YSI 6200 data sondes were deployed vertically in a pool deep enough to contain water during dry conditions. The sonde was deployed in a PVC tube, which was attached to ree-bar driven into the stream bed. The PVC tube had holes drilled to allow adequate water circulation. Dissolved oxygen measurements are of good quality because detritus did not accumulate in the bottom of the pool (unlike our suburban site). The PVC tube was surveyed upon original deployment in 2001 and resurveyed in 2002 to ensure that elevation did not change during winter ice period. No change was detected. Recalibration was performed roughly every 4-6 weeks. Instrument drift during deployment periods was not significant.

RESEARCH LOCATION: Locations are in Massachusetts State Plane coordinates. The site is located on Fish Brook just upstream of Middleton Rd. in Boxford (~31 km2 drainage area). The contributing area includes mainly forest and no public water withdrawals.

STATION STATE X STATE Y
YSI-FB 240600 934310

NOTES AND COMMENTS:
Discharge could not be determined due to inadequate rating curve.
Dissolved oxygen concentrations reflect water column levels.
NA refers to data not available.