Detection of chemical pollution in water - by studying effect on rainbow trout in a vortex

摘要

Detection in water of chemical pollution, which is (sub-) lethal to fish, is effected in a circular current of water in a funnel; a vortex is created by the tangential feed of the liq by the pump. The funnel is connected to the reservoir and to the pump. A probe is connected by the cable to a timing clock and to the pump. The degree of pollution is indicated by its effect on a living fish, such as a rainbow trout. Normally the level of the liq. remains constant but when the fish swimming in the vortex can no longer struggle against the current it blocks the outlet and the water rises till it touches the probe; this stops both the clock and the pump. The period of time that the fish can resist the suction effect of the vortex is a measure of the toxicity of the liq. The test can be used for the detection of chemically pure toxic substances in water and also for the evaluation of the toxicity of complex mixts., such as effluents discharged into natural waters. Synergistic effects can be studied and the overall toxicity of a raw effluent to fish can be determined.