To receive more information on oyster seed collection or the purchase of hatchery seed, please give us a call or send us a message using the form below (or to the right). Just as an Upweller, the Downweller is designed to aid in the growth of juvenile oysters. The downward flow of water provides essential nutrients for the setting oysters. This promotes rapid growth of the spat.Īlong with providing essential nutrients, a FLUPSY can protect oyster seed from predators, competition from other shellfish and biofouling in the early stages of development.Ī Downweller System provides hatchery operations with a clean substrate and proper environment nylon mesh, finely crushed shell (microcultch) or another suitable material. In a FLUPSY, the seed sit in silos and are fed a constant flow of naturally occurring nutrients called phytoplankton from the upwell of water that the structure generates. To aid in the growth of juvenile oysters before they’re ready to be transferred to grow-out equipment, producers are beginning to adopt the use of an Upweller or FLUPSY (Floating Upweller System). Upwellers (FLUPSY) and Downweller Systems Most hatcheries are now offering triploid oyster seed, given the benefits. They can be harvested at any time, including the summer months (depending on local conditions). Triploids do not spawn and continue to grow throughout the year. Invented in 1979 by Standish Allen, triploid oysters have three sets of chromosomes which making them sterile.
Technological advances have been made to develop non-spawning oysters. By setting our own larvae, we raise oysters to support our farming operations and sell oyster seed to growers. We opened Maryland’s first commercial oyster hatchery on the clear waters of Fishing Bay in Crocheron with the goal of producing as much larvae as possible. Using hatchery spat allows oyster Farmers to cut down on labour costs while beginning the growing process with healthy, certified seed that are resistant to disease. The goal is simple the process is complex. Hatchery spat are grown in laboratory conditions and fed nutrients that can enhance growth. In most all situations, the collector is covered in a thin layer of a cement, lime and sand mixture to assist in setting. The use of these methods is subject to an oyster Aquaculturist’s own personal preference in collection, depending on the conditions in the area. Oyster spat collector trays are used primarily on tidal flats to collect seed in the intertidal zone. Long lines and raft culture are other methods of collection. More modern methods of seed collection include using oyster (Chinese) hats, coupelles, and modified drain pipes. Although still widely used, these methods of tradition collection leave the oysters susceptible to predators in the wild and have made way for more advanced options for oyster seed collection. They have been a mainstay in Australian and Japanese oyster farming for centuries. Oyster sticks are another method of traditional seed collection in the wild as well as in hatcheries. These oyster beds are most often situated in an intertidal zone to prevent fouling and strengthen the abductor muscles of the oysters. Over time, spat (oyster seed) settle on the empty oyster shells, maturing to a harvestable size. On-bottom traditional seed collection includes the spreading of cultch, recycled oyster shells, on the sea bed. The off-bottom growth is significantly faster than those that are grown on-bottom and their shell has a different character.Oyster seed collection can occur in a variety of ways. These oysters are spread on the tideland on firm substrate, placed in plastic mesh bags supported off the ground by lines, placed in various plastic mesh baskets off-bottom, or placed into trays.
Once the single seed has grown to ½” – ¾” size, they are planted out to our tidelands. The cultchless seed is fed the same microalgae for 4-8 weeks before moving them to an upwell system in the bay, where they can then feed on natural algae. Some of our cultch seed is strung onto ropes that are supported off-bottom for accelerated growth where the substrate is soft or acidic. The shell with small oyster spat can then be scattered across the tideland for growth to maturity. The cultch seed is fed with tank-grown microalgae for 1-2 weeks before being moved to tidelands for 3-6 months of growth and hardening.
Currently, Rock Point uses a remote setting facility to assist acquired oyster larvae in settling onto both shell in plastic mesh bags (cultch seed) and in trays (cultchless single oyster seed).
These are now allowed to grow to maturity and sold as single oysters. In years past, we sold tiny oysters that had naturally set on our gravel tideland as gravel seed. Single oyster seed is periodically available from our nursery. Bags of cultch oyster seed is available from our setting tanks or seasoned from one of our farms. Pacific oysters are set on whole oyster shell in bags or on micro-cultch shell as singles in our remote setting/nursery facility.