Assessing field outplants at Manchester
This post details assessments on our 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:
Overview
In this project, we conducted a 2-week thermal hardening of seed provided by the USDA ARS POGS program.
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 were outplanted at Manchester on the docks in SEPA cages to assess survival and growth over the summer.
Oysters were outplanted on June 16, 2025. Today we assessed survival and growth.
Outplants were redeployed today and will be checked again in fall/winter.
Growth and survival
Today we removed oysters from their mesh bags, counted live/dead, and imaged them for size. Oysters were put bag in their same bags and into the same SEAPA cages.
Cages have been cleaned and maintained weekly by PSRF. Everything was clean and looked good!
Oysters have grown and there was minimal mortality (1-5 oysters per bag).
Here are some images from today.
I then plotted mortality (% of total oysters) for each family based on original hardening treatment.
Mortality is low (<12%) for all bags with variable results between families. Some familes have a trend for more or less mortality based on treatment while others show no difference.
Note that there are no significant effects of treatment, family, or their interaction on mortality so far.
I then plotted overall mortality based on treatment.
There is no difference based on treatment. This is not surprising as mortality was low and variable.
We will analyze size next!
Temperature loggers
I downloaded temperature loggers and plotted temperature data from the deployment so far.
Loggers 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 |
Temperatures from the hardening experiment:
Temperatures from the field period:
