This post details activities at Goose Point from 9 September 2024 to collect survival and growth data from our June outplants.

Overview

Today Steven and I took survival and growth measurements for all oysters at Goose Point. Tha manager at Goose Point pulled out our cages at about 11:00am and brought them to the Palix River dock. We processed all oysters for measurement and the oyster cages were returned to the field on 10 September 2024.

Temperature loggers

I downloaded data from all temperature loggers at about 11:30am. The logger files are available on GitHub here. They only used 4% memory, so they were left in the cages to continue logging. I cleared off as many barnacles as I could from the loggers.

Cage condition

All of the cages had pretty uniform coverage of barnacles. There was one cage (cage 082) that was damaged and was replaced with a new cage recently, so this one didn’t have many barnacles. All cattle tags and temperature loggers were in good shape! In general all oysters looked good and have grown quite a lot!

As a future note, we should think more about barnacle growth affecting flow, nutrients, microbial communities, etc. The large amount of barnacle set on the cages was very notable!

Survival

Survival was very high in all bags. Here is a list of the number found dead in each bag (all started with 100 oysters):

Bag 085: 0 dead
Bag 084: 0 dead
Bag 083: 3 dead
Bag 091: 0 dead
Bag 082: 2 dead
Bag 086: 1 dead
Bag 095: 0 dead
Bag 088: 0 dead
Bag 096: 0 dead
Bag 094: 1 dead
Bag 087: 0 dead
Bag 097: 2 dead
Bag 081: 0 dead
Bag 080: 0 dead

I started a data sheet for survival on GitHub here. I set this up to have a column for the number alive and number dead in each bag.

Size/growth

The data sheets from yesterday are below. We noted dead oysters with a “*” and measured the size of the dead/empty shell. We also noted where two oysters were stuck/attached to each other with “stuck” in the data sheet. We measured the size of each.

We measured the length, width, and depth of each oyster with a caliper (0.01 mm resolution) and recorded the measurements in that order in the data sheets. After the first bag, we stopped recording the decimal place and recorded the length with continual numbers. For example, a length of “3216” means that the length was 32.16 mm. If a reading was 0952, the length was 9.52 mm.

I’ll start entering this data. We will have lengths for approx. 1400 oysters. We will use the number of sizes entered for live oysters as our count for the number of live individuals in each bag (should be at or near 100).

I started a growth data sheet on GitHub here. I set this up to enter the bag number, the date (20240909), a running number for each oyster (e.g., 1 - 100), and columns for length, width, and depth. There is also a column for dead (1 if dead, 0 if not dead) and stuck (1 if stuck, 0 if not stuck).

Notebook images

All of the data sheet images can be found on GitHub at this link.