Today I went to Point Whitney to prepare PolyIC project oysters for field outplants.

Overview

In this project we exposed broodstock oysters to Poly(I:C) immune stress and then reared and conducted experiments on the offspring. The seed from these parent groups are now about 8 months old and are ready to be outplanted.

All information for this project can be found on our GitHub repo.

All outplant data is available in the outplant folder here.

Oysters will be outplanted on 10 July 2025 at the Sequim Bay site in 3/8” grow out bags.

Moving oyster stocks

I first moved the PolyIC seed in the indoor silo system to seed bags and onto the dock system. We need to move them to provide more space for Point Whitney.

I attached green tags to each seed bag and hung them with our current dock stocks.

The tags are as follows (green ear tags):

• Control silo = 047, 049, 051
• Treated silo = 048, 045, 050

These can be used for further experiments if desired.

I downloaded and stopped the loggers from the two silos. There is one logger with the dock group recording temperature every 15 min.

I’ll need to return to clean and check the seed bags in a few weeks.

Preparing outplants

I then screened and counted oysters for preparation for outplants. We will outplant in 3/8” bags and I screen oysters onto a 1/2” screen to keep the largest oysters.

We have PolyIC oysters in a set of 8 Heath trays in 1 stack at Point Whitney, identified with purple cattle tags. There are n=4 trays per PolyIC treatment. Based on the size and number of oysters available, I decided to prep oysters for 8 outplant bags - 1 bag per tray.

Matt and I agreed to outplant 100 oysters per bag.

Here is what I did to prepare outplants:

• Take out oysters from each tray and screen onto a 1/2” screen.
• Count out 100 of the largest oysters
• Take an image of the oysters with a scale bar and outplant tag for growth analysis
• Add oysters and tag to a seed bag
• Add loggers to n=2 bags
• Continue for all 8 trays

After preparing all of the bags, I kept the seed bags with our outplants in a 10-holer. I can then pick these up quickly the morning of the outplant to transport to Sequim.

I noticed that the top tray had much larger oysters than the lower trays. Many of the lower trays had lower density and smaller oysters. They should be just barely big enough and hopefully grow a bit more over the next couple of weeks before outplanting.

Here is a table with outplant information:

source_tag	outplant_tag	treatment	rearing_tank	number	logger	deploy.date	notes
33	20	Treated	Treated4	100	22023399	20250710	top of health stack, largest group
34	19	Control	Control1	100	22023398	20250710
49	18	Treated	Treated5	100		20250710
39	17	Control	Control2	100		20250710
31	16	Treated	Treated4	100		20250710
60	15	Control	Control1	100		20250710
40	14	Control	Control2	100		20250710
50	13	Treated	Treated5	100		20250710	bottom of stack

Here is an example of a size image from one outplant group.

Notebook images

Next steps

• Pick up oysters from Point Whitney and outplant in field bags at Sequim Bay on 10 July 2025.
• Matt is checking into availability of bags - if not available we will need to order some.