Developing Automated Multispecies Biosensing for Contaminant Detection

Automated biomonitoring may provide real-time functional information from cause/effect relationships between developing toxicity and a representative aquatic animal. However, since the applicability of single-species biomonitoring information may be subject to question when viewed in light of community toxicity and ecological quality control programs, we developed a computer-assisted multiple species biosensing system for water quality monitoring. In addition to fish, emphasis was placed on detecting species-specific bioelectric potentials produced by unrestrained mussels, burrowing mayfly nymph (Hexagenia spp.) and preliminary work with case building caddis fly larva. A specially designed differential amplifier was used for measuring bioelectric potentials induced from various activities of test subjects. Selected responses were detected as discrete analog signals, digitized and filed on computer disk. A management program provided various means for data gathering, filing and retrieval. Two pilot biomonitors were developed, each consisting of an instrumentation minicomputer with up to 12 biosensor input channels and various output peripherals including hardcopy and modem. These systems, combined with an IBM-XT personal computer based biomonitor interfaced to 24 multi-channel biosensor and physical parameter inputs, complete the present network. Results show that bioelectric signals generated from a variety of freshwater species may be easily monitored in a similar manner and viewed as representative measures in community toxicity testing.