Other countries have been farming oysters a lot longer than us here in the States and so they have some industrial sized operations going on. If you like growing in oyster bags I thought these pictures might give you some ideas of what you could do in the future with a little rebar, some welding, a water column permit, and a whole lot of bags. This is like "rack and bag" on steroids!
Each one of these units is hoisted in and out of the water by crane.
Bags can be placed in rebar containers and then filled with oysters and closed.
Notice the rebar pins that keep the bags in place, also notice the black rubber strap with the "s" hook, it has and end that fits into the hole in the bag but won't slip out, easy to install and works nice...here's a picture of some below...we can get these if you are interested.
Alot of companies, will harvest their markets and then store them in the water until they have an order to fill. These baskets are nice because you can pre-count your product not just pre-sort. Also, check out the triangular basket in the background, it looks like it has a pvc piece running through its center so it can spin around, I'm assuming it is for seed growout...interesting, I'll look into that. This gives a good view of the feet.
Close-up on the rebar pin(simple) and those bag closures.
Great video of these cages or similar ones at work...and no, this is not a local oyster farm I think its in the UK somewhere...either way cool video...notice its one buoy to several cages, deep water, and they are using the rod to close the bags...can get those if interested.
For all of you who are patiently waiting for bags to arrive the container is still scheduled to be here by the end of October begining of November. We'll post it once they are in.
Here's that seed from this spring ABOVE and here it is again BELOW from two days ago. We've said it before don't wait until the fall; get your seed as early as you can. If you don't want to wait on us or other guys get yourself some type of upweller system so you can get your seed direct from the hatcheries as soon as its ready. Now it doesn't just majically get big without some help. Got to upwell. There are three tanks in this picture plus two floating upwellers in the background. We sort the seed out of the upwellers at 1/2" and send it out directly in .5"x.5" cages. Then we start splitting... and sorting... and building lots of .5"x.5" cages...we had a lot of seed... more sorting and splitting.... lots more...its exponetial...1-2-4-8-16 and so on until you reach that final density for growout. cages coming in Splitting seed on the farm, we do this twice before it comes back in for sorting. Older seed coming in to be sorted, it will go back out in two different grades typically. Running older seed in QuickTube...huge help, it mows through a hopper of oysters like this and you end up with a good pre-cull for later...we are selling this stuff right now, it blew up over the last month.
Splitting again...this is the KEY to having beautiful oysters in short order... but you need to be on it every two to four weeks depending on how fast your stuff is growing...2-3weeks for us.
OYSTER SEED IS AVAILABLE!!!!!!!!!!!!! CALL STEPHANIE AND ASK FOR PRICING AT 804-338-6530
If you have an order in with us we should be contacting you soon. If you just need a few thousand for your garden, call Steph and swing over and pick them up. Don't forget we are at the Irvinigton Farmers Market every month with all of our goodies. That is the first Saturday of each month until November.
This is how small the seed was after we had it for a week...it was half that size to start. Your seed will been sorted and ready for you at whatever size you are looking for...3/16", 1/4", 1/2" and up. Prices vary by size.
Probably the thing that trips up most new oyster farmers is falling behind on seed work.
When oysters, especially when they are young, have warm water and lots of food they grow FAST!!! If you loaded a bag about a quater full of 1/2" seed today in about two weeks during the growing season you could easily have 1/2 to 3/4 full bag of oysters. If you let that go another two weeks you'll have a solid brick of oysters and the beautiful minature half shell style oysters will start to get real crazy looking as they run into one another reaching for more water and room. It can be an expensive and discouraging mistake to make. After years of fighting bags and working our tails off to stay on top of our seed (often to no avail)we finally started using .5"x.5" low profile cages to do all of our seed work out on the farm.
Now, we haven't completely gone away from bags because when the seed is humming out of the upweller and it needs a place to go yet its too small for .5"x.5" we put them in 4mm bags. We'll let them ride there for two weeks then into the half by halfs if we are in a pinch. The best scenario is to run them long enough in the upweller so they can go directly into the half by half cages. A couple of things are great about the half by half cages... 1. Holds a lot of oyster seed 2. Easy to open and close 3. Can be split out on the water in a rapid fashion 4. Can hold the oysters all the way to a size compatible with our 1x1 cages
When we are doing seed splits we will hoist a cage on deck and dump it on the bow as seen in these two pictures. Once its on the bow we will fill orange bushels to a desired level, usually 3/4's full and we'll use that volume as our guage for reloading the cages to go back in the water. So we will add 3/4's of a bushel to the top and bottom of a lowpro cage. The amout of oysters that are left over will vary depending on how long you waited to do a split, but those oysters as seen in the picture above will go in another empty cage that we brought out with us. If you want to cut the bill on your seed just hang the bushels over the side and shak'em up until they are nice and clean, we only do that if we let a cage get really loaded or if there is just a lot of junk and we want to rinse it out of the oysters for a fresh start.
Check out the video...
The bottom line seems to be no matter what you end up doing stay on top of giving your oysters room to grow.
If you want to grow a large volume of oysters you need to buy a bunch of seed and at $25/1000 a million oysters gets expensive. So this would be the first reason to have your own upweller. An upweller allows you to purchase seed directly from a hatchery at a much smaller size and price. Right now 1-2mm seed from a hatchery will run you anywhere from $7-9/1000 based on strains and genetic characteristics (triploid/diploid). Picture with penny shows 2mm seed.
Some hatcheries will even go a little cheaper by selling it to you a bit smaller say .5mm, this gets a little tricky for some because .5mm is SUPER SMALL!! This stuff acts like dust once it gets dry and will blow away.
What is upwelling and why does it work?
You can upwell or downwell; one moves water up, one moves water down...the diagram explains it better.
When you are trying to set spat on micro-culch (tiny pieces of oyster shell) to get single oysters a method known as downwelling is used and is most frequently a closed system (recirculating water). Once the spat are set upwelling is used and it can be an open or closed system but the methods we will refer to are all open systems or flow through.
Upwelling brings a constant supply of nutrient rich water past your animals. All they need to do is open up and feed, which they do constantly as long as the food is in the water. This method produces hearty oysters in short order that continue to feed at a rapid pace when placed out on the farm.
When running large quantities of oysters we recommend a combination of two systems, bucket upwellers for handling the small 1-2mm seed from the hatchery and larger floating upwellers for 1/4"and up. We upwell to a size that will seive off a 1/2" screen then it goes out to the farm.
So if upwelling is so fast why not run the oysters up to a larger size?
The answer is efficiency. There is a sweet spot between size and volume and once you start to get past the 3/4" size oysters you begin to run out of space rapidly and can run into ugly anoxic situations especially as the water heats with summer temperatures. Its doable but you will need more upwelling units or silo space.
BUCKET UPWELLERS
Since our spat comes so small we use a bucket upwelling system first.
The two pictures above show the tank upweller that we build and sell. We do our own fiber glass work and the tank upweller can be purchased assembled ready to go, as a kit, or just the tank with or without holes.
Prepping to make a new tank mold
As you can see in the picture its a series of buckets (in this case literal 5 gal buckets) that have mesh in the bottom and hold the seed. The buckets are in 4'x10' tanks. Water is pumped into the tank from a submersible pump (low pressure high flow) which fills the tank and the only way for the water to escape is to pass up through the buckets, taking the algae rich water passed the young oysters. The water is then sent back into the bay. Bucket upwelling is a simple principle that can be applied to any size tank, container, or bucket. This method is great for handling small seed but in order to get speed and volume it is essential to move to a floating upweller system.
FLOATING UPWELLERS
We recommend and offer our 27" version of the floating upweller system. 27" is the size of the silos in this unit. We can produce custom size silos, as we do our own glass.
Upweller float with doors ready to deploy
A floating upweller operates on the same upwelling principle as explained above but on a larger scale. In this case a fan pump removes water from a trough, the trough is filled back up by water flowing up and through 8 individual silos and the seed sits on mesh in the silos. The system sits in an 8 'x 20' floating dock and can handle 1 million animals/ per unit with ease.
A deployed upweller with doors up.
We run upwards of 10 million seed through our system in a nursery season and use three tank upwellers and four floating upwellers.
We use this many units so we can take large quantities of seed from the hatchery all at one time (4-6 million at a whack). If you can space out your seed purchases you can get away with fewer units.
Original method for rafting and tying up four units
Improved setup on pilings with rollers
Improved method with pilings installed so dock can move
with the tide and waves and stay close to the pier.
Also, note that we do not use doors, over the years we found them to be a hassle. Bins on dock are for water to adjust float height as it will vary based on salinity and load.
Bonuses to floating upwellers...
- cheap to run
- high rates of growth
- high animal capacities
They are inexpensive to run because you are moving the water laterally so gravity and equilibrium take care of the rest of the work.
We offer all of this equipment completely assembled, in kit form, or by individual components.
Want the tank and get your own buckets or just all of the glass and you'll get the other hardware, we can do that as well.
8'x 20' FLOATING UPWELLER KIT Kits include everything pictured above including the hardware and instructions so you can build the frame below (you purchase the wood, nails etc on your own).
Kits can also come with no floats or just with the glass with or without holes.
Silos without hardware
Floating upweller kit, no floats, ready to be crated and shipped
Each one of these units is hoisted in and out of the water by crane.
Bags can be placed in rebar containers and then filled with oysters and closed.
Notice the rebar pins that keep the bags in place, also notice the black rubber strap with the "s" hook, it has and end that fits into the hole in the bag but won't slip out, easy to install and works nice...here's a picture of some below...we can get these if you are interested.
Alot of companies, will harvest their markets and then store them in the water until they have an order to fill. These baskets are nice because you can pre-count your product not just pre-sort. Also, check out the triangular basket in the background, it looks like it has a pvc piece running through its center so it can spin around, I'm assuming it is for seed growout...interesting, I'll look into that.
This gives a good view of the feet.
Close-up on the rebar pin(simple) and those bag closures.
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