Preparing for an Oyster Set!
A look at the most recent oyster set! All those “dots” are baby oysters!
Recycled shell that has been collected and is being left to cure.
Recycled shell that has been cured and cleaned.
The set tank filled with crates of shell and ready to be filled with heated seawater.
The spat-on-shell will remain in the set tanks until deployment day!
Oysters start out as free-swimming larvae, but need to permanently attach or set on a surface to continue to grow. Once the larval oysters have set, they are called spat. We set our oysters on recycled shell that is collected from our recycling network partners. (Learn more about how to participate in our shell recycling program here) These oysters are referred to as spat-on-shell. This spat on shell is then moved to our restoration sites in an effort to create oyster reefs!
A look at the four set tanks located outside the hatchery.
When preparing for an oyster spawn, the hatchery crew has more to do besides conditioning the oyster broodstock and taking care of the larvae! In order to raise spat-on-shell oysters, the set tanks need to be cleaned and the recycled shell prepared!
The hatchery crew cleaning crates and using the shell washer to clean the shell.
Outside the hatchery are four large setting tanks. When the oyster larvae go to set, they are moved into these tanks which are filled with trays of recycled shell. Prior to putting the oyster larvae in, the recycled shell needs to be cured, cleaned, and conditioned. The shell is cured by sitting outside in the sun for a period of time, this helps to naturally clean the shell of any organic material. The shell is then cleaned through the use of a shell washer. Shell is loaded into the base of the washer and moves up a conveyor belt and into the tumbler. The shell is tumbled and rinsed to remove any remaining debris and remove any pieces of shell that are too small to use. They shell than pours out of the washer and is collected and sorted into crates. These crates are then placed into the set tanks to be conditioned. This is done by filling the set tanks with raw seawater. This allows the shell to accumulate a natural biofilm before the oyster larvae are placed into the tank.
Once the shell is conditioned, the tanks are drained and filled with filtered, heated seawater and the larvae are added in! The tanks are covered to prevent the loss of heat and block out the light as the oysters set over the next few days. Once set, the oysters will be switched onto raw seawater and left to grow until it’s time to deploy them to the restoration site! Check out the Marine Minute Monday video below to learn more about spat-on-shell!