Winter Effects On Oyster Quality

From February to April, we tend to see quality issues on certain varieties of oysters. It’s something that happens each year, so we put together this FAQ to help address your winter concerns.

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What are oysters doing during winter?

When we’re asked to think of animals that hibernate, bears, bats and other small mammals usually come to mind. But did you know, oysters also “hibernate” during the winter? Contrary to children’s books and fairy tales, animals in hibernation are not sleeping. Hibernation is a form of dormancy in which animals conserve energy to survive harsh environmental conditions. Oysters go dormant during winter because water temperatures can stay below freezing for months. Evolution has also taught them that there is no food in the water when everything is iced over.

How do oysters survive their winter dormancy?

To prepare for winter dormancy, oysters feed like crazy during the fall to build up glycogen, their sugar stores — which is why they are so sweet in autumn. When the water temperatures drop to 40° F, it signals the oyster to stop metabolizing and go dormant. The oyster will barely pump during this time and survive on its glycogen to get through the winter. When the waters warm up and food is back in the water, the oysters will become active again and start feeding. They will pump, filter, and eat from spring to fall until water temperatures drop again, triggering another cycle of dormancy.

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What is winter kill?

Inevitably, there are oysters that will die during winter dormancy. This phenomenon is called winter kill. Oysters run out of glycogen to stay alive or they are too weak to withstand the harsh conditions. The worst part is, some of these oysters die remaining shut. This makes them difficult to detect even when harvesters go through them by hand.

What are some signs of winter kill?

Because some oysters die shut, they cannot be detected until they are shaken up or shucked open to reveal dry, shriveled, smelly meats. Dormant oysters are weaker and have difficulty healing themselves, so any chipping during harvest, culling, packing, or transit can lead to liquor loss.

Once we hit late February and into March, we are basically asking the oysters to do the most impossible journey possible. Out of the water, through the packing house and shipped across the [Canadian] border by refrigerated truck. If at any point in that journey, the oyster [attempts] to feed or gets jostled in a harsh manner that loosens the abductor muscle, the oyster will spill some of its precious liquor and there’s no opportunity to replace the liquor… The oyster will not likely open again until spring when he’s either bone dry from survival or is sufficiently convinced that the water temperatures are steady again.
— Jacob Dockendorff, PEI Producer

Why does winter kill affect certain varieties more than others?

If you are a Pangea Shellfish customer, you will notice that certain oyster varieties are unavailable from March to May like wild-harvested Malpeques. These are the months when winter kill is most apparent, and Canadian supply is a great example.

Canadian waters get colder earlier in the year than locations down south. This also means the oysters enter dormancy earlier than its southern brethren. If a Canadian oyster enters dormancy in early November, it may not start feeding again until May when waters warm. It basically needs to survive on its glycogen that whole time! It’s impossible to ask the oysters to be in tip-top shape from March through May when they have not eaten for six to seven months.

You will also see signs of winter kill in New England oysters as we approach March, but it’s not as noticeable because their dormancy period is shorter. New England oysters are likely feeding until the end of November and start feeding again in late March. They have to survive about four months compared to the six months Canadian oysters endure.

Average Water temperatures in Summerside, PEI.  Water temps drop to 40F by early november and do not warm back up until late May. Oysters are dormant that entire period.  Source: NOAA

Average Water temperatures in Summerside, PEI. Water temps drop to 40F by early november and do not warm back up until late May. Oysters are dormant that entire period. Source: NOAA

Average Water temperatures in Barnstable, MA.  New England water temps do not drop to 40F until late November / December, which allows the oysters to feed longer and remain in dormancy for a shorter amount of time compared to Canadian oysters.  Source: NOAA

Average Water temperatures in Barnstable, MA. New England water temps do not drop to 40F until late November / December, which allows the oysters to feed longer and remain in dormancy for a shorter amount of time compared to Canadian oysters. Source: NOAA

Which varieties are less susceptible to winter kill?

Winter kill is less of an issue for southern varieties because of warmer water conditions, but generally, farmed oysters have a better chance of survival than wild oysters. Growers make sure their oysters have the best access to food throughout the year and condition them to have stronger abductor muscles. Farms also have different wintering and culling methods to tackle winter kill and limit its effects on product quality. So, despite Canadian oysters being more susceptible, many of the cultured Canadian varieties look nice throughout the season.

When will quality improve?

When the oysters finally start pumping and feeding again, it will take a couple of weeks for their quality to improve as they replenish themselves. Timing will vary by area because water temperatures differ by location, but we will see most varieties in better shape by late May.

Is there anything I can do to limit the effects of winter kill?

Yes! Be gentle. The oysters are weak, so any tough handling will result in dry or dead oysters. Give them extra attention and protection, especially in transit.

If you encounter a smelly bag, make sure to go through the bag or box because it could just be one dead oyster responsible for the smell. Discard the dead and rinse the rest. The remaining live oysters are just fine!

If there are any issues, contact your supplier. Dead oysters can go unnoticed until shucked, so giving your supplier feedback can help them assess the situation.

Duxbury Bay, January 2019, Mike Cesarini.

Duxbury Bay, January 2019, Mike Cesarini.

Special thanks to our Canadian producers for contributing to this piece.

Have a winter quality question not listed here? Ask it in the comments section below.

Oystoberfest 2016: The Case for the Fall Oyster

Oystoberfest 2016: The Case for the Fall Oyster

At last, the final traces of our New England summer appear to be fading into the rearview here at Pangea World Headquarters. Long days beside the ocean eating oysters have been replaced by shorter days, slightly further away from the ocean, eating much better oysters. It’s a rough lot we have in life, but we carry the burden stoically.

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Where are the Nantucket and Vineyard bay scallops?

For many Northeast seafood lovers, November is one of the best times of year because it’s the start of bay scallop season! Bay scallops are the jewels of the sea – super sweet and buttery, especially when they are freshly shucked and eaten raw. Sea candy, we like to call them.

But if you’ve been looking forward to the season like us, you’ve probably noticed that it has been disappointing, especially bay scallops from Massachusetts. Prices are high and retail markets are selling previously frozen to keep up with demand. What’s driving this season’s limited production? And is there a way to anticipate supply for next fall?

For basic info about bay scallops, read The Skinny on Bay Scallops here.

Bay scallop seed affected by last winter

Last winter was one for the books. Massachusetts received a record amount of snow and cold weather. This had significant repercussions for many shellfish farms and fisheries, bay scallops included. It takes two years for bay scallops to reach adulthood before they can be harvested. Unfortunately, the harsh winter conditions wiped out much of the juvenile scallops that would have been adults and ready for harvest this past fall.

Town regulations and area closures

Bay scallop fisheries are typically open from November 1 to March 31 of each year to protect the scallops and give them time to repopulate in the summer. Since bay scallops have a two-year life span, it’s hard to overfish them as long as fishermen are harvesting adult scallops. But since there aren’t many adults in the water as noted above, shellfish constables and town regulators have decided to close areas to protect the seed. On Martha’s Vineyard, these closures have upset commercial fishermen who rely on scalloping for a living, but regulators argue that harvesting, typically by dredging, disturbs the brood stock and it’s hard to regulate fishing of under-sized scallops.

The acrimony comes during a poor scalloping season... It is illegal to take seed scallops... even though many are almost as large as adult scallops. Mr. Grunden invoked his authority under state law to close Sengekontacket Pond to scalloping before the season officially opened... Yields in other Oak Bluffs waters have been marginal, and town officials are considering the closure of other usually abundant waters.
— Steve Myrick for the Vineyard Gazette

Poor water quality and eelgrass loss impacting scallop growth and recovery

Massachusetts scallop fisheries have seen a widespread decline since the mid 1980s. Many scientists point to poor water quality as the primary culprit. Water pollution from increased tourism, coastal housing developments, and fertilizer runoff adds more nitrogen to the water, which accelerates algae growth. As algae density increases, water clarity decreases. This affects the amount of sunlight that can penetrate the water to reach the eelgrass meadows, the bay scallop’s habitat.

Studies have shown that there is a direct relationship between eelgrass density and scallop survival. Scallops like to attach to the upper eelgrass canopies to stay away from their benthic predators, and they have access to more particulate food collected by the eelgrass blades. As eelgrass further decline on the Vineyard and Nantucket, bay scallops will continue to struggle due to habitat loss.

On Nantucket, the harbor used to be one of the main scallop fisheries on the island. Unfortunately, the geography of the harbor is not very conducive to tidal change. This exasperates the water quality issue and provides less food for the scallops to feed. Boat traffic and mooring field maintenance also disturbs the seed and their habitat. Now, much of the Nantucket bay scallop volume has been coming from the west end of the island instead of the harbor.

Less product around, less fishermen around

With less adult scallops around to fish, fishermen are looking for other sources of income instead. According to Jeff from Salty Balls, there are typically lots of fishermen up until Christmas. At the start of the season, there were around a hundred boats. But after seeing disappointing catches over the first few weeks, fishermen have moved on to find jobs on the island or fish for something else. If there's no one fishing, it doesn't really matter whether there are any adult scallops still in the water.

What will supply look like moving forward?

As we enter the coldest months of winter 2016 (it was -6º F windchill two days ago...), bay scallops will become more and more limited than they already are. Fishermen cannot or are not allowed to fish if there is bad weather, strong winds, or cold temperatures. When the air temperature is 28º F or below, the scallops will freeze once out of the water. Expect product to be extremely tight or non-existent until the season closes.

And as for the next season in November 2016... Well, we wish we had better news to tell you, but there's really no way of knowing. "There may be a good amount of seed in the water [ready] for next fall, but it's hard to tell what will happen after winter. There won't be any supply indication until the [fishermen] start poking around in November," says Jeff from the Net Result Fish Market.

So what can you do if you're desperate for bay scallops? One option is to look for bay scallops from other regions like Long Island and Nova Scotia or try to source them previously frozen. Of course, fresh is always best, but frozen bay scallops thawed correctly can work well too. Look to change up your menu with items like Maine dayboat sea scallops that are in season right now through April. They're definitely not bay scallops, but they're equally beautiful and tasty!

Special thanks to Jeff from Salty Balls and Jeff from Net Result Fish Market for contributing to the research of this piece. Photos from


Winter 2015 disrupting Northeast shellfish supply

This year's winter weather has really taken a toll on shellfish supply. "I don't remember it being this bad since the 80s," Norm recalls. Of the many farms we reached out to, Norm Bloom and Son in Norwalk, CT was one of the handful that was still able to get out and harvest shellfish. Even as a larger shellfish producer, Norm and team has found it difficult to operate in this weather, too.

The eastern side of Duxbury Bay, MA where some of our standish shore oysters are harvested. Taken on Feb. 16, 2015.

The eastern side of Duxbury Bay, MA where some of our standish shore oysters are harvested. Taken on Feb. 16, 2015.

Ice and frigid temperatures have been the main culprits for this winter's shellfish shortage. Many of our growers cannot access their farms because the ice is so thick. Some areas have called in the Coast Guard and icebreaker boats for help. Mussel and clam supplies have been hit especially hard. Major mussel producing areas like Prince Edward Island and Maine have been completely frozen over, and it is almost impossible for New England clam diggers to reach the ocean bottom.

Floating ice is also very dangerous. Even when moving slowly, 6-inch-thick ice can easily puncture a hole into a boat with a wooden or fiberglass hull. Unless you have a boat with a steel hull, it is pretty risky to sail out when the ice is broken up.

Aside from ice, there are regulations in many towns that do not allow shellfishing when the air temperature is 28º F or below. Law or not, shellfishing in these temperatures is not ideal because the shellfish will literally freeze to death when it makes contact with the air once out of the water.

So where's the supply in the Mid-Atlantic then? Isn't it warmer there?

Some parts of the bay have been frozen for the whole month of February. People don’t realize the hardship that a hard winter puts on us.
— Robert T. Brown, President of the Maryland Watermen's Association

The Chesapeake Bay has brackish water -- water that is saltier than freshwater, but not as salty as seawater. Salty seawater is more dense, so it tends to sink to the bottom where it's warmer. The surface of the Chesapeake's brackish water, however, has completely iced up after enduring numerous inches of snow and long periods of subzero temperatures. Like New England, there has been very little oyster and clam production. The Baltimore Sun does a great job covering the Chesapeake in-depth and also provides an aerial view of the bay if you would like to learn more.

What should we expect for supply in the next few months?

Good news is temperatures are going to start warming up in the next few days (and weeks, we hope), which will provide a window for the ice to thaw and allow some growers to access their farms. Bad news is winter kill can be a common problem. Possible reasons for shellfish mortality include being frozen by the ice, smothered by vegetation or silt, or being simply too weak to last through winter hibernation.

With those considerations in mind, we do expect shellfish supply to improve, however, oyster varieties will continue to be limited through late summer. Oyster supply will depend on the rate of winter kill and the volume of market product remaining from this past fall.

We ask for your patience, understanding, and flexibility as we weather through this difficult time of year. Please educate your colleagues and customers now as supply may become more limited. And of course, please thank your local fishermen, oystermen, and seafood purveyors because they are working hard for you, especially during this wintry weather.

Check out the winter content from our growers below.

Stay warm out there!

Lessons of Winter On the Standish Shore Oyster Farm

Winter in Duxbury... It's been a real difficult one, thank god it's finally spring! It's hard to put into words how stressful it is for oystermen here during the winter. Imagine putting your life savings into the bay in October, tying it down, and returning in April, hoping it's all still there. I truly believe it's something you have to experience for yourself to really understand, but here's a quick overview of how an oyster farm typically operates in Duxbury:

Imagine putting your life savings into the bay in October, tying it down, and returning in April, hoping it’s all still there.

First, we purchase oyster seed from a hatchery, which usually comes in mid-May. We let it grow in an upwelling system, which basically circulates seawater very quickly around the oysters so they can filter more water and grow faster. Around July, they get moved into large mesh bags and slid into cages. They remain there until October. Sounds simple, but things get dangerous in October when the water temperature starts to plummet and the oysters go into hibernation mode.

The oysters need a safe environment until spring when they start growing again. So, farmers are left with a few options. The most common approach here in Duxbury Bay is to "plant" the seed. Which means you literally throw your seed off the side of your boat and spread it across the bottom of your lease. This has its advantages and disadvantages. The most obvious disadvantage is that you're going to lose some of your crop; I'm not talking just a few thousand oysters here, I'm talking a few hundred thousand. The oysters are fair game to crabs, fish, birds, or any other parasite that prays on baby oysters. They could get silted into the mud and never return. They could be washed away in any of the massive storms we get here in New England, or even worse, crushed by ice. After reading all these potentially negative outcomes, you're probably thinking, "So, why would anyone ever choose to bottom plant in October?"’re going to lose some of your crop; I’m not talking just a few thousand oysters here, I’m talking a few hundred thousand.

We do it for one simple reason: it produces the highest quality oyster possible. The oysters planted on the bottom are like no other oyster on the market. The shells are extremely tough and durable. If you buy a bag of 100 count oysters you will receive 100 usable oysters. They don't break under the knife, which in my opinion is one of the most important traits of an oyster. They grow perfectly. There are minimal flares on the edges and very little hooked or misshapen oysters. On top of all that, the taste is second to none. This is what we are known for here.

The alternative to bottom planting would be to "cage culture" the oyster, which means the oyster spends its life growing in a cage. This has proven to grow what I call "potato chips": long, skinny, weak oysters with no cup. The bottom planting approach is what separates us from the rest and helps us grow one of the best oysters on the East Coast. It's because we go the extra mile with everything we do. Every farmer in this town cares about quality over quantity. That's the key behind our success for the last decade. My friend and fellow oyster farmer, Greg Morris, calls it "the free range look." It's a look that only we produce here, and it's made possible by bottom planting.

This winter, our farm took a different approach and added a twist to bottom planting. After tumbling the oysters one last time, we put the oysters into plastic mesh bags, and then put heavy duty zip ties on each bag. We then ran an 80 foot line through each hole on the zip tie and drilled augers into the mud to keep the lines from floating away. This less popular technique is known as "long lining." Though the seed is still in bags, they are tied down by the line to ensure they are bottom planted through the winter. This way, we are not losing our seed to Mother Nature and still being able to bottom plant.


After checking the seed today, I think we made the right choice. We kept our two million oysters safe and sound all winter. I chalk this up to one thing: luck. Everything that happens in the winter is based on pure luck. A very skilled and seasoned oysterman from Duxbury named Christian Horne told me something a while back that stuck with me. He said, "Just because it works one winter doesn't mean it will work the next." I learned that firsthand this winter. The variables are endless: wind, temperature, tide, environment, atmospheric pressure, barnacle sets, ice bergs, the list goes on. We could have had an iceberg sweep across our long lines and take them all out to sea, but it didn't happen. Mud could have silted over the bags and suffocated the entire crop, but that didn't happen. People swore to me the seed would be to exposed during negative tides and the elements would freeze and kill the oysters, but that didn't happen either.

Now, we're here at the end of March, left with two million healthy juvenile oysters ready to be safely bottom planted and released from their wintertime prison. So, this summer when you're sitting at that raw bar, drinking an ice cold beer, and about to eat those twelve perfectly shucked Standish Shore Oysters, try and remember the journey each oyster had to make. In this industry, oysters come and go. Very few harbors are consistently pumping out a high quality product year-round, but I think if we continue to outsmart Mother Nature while respecting her at the same time, Standish Shore Oysters will be here to stay.

What "NA-ICE" Really Means: Harvesting Shellfish In Winter

Harvesting shellfish is a hard job.

Now, imagine harvesting shellfish in winter...


Single digit air temperatures... 35º water temperatures... The risk of your boat getting stuck out in the water...

These are all considerations shellfish harvesters have to think about doing their jobs.

Around this time of year, customers tend to see more "NA-ICE" on our price lists, and that is because many of our suppliers are battling icy and potentially dangerous conditions. For the harvesters that are willing to bare the extreme cold, they still have to break through the ice to get to their oysters.

Some use their boats to blaze a trail...


And others use a power saw...


To each their own! And even if our harvesters can get access to shellfish, sometimes the air may be so cold that it freezes the product once out of the water.

At the end of the day, we owe a huge thank you to our harvesters and growers for weathering cold winds and treading through frigid waters to supply product to our customers. We ask for our customers' patience and understanding because harvesting shellfish is a hard and unpredictable job.

Hear Ben's firsthand experience dealing with ice or scroll through the photos below to see some Canadian ice fishing in action. Leave a comment below to thank all of our shellfish fishermen, and we'll make sure to pass them on personally!

Photo compliments of Five Star Shellfish and Indian Cove Aquaculture

Happy Holidays From Pangea Shellfish!

Pangea Shellfish Holiday E-Card

'Tis [five days] before Christmas, and in the back of the house
The wait staff is stirring, the bartender half-soused,
The patrons are perched and can't help but stare
At the beautiful Standish Shore oysters to share.

- Lori Budlong

To our customers, vendors, supporters, and fans -- thanks for a great year! We wouldn't be here without you!

From our Pangea family to yours, happy holidays and have a wonderful and joyous holiday season!