Gigas Larvae Day 8

Immersion heaters are pesky

Overall, today was pretty smooth. Olivia and Grace helped me screen my larvae. At first, I thought I would be able to screen on both an 80 micron and 60 micron screen. However, after screening the first two buckets, Bucket 11 and 6, I didn’t count any larvae from the 80 micron screen. I decided to continue just screening on a 60 micron screen, and try again with two screens on Wednesday. I did something different today where I added food to the bucket before restocking, instead of adding food to all buckets at the end. I think this method is better because the larvae get fresh algae after being stressed by the screening process, so I’ll continue to do this. While screening Bucket 12, Grace accidentally screened through a 48 micron screen first. She caught her mistake very quickly, but it’s possible some larvae were lost with this additional screen. All of my larvae are at about 2 larvae/mL, which is the stocking density I want at this point. You can see my counts and feeding log here.

Now here’s the annoying part. Totes 3, 4, 5, 7 and 9 all had their high alarms (27ºC) go off after the buckets were restocked. Tote 4 and 7 had their alarms go off multiple times! To reduce temperature, we used tripours to drain out some of the water in the tote, and then we refilled with ambient freshwater instead of using the water from the heating reservoir line. This quickly brought our temperatures down. I think refilling totes with ambient freshwater should be our standard now. Adding heated water to a tote that’s already at temperature may set it over the edge.

For tomorrow:

  • Record tote positions
  • Add new HOBO loggers buckets without them
  • Feed oysters
  • Finalize help schedule for this weekend
  • Prepare task lists for those helping
Written on August 7, 2017