Tolerance of copepods to short-term thermal stress caused by coastal power stations

Abstract

The tolerance of marine copepods to short-term thermal stress was measured by the median lethal temperature (LT 50) tests in laboratory. Experiments on LT 50 of copepods from different acclimation and acclimatization conditions collected from the Yueqing Bay were carried out under heat exposure for 15, 30 and 45 min. The LT 50 of copepods decreased with increasing exposure time but increased with rising acclimation and acclimatization temperatures. However, the differences in copepod LT 50 decreased with rising acclimatization temperatures, which suggested that entrained copepod mortality increased with raised water temperature due to the acute thermal stress of coastal power stations. Results also revealed that the thermal tolerance of Labidocera euchaeta was much higher than that of Calanus sinicus in spring. The thermal tolerances of different copepod species in summer were in the order, Pseudodiaptomus marinus, Acartia spinicauda, Acartia pacifica and L. euchaeta.