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1 May 2012 - First day on the Columbia River Estuary

FilteringMay 1. We were delayed a little crossing the bar into the Columbia River estuary by the rapid river flow, but once the current settled down we moved into the estuary and motored up to a site near SATURN-01 in the north channel of the estuary. We dropped anchor and got set up to deploy the Winched Profiler and the CTD. We cast the CTD several times to watch for an ETM. We detected a small ETM at 1428 PDT (2128 GMT) and filled two carboys and a bucket with water from near-bottom depth. We put the bucket on a stir plate in the wet lab, dropped in a large stir bar and got it mixing to keep the particles homogenously distributed.

We subsampled this bucket for:

  • Suspended particle mass (SPM)
  • Particulate organic carbon and nitrogen (POC/N)
  • Chlorophyll-a (chla)
  • HPLC Pigments (pig)
  • Transparent exopolymer particles (TEP)
  • Nutrients (nitrate+nitrite, phosphate, ammonium, silicate)
  • Dissolved organic carbon (DOC)
  • Total dissolved nitrogen and phosphorous (TDN/TDP)
  • DNA
  • RNA
  • Bacterial abundance (gluteraldehyde for microscopy, paraformaldehyde for flow cytometry)
  • Bacterial production (Leucine incorporation, thymidine incorporation)
  • Respiration (change in DIC and oxygen during dark incubations in gas-tight bottles)

We also measured bacterial abundance, production and respiration on water that was gently filtered with a large 3um poresize polycarbonate filter. Whew!