Factors influencing the upper temperature tolerances of three mussel species in a brackish water canal: Size, season and laboratory protocols

Mussels are the most problematic organisms encountered in the water intake systems of electrical power plants. Various fouling control measures are adopted, among which heat treatment is considered the relatively more attractive from economic and ecological points of view. Thermal tolerance experiments were carried out to determine the effects of mussel size (2 – 20 mm shell length), season (breeding vs non-breeding), nutritional status (fed vs non-fed), acclimation temperature (5 – 25°C) and acclimation salinity (1 – 35‰) on the mortality pattern of three important mussel species, viz. a freshwater mussel Dreissena polymorpha, a brackish water mussel Mytilopsis leucophaeata and a marine mussel Mytilus edulis under different temperatures (36 – 41°C). The mussels in the 10 mm size group exposed to 36°C showed 100% mortality after 38 min (D. polymorpha), 84 min (M. edulis) and 213 min (M. leucophaeata). The effect of mussel size on M. edulis and M. leucophaeata mortality at different temperatures was signif...