It’s been 21 days since the oysters started their OA treatments, and we spent the afternoon doing the standard weekly maintenance. Things are going smoothly! So far no major catastrophes, and water conditions are holding relatively steady.

Tasks for the day included:

• Sampled water for chemistry - 4oz bottles killed with HgCl, and 1L grab samples measured for T, S and pH (mv)
• Read the standard curve of TRIS
• Replaced all filters: used a new 1um, and used 5um and 20um that had been used for 1 week, and was cleaned and dried for 1 week.
• Bleached algae lines: bleached with 20 mL of bleach into 6 L of water, then run a full bucket of freshwater through to rinse.
• Siphoned poop out of tanks
• Sprayed Oly’s down with fresh water
• Moved pH probes
• Tried to install a water alarm in the large header tank; if the water level drops below 2/3 (the level at which I positioned the float that triggers the alarm), it makes a very loud noise. It seemed to work for a few minutes, but then the turbulence caused the float to bounce around, triggering the alarm erroneously. I turned it off, and will move it to one of the small header tanks on Wed 3/15 to see if that works.

Note about algae:

After PSRF increased the daily allotment of Reeds Shellfish Diet to 500ml/day you can really see the difference

It’s a bit too much, so I’ve asked them to lower it to 450mL. They’re tracking the daily algae feeding, so we’ll have a record of how much food they got per day.

Note about mortality:

One of Yaamini’s oyster in the low pH treatment died, and another was very slow to close its shell when removed.
I also noticed 3 empty shells in separate tanks/treatments. We’ll monitor things; if mortalities continue we’ll need to increase our cleaning regime.