Author
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Davis Jr, Kenneth |
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Submitted to: American Fisheries Society Annual Meeting
Publication Type: Abstract Only Publication Acceptance Date: 5/7/2004 Publication Date: 8/22/2004 Citation: Davis Jr, K.B. 2004. Consequences of stress in aquaculture [abstract]. American Fisheries Society Annual Meeting. p. 159. Interpretive Summary: Technical Abstract: Physiological stress is a non-specific response initiated by many types of environmental changes. Stress in freshwater fish can be characterized by changes in plasma cortisol, glucose, and electrolyte concentrations, and is quantitatively related to the severity and longevity of the stressor. A hierarchy is evident among the physiological changes, such that adrenalin from sympathetic nervous system activation is the most sensitive indicator to stress, followed by cortisol, and then glucose. Plasma electrolyte disturbances may not occur until the stress is severe and present for an extended time. Adrenalin increases plasma glucose by stimulating liver glycogenolysis, which represents energy loss to the fish. The activities of cortisol include induction of gluconeogenesis and suppression of the inflammatory response. Maintaining osmoregulatory homeostasis is an energetically expensive process and disturbances deplete energy reserves. Commercial aquaculture involves raising fish at very high densities and requires minimizing stressors such as water quality deterioration, disease treatment, and handling to maintain healthy growing fish. Recent experiments have shown the importance of distinguishing between acute and chronic responses to stress. Acute responses to stressors may be beneficial to the fish and extend their normal adaptive ability, whereas chronic exposure to stressful conditions may result in decreased performance or survival. |
