FLUPSY nursery management: tracking oyster spat from delivery to grow-out

Mussel App supports FLUPSY nursery management for oyster (and mussel, if needed) spat, from the day the seed arrives through to early growth and the move to baskets or trays. Every step is recorded against a specific position in your FLUPSY, so you always know where each batch is, how it is growing and when it is ready to be seeded out.

What is FLUPSY?

A FLUPSY (Floating Upweller System) is a floating nursery for young oysters. A FLUPSY draws seawater up through bins or silos that hold the spat on mesh screens, so the seed gets a steady flow of food without leaving the water. It protects tiny spat during their most fragile stage and speeds up early growth before the oysters move on to baskets, trays or bags for grow-out.

That also makes a FLUPSY one of the hardest parts of an oyster farm to keep track of. Thousands of spat sit in many small containers, and farmers grade, thin and move them on in stages. Paper records and spreadsheets fall behind quickly.

FLUPSY stages

1. Delivery

The spat arrives from the hatchery as tiny seed, and farmers load it onto mesh screens in the FLUPSY bins. They usually measure it by volume or weight rather than counting it one by one.

2. Early growth and counts

Once the water is flowing, the spat grows fast. Farmers check on it regularly, take samples to estimate how many spat are in each bin, and clean the mesh so water keeps moving through evenly.

3. Grading and sieve sizes

Not all spat grows at the same speed. As it grows, it is graded through sieves and sorted into size groups. Smaller spat goes back for more time, larger spat moves up, and bins are thinned out so there is room to keep growing evenly.

4. Ready to seed and moving on

When the spat reaches the size the next gear can hold, it leaves the FLUPSY and is seeded into baskets or trays for grow-out.

Every record stays attached to the batch and its position, so traceability carries through from delivery to grow-out.

FLUPSY nursery records at a glance

Stage	Records captured
Delivery	Source, delivery date, batch, starting amount, position in the FLUPSY
Early growth	Counts at each check, mortality since the last check
Grading	Sieve sizes, size group, counts per size group, mortality found during grading
Ready to seed and moving on	Change of stage to ready for seeding, move to baskets or trays, final count, mortality at transfer

How Mussel App records your FLUPSY

Build your FLUPSY layout

Start by building your FLUPSY as a grid: choose the crop type, the number of buckets in each section, and the size of your raft in sections, with height and length. A raft that is 4 sections high by 4 sections long gives you 16 sections, and each section holds multiple baskets.

See every basket at a glance

Once the layout is set, the spat storage view shows your whole FLUPSY on one screen. Every basket has its own position code and its size, so you can find a batch without walking the raft.

Track growth, then track the transfer

Once your spat is in the layout, Mussel App starts building its history. Each count, sieve size and mortality entry adds to the batch’s growth record, so you can see how the spat is developing over time and not just where it is sitting.

FAQ: FLUPSY Management

Keep reading