Biological monitoring in its most rudimentary fonn probably had its origin in the minds of fish wardens, river keepers, and minders of lakes and ponds. Anyone living near a water body has a sense of biomonitoring, although not necessarily a scientifically rigorous one. Sentinel human noses have smelled septic hydrogen sulfide at remarkably good analytical levels. Aristotle, who. is credited with dabbling in nearly every known area of modem science, is known to have placed freshwater fish in salt water to observe their reactions. We define biological monitoring as surveillance using the responses of Jiving organisms to determine whether the environment is favorable to living material. Biological monitoring is not new, as the king's wine taster attests. In the early days of the industrial revolution, canaries were kept in underground coal mines. If a canary showed adverse reactions to conditions in the mine, the miners left. Biological monitoring also implies quality control· in which some corrective action will be taken if expected conditions are not met; but the existence of a feedback mechanism that involves a response to indications of failed environmental health is problematic in most countries. Not until the industrial revolution did the impact of human activities on water resources become clear to almost everyone. During the eighteenth century, the River Thames flowing through London produced a stench so nauseating that sheets soaked in vinegar were hung in Parliament to partly offset the noxious air wafting in from the river (Gameson and Wheeler, 1975). An uncharitable person might note that, even under these circumstances, Parliament was not quick to act to remedy the situation until human health concerns, such as typhoid fever and cholera (from the infamous Broad Street pump), surfaced as serious threats to the ebb and flow of" modem" life. The protection of human health still drives much of the pollution control regulation and technology in the developed world. The realization that unmanaged ecosystems soon fail to provide free ecological services, such as