This post details launching field deployments for our Manchester hardening experiment at the Manchester NOAA station.

GitHub repositories

Data for these projects are stored on GitHub in the following location:

• Manchester Hardening

Overview

In this project, we conducted a 2-week thermal hardening of seed provided by the USDA ARS POGS program. These oysters were shipped on May 29-30, 2025 under a WDFW permit and the experiment was launched on 6/2/2025.

Oysters were exposed to the following conditions:

• Control: Ambient temperatures (approx. 14-16°C)
• Treated: Daily exposure to elevated 25°C temperatures for approx. 5 hours

After 2 weeks of these treatments, oysters are going to be outplanted at Manchester on the docks in SEPA cages to assess survival and growth over the summer.

Here are the activities we performed to deploy oysters in the field for the experiment on June 16, 2025.

Mortality assessment and cleaning

Before field deployment, I checked oysters for mortality and did not find any dead oysters. Oysters were assessed from 10:00-11:00.

I then added another layer of mesh bag to the oysters so they are secure for deployment.

Oyster bags will retain their original ID tags.

Field deployment

Oyster bags were kept in their tank groups and placed into SEAPA cages. For example, all oysters from Tank 1 were added to the same cage for a total of four cages (see metadata below).

Each bag also contained the respective temperature logger for each tank group. Oysters were deployed at approx. 11:30.

We removed barnacles from the cages and then hung the cages off of the Manchester dock.

Mac and I will return monthly to assess and clean the cages. The Manchester folks will also keep an eye on the cages and clean lines as needed.

tag	family	oyster-count	tank	treatment	field_tag
52	YC24-105	18	1	High	B028
56	YC24-153	45	1	High	B028
60	YC24-158	17	1	High	B028
62	YC24-116	20	1	High	B028
65	YC24-163	28	1	High	B028
73	YC24-164	14	1	High	B028
79	YC24-099	10	1	High	B028
86	YC24-137	16	1	High	B028
87	YC24-148	14	1	High	B028
90	YC24-087	38	1	High	B028
53	YC24-105	18	2	High	R013
57	YC24-153	45	2	High	R013
61	YC24-116	19	2	High	R013
64	YC24-158	17	2	High	R013
67	YC24-163	28	2	High	R013
72	YC24-164	14	2	High	R013
78	YC24-099	10	2	High	R013
82	YC24-087	38	2	High	R013
85	YC24-137	16	2	High	R013
88	YC24-148	14	2	High	R013
55	YC24-105	18	3	Control	R008
58	YC24-153	45	3	Control	R008
66	YC24-164	14	3	Control	R008
68	YC24-158	17	3	Control	R008
70	YC24-163	28	3	Control	R008
75	YC24-116	20	3	Control	R008
77	YC24-099	10	3	Control	R008
81	YC24-087	38	3	Control	R008
84	YC24-137	16	3	Control	R008
92	YC24-148	14	3	Control	R008
54	YC24-105	18	4	Control	G058
59	YC24-153	45	4	Control	G058
63	YC24-158	17	4	Control	G058
69	YC24-163	28	4	Control	G058
71	YC24-164	14	4	Control	G058
74	YC24-116	20	4	Control	G058
76	YC24-099	10	4	Control	G058
80	YC24-087	38	4	Control	G058
83	YC24-137	16	4	Control	G058
91	YC24-148	14	4	Control	G058

Temperature loggers

I set up Hobo TidBit MX400 temperature loggers in each tank. The loggers stayed with their respective oyster cohort/tank group.

• Logger 22105353: Tank 3 (Control) > field tag
• Logger 22105354: Tank 1 (High) > field tag
• Logger 22105356: Tank 4 (Control) > field tag
• Logger 22105358: Tank 2 (High) > field tag

Loggers will log temperature (°C) every 10 minutes throughout the deployment.

logger	tank	treatment	header	field_tag
22105353	3	Control	1	R008
22105354	1	High	2	B028
22105356	4	Control	1	G058
22105358	2	High	2	R013

June 11 2025 - checking temperature loggers

I went to Manchester to download the loggers on June 11 2025 to make sure the temperature exposure was working correctly. We had a power failure in the middle fo the experiment, but this was resolved after a couple days. Exposures were back to normal for the second week of the experiment.

Schedule of activities

• August - September: Monthly survival and growth assessments