Abstract
A method based on the image analysis of the activity of Medaka (Oryzias latipes) was investigated for continuous water quality monitoring. The image dots of 5,760 were set in the monitor tank (39cmW×45cmL). The number of dots in which the image was changed in one second was continuously counted, and then standardized using their daily average value in order to evaluate the relative activity. The control of the circulation water speed in the monitor tank was important for the image analysis of the activity of moderately stable Medaka swimming. The change in temperature to lower than 15 ℃ or higher than 40 ℃ produced a severe drop in Medaka’s activity even without chemical contamination. The useful alarm for a water quality problem could become available by the classification of the relative activity within a few hours depending on the concentration of the chemicals.
