HAVBRUKS-Havbruk - en næring i vekst

To improve welfare of farmed fish there is a need to develop objective indicators that can be used to assess, manage and document welfare. The high number of individuals in aquaculture production units puts constraints on which indicators that are likely to be operational in the industry. Behavioural indicators are prime candidates as the are sensitive, observable, and can be used on the group level. Behaviour is controlled by complex underlying motivational and physiological coping mechanisms. Motivation is a key concept in behavioural biology that describes emotional or affective states and regulates the strength of the behavioural response. Our knowledge about motivation and the behavioural needs of the major farmed fish species is very limited. Phsyio logical coping is defined as the physiological mechanisms an individual is using to deal with a threat against its mental and physiological stability in order to grow, survive and reproduce well. Challenged with unfavourable external conditions (like poor water quality) or internal conditions (e.g emotional stress), the fish seeks to maintain homeostasis through altered behaviour and physiology. A stress response does not necessary lead to reduced welfare, but the costs of repeated acute or chronic stress can in the long run lead to reduced health and welfare. Using Atlantic salmon and cod as model organisms, this project aims at reveal fundamental relationships between physiological coping ability, motivational states and behaviour in groups of fish expo sed to stressors relevant to commercial aquaculture. Methods to measure motivation will be developed. Fluctuations in water quality (temperature, CO2, O2) and handling stress (decompression) will be used as acute stressors, while chronic stressor will be deteroiating water quality ambient. The results from the project will be implemented in complemenatry ongoing projects and contributed to networks which aim to develop operational protocols for welfare assesment