This post details seed exposures at Point Whitney on 3/19.

Overview

Today I went to Point Whitney to do another round of seed exposures, check the systems, and measure growth on the lifestage carry over oysters.

The GitHub repository for this project is here.

Tasks

Note that the hatchery closed down early today, so I wasn’t able to finish everything I wanted to. I did not have time to offload the loggers, so we should do that at our next opportunity to verify treatments are working as expected.

I also did not see Matt today, so we need to touch base with him next time we are out regarding outplanting adults.

Increase lifestage carry over grow out temperature

At 15:00 I increased temperature in the LCO grow out tank by 2°C, from 14 to 16°C. There is one heater in this tank attached to a thermostat. This was the thermostat I was using for the seed exposures, so we will either need to find another thermostat/heater set for next week’s seed exposures or the temperature will need to be reset back in the LCO tank if it is used for next week’s exposures.

I tested that all heaters for the adult conditioning and LCO can be on at the same time and there weren’t any electrical problems.

Check survival/status of all oysters

All oysters were alive and looked good! I cleaned the LCO spat chambers.

Do another round of seed exposures

I set up seed exposures as Steven did on his last trip. I heated water in a large bin to 24°C using a 800W heater and thermostat with a recirculating pump. This took about 20 min to come to temperature. at 14:25 I added the spat to the bin by rinsing them down to the bottom of each tray with the hose. The two stress trays were added to the bin and the stress was ended at 14:55. Trays were returned to their home.

Measure growth of lifestage carry over oysters

I started to measure growth for these oysters, but couldn’t finish because the digital caliper broke and the hatchery was being locked up early for the day. Today while taking growth measurements the digital caliper went haywire and started displaying highly variable and incorrect values. I temporarily fixed it by taking the battery out, cleaning it, and putting it back in. But after about 5 minutes it started malfunctioning again and I could not fix it by replacing the battery. I submitted a GitHub issue for a replacement and next time I am out I’ll try to fix the caliper.

Measuring growth was really easy, however! I was able to measure size of the oysters while in their mesh bags and the labels still looked ok. I will need to add better tags to each bag next time, the waterproof paper will degrade over time. The bags are still in the same order on the rack, so if a label falls off between now and then I’ll still be able to tell who is who.

Here are the spat images for size measurements from today. Left spat 1 and 2 indicate two replicate containers for the “left spat” group. The same labeling is true for “right seed” with replicates 1 and 2.

We have initial growth measurements from 3/5, so its fine that we don’t have data from today. I’ll get the full size data next time I am out in a couple weeks.

Notebook images

Here are the notebook images for today.