May 2, 2019 Geoduck larvae at Pt. Whitney
Check on heath stack setup
- food still dicey, sometimes the food is unevenly distributed.
- ordered a new pump head today and they are sending some sample tubing to see if it will solve the problem (see below for more details).
- animals looked good but some algal floculation
- counted about 5-7 animals in ~15 mL water/sand grab from second tray in heath stack (“extra” juveniles from variable low pH parents)
- need to clean mesh next week
- need to shuffle trays around
Matt recommended setters should get a concentration of 100K/mL, but not more than that.
- Inflow algal counts direct from the feeding tube were:
- H2 (ambient): 4.73 x 10^6 cells/mL
- H1 (ambient/low pH): 4.8 x 10^6 cells/mL
- Flow rate of the feeding tube is 10mL/13 seconds = 0.77mL/second = 46.2 mL/minute = 66,528 mL / day = 35,260 M cells/day (66,528mL * 5.3 x 10^5 cells/mL)
- 35,260M cells get into the header tank each day
- Outflow algal counts were:
- H2 (ambient): 5.3 x 10^5 cells/mL
- H1 (ambient): 3.8 x 10^5 cells/mL
- Flow rate of the outflow is 10mL/3 seconds = 200mL mL/minute = 12,000 mL/hour = 288,000 mL/day
- 288,000 mL * 5.3 x 10^5 cells/mL = 1.5264 x 10^11 cells/day
FAO manual recommends 0.4mg dry algae per mg spat per week - 10^6 Iso cells = 0.02mg, so 20M cells/week or 2.857M cells/day
- Setter weight ~= 0.07mm^3 = 0.07mg? - H2 has ~ 52000 animals = 3.640 mg spat - H1 ambient has ~ 60,000 animals = 4.2mg spat
- Ambient should be getting ~ 22.4M cells/day (2.857M cells/day * 7.84 mg total spat)
- they are seeing 152,640 M cells/day
- they are getting about ~6800X more than they need (152,640 M / 22.4 M)
- will try reducing the diameter of the masterflex tubing
- Cole-Palmer sending a free 1-ft. sample of skinnier masterflex tubing. It’s about half the diameter of the one currently being used and flows at 1/2 the speed.
ordered another pump head from Cole-Palmer to eliminate the inconsistent feeding from the “T” splitter that’s currently being used to split the rations between headers
- ordered more 1/4” clear tubing from Amazon to run from the algae header to our headers
- Still need to run poisoned samples from H1T5-T8 from 4/19 and from 5/2. We can do this next week.