The relationship between the oyster growing cycle and supply

Standish Shore Oyster Seed

As water temperatures finally warm up, food in the water is slowly growing more abundant for our baby oysters! Around May and June, growers in New England receive their new seed to put in their oyster nursery to grow for next season's oysters.

Witnessing the beginning stages of our oysters inspired me to think about the schedule on an oyster farm. I realized as Standish oyster growers, it's an important topic for us to share with all oyster handlers and explain why suppliers should care.

The Oyster Life Cycle 101

Oysters are hermaphroditic bivalves that spawn when temperatures fluctuate drastically. In the wild, this typically happens during the summer. Depending on the oyster's environment or life stage, the oyster can be male or female, but never both at the same time. Once the oysters spawn, eggs and sperm are released into the water to be fertilized. Adult females can release as many as 5 to 8 million eggs at one time!

A great summary of the oyster life cycle. Farmed oysters spend most of their pre-seed lives in hatcheries and then move to farms for growout.

A great summary of the oyster life cycle. Farmed oysters spend most of their pre-seed lives in hatcheries and then move to farms for growout.

Once the eggs are fertilized in the water, the developing larvae float around until they are ready to attach to a resting spot. These young oysters, also known as spat, will now need ample food (and time) to develop their hard shells for protection as they grow in size.

The Oyster Life Cycle, Hatchery Edition

In many areas including Duxbury Bay, water temperatures do not fluctuate enough for oysters to spawn. If they do, there is not enough spat to collect to seed a farm. So instead of collecting wild spat, some oyster farms buy spat that has been spawned and fertilized in a hatchery. Oysters on our farm arrive when the spat is about 2mm in size.

The oyster life cycle very much dictates the growing schedule on a farm. It takes 18 to 24 months for oysters to become adults or grow to market size, approximately 3 inches. Since growers only have a finite amount of land, they also only have a finite amount of oysters they can grow on their farm. Some of that area has to be devoted to oysters that are maturing to market size. Very much like agricultural farming, growers have to plan their farming schedule to allot enough time for growout.

Understanding the Growing Cycle on the Farm

Lately, oyster supply has been really tight and in New England, much of it is due to the growing cycle. Most New England growers receive their oyster spat in late April or May when the waters are warmer and contain more food. Starting baby oysters in the winter would annihilate them. As mentioned above, it takes at least 18 months to grow an oyster to 3 inches, so if you count 18 months from April, the oysters will be ready the next October as summarized below.

Many growers are close or already out of market size oysters from the 2012 crop. Those oysters were sold last fall. Now, growers are waiting on oysters to sell from the 2013 crop, and unfortunately, the late spring this year gave these oysters a slow start. Farms also sold many of their petites in the winter from the same 2013 crop for some extra sales, so we're seeing very limited number of those as well. Summer tends to be tight months for New England oysters because market size oysters are sold out, so the oysters left are those racing to reach 3 inches or simply little spat barely mature.

So, what about wild oyster supply?

As farmed supply declines, there is some pressure on wild supplies. Wild oyster growing cycles typically follow the oyster life cycle and should technically have consistent numbers. Unfortunately, it's hard for people to leave wild oysters undisturbed. It's tempting to harvest anything market size because of the sales potential, and with climbing demand, oyster beds are being picked over in areas like Wellfleet.

Most of the pressures on wild supply, though, are due to regulations. Regulations obviously limit harvest amounts and implement sizing restrictions, but more recently, the development of vibrio regulations have had even greater impacts. As an example, the new vibrio regulations from Connecticut this summer have greatly limited the ability for fishermen to harvest Blue Point Oysters. The lack of New England oysters are definitely more noticeable now without the support of wild supplies.

Standish Shore Farm Update

graded seed.JPG

So, as we wait for our oysters to grow, we're getting the farm ready for our new seedlings that arrived in May. Last week, we finished our first grading of 2 million seed from our upweller nursery, and soon, they will get ready to grow in their aqua purses out on the tide.

We have new help on the farm and a lot to do. Even though we can't sell these oysters yet, they will be 3 inches by next fall before you even know it. We're looking forward to the warm weather and the wonderful summer winds in Duxbury Bay. A new crop for a new season -- to 2015 and beyond!