Abstract
The response characteristics of an aquatic biomonitor that detects toxicity by monitoring changes in bluegill (Lepomis macrochirus Ra๏ฌnesque) ventilatory and movement patterns were evaluated in single chemical laboratory studies at concentrations near the 96โh LC~50~ concentration and at the EILAToxโOregon Workshop in sequential tests of multiple unknown samples. Baseline data collected prior to exposure allows each ๏ฌsh to serve as its own control. When at least 70% of exposed ๏ฌsh exhibit ventilatory or movement parameters signi๏ฌcantly different from baseline observations, a group alarm is declared. In the laboratory studies, the aquatic biomonitor responded to the majority of chemicals at the 96โh lc~50~ within an hour or less, although substantially higher response times were found for malathion and pentachlorophenol. Workshop tests of single chemical concentrations presented as blind samples were consistent with the laboratory test results. There were no alarms under control conditions in any test. Although data are limited, the aquatic biomonitor appears to respond more rapidly to chemicals causing membrane irritation, narcosis or polar narcosis than to acetylcholinesterase inhibitors or oxidative phosphorylation uncouplers. All four monitored parameters (ventilatory rate, cough rate, ventilatory depth and movement) contributed to identi๏ฌcation of ๏ฌrst alarms at acutely toxic levels. Understanding these response patterns can be useful in data interpretation for biomonitor applications such as surface water monitoring for watershed protection, wastewater treatment plant ef๏ฌuent monitoring or source water monitoring for drinking water protection. Copyright ยฉ 2004 John Wiley & Sons, Ltd.