is about 1.5 m, the tidal exchange is about 2 x 

 10^ m''/s, which over a 12.5-hr tidal cycle, pro- 

 duces strong tidal currents (3 - 5 knots) in the 

 Race, the geographic feature through which most 

 tidal flushing of LIS occurs (NO A A 1987). 



The MNPS monitoring program covers an ap- 

 proximately 50-km'^ study area 2 km west of 

 Black Point, 2 km south of Twotree Island and 

 2 km east of White Point (Fig. 1). In this area, 

 water depth varies, reaching 15 m in Twotree 

 Island Channel and up to 20 m in one area south- 

 west of Twotree Island. The bottom throughout 

 the study area is generally composed of fine to 

 medium sand but includes some rock outcrops 

 and muddy-sand in nearshore areas (NIJSCO 

 1975c). 



The tides in the study area have a mean and 

 spring range of 0.8 and 1 m, respectively (NOAA 

 1987). Because of the Station's proximity to the 



Race, tidal currents dominate natural water move- 

 ment in the area. In particular, the flow into and 

 out of Niantic Bay forms a strong current past 

 MNPS along a line running from the site through 

 Twotree Island Channel. Currents in Twotree 

 Island Channel are on the order of 1 to 1.8 knots 

 and currents passing the Station are on the order 

 of 1 to 1.5 knots (NUSCO 1975b) which produces 

 a tidal exchange in Niantic Bay of 2.8 x 10" m /s. 

 In contrast, currents in .Jordan Cove, even during 

 the strength of ebb and flood tides are relatively 

 weak (NUSCO 1975b). 



The salinity in LIS ranges from 26 to .30%o and 

 water temperature can vary from less than PC to 

 more than 23''C (Nixon 1983). NUSCO (1975c) 

 reported that salinities near MNPS range from 26 

 to 30%o and water temperatures range from less 

 than to 25°C; since 1976, water temperature 

 and salinity values near MNPS have continued 

 in these ranges (Fig. 2). Thermal and salinity 



Fig. 1. The area where biological monitoring studies are conducted to assess (he efTccts of the operation of 

 MNPS. 



