Oyster Spat Production

Oyster spat production is what we specialize in. Here is a brief overview of the oyster spat production process and what it takes to raise healthy oysters.

BROODSTOCK

At Paternoster Oyster Company our selected broodstock oysters are conditioned and cared for under controlled conditions for rapid gametogenesis. The strongest batches are spawned multiple times in a season ensuring a consistent supply of healthy oyster larvae.

SPAWNING

Oysters utilize the most common reproductive strategy for marine organisms, namely broadcast spawning. Eggs and sperm are released into the water column and fertilization occurs externally. When our broodstock oysters are ready for spawning, they are cleaned thoroughly and introduced to filtered seawater at a temperature 10°C higher than that of the conditioning tanks. This thermal shock induces spawning where eggs and sperm are released into the water over a 3 to 4-hour period. Fertilization occurs and after 24 hours larvae are present in their first phase of planktonic life.

LARVAL REARING

For two to three weeks the oyster larvae grow and develop through multiple stages in the free-living planktonic phase. They are fed a mixed diet of high-quality algae species, grown in our own algae hatchery. Larvae are assessed, measured, and graded every second day to ensure a healthy, clean environment for them to flourish.

LARVAL SETTLEMENT

Once the larvae reach the pediveliger phase, you might see a little foot reach out in search of something solid to latch onto. At this stage the larvae are ready for metamorphosis and are placed in nets along with crushed oyster shell. Also known as cultch, the powdered shell presents a surface for larvae to attach to, whereafter they start building their very own shell. After around six weeks the spat can reach a size of 6mm and are ready to be sold to grow-out farms.

ALGAE PRODUCTION

The algae hatchery is one of the most important and most expensive parts of the oyster production system. Nine different species of algae are grown at POC as feed for larvae and adult broodstock oysters. One single algae culture takes between 5 and 7 days to reach optimal growth within its volume, whereafter it is split into multiple vessels of the same size or used to inoculate a larger vessel. Great care and attention to detail are needed to ensure a sterile, optimal culture environment.