Raising Happy Shellfish

There are certain things that all living things require; food, water, sunlight, oxygen. And they need a way to protect themselves from being eaten by predators! To get them started we grow them in a large tank called an upweller. This is really a shellfish nursery.
RCTB purchased about 500,000 seed clams from hatcheries. Baby clams, called seed are grown at various locations in upwellers. The yield is the estimated number of clams received from the hatchery minus the culling of very small clams that are not growing well, mortality and statistical variation in measurements. The typical yield is about 80%, about 400,000. Most of these clams are taken to the RCTB lease site in *Waretown or Island Beach State Park and placed under predator control screens. Some were left at Beach Haven to overwinter in our floating upweller system (FLUPSY).
*At the Waretown lease, approximately 30 percent of the crop planted in then moved to the Marine Conservation Zone (MCZ) managed by the DEP Bureau of Shellfisheries.
Oysters

Spat is the industry term for baby oysters. Oysters naturally want to grow in a group (cultch). Since restaurants prefer individuals (cultchless) oysters, RCTB does grow cultchless oysters for demonstration purposes. However, when growing spat for living shoreline projects, another technique called remote set works better. With remote set we create a colony either on a shell or on oyster castles. The remote set technique, introduces eyed larvae (a particular time in their development, just prior to set) to a mixing tank containing the shell (in bags) or oyster castles. Within two weeks, the larvae will set on the material provided. A piece of shell will have a colony of from 75 to 100 spat. An oyster castle might contain 500 to 1,000. The advantage is that the large shells or interlocking oyster castles provide a habitat that reduces predation. RCTB has been experimenting with the remote set technique. The goal is to improve the percentage that do set on the shell or oyster castles.

Clams
RCTB purchased about 500,000 seed clams from hatcheries. Baby clams, called seed are grown at various locations. The yield is the estimated number of clams received from the hatchery minus the culling of very small clams that are not growing well, mortality and statistical variation in measurements. The typical yield is about 80%, about 400,000. Most of these clams are taken to the RCTB lease site in Waretown or Island Beach State Park and placed under predator control screens. Some were left at Beach Haven to overwinter in our floating upweller system (FLUPSY). Note: – At the Waretown lease, approximately 30 percent of the crop planted in then moved to the Marine Conservation Zone (MCZ) managed by the DEP Bureau of Shellfisheries.

Those facts generate more question that we cover during RCTB educational sessions:

  • How do they feed so we can understand why oyster filter more water that do clams.
  • What is the life cycle? How they reproduce?
  • How are grown commercially
    What are the different roles that play in the environment?