Milkfish (Chanos chanos) under stress: Contributing to fish welfare in tropical aquaculture by identifying and quantifying potential stressors
Summary: Due to an ever-growing world population, the demand for aquatic food resources has increased constantly in the last decades and will continue to do so in the future. In order to meet the growing demand, aquaculture practices have intensified tremendously over the last decades. Current intensification of management practices is considered as a potentially severe threat to fish welfare and a sustainable production. Besides potential stressors due to the lack of optimization of management procedures, outdoor-based aquaculture systems are additionally prone to daily and seasonal environmental fluctuations. Therefore, cultured fish have to be able to cope with environmental fluctuations, such as changes in temperature and/or dissolved oxygen concentration, which could potentially cause stress. Stressful stimuli initiate an endocrine response in fish. For teleost fish, this includes among others, the release of cortisol via the hypothalamic-pituitary-interrenal axis. Furthermore, stress induces glucocorticoid-mediated changes in the fish's energy metabolism (e.g. reallocation of energy resources) to provide energy in order to restore the homeostatic state, and subsequently to cope with the stressor (more info attached)