Raising oysters at home is a form of aquaculture, which is the farming of aquatic organisms such as fish, crustaceans, and mollusks. Oysters are actually a type of mollusk and there are over 60 species.
More and more people are starting to understand the benefits of raising oysters, and beyond the obvious reason of adding to the sustainability of your own household’s food supply, there are a number of other compelling reasons.
By raising your own oysters, you’ll assure that you’re getting the best quality if you control as many factors as you can. The oysters will always be much fresher (if you want them to be) than purchasing them anywhere else, and you can even grow them for profit if they are well-managed.
Other advantages of raising oysters include water cleaning/filtration provided by the oysters and the fact that (unlike all other forms of aquaculture) oysters require no food supply provided by the farmer.
Table of Contents
Methods of Growing Oysters
The topic of how to raise oysters using which methods can be very in-depth and extensive, but to simplify as much as possible, there are basically 2 methods of growing oysters. One method is called bottom culture which allows oysters to use the natural sea floor as a growing environment. The other method is off-bottom culture which suspends the oysters in cages or mesh bags that float just under the surface.
Each method has its pros and cons, but after researching extensively, it seems like a floating or suspended cage or bag is bit easier since it doesn’t rely as much on tidal movements and it allows the oysters to remain close to the surface where they’ll have the most dissolved oxygen.
The off-bottom system is also a bit more controlled and it’s safer for the oysters.
Can I Raise Oysters at Home?
One can certainly raise oysters in a backyard aquaculture environment, with a relatively low start-up cost and few barriers to entry. However, growing oysters outside of the ocean does require meticulous monitoring of water conditions and attention to detail, along with some very specific knowledge and training.
Here are some basic steps you’ll need to take in order to create your own backyard oyster farm, and we’ll expand on the details later in this article.
- Obtain oyster spat (baby oysters) from a hatchery or supplier. These can be purchased in bulk or as individual units, such as oyster shells with attached spat.
- Prepare a tank or container that can hold water and has a filtration system to maintain the water quality. The tank should have enough space for the oysters to grow, with a minimum volume of 20 gallons (75 L) for every 1,000 oysters when they are small.
- Place the oyster spat in the tank, along with clean oyster shells for them to attach to. Make sure to provide them with adequate light, water flow, and oxygen.
- Maintain the water quality by regularly checking the pH, salinity, temperature, and oxygen levels and adjusting as needed. The water should have a pH of 7.5-8.5, salinity of 25-35ppt, temperature of 60-70F, and oxygen level of 4-5mg/L.
- Feed the oysters by adding a phytoplankton supplement to the water.
- Harvest the oysters after they have grown to a suitable size, which typically takes around 6-18 months depending on the species and the growing conditions.
It’s important to note that oysters are filter feeders and they consume phytoplankton and other small particles present in water, thus it’s recommended to grow them in natural water in your home, such as a marine aquarium or a pond with an appropriate salinity and temperature.
PRO TIP If at all possible, it’s best to grow oysters in their natural environment, and several states offer help for those getting started. You can obtain licenses/permission to grow your oysters in the ocean even if you don’t have access to the water from your home. This type of farming is far different than using your own water in a tank or pond on your inland property.
PRO TIP #2 For very small-scale oyster farming, here’s a very helpful, illustrated step-by-step guide to start your own oyster farm. You may want to skip the hatching part (my opinion) and buy the baby oysters (called “spat”).
If you’re looking for an in-depth, scholarly article that is more exhaustive and technical, THIS ARTICLE will be what you’re looking for. This is a good starting point to begin a serious oyster farm (especially in Canada or the Northeastern U.S.)
What Tools, Supplies and Equipment do I Need to Start Oyster Farming?
If you’re farming oysters in the ocean, you’ll need a small pickup truck, a small dock and a small work boat to get started, along with just a few other tools like cultivation bags and a rake.
Here’s a list of some of the tools and supplies you’ll need and what they’re used for:
- Oyster seeds or spat: These are the young oysters that you will grow. They can be obtained from a hatchery or from wild oysters that have been harvested.
- Floating cultivation trays or bags: These are used to grow the oysters. They can be made of plastic or mesh and are designed to be suspended in the water.
- A boat or other means of transport: To move equipment and oysters around on the water.
- Harvesting tools: such as tongs or rakes, to harvest the oysters when they are ready.
- Water quality testing equipment: such as a pH meter, a dissolved oxygen meter, or a turbidity meter, to measure various water quality parameters and ensure that the conditions are optimal for oyster growth.
- Drying racks: are used for storing oysters before packaging and shipping, or for allowing oysters to harden their shells prior to planting.
- A secure storage area: to keep your oysters and equipment safe from theft or damage.
- A water source: to get the water for oyster farming. It can be from the sea or from a nearby bay, estuary, or river.
Do Oysters Need to Stay Submerged or Can They Live Out of Water for a Time?
Oysters are aquatic animals that require a consistent water supply in order to survive. They are bivalve mollusks, which means they have two shells that protect their soft body and gills. Oysters filter water through their gills to extract oxygen and food, and they also use their gills to excrete waste. Therefore, if oysters are removed from water, they will quickly suffocate and die, due to the lack of oxygen, and also they need water to filter and consume food.
However, depending on the species, some oysters have the ability to close their shells and survive for short periods of time out of water, in a moist and shaded environment. But this is not a sustainable way of living for them. They will eventually die if they are not returned to an aquatic environment.
That said, many farmers raise oysters in a tidal environment where they are exposed for a short time. Over 24 hours is not good and they will likely die if out of water for longer periods than that.
It is important to place oyster reefs in inner-tidal areas that are below mean low tide.
Additionally, as oysters filter the water to extract food, it is important to consider the quality of the water since oysters can suffer when the water has low oxygen levels or is polluted.
PRO TIP – When researching methods on how to grow oysters, it’s important to note that there are several very different methods, and it’ll be necessary to choose one and stick with it. Methods range from placing mesh bags on the sea floor and allowing the tide to advance and retreat over them, to scattering them on a mud flat or beach (bottom culturing), to containing them in floating cages.
Can I Raise Oysters in a Fish Tank?
Yes, it is possible to raise oysters in an aquarium. However, it is important to note that oysters are filter feeders and require a steady supply of phytoplankton or other microorganisms on which to feed. Therefore, the aquarium would need to be set up with equipment and conditions that can support the growth of these organisms, such as a protein skimmer, strong lighting, and proper water flow.
Additionally, the aquarium would need to be large enough to accommodate the oysters as they grow, and you would need to be able to provide a suitable environment for them. This can include things like temperature control and keeping the water conditions stable.
Generally, a 20-gallon aquarium can handle 20 adult oysters, but more water per oyster is best.
PRO TIP Most oysters grown in an indoor aquarium are grown for their pearl potential. Because it takes so long to culture an oyster from spat (baby) to adult (ready to eat), it’s best to grow them in a natural, ocean environment where nature provides all the nutrients and water conditions necessary for healthy oysters.
What Do Oysters Eat?
Oysters are filter feeders, which means they filter small particles, such as phytoplankton, out of the water for food. In their natural habitat, oysters feed on a variety of microorganisms, including algae, diatoms, and zooplankton.
If you’re considering raising your own oysters, this is good news. You’ll never need to buy oyster feed.
In aquaculture, oysters typically feed on a diet of microalgae, such as phytoplankton, that is rich in protein and essential fatty acids. This microalgae diet is most often available naturally in the ocean environment but may be cultured if you’re raising oysters in a closed aquaculture system.
It is important to note that oysters, like all bivalves, also filter water for suspended particles, sediment, and nutrients and keep their habitat clean and healthy.
Oysters can help improve water quality by removing suspended particles and excess nutrients, which can reduce the growth of harmful microorganisms and improve overall water clarity.
Water Quality and Temperature for Oysters
As mentioned earlier, water quality is a crucial factor in raising oysters, as it can have a significant impact on their health and growth. Some key aspects of water quality that are important for oysters include:
- Temperature: Oysters prefer cooler water temperatures, and extreme heat can cause stress and lead to death. The ideal temperature range for oysters is between 10-20°C.
- Salinity: Oysters need a specific range of salinity to survive, which is typically between 20-35 parts per thousand (ppt). Variations in salinity can cause stress and affect the growth and survival of oysters.
- Dissolved oxygen: Oysters need oxygen to survive, and levels must be above 5 mg/L. Low dissolved oxygen can cause stress and lead to death.
- pH: Oysters prefer a pH range of 7.5-8.5. Extreme pH levels can impact the oyster’s ability to calcify its shell and can lead to death.
- Water flow: Oysters need a steady flow of water to filter feed and remove pollutants. Low water flow can lead to poor growth and survival.
- Pollutants: Oysters are sensitive to pollutants such as heavy metals, pesticides, and certain bacteria. These pollutants can cause stress and lead to death.
- Bacterial: Oysters are filter feeders and they are extremely sensitive to bacteria. This can lead to mortality and diseases in oysters.
Overall, it’s important to maintain water quality within the appropriate ranges to ensure healthy growth and survival of oysters.
Do Oysters Pollute or Clean the Water?
Actually, oysters do quite the opposite of polluting. Oysters clean water by filtering water through their gills to extract food. In the process of filtering the water, oysters also remove pollutants, such as excess nitrogen and phosphorus, which can contribute to algal blooms and other water quality issues. Oysters can filter an impressive amount of water for their size, with an adult oyster able to filter up to 50 – 60 gallons (189 liters) of water per day.
Oyster reefs or beds also provide other important ecological services such as shoreline stabilization, habitat provision for other organisms, and also recreational areas.
Oyster reefs also can be used as natural infrastructure, they can act as a barrier against coastal erosion caused by wave energy and storm surge. This is one of the reasons oyster reefs were historically common in estuaries and coastal areas.
It’s also important to keep in mind that oyster reefs can’t solve all water quality problems, and other measures, such as reducing pollution and managing nutrient inputs, should also be implemented in conjunction with oyster restoration.
In some parts of the country, local and state governments are actually paying citizens to grow oysters under their docks for the sole purpose of cleaning the water.
Many owners of coastal water homes or cottages can attest to cleaner water and better fishing once oysters are introduced into the aquatic environment.
An oyster and clam opening tool like this can make your entire oyster-raising experience easier – especially once you get to the very end – the kitchen table!
How Long Does it Take to Farm Oysters?
The time it takes to raise an oyster can vary depending on a few factors, such as the species of oyster, the growing conditions, and the size of the spat (baby oysters) at the start of the cultivation process, but for most oyster species, it can take between 6 to 18 months to raise an oyster to a marketable size. Oysters can grow up to 20 centimeters (8 inches) wide. However, most types of oysters average around 3 to 5 inches in length.
This time frame can be shortened or lengthened depending on the species, some species of oysters are faster growing while others are slower.
In the case of the Pacific oyster and European flat oyster, it can take around 1-2 years to reach a marketable size if they are farmed.
Farmed oysters are typically faster-growing than wild oysters which can take 3 years or longer to get to marketable size.
However, the growing conditions can affect the time frame as well, oysters grown in optimal conditions such as ample sunlight, adequate water flow, and high-quality water with the appropriate temperature, salinity, and oxygen levels, will reach marketable size faster than oysters grown in suboptimal conditions.
It’s also worth noting that oyster farmers may choose to harvest oysters at different sizes depending on market demand and personal preferences, hence the size and time for harvest are not fixed.
Will Oysters Reproduce?
Oysters reproduce sexually. They release sperm and eggs into the water, where fertilization occurs. The resulting larvae then settle onto a suitable substrate and grow into adult oysters.
Some oysters, like the Pacific oyster, are also capable of reproducing asexually by forming new individuals from fragments of the adult.
Because the process of reproduction is a bit random in the wild, it’s best to rely on a steady source of reliable spat. New, young oysters are relatively easy to source and quite inexpensive.
Where Can I Get Young Oysters to Grow?
Fortunately, there are many shellfish hatcheries or specialized producers that can provide you with spat (baby oysters) to begin the growing process. This is the recommended method of growing oysters rather than working through the oyster spawning process.
It’s possible to allow oysters to reproduce naturally, but it’s not the best method because of the unreliable nature of spawning variables like environmental conditions, weather, water issues and more.
Key Takeaways – Raising Your Own Oysters
Raising oysters for your homestead will probably be more challenging than raising fish in an aquaculture environment, unless you have easy and direct access to salinated water (like a home with a property that borders an ocean or brackish creek, etc.)
Raising oysters in an aquarium is about your only other option, but since it takes 2 years for oysters to reach eating size, an aquarium can be a time-consuming and expensive way to get a small amount of oyster meat.
If you live near the ocean (but not on it), you can contact your local fisheries authority to find out what programs are available to help you access an appropriate area and other needed resources for your small-scale oyster farm.
References:
- https://www.hobbyfarms.com/oysters-farming/
- https://www2.gnb.ca/content/dam/gnb/Departments/10/pdf/Publications/Aqu/oyster.pdf
- https://www.wikihow.com/Grow-Oysters
- https://sciencing.com/isopod-life-cycle-12206033.html
