Oyster gardening is a volunteer oyster restoration program in both Mississippi and Alabama. Your friends and neighbors have been growing oysters as a part of a collaborative oyster reef restoration effort for years.
We have seen great successes in Mississippi-Alabama Sea Grant-supported programs in both states, both in terms of oysters produced as well as numbers of participants and reported these through this blog. Have you ever wondered where the oysters themselves come from? That is the focus of this week’s blog; we know we love oysters and all they do, but how do we make more of them?
Oysters come from hatcheries
For the oyster gardening programs in both states, volunteers grow “florets,” or spat on shell. This is preferable as it more closely resembles the natural reef structure. That is, three dimensional, yielding both oysters for filtration AND great habitat for the more than 300 other species that spend some of their life cycle in, on or around oyster reefs. To achieve this, hatchery managers will select broodstock, flood them with warm water, tricking them into thinking it is spring, to induce spawning.
Once they have spawned, hatchery personnel mix the eggs from the females and the sperm from the males to allow for fertilization. The resulting larvae will then spend the next 10-14 days, depending on the temperature, as free-swimming entities. They are fed regularly and watched closely for signs that they are ready to settle and undergo metamorphosis. At that time, the hatchery personnel will provide whole oyster shell, make the water flow down (down weller) to help push the larvae down onto the shell and cover them up in near total darkness. Oyster larvae prefer to settle and metamorphosize in the dark. After a couple of days, the oyster larvae have completed settlement and affixed themselves to the whole shell where they will remain their entire lives.
That is how we make more oysters, but we have not yet considered where the shells themselves come from.
Shell comes from recycling program in Alabama
In these programs, we use recycled shell out of the Alabama Oyster Shell Recycling Program, managed by the Alabama Coastal Foundation. They get them from area restaurants that sell oysters that we all enjoy. So, when you go to enjoy your favorite oysters, whether cooked or raw, consider asking what happens to the shells.
If the restaurant is a participant in the recycling program, you can be confident that your shells will be collected and transported to a seasoning site before being utilized in oyster gardening or any number of other restorative projects in the region. The key here is that your shells are NOT going into a landfill; they are much too valuable to our estuarine ecosystem to be simply discarded as trash. Seasoning is critical and takes a minimum of six months. This is the time during which all the soft bits of oyster tissue, butter, cheese, etc., that may be left behind after you have finished eating decay. Allowing this material to be put into the water can cause micro-environments with low dissolved oxygen and reduce the viability of reefs.
Mississippi shell recycling program is on the way
Much of this discussion has been about the Alabama Oyster Shell Recycling program, which has been active for a number of years. Mississippi is in the process of setting up its own version of the shell recycling program, which will provide a similar opportunity for the many restaurants along our coastal region to participate in restoration efforts.
As consumers, all you have to do is ask where your shells are going, and if your favorite establishment is not aware of the recycling effort, encourage them to reach out to us. The more seasoned shells heading back to the reefs, with or without spat, the better off our estuaries will be.
Meet the author
P.J. Waters, Ph.D.
Associate Extension Professor
P.J. is an associate extension professor with Auburn University. He coordinates the Mobile Bay Oyster Gardening Program and its projects, as well as K-12 aquaculture/aquascience programs. PJ works... Read more
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