numbers of species (no./core) collected from March 1979 through March 1986. As noted previously, 

 natural temporal and spatial fluctuations in infaunal communities often reflect environmental changes 

 due to climatic conditions or to life history cycles of the organisms comprising these communities. To 

 remove this natural variation, the following were used as explanatory variables in our multiple regression 

 models: 



A. Precipitation 



Daily precipitation records compiled by the U.S Weather Bureau at the Groton Filtration Plant 

 were obtained from June 1976 through March 1986. Values to the nearest 0.01 inch were used as our 

 "rain" data for the regression model. 



B. Water and Air Temperature 



Ambient water temperatures (at the Millstone Intake Structures) and air temperatures (at the 33-foot 

 level of Millstone meterological tower) were extracted from the Northeast Utilities Environmental Data 

 Acquisition Network (EDAN). Daily averages, based on observations made at 15-minute intervals, were 

 calculated for the period June 1976 to March 1986. 



C. Wind Speed and Direction 



Wind speed and direction (at the 33-foot level of the Millstone meterological tower) were extracted 

 from the EDAN database at 15-minute intervals from June 1976 to March 1986. These values were 

 used to calculate a Wind Index which weighted wind speed according to wind direction. A NOAA 

 navigational chart of the sampling area was used to calculate site-specific wind direction weights according 

 to the particular wind direction responsible for potential wave-induced sediment disturbances at each 

 sampling station. The directional weight ranged from 0, when wind would not influence the station, to 

 1, when the wind could result in waves directly affecting the area. The Wind Index was then computed 

 by multiplying the directional weight times the wind speed. Because the effect of wind was assumed 

 to be cumulative, daily averages were derived using only Wind Index values greater than (i.e., wind 

 direction and speed during the 15-minute periods when such wind-induced effects could have occurred). 



