Coastal Residents Growing Oyster Gardens Under Their Dock

Mar 28, 2017

Oyster spat collect on oyster cultivation containers like this one. In two to three years, the oysters will be fully grown and ready to harvest.
Credit NCDMF

Participants with the North Carolina Under Dock Oyster Culture Program can attach up to 90 square feet of oyster "cages" to their coastal dock or pier and harvest their oysters any time of the year.

How do you like your oysters?  A little hot sauce, maybe a little butter, maybe served on a cracker?  Oysters are a delicacy along the North Carolina coast.  And can you believe they're good for you too, with copious amounts of vitamins, minerals and organic compounds.  More good news, access to fresh, local oysters is improving along our coast thanks to restoration efforts by local scientists, the State Division of Marine Fisheries, conservation groups and local fishermen.  But what if you could grow your own oysters in your backyard and harvest them whenever you’d like?  That’s the idea behind the Under Dock Oyster Culture Program, or UDOC.  Tere Barrett is the aquaculture coordinator with the North Carolina Division of Marine Fisheries.

“You have to have a dock that you own, so it’s really is limited to waterfront property owners.  So the dock has to be an authorized, legal dock permitted, and under that dock is where you can have 90 square feet of cages for the oysters.”

UDOC participants place oyster cultivation containers similar to crab pots under their dock or pier.  Over time, oyster spat begin to attach to the two foot by three foot cages.  In about two to three years, they’re fully grown and ready to be harvested.  Sounds easy, right?  Well, Barrett says the process is a little more involved.

“You do have to watch them and clean them regularly and turn them, check your cages.  I think it’s a little more involved than people expect.”

Currently, there are only 17 people in North Carolina who participate in the UDOC program, administered by the Division of Marine Fisheries in conjunction with North Carolina Sea Grant.  When it started back in 2004, about 40 people were involved.  Barrow thinks interest has waned due to the difficulty in growing oysters and the regulations that are part of the process.  But those up for the challenge, reap the rewards. 

Shucked oyster, revealing the inner meat for researching bacterial counts.
Credit B.Fitzula/UNC

“Once you have a UDOC permit, you can take the oysters pretty much any time of the year and you can take them under size.

That means fresh, local oysters any time – not just in months that end with “R.”

“But what comes with that is the responsibility to know about the organism, about water temperatures and rainfall, and bacteria in the water and shellfish closures.”

All of these factors affect oysters and being able to determine if they’re safe to eat.  Oysters feed by filtering up to 50 gallons of water per day which is great for improving water quality but makes them susceptible a bacteria which collects in their tissue known as vibrio.  Dr. Brett Froelich is a research assistant professor at the University of North Carolina’s Institute of Marine Sciences in Morehead City.

Dr. Froelich collecting oyster samples at Hoop Pole Creek, NC.
Credit UNC Research

“We’re looking specifically at two bacteria, both of them are vibrio.  One can cause you to have intestinal discomfort when you eat raw oysters, and the other can be more severe leading to some severe diseases.”

Vibrio volnificus and Vibrio parahaemolyticus thrive in warm environments.  So that’s why there’s a greater risk of getting sick from consuming raw oysters during warm months.  Dr. Froelich is involved in an ongoing study which monitors bacteria in local oysters.

“But we’ve only been looking at wild oysters.  And we realized that farmed and gardened oysters are a big part of what we do here in the state as well.”

By farmed, Dr. Froelick is referring to oysters grown through large scale aquaculture practices.  And by gardened, he means the UDOC program.

“So, we decided and we were given some money by NC Sea Grant to take a look at what’s going on with our farmed oysters including those in some people’s backyards or back water areas.”

Oyster cages are placed under a dock in the shade while natural oyster reefs usually experience full sun and different boat traffic.
Credit NCDMF

Cultivating your own oysters is a relatively new idea.  To date, there hasn’t been any research done in North Carolina to compare how gardened oysters differ from wild ones.

“Gardened oysters are a little different, they’re grown differently, they’re shaded from the light, they have different boat traffic that gets over them.  They really are something completely different.”

To conduct his study, Dr. Froelich purchases several oysters from participants with the UDOC program.  The samples are taken to the lab, shucked and pulverized into a liquid.  

“From there, we grow the bacteria up, and we examine what’s in there.  We also save some of the DNA that’s in there and we do what’s called molecular testing in which we are looking for bacterial DNA.”

The results will be posted online and Dr. Froelich says participants will be able to access the data to make sure their oysters are safe to consume.  Contrary to popular belief, hot sauce or lemon doesn’t kill Vibrio bacteria. The only way to eliminate any potential health risk is to fully cook oysters. 

Credit NCDMF

Growing your own oysters is an appealing idea.  But before you start making plans for an oyster roast, you have to get a permit.  There’s a 20 question test you must submit to the State Division of Marine Fisheries.  And, Aquaculture coordinator Tere Barrett says your dock must be located in waters approved for the harvest of shellfish. 

“The first thing they do is email me and I will send them the test and they do the test and submit it to me and once they pass the test then they can submit an application and then we go from there.  I’ll go and look at it and make sure it’s a legal dock, it’s not impairing anybody’s navigation.”

Signs are also posted to let people know the oysters are private property.  Cages can be purchased from the North Carolina Shellfish Growers Association or Sea Grant.  Add some spat and you’re ready to start growing your own oysters.

“Oysters are good for the environment and oysters are good one the plate as well.  And this is a good way for people to essentially improve both things right here at home.”

To learn more about the NCDMF's NC Under Dock Oyster Culture Program, go to: http://portal.ncdenr.org/web/mf/nc-under-dock-oyster-culture-program1 

Credit NCDMF