Investigation On Effect Of Different Pollutants On Fish Swimming Behavior By On-line Monitoring Method

Recently water pollution accidents especially serious or sudden ones have happened frequently in China, influencing our daily life and production safety. Considering the current pollution status, it is necessary to establish a real-time biological monitoring system to survey the water pollution.On-line biological monitoring method is a new technology that can clarify the environmental pollution situation through swimming behavioral responses of fish. This system consists of three parts:water tank, computer and peristaltic pump. In the system, fish movements were tracked by three-dimensional (3D) biomonitor under the flowing water. Then behavioral responses of fish were recorded and converted into the3D data which can reveal the water quality.This research focused on sudden water pollution accidents, chosen zebrafish, red carp and medaka as experimental animals, investigating the effects of PCP (pentachlorophenol), phenol and terramycinon fish behaviors by acute exposure test and water quality on-line monitoring test. In the present study, the3D data of fish behavioral responses before or after exposure to different chemicals was recorded and analyzed, including movement trace, swimming speed (median), surface behavior frequency and entropy.In addition,the swimming speed (median) and surface behavior frequency were analyzed at LC50(Lethal Concentration50) of different chemicals. The results showed as follows:(1) Zebrafish, redcarp and medaka swimmed fast after exposing to50mg-L"1phenol, and the durations of this phenomenon of three fish were10min,30min and20min respectively. Zebrafish and medaka were more suitable than redcarp for on-line monitoring test and the sensitivity sequence from high to low was zebrafish, medaka, red carp.(2) There was no significant difference on swimming behavior of fishin groups treated with0.25mg-L"1,0.5mg-L"1PCP and250mg-L-1terramycin in comparison with the control. However, exposure to the moderate concentrations (1,2,4mg-L"1) of PCP and50mg-L"1phenol had dramatic impacts on behavioral responses of zebrafish compared with fish before exposure.(3) After exposure to LC50of different pollutants, there was a positive correlation between the LC50and swimming speed (median), whilethere was a negative correlationbetween the LC50and surface frequency within the first10min. In general, the behavioral responses of fish were dependent on the exposing concentrations of pollutants. We can detect pollution status by monitoring the swimming behavior of fish through3D-biomonitor. It could be expected that fish swimming ethology would play an important role in monitoring the water pollution accident.