meter above the bottom in water 4 meters deep. The DAISY was serviced once during the 

 deployment period on November 11, 1993, at which point data were downloaded and sensors 

 were examined for biofouling and cleaned by divers. The array was inadvertently moved 

 from its original position of 41° 17.008' N, 72°54.973' W and redeployed at 41° 17.018' N, 

 72°54.966' W. This movement, of just 20 meters within water of the same depth, is 

 considered insignificant for the purposes of this study, and the data are treated as if they 

 were measured at one location. The resulting time series from the DAISY sensors for the 

 entire deployment period is presented in Figure 3-26; A-E. A statistical summary of the 

 hydrographic parameters (current velocity, temperature, and salinity) is presented in Table 

 3-3. 



The area is characterized by relatively low energy with current speeds rarely 

 exceeding 20 cm-s"' (Figure 3-27; A); the overall mean velocity is 6.3 cm-s ^ There is a 

 bidirectional tidal signal (Figure 3-27; B) although with a fair amount of spread about the 

 principal axis, a result of the low current velocities. Using the methods of Mardia (1972), 

 the mean direction on the ebb is 184° True and on the flood, 356° True. The average 

 velocities are the same for both flood and ebb, although the ebb displays more variability and 

 a higher maximum (Table 3-3). Energy spectra (Figure 3-28) show the north-south (along 

 channel) component stronger in magnitude than the east-west Oateral) component and that 

 most of the energy occurs at the semi-diurnal period of 12.42 hours (2 cycles per day). The 

 data was of sufficient length, covering several spring-neap cycles, for determination of 

 residual transport. Using a low pass filter with a 48-hour cutoff frequency, (Figure 3-29) the 

 residual drift, at the DAISY site, is to the southwest with a velocity of 0.5 cm-s'. 



The time series of suspended material provided by the DAISY optical sensors indicate 

 that background concentrations along the western margins of upper New Haven Harbor 

 average approximately 8 mg-l"'. During a tidal cycle concentrations range 15 mg-1"*, peaking 

 at about 25 mg-1"'. These values are consistent with the water samples obtained at sites 

 throughout the study area prior to dredge operations, which suggests the suspended material 

 field in New Haven Harbor is relatively homogeneous. The DAISY data show several 

 aperiodic events resulting in concentrations approaching 100 mg-l* early in the deployment 

 period and more than 700 mg-1"' during the latter half of the deployment. The elevated 

 concentrations observed on October 25 and then again on November 11 are the result of 

 disturbances from positioning the DAISY array during deployment. The remaining 

 perturbations may be the result of a variety of factors including the dredging operations, 

 stream flow variations (indicative of rainfall events), winds and wind waves, and discharge 

 from municipal sewage treatment facilities and CSOs. We explore the relative contribution 

 of each of these parameters in the following paragraphs. 



Throughout the first half of the DAISY deployment period, a series of short-term, or 

 spiky, high concentration events occurred (Figure 3-30; A) sufficient to increase suspended 



Dredged Sediment Dispersion in New Haven Harbor 



