OA System Breakdown

Today Steven, Laura and I tied up loose ends from the OA exposure and prepared the system for the next month or so.

But first, some housekeeping from last week:

I didn’t look at the data Grace collected until today, but looks like we don’t have any conductivity information. This is not a huge deal because we think those values aren’t reliable anyways.

Figure 1. Water Chemistry Data from the last day of OA exposure

I also uploaded data from the oysters I sampled here. I plan on visualizing the data soon!

Alright, let’s get into what I did this week.

My first task was moving all of my oysters into two larger tanks so Laura could use the space she needed for her spawning set-up. I took the oysters in each tank and removed all epibionts and rinsed them with freshwater. I mainly removed barnacle and polychaete worms. I noticed that larger worms like to hide in the crevices between a larger oyster shell and a small attached shell. If I could safely remove a shell that was attached to a larger oyster and remove more polychaetes, I did. I put the epibionts in a bucket with bleachwater to sit until Laura returns to Manchester on Thursday.

I then split the oysters in each tank into two separate oyster bags.

Table 1. Number of oysters in each bag per tank.

Tank	A	B	Total
1	8	9	17
2	9	8	14
3	7	7	14
4	9	8	17
5	9	9	18
6	8	8	16
Total	50	49	99

Bags labelled “A” went into the tank furthest from the dry lab, and bags labelled “B” went into the tank closest to the dry lab. We added a direct ambient line and airstone to each tank. All of these tanks were cleaned by Laura while I was removing epibionts.

Figure 2. Arrangement of holding tanks. The bottom left tank is Tank A, and the bottom right tank is Tank B. The top tank (closed, with lid) houses half of the oysters that were originally being held on the bottom shelf. The other half are in the yellow tray on the right, and were transported to SAFS.

Figures 3-4. Arrangement of oyster bags in Tanks A and B.

I then added a HOBO to each tank. HOBO 1 went into Laura’s conditioning tank, HOBO 2 into my original holding tank, HOBO 3 in Tank A, and HOBO 4 in Tank B.

Figures 5-6. HOBO loggers placed in Tank A and B.

Finally, I measured the flow rates for Tank A and B. They were approximately equal (Tank A: 1L in 1:23.34 min, Tank B: 1L in 1:25.98 min). The flow rate was roughly .75 L/min, which I figured would be enough. I will ask Laura to adjust flow on Thursday if the tanks look too gross.

Figures 7-8. Flow rates for Tanks A and B. They were both roughly .75 L/min.

Another productive day at Manchester! I don’t think I’ll be out there for a week or two until I have to do my heatshock. Ideally, I would like to learn how Laura is caring for her spawning individuals and larvae so I can do similar things when I spawn. For funsies, I’ll leave you with a picture of me with an oyster that looks like a heart.