Update from Manchester: 2/5

Minor catastrophe! Filters clogged in the early morning hours on Thursday, draining the large header tank and sucking the temperature probe into the pump intake. The pump was thought to have been damaged, but (!) after opening up the impeller and removing a portion of the temperature probe’s wiring, the pump appears to function normally! Major lesson learned: be very diligent about changing water filters; PSRF recommends at least 1x/week. 

Not wanting to risk running a (potentially) damaged pump for two days without being able to check on it, I drained the system of FSW, rinsed the tanks with fresh water, and left it empty for the weekend.

Spoke with Dave Kuligowski, NOAA’s safety guy at Manchester, and he gave me the protocol for using HgCl. Here are the main points:

  • All HgCl use must be in a hood; he arranged for us to use it in Barry’s lab in the main building.
    • NOTE: we need to communicate with Barry when we anticipate starting to use his lab for HgCl handling, and our desired schedule henceforth. Ryan Crim will facilitate.
  • HgCl must be kept in the chemical cabinet in Barry’s lab when not in use.
  • Must wear goggles, gloves (nitrile OK) and long sleeves when using HgCl.
  • Any materials that come in contact with HgCl (gloves, pipette tips) must be double-bagged, labeled, and thrown away in the proper receptacle (TBD); Dave will provide the bags and labels.
  • Dave would like to be present at our first couple HgCl uses.

Continued work on banjos; by Monday we will have sufficient 60um banjos.

Spoke with PSRF regarding use of Oly larvae in 24hr water chemistry sampling; they can provide larvae, but not much.  Question: how much larvae do we need for the 24hr water chem. sampling?  We estimated using 1M geoduck larvae per culture tank; need we use the same stocking density? If so, that may be too many larvae for PSRF to provide out of their current production.

Temperature and pH still holding

  • Received an email from Brent: geoduck spawned early at Taylor but with little larvae; will need to wait until next spawn (2-3 weeks) and hope for good production.
  • After 4 days running the OA system with Ryan’s CO2 adjustments, here are the readings at 9:30am. Reminders:
    • Only ambient FSW @ ~10degC was flowing into the system at the maximum flow rate (no drippers on the hoses)
    • Left Honeywell readings = 25L larval tanks (yellow=treatment; green=control)
    • Right Honeywell readings = header tanks (blue=treatment; green=control)


  • To attempt a temperature of 14degC in the larval tanks, I opened the heated sea water line’s valve, increased the temperature set point to 12.5degC and left it overnight.
  • Other progress today: banjos and taping the plumbing line insulation.