Within the AquaMax project, attention has been given to the health and welfare of the farmed fish fed with the new diets created in the AquaMax project.

Objectives

The main objective is to ensure that feeding diets containing alternatives to fish meal and fish oil do not affect the immune system and susceptibility to pathogens; that they do not induce production disorders like skeletal deformities; and that the fish's ability to cope with stressful rearing conditions is not affected. Specifically, studies will focus on mechanisms and routes of potential harm-full effects of the new diets on fish health and welfare.

Description of work

A range of methods including morphological, physiological and molecular analysis of processes relevant to fish health and welfare will be used. We will follow the development of possible production related disorders and welfare problems, such as cataracts, bone deformities and reduced skin quality through a full production cycle, as a consequence of new dietary regimes, or combinations of new diets and exposure to stresses normally encountered when farming the different species, e.g. crowding, high density, low oxygen availability, over-wintering.

The potential effects on innate and adaptive immunity, as well as resistance to infectious diseases and tissue antioxidant defence mechanisms will be studied using both conventional biochemical assays.

Analysis of symptoms of production related disorders, such as cataracts, bone deformities and reduced skin quality, will be performed using appropriate screening techniques and established biomarkers.

Oxidative stress on gastrointestinal tract integrity and body antioxidant defence mechanisms will be recorded using morphological, immunohistochemical, classical biochemical/nutritional (antioxidant vitamins, GSH, antioxidant enzymes) and molecular (mRNA expression of stress genes) techniques.

Challenge tests will be performed with model species and existing established biomarkers and new molecular tools applied to these and other species. High throughput molecular tools such as DNA microarray hybridisations will be applied to search for genes that are up- or down-regulated following exposure to alternative diets to identify underlying mechanisms for potential harmful effects on fish health and welfare.

Collaboration with on-going EU project

We will benefit from collaboration with on-going EU projects (WEALTH; MYXFISHCONTROL, AQUAFIRST) for defining relevant stress and immune parameters or undertaking challenge tests.

For more details on these projects, click here.