conditions (Figure 2-2). Within each reference area, triplicate REMOTS® 

 photographs were taken at each of thirteen stations arranged in a cross-shaped 

 pattern and spaced 100 m apart. These reference areas, also occupied during the 

 July 1988 survey, were approximately 2000 m west (2000W), 2000 m south (2000S), 

 and 2200 m northeast (WLIS-REF) of the "B" mound. 



23 CTD and Dissolved Oxygen Sampling 



An Applied Microsystems CTD probe (Model STD-12) obtained vertical profiles 

 of temperature and salinity at the center of each reference area and at the center 

 and four distal points (400N, 400E, 400VV, and 400S) of the WLIS "D" REMOTS® 

 sampling grid. The STD-12 (used to measure conductivity, temperature, and 

 pressure) samples up to 8 scans per second and stores up to 7648 scans in 56k of 

 internal RAM (random access memory). A Compaq Portable II microcomputer sends 

 commands to and reads data from the instrument via an RS-232 serial interface. 

 During deployment, the STD-12 recorded data at 2 second intervals. The 

 microcomputer received and stored data on a floppy disk for later analysis. Salinity 

 calculations followed the procedures described by Perkin and Lewis (1980). 



A YSI Model 58 Dissolved Oxygen (DO) probe, attached to the CTD, obtained 

 depth profiles of dissolved oxygen. The CTD was lowered slowly to the seafloor, 

 stopping (for approximately 1 min.) at 2 m intervals to allow for equilibration of the 

 DO probe and shipboard recording of the DO measurement. 



At selected REMOTS® stations, dissolved oxygen was measured by Winkler 

 titration. In these cases, a Niskin bottle was used to obtain water samples from 

 approximately one meter above the bottom. A 300 mG subsample was drawn from 

 the bottle, preserved, and titrated within 12 hours using a modification of the 

 standard Winkler titration method (Strickland and Parsons, 1972; Parsons et al., 

 1984). The original intent of this sampling was to provide an in situ check on the 

 YSI dissolved oxygen probe. However, during water-column profiling, the YSI probe 

 consistently failed at depths greater than approximately 3 m and therefore only the 

 results of the Winkler titrations were reported for the bottom oxygen concentrations. 

 Surface oxygen values from the YSI probe were considered reliable because the 

 sensor was calibrated to an air-saturated standard immediately prior to deployment. 

 These values were compensated for in situ salinity using the CTD results and the 

 algorithm of Benson and Krause (1984). 



2.4 Sediment Chemistry and Grain Size 



A Smith-Mclntyre grab sampler (0.1 m 2 ) was used to collect triplicate sediment 

 samples at the center of each reference area and at the WLIS "D" disposal point. At 

 each station, four polycarbonate plastic core liners (6.5 cm ID) were pushed into each 

 grab sample, extracting a minimum of 10 cm of sediment. Three of these cores were 

 combined and placed into a sealed plastic bag for chemical analysis. The remaining 



Monitoring Cruise at the Western Long Island Sound Disposal Site 



