This post details activities at Point Whitney from 19 June 2024.

Overview

Today I went to Point Whitney to check larvae, take probe measurements, check gonad development in broodstock, and start a new broodstock stressor.

Checking on larvae

I checked on the larvae today that Steven and Carrie put in the HUDLs last week. I poured the contents of one HUDL onto a 40um screen and rinsed the larvae into a small volume.

I then viewed the larvae under the scope.

I estimated that we had approximately 60K larvae in one HUDL.

The HUDLs look good, but have a lot of algae on the filters.

Fluorometry measurments in HUDLs were 29, 12, 90, 74, 32, 16, and 24. Fluorescence was variable and a bit high. We want something closer to 15-20. We will need to lower the pump next time we are out. Outdoor tanks were at 1, 4, and 1.

I added seawater to the food bucket to dilute it and fill it.

I added EDTA at 1g/1000L concentration. I mixed 0.2g EDTA with some hot fresh water, mixed, and added to our 55 gallon header (208 L).

Larvae were returned to the HUDL.

Probe measurements

Weekly tank measurements:

tank	date	time	temp.C	pH.nbs	sal.psu	initials	notes
HUDL	6/19/24	11:30	26.9	8.12	31.79	ash	larvae
HUDL	6/19/24	11:30	28	8.09	30.92	ash	larvae
HUDL	6/19/24	11:30	27.3	8.13	30.37	ash	larvae
upweller	6/19/24	11:30	18.1	7.75	28.95	ash	effort C
upweller	6/19/24	11:30	18	7.74	28.93	ash	broodstock
upweller	6/19/24	11:30	18.3	7.7	28.86	ash	efforts BED
outdoor_tray	6/19/24	11:30	15.5	7.67	29.29	ash	left stack
outdoor_tray	6/19/24	11:30	14.9	7.74	29.17	ash	right stack

Measurements are on GitHub here.

Stressor treatments:

treatment	date	time	temp.C	pH.nbs	sal.psu	initials
temperature	6/19/24	11:30	25.7	8.01	30.11	ash
fresh	6/19/24	11:30	15.9	7.96	0.249	ash
control	6/19/24	11:30	12.7	7.61	29.3	ash

Stressor measurements are on GitHub here.

Effort E spat weekly stressors

I conducted one more set of weekly stressors on Effort E spat. These will be outplanted at Goose Point next week. See probe measurements above for treatment conditions. Treatments took place in 5 gallon buckets at the treatment conditions from 11:00-11:30. Control oysters were placed in the indoor tank at ambient conditions (recorded above).

Lifestage carryover size measurements

I measured the length of all LCO oysters today and took photos of spat for image analysis. The images are on GitHub here. Size is analyzed in ImageJ by using the caliper as a scale bar and measuring ~120 spat in each image. I do this by zooming in on 4 non overlapping areas and measuring all individuals that I have a clear view of maximum length and measure length in mm until reaching 120 individuals.

I entered data from size measurements from the LCO project today. The size data is on Github here.

Spat data from image measurements are on GitHub here.

Checking broodstock gamete development

I cracked open two oysters from family 27.052 to check for gamete development. I got lucky and had one male and one female. The gonad tissue wasn’t very big, so they may need a couple more weeks of conditioning. I was able to see concentrated egg and sperm! The eggs looked concentrated and mostly tear drop shaped. The sperm was concentrated but I didn’t see much motility.

Eggs:

Sperm:

Broodstock stressors

We decided to trial a fresh water stress on the new broodstock from USDA. I chose two families, assessed any mortality, rinsed them, and separated them into two bags - one treated and one control per family. Here is the information:

Family 27.052

• n=10 into treated bag
• n=15 into control bag
• We had no mortality in this family
• Sampled two for checking gametes
• Treated bag = cattle tag 099
• Control bag = cattle tag 029

Family 27.009

• n=9 into treated bag
• n=9 into control bag
• 2 in this family were dead and shells were removed
• Treated bag = cattle tag 100
• Control bag = 035

I recorded sizes of all individuals. I placed the control oysters in an indoor tank at ambient conditions and put the treated oysters in fresh water for 30 minutes from 11:45-12:15. See probe measurements for conditions. Returned to upwellers.

Initial sizes (length x width x depth) are recorded on GitHub here.

An updated tag inventory is on GitHub here.

Prepping for Goose Point outplants next week

I launched some loggers in preparation for outplanting, set to start logging on Monday at 09:00.

logger	date.launched	time.launched	date.deployed	site	model	interval
22023394	20240606	09:00	20240624	Goose Point	Hobo Tidbit MX Temp 5000	15 min
22023397	20240606	09:00	20240624	Goose Point	Hobo Tidbit MX Temp 5000	15 min
22023403	20240606	09:00	20240624	Goose Point	Hobo Tidbit MX Temp 5000	15 min
22023400	20240606	09:00	20240624	Goose Point	Hobo Tidbit MX Temp 5000	15 min

Data for Goose Point outplanting is on GitHub here.

Notebook images