Résistance thermique supérieure de Gammarus fasciatus, Say (Crustacea, Amphipoda) et son utilisation en situation de rejets thermiques
The upper thermal resistance limit (dose–time analysis of mortality at high temperatures) has been determined in the amphipod G. fasciatus on a time scale of up to 5 days. LTm's (median tolerance limit: 50% survival time) show a 1.12 mean multiplication factor for each degree of acclimation between 5 and 25 °C and a mean reduction factor of 2.06 for each degree of exposure between 25 and 38 °C. Toxicity curves relating LTm, acclimation, and exposure temperatures serve to establish short-term survival diagrams that can be used in various situations of thermal shock. Priority should be given to the ΔT (interval between exposure and acclimation temperatures) or its duration. Thus, a 10 °C ΔT seems to be tolerated during an indefinite period of time when the water temperature is 15 °C or less. Predicted survival times are only 2 days and 2 h, respectively, when temperatures reach 20 and 25 °C. The methods used in this study helped to establish some short-term protection criteria for this species. These methods are also applicable to the study of other species or groups of aquatic organisms.[Journal translation]