You are here

15 Aug - Strawberry Hill Line, sampling methods

First full day of sampling along the Strawberry Hill line. The latitude of our line is not parallel with the real Strawberry hill; it is closer to Cape Perpetua. We sampled water at four stations collecting surface, deep chl max and bottom (stations SH-30. SH-70, SH-b and SH-f). No coring, no big JCVI samples. Detected hypoxia in bottom waters at the 100m station and the 1500m station. Started sampling at 1045. Last sample was collected after dark, although cast began at dusk - deep cast to 1500m required about an hour, and we collected surface water at the end of the cast.

Overnight CTD casts along Lincoln Beach line were cut to 4 casts in order to get to NH-1 right after breakfast on the 16th.
Water collection method: Six 10L niskin bottles are fired for each sample. Once on deck, 4 bottles per sample are drained with sample-rinsed 0.5" tubing into sample-rinsed 6-gal buckets (2 bottles/bucket). Water for respiration measurements, oxygen measurements, and HPLC pigment analysis are drawn directly off the last two bottles. Respiration samples are collected in 1 gal cubitainers, Oxygen samples are collected directly into BOD bottles and preserved for Winkler titration, and HPLC samples are collected in brown PE bottles. The remainder of the water in the final 2 bottles is then drained into buckets as above. Note - Water drains faster if top end-cap is opened. To do this, un-clip the bottom end-cap, and cock the top end cap. After water is drained, re-clip the bottom end-cap.

Sample processing:

DNA/RNA samples are filtered through 6 sterivex filters using a 3-head peristaltic pump and Y-split outports so that each pump tube forces water through 2 filters. Wear Gloves! Sterile 10ml plastic pipettes are used as dip-tubes to prevent contamination from the outside of the tubing. A minimum of 20L is filtered per sample (3.33L/filter). Force water out of filters with pump and/or with a 60cc syringe. Seal the outport with cha-seal putty. Add 1 ml DNA extraction buffer (DEB) to two filters, and 2ml RNAlater to four filters. Seal inport with sterile polycarbonate luer caps.