Mortality of small (60-100 mm total length) Eurasian perch Perca fluviatilis after marking with coded wire tags (CWTs) in relation to water temperature (6.9, 14.2, 17.8, and 22.6 °C) was experimentally tested and exclusively occurred within the first day of the experiments. Moreover, mortality rates were generally low with a maximum of 4%. No increased mortality at higher water temperatures was observed. ; JRC.G.3-Agriculture