Choosing the best equipment

Choosing the best equipment

Zapco Aquaculture’s Grow Out Oyster System allows you to grow oysters near the surface of the water. The oysters benefit from the excellent exposure to oxygen and phytoplankton (their food source), and helps produce big, healthy mature oysters.

Zapco Aquaculture is the leading innovator and manufacturer of oyster growing systems and equipment. Our equipment is suitable for commercial oyster growers and for oyster gardeners.

Depending on your experience –  we have a few options to choose from .

For the beginner oyster grower

For those oyster gardeners that are just beginning, Zapco Aquaculture can partner you in this very  rewarding and educational experience.

We highly recommend growing oysters from spat to full grown oysters in our Grow-Out Tumblers.

The Zapco Tumblers work by rotating with the incoming and outgoing tides, allowing the tumbler to rotate. This rotation increases the feed rates of the oysters, allowing each oyster to receive an equal amount of feed during each tide cycle.

Because of constant movement of the oysters in the Grow-Out Tumblers the oyster feed rates are much better than stationary intertidal systems where the oysters are stationary and live on top of each other.

The other big advantage is that while the tumbler is rotating the oysters, the shape of the oyster is changed so it is more uniform with an increased oyster cup size.

oyster gardening grow out tumblers
oyster gardening grow out tumblers
oyster gardening grow out tumblers

Setting Up

Once you have selected a suitable location to grow, it is time to set up your Spat Grow-Out Tumbler kit in the water.  

Each Spat Grow-Out Tumbler kit comes with 4 tumblers.

1 x  1/8″ x 1/8″ diamond shaped mesh pattern.  This tumbler is suitable for growing spat 1/8″ up to1″ or out to fully mature oysters

3 x 5/16″ x 5/16″ Diamond shaped mesh pattern tumblers. The larger mesh pattern is for growing out oysters from 5/16′ out to fully mature oysters around  3 1/2″ to 4″.

When you purchase your spat – we suggest purchasing 1 to 1.5 quart of spat that is 1/8 inch to 5/16″ or bigger. You can find a hatchery list here to purchase spat.

Each Kit also includes 33″ feet (10 meters) of Zapco’s Stormline and Storm Clips to attach the Tumblers to the line. You must securely and tightly tie the Stormline between two posts or pier poles  to ensure the tumblers do not float away. The line has to be set up at mid tide level to allow the tumblers to rotate with incoming and out going tides. 

Stock volumes of oysters

The best way to work out required volumes of oyster is by starting with 1 to 1.5 quarts of 1/8″ to 5/16″ spat.

Place them in the 1/8″ tumbler to begin the growing process.

This may not seem like many oysters but the estimated volume of oysters per quart  is 2400 to 1800 depending on size 1/8″ or 5/16″.

Place the oyster into the tumbler and clip on the line making sure there is a space of 18″ between each tumbler.

 Let the oysters grow until their volume reaches approximately 6 quarts in the tumbler. This doesn’t have to be exact but we highly recommend not to exceed this volume as it will over crowd your tumbler which will affect growth rates and increase mortality.

Once you have 6 quarts of spat in the Tumbler it is time to grade and reduce the oyster volume back to 1.5 -2.0 quarts.  Learn more about grading oysters. 

Oysters can have a high mortality rate so you need to grade the oysters to remove any dead oysters and separate the oysters by size from small, medium and large each time the Tumbler reaches a Volume of 6 quarts.

 Note that the mortality rate can be around 30% to 50% from start to finish.

You can now add the graded oysters into your 5/16″ x 5/16″ Grow Out Tumblers using the same volume as the 1/8″ x 1/8″ Tumbler, that is, 1.5 to 2.0 quarts per tumbler.

Repeat this process until the oyster reaches 3 1/2″ to 4″

Once they reach this size you can either donate them to a Local oyster reef Project or use them for your own consumption. Please make sure you ask your local authorities to make sure the oysters will be safe to eat in your location.

Don’t forget to keep an eye on the volume in each Tumbler to make sure they are not over stocked.

 

Zapco Acquaculture can provide set up instructions  to all customers purchasing products in the Zapco Aquaculture Grow Out System

 

Transferring oysters FromTumblers to Floating Bags to expand your Oyster garden

The process to transfer your oysters from Tumblers to Floating Bags is a simple one.

Floating Bag set up

Floating Bag set up is very easy to do .

Place two posts 16  to 20 feet apart, attach the line to the first post and then attach the other end off the line to the second post

Make sure the line is set up so it is loose and can swing 4-6 feet from side to side on the in coming and out going tides  This allows the sunlight to reach the bottom marine life and vegetation.

Its important to make sure the bags do not go under the water in high tide and do not sit on the ground in low tide.

Loading the Floating bags with oysters

First grow out your oysters in Tumbler to 3/4″ to 1″or purchase 1/2″ and up spat from your local hatchery

Once the oysters reach the required size of 3/4″ to 1″ inches in the tumblers we suggest removing the oysters from the tumbler into the floating bags.

Using the same volumes and processes  we have recommended for the Tumblers 1.5 – 2.0 quarts per floating bag, grade the oysters when the bag volume reaches 6 quarts. with in 12 weeks or less depending on location.

Regrade the oyster and repeat this process until the oysters reach 2/1/2″ – 3″  then place 100 to 120 oyster into each bag to grow out to full size of 3 1/2″ to 4 1/2″ Do not over stock your oyster bags

The densities of oysters in the bags is an extremely important part of growth rates and varies from one location to the other. We highly recommend you do not over stock your bags as this will reduce your growth rates and increase your mortality rates.

Once the correct volume of oysters is placed into the bag clip the bag onto the line then place the second bag directly opposite the first bag.

Removing over catch by Flipping bags
 
The Zapco Flipping system is the best way to reduce Over Catch.
 
What is Over Catch? It’s an expression used when 
Marine organisms like Tunicates, Barnacles, Mussels and other Marine organisms attach  to your oysters and equipment. 
 
Its very important that you remove the Over Catch.
 
 To achieve this simply flip one bag on top of the bag next to it. This enables the bag to air dry for 24 -36 hours then reverse the process with the bag next to this one  (bag on other side of line). This simple process kills off 99% of the over catch, 
reducing your labour work.
 
It is recommended this process is performed every 3 to 4 weeks depending on location and Over Catch rates.
 
The best part of the system is you don’t have to do much work and rewards are fantastic oyster and a cleaner environment. for the future.
oysters in mesh bag
oysters in mesh bag
oyster gardening - floating bags in the water