Two upper Piedmont streams were studied to determine the effects of road construction, especially sediment inputs. Benthic macroinvertebrate data suggest that the stream community responded to sediment additions in two different ways. Under high flow conditions the benthic fauna occurs mainly on rocky substrates. As sediment is added to a stream the area of available rock habitat decreases, with a corresponding decrease in benthic density. There is, however, little change in community structure. Under low flow conditions, stable-sand areas may support high densities of certain taxa. Density of the benthic macroinvertebrates in these areas may be much greater than the density recorded in control areas, and there are distinct changes in community structure.

Instream toxicity was predicted with whole effluent toxicity tests. These results were then compared to the observed instream response of the aquatic community. Forty-three comparisons were conducted in freshwater flowing systems using Ceriodaphnia dubia chronic toxicity test procedures and standardized qualitative sampling of benthic macroinvertebrates. In 88% of the comparisons there was agreement between both measures. These data suggest that the use of effluent toxicity testing results as a regulatory tool is effective and appropriate. Comparisons used whole effluent toxicity limitations similar to those being written in North Carolina's NPDES permits for discharge to surface waters.

Recent advances in site-specific detection of fish's physiological responses to continuous stream flows now complement surveillance programs utilizing remote automated water quality monitoring stations. Developments in automated biosensing provide methods for measuring in situ fish breathing rate changes to stream episodes and add a real-time biological monitoring dimension to remote water quality networks incorporating automated data collection platforms and satellite data retrieval options. In meeting our objective of developing automated biosensing capabilities for remote monitoring, a series of field trials was designed to test various configurations of in situ fish-holding chambers, breathing rate detectors, and system interface to streamside water quality data collection platforms for satellite data retrieval. Results were used to design groups of automated biosensing devices for detecting rainbow trout breathing rate responses and to implement eight units at each of two data collection, platform-equipped, water quality stations located along a stream subject to acid precipitation influences in the Southern Appalachian Mountains. Remote stations are being maintained for real-time data needs as a part of the 5-year Acid Precipitation Mitigation Program initiated in 1985 by the U.S. Fish and Wildlife Service to evaluate stream ecological responses to regulated liming operations.

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