experimental plans

biological response measurement ideas

options for low pH treatment:

  1. piggy-back on Sam’s treatment: constant low pH 7.0 total scale
  2. variable diel low pH to simulate lagoon conditions

options for high temperature treatment:

  1. constant high temperature of 20C
  2. constant high temperature of 29C (this will likely kill them before 1 month)
  3. variable diel high temperature of 29C to simulate lagoon conditions


  • There is space avaiable across from our current heath stacks where the totes to put another heath stack in.
  • Matt should have space for 4 trays in some other heath stacks to house any left over animals if needed


  • begin heath stack set up directly across from heath stacks
    • test out heat control, flow, etc.

Equipment update

  • Thermometer for discrete temp measurements errored out. See slack post. It may just be the probe, but need to test this.
  • Apex status:
    • Controller not lighting up at all when plugged into everything. Need to call support and get help troubleshooting this
    • Power strip lights up fine
    • Aqua buses:
      • how many can be linked to 1 Apex controller?
    • Probes:
      • ideally need 12 pH + temp sets
    • brought Controller back to UW to troubleshoot
  • Have 20 total heath trays plumbed for downwelling
  • Can use 1 micron screen mesh tray inserts with large grain sand (Matt has extra).
    • NEED to check:
      • # of good quality inserts we have (ideally 10)
      • # of inserts that need dividers added
        • can cut dividers from black plexiglass upstairs in the hatchery
  • Controlled heating source:
    • NEED 2 heat rods that can be plugged into the apex
      • have these at UW, need to test
  • Flow:
    • if doing constant pH, NEED 4 pumps with adjustable flow if using same header conicals as Sam
    • if doing diel variable pH, use different conical and don’t need adjustable flow
      • extra pumps at hatchery (imagitarium secondary pumps used for circulation in broodstock experiment)
      • would need additional probe set
  • More equipment will free up when Sam is done by the end of August

Checked on animals

Size difference between H2T3 animals and H2T1 animals from cascade feeding

In-flow hose was not going directly into the heath tray insert in H2T1:

Tried to break up algae and clear mesh to improve flow of food and shuffled trays around to new order:

  1. H2T1
  2. H2T5
  3. H2T7
  4. H2T3
  5. H2T6 (extras)
  6. H2T2 (low density)

*only swapped H2T3 with H2T1 because these trays showed the biggest size differences.

*Left H2T6 and H2T2 in same positions because they had a lot of die off and aren’t going to be part of the experiment.

Size data (photos) for all animals are here. Size ranges for all are about 2-6mm. I will do individual measurements with image J

Survival and size data for larval rearing through now I think is too convoluted to draw conclusions from parental exposure.

Prior to pH x temp experiment, I can size select to start with animals of similar sizes across the board.