22 May 2009 – Continue plume feature tracking, begin SATURN-01 survey.

The plume feature tracking exercise continued until 1100.  We collected water samples for the micro baseline sample set at four depths at stations PLT-7 (cast 85, 0100), PLT-13 (cast 91, 0600), and PLT-18 (cast 96, 1100).  We also collected water at PLT-13 for a primary production measurement and for Florian Moeller’s ammonia oxidation experiments. 

After completing the plume feature tracking exercise we crossed the bar into the estuary and anchored at station NC-11 in the north channel near the SATURN-01 station. We transferred the seabird CTD and other sensors to a small, heavy frame and attached the end of a pump hose for sampling in the estuary.

We then began a 24-hour series of CTD casts in coordination with the R/V Point Sur, which was positioned down-estuary at station NC-7. The R/V Forerunner was also in the north channel this day.  Scientists aboard this ship deployed an autonomous underwater vehicle (AUV) that traveled down-estuary from the bridge for several kilometers, turned, and returned during a 1 hour period in the afternoon. This series of measurements in the north channel served several research projects. New Horizon and Point Sur CTD casts will be compared with measurements made by the SATURN-01 station to determine how well the station measurements represent the rest of the system.

Water samples were collected from three depths at five time points during the tidal cycle as part of a study of the timing and extent of Myrionecta rubra blooms. Bottom samples were also collected before, during and after the flood tide resuspension event as part of a study of microbial diversity and activity in estuarine turbidity maxima. Matt Wolhowe sampled surface and bottom waters for methane concentration, and Misty Blakely sampled water for a study of fluorescence.