatment. Current knowledge is incomplete and fragmented and a holistic view of the problem is still lacking. Therefore, the WEALTH project aimed to:
1. develop knowledge on health and welfare of farmed fish by focusing on Atlantic salmon and sea bass and transferring the obtained results to other species;
2. examine various prevailing environmental factors and husbandry practices in different aquaculture systems in order to identify their effects on health and welfare;
3. increase understanding of the physiological and molecular mechanisms underlying the interactions of environmental and farming conditions on fish stress;
4. identify innate and acquired susceptible immune parameters and develop effective molecular tools to study and monitor the immune function, barrier functions and stress responses of fish;
5. develop and validate operational husbandry protocols for improved health and welfare, including compromised welfare and methods for early prediction and management of disease outbreaks.
The project was structured in five distinct, yet interrelated, work packages (WPs). A series of experiments was conducted to represent different conditions of farming and varying oxygen availability. The response of sea bass to anaesthesia and dissolved CO2 concentrations was also investigated.
In addition, new labelling techniques for pathogenic bacteria were developed and the existing non-invasive stress assay methodology was transferred to the targeted species' studies. Creatinine was selected as a measurable normaliser for loading density and was monitored using a colorimetric plate assay. Moreover, causal relationships were established between endocrine control, physiology and immunology of the Atlantic salmon, while the behavioural stress responses of sea bass were thoroughly examined.
Apart from that, the physiological stress responses of the fish were monitored and an attempt to identify patterns of the morphology of primary barrier tissues under stress conditions was undertaken. Intestinal barrier functions were analysed, along with the potential translocation of enteric pathogens through a series of innovative experiments. Endocrine profiles were also generated.
The communication between the immune and endocrine systems of the organisms was reviewed in detail because of its importance for the maintenance of homeostatic function. Moreover, the effects of husbandry conditions on the immune competence in sea bass were investigated. A genomic analysis was subsequently elaborated to identify new stress tools and markers. Finally, WEALTH activities included monitoring and sampling from commercial facilities, so as to evaluate the project assumptions and results under actual operating conditions.
The generated knowledge was utilised for the development of recommendations and husbandry protocols aiming to improve farmed species' conditions. Moreover, WEALTH pinpointed knowledge gaps and issues that required additional research efforts. The proposed tools enabled the design of new studies to verify threshold and optimum levels for a range of biotic and abiotic factors and husbandry practices. Finally, the project outcomes were essential in validating welfare indicators and measuring coping costs in cases when the individuals tried to maintain their normal physiological and behavioural functions.
1. develop knowledge on health and welfare of farmed fish by focusing on Atlantic salmon and sea bass and transferring the obtained results to other species;
2. examine various prevailing environmental factors and husbandry practices in different aquaculture systems in order to identify their effects on health and welfare;
3. increase understanding of the physiological and molecular mechanisms underlying the interactions of environmental and farming conditions on fish stress;
4. identify innate and acquired susceptible immune parameters and develop effective molecular tools to study and monitor the immune function, barrier functions and stress responses of fish;
5. develop and validate operational husbandry protocols for improved health and welfare, including compromised welfare and methods for early prediction and management of disease outbreaks.
The project was structured in five distinct, yet interrelated, work packages (WPs). A series of experiments was conducted to represent different conditions of farming and varying oxygen availability. The response of sea bass to anaesthesia and dissolved CO2 concentrations was also investigated.
In addition, new labelling techniques for pathogenic bacteria were developed and the existing non-invasive stress assay methodology was transferred to the targeted species' studies. Creatinine was selected as a measurable normaliser for loading density and was monitored using a colorimetric plate assay. Moreover, causal relationships were established between endocrine control, physiology and immunology of the Atlantic salmon, while the behavioural stress responses of sea bass were thoroughly examined.
Apart from that, the physiological stress responses of the fish were monitored and an attempt to identify patterns of the morphology of primary barrier tissues under stress conditions was undertaken. Intestinal barrier functions were analysed, along with the potential translocation of enteric pathogens through a series of innovative experiments. Endocrine profiles were also generated.
The communication between the immune and endocrine systems of the organisms was reviewed in detail because of its importance for the maintenance of homeostatic function. Moreover, the effects of husbandry conditions on the immune competence in sea bass were investigated. A genomic analysis was subsequently elaborated to identify new stress tools and markers. Finally, WEALTH activities included monitoring and sampling from commercial facilities, so as to evaluate the project assumptions and results under actual operating conditions.
The generated knowledge was utilised for the development of recommendations and husbandry protocols aiming to improve farmed species' conditions. Moreover, WEALTH pinpointed knowledge gaps and issues that required additional research efforts. The proposed tools enabled the design of new studies to verify threshold and optimum levels for a range of biotic and abiotic factors and husbandry practices. Finally, the project outcomes were essential in validating welfare indicators and measuring coping costs in cases when the individuals tried to maintain their normal physiological and behavioural functions.
