Part-grown oysters prior to washing and grading

PART-GROWN

As well as selling seed from Walney Island some of our seed is grown further to sell at a later stage as part-grown.
These oysters are grown in Morecambe Bay some 2 miles off shore where if it’s a spring tide and low water we can harvest the oysters by tractor & trailer for routine grading or selling.
The oysters are grown using the traditional bag & trestle method, seed are sealed in plastic mesh bags and attached to steel trestles using very strong rubber bands.
We put seed no smaller than 15-20mm in length in 7mm aperture bags and leave them no longer than 6 weeks before bringing ashore, grading and returning in clean, and larger mesh bags where possible, we never turn bags we always grade.
If the faster growing oysters are not removed from the proximity of the smaller ones soon enough or often enough the smaller ones can become runts and then never grow.

Also a 7mm aperture oyster bag will reduce the water flow by as much as 60%, because of this we don’t use bags smaller than 7mm, as we want as much water as possible bringing food to the oysters.
We no longer use the 14mm mesh bag as we were suffering serious losses to oyster catchers, they cannot open their beaks when poked through a 9mm bag and cannot therefore eat the oysters.
The exposed location of the on-growing site makes it prone to storm damage so all our trestles are fixed securely to the ground with recycled plastic posts.
The 10 metre tides and severe wave action does produce a very strong and hardy part-grown oyster which when transported to other grow-out sites grows extremely well.
As long as we keep selling part-grown oysters a lot of bags do not need returning to the sea so we can fill the empty spaces with the next batch of seed from the nursery.
We have a range of equipment including hoppers, graders and bagging machines that are specially made for handling oysters.
The bagging machines can be used for a variety of tasks not just for grading part-grown oysters but also for filling seed bags, filling sacks or bulk bags for sale.
Whichever way, we can handle large quantities easily and efficiently.

Part-grown oysters at Roosebeck ready for shipping