The Selection And Application Of Early-warning Fish In Online Water Quality Monitoring And Early-warning System

In the research, the application of five common small ornamentalfishes-Zebrafish(Danio rerio), guppy(Poecilia reticulata),red swordfish(Xiphophorushellerii), tiger barb(Puntius tetrazona)-in raw water quality early-warning wasinvestigated. First, the sensitivity of fishes to heavy-metal was determined through24h acute toxicity test in pure-water. The suitability and stability were consideredtogether to determine one kind of fish as the early-warning fish. Then, theearly-warning fish was tracked and monitored with early-warning software. Thechange of its behavior and body color was used to monitor water pollution incidents.The content of this research include:1. The comparison of sensitivity of target fishes to different heavy metalThe of24h acute toxicity test in pure-water was conducted to study the24h-LC50four heavy metal to target fishes. It turned out that24h-LC50of differentheavy metals on zebra fish (blue, red)(Danio rerio), red swordfish (Xiphophorushellerii), guppy (Poecilia reticulata), tiger barb (Puntius tetrazona) were as below:Cu2+：0.017、0.020、0.102、0.028、0.009mg/L；Hg2+：0.085、0.088、0.173、0.075、0.092mg/L；Cd2+：0.375、0.378、0.408、0.146、0.983mg/L；铬：34.458、34.709、22.792、10.196、23.884mg/L. The sensitivity of target fishes to heavy metal wasdifferent. The result showed that the sensitivity of five target fishes was bluezebrafish>red zebrafish>guppy>red swordfish>tiger bar.2. Domestication of the target fishes in the raw waterThe pure water that target fished lived in was replaced by Huangpu raw water.the replacement amount was20%、40%、60%、80%、100%. Each test of differentconcentrations lasted for24h. In the test, the death amount of target fishes wasrecorded, and the death rate was calculated. The result showed that the adaptabilityof the five fishes to raw water was blue zebrafish>red zebrafish>swordfish>tiger bar>guppy. The following test confirmed that10days were needed to complete thedomestication.3. The selection of early-warning fishWe scored the target fished through four parts below:a. The sensitivity and stability to toxic substances（24h-LC50）b. The influence of their color and activity to monitoring software.c. The stability to raw waterd. The time of toxic reactionThrough the comparison, the result indicated that blue zebrafish got a highestscore, so it was selected as the early-warning fish in final.4. The monitoring of early-warning fish behaviorA new developed online early-warning system was used to track theearly-warning fish. Then its behavior was analyzed with monitoring software tomonitor the quality of water through early-warning fish Group-Activity andGroup-Center-Coordinate. The monitoring result showed that as the early-warningparameter, the time when Group-Activity changed had an obvious Dose-responserelationship with the concentration of pollutants. The distribution of Group-Center-Coordinate could reflect the distribution of fish group in the tank, and then reflect thestatus of the group. So the Group-Activity and Group-Center-Coordinate could beused as monitoring parameters to detect the water quality...