Oysters are a Bargain: The Time, Effort, and Risk of Growing Oysters Throughout the Year

Our Wicked Fish, Inc., got a speed lesson in oyster aquaculture from Jennifer and Scott Mullin of Scorton Creek Oysters. After one afternoon, we were astounded with how much time, effort and risk goes into raising oysters in Massachusetts.

(Disclaimer: These are, by no means, the only steps during these seasons) 

1. Find a piece of seafloor bottom that is suitable for shellfish aquaculture.

It can't be too soft, too hard, too exposed at low tide, or too submerged at high tide. The water that comes in and out with the tide needs to be cold and filled with phytoplankton for your shellfish to feed on.  Hopefully, this piece of bottom is not booming with predators that want to feed on your shellfish (such as whelks and sea stars).  Once this seafloor bottom is found, there are biological surveys that the state conducts and then best of luck getting a permit from the town.  There are limits on how many aquaculture farms a town can have and the waitlists for these town permits are long.

2. Now that you have farmland, you need crops!

Oysters are still referred to as crops and they arrive to you as seed.  Seed arrives in a small plastic bag from an approved hatchery. Seed looks like a bag of sand. This small sand-looking bag just happens to cost several thousands of dollars.

3. Spring is for Seed

A bag of oyster seed. Photo provided by Jennifer Mullin

A bag of oyster seed. Photo provided by Jennifer Mullin

Oyster seed needs water, food, and protection.  Seed is placed in tubes created out of fine mesh lining.  The fine mesh lining allows water to inundate the seed while preventing predators and large obstacles from harming the seed.
The oyster seed filter feeds  and then excretes waste. Since the waste will clog up the opening in the lining, the lining needs to be brushed and cleaned constantly to ensure free flowing water.

4.  Oysters need constant care and attention.

Oyster seed with small cup for scale. Photo provided by Jennifer Mullin

Oyster seed with small cup for scale. Photo provided by Jennifer Mullin

Oysters grow quick in the beginning. Seed will grow exponentially in the first few weeks. As they grow, they need to be moved into different bins with less oysters.  Since a grower can only reach the oysters during low tide a grower only has a few hours every day to get out to their farm, check, monitor, move,  and care for their oysters.  Since the timing of low tide changes everyday, growers have a varying schedule.  For instance, if low tide is around 6 a.m and 6p.m., a grower may be on the farm from 5-8 a.m. and from 5-8 p.m. that day.   

5.  Summer is for Spawning

As the water temperature rises in the summer, diploid oysters (those that have two sets of chromosomes) will want to start focusing their energy on reproducing rather than growing their shell or their meat. Triploid oysters (raised to have three sets of chromosomes) will not reproduce so they continuously grow their shell and their meat in the summer.

6. Summer and Fall is for Vibrio

Tubes holding small oysters. Photo taken by A.Davis

Tubes holding small oysters. Photo taken by A.Davis

Summer and Fall is vibrio control and management season.  Vibrio is a naturally occurring bacteria that is present in coastal estuaries. It thrives in warm water.  It is tasteless, odorless and doesn't affect the appearance of shellfish. If it accumulates to high levels in shellfish, it will make the consumer seriously ill.   While a grower can not rid of vibrio in the water, they can take measures to prevent a contaminated oyster from being on the market.

To handle vibrio, Scorton Creek Oysters shade their oysters when exposed they are exposed to the air. Additionally, while the state department requires growers to have oysters on ice within two hours of being out of the water, the Mullins move their oysters in ten minutes from racks in the water  to the boat then to a refrigerated truck waiting for them with ice at the boat landing. Furthermore, their wholesaler runs tests on every shipment to ensure quality and safety.

7. Fall is the Final Countdown

11 month old oysters. Photo taken by A.Daivs

11 month old oysters. Photo taken by A.Daivs

Fall is considered to be a great oyster season.  The diploids have finished spawning and have been building their biomass.  They're great to eat right before they become dormant.  

8. Winter is for Worrying

Oysters go into dormancy during the winter. Dormancy is when their physiological functions slow down and take a break.  Some growers take their oysters out of the water once they’re dormant and "pit" them- either storing them underground below the frost line or in commercial refrigerator.  

Scorton Creek Oysters, however, are in business all year round.  They keep their oysters out in the estuary during the winter so they need to keep their attention on the weather.  When there's the threat of ice flows, they head to the farm to bring the oysters in.

9. Spring (again):

Congratulations!  In a few months your seed from last spring may be market size (2.5 inches).  Will you have every oyster that you started with last spring? Of course you won't!

What could go wrong?

Last summer your oysters looked so good that someone stole a few bins (theft is not unheard of!). Your neighbor grower had poor disease management procedures in the fall.  As an effect, 20% of your crop was infected.  It didn't help that this past winter was brutal-25% of your crop was crushed and stressed by ice.

Scott Mullin cleaning oyster tubes. Photo taken by A.Davis

Scott Mullin cleaning oyster tubes. Photo taken by A.Davis

After working long days and investing a lot of your time and money, you can sell about 50% of your initial crop (if you're lucky!).  Better move these oysters quick, you need space and money for this season's seed!  

The Mullins have been in business for 20 years.  Some of those years were really good, other years there was only a small percentage of their initial crop to sell. Despite all the hard work, time and risky investment, the Mullins were grinning ear to ear while lifting heavy crates piled high with glistening sharp shells. They both agreed, "We wouldn't want to do anything else...we'll be doing this until our backs won't let us.".

Are Oysters Expensive?

Oysters vary in price up and down the east coast. Oysters in the south are much cheaper than oysters in New England. How much should a MA oyster cost? Price can depend on availability, and after a bad winter like this past year, a lot of crop is compromised. So gobble up those $1 happy hour oysters when you can, and perhaps $2 or so a piece is understandable.  While upscale restaurants do place a hefty premium on a dozen, knowing what you know now, oysters at most places are a true bargain.