Friday 7/3/15

My fiancé Michael Alcorn had a vacation day, so was able to come out to the hatchery and finally find out what I do all day. He did some of the counts, but quickly found those to a bit too mind numbing for him so mostly helped out with cleaning. We also tried to cut up the PVC sheet into tiles, but weren’t able to do so with the tools in the hatchery workshop.

Became really concerned about the mortality going on in the 100L larval tanks, as all of them had a lot of larvae sitting on the bottom. With it being the holiday weekend, most of the hatchery staff were out of town so I didn’t have much advice on how to proceed. One of the hatchery technicians, Alice, said they were having mass mortality with their larvae as well making me think it was a hatchery-wide water quality issue. She gave me some advice to minimize time the larvae are spent in small containers or out of the water which I started implementing. I decided for today to empty out the HC1 larval tank, do counts for the different size classes, save some for a DNA sample, and then put all the newly spawned HC larvae in that tank.

Piles of dead oyster larvae on the bottom of the SS2 larval tank

Checking for larvae

• Lots: HC5, NF2, HC3
• Some: HC2, HC1

Larval counts

Notes on growth experiment

• CGW/Tiso/Chagra
• 19degC
• 30 ppt salinity

Sunday 7/5/15

I filtered out SS_Tank1, NF_Tank1, and HC_Tank2 over various sizes to look at how far they grew and the estimated mortality. I did not put SS_Tank1 larvae back in the tank, and instead cleaned it out for the newly spawned larvae. I also changed the water on my growth experiment, filtered out new larvae, and changed my banjo filters.

Checking for larvae

• Some: SS4,NF5,HC5
• Lots: HC2,HC3,HC4,SS5

Notes on growth experiment

• CGW/Chagra
• 19degC
• 29 ppt salinity