Exploring the Upsides and Obstacles of Growing Pacific oysters in Alaska’s Cold Waters

Alaska may be known for its wild salmon, but another coastal delicacy is making waves: Pacific oysters. These shellfish make up the bulk of Alaska's mariculture production. New research is shining a light on what makes them unique-and how they could play a growing role in the region's seafood industry.

A team of NOAA Fisheries scientists and partners conducted a 3-year study at an oyster farm near Juneau, Alaska. They explored how the cold, nutrient-rich waters of Southeast Alaska influence oyster growth and quality . The findings suggest that Alaska's subarctic environment offers both surprising benefits and potential challenges for oyster farmers.

Alaska Oyster Farming

Oyster farming is a burgeoning industry in Alaska; the state's cold, clean waters provide ideal conditions for raising high-quality shellfish. With a growing population, the demand for aquaculture and need for resilient seafood systems is increasing. Understanding how extreme environments affect ocean food production is becoming increasingly important. This is especially relevant as risks such as climate variability, ocean acidification, and disease outbreaks impact shellfish farms worldwide.

"Alaska's Pacific oyster farms are among the northernmost in the world, and we are still learning how local and regional ocean conditions shape oyster growth and quality," said Becca Cates, mariculture biologist at the Alaska Fisheries Science Center.

Alaska's Cold Waters Grow Resilient Oysters

Thanks to cold water and high-quality plankton, Pacific oysters grown in Alaska tend to have more fats and heart-healthy polyunsaturated fatty acids than their southern counterparts. These essential nutrients are vital to various bodily functions. That cold water also keeps oysters from spawning, a process that typically drains their energy and reduces their meat quality. As a result, Alaska oysters can stay plump and flavorful all year round.

In addition to producing high-quality oysters, Alaska's cooler waters may provide a natural buffer against marine heatwaves. Heatwaves can lead to shellfish die-offs and contribute to complex challenges like disease outbreaks and harmful bacterial growth.

Growing Pains: Challenges of Farming Oysters in Southeast Alaska

Still, farming oysters in Southeast Alaska isn't easy. Because of the region's high latitude, farms experience shorter growing seasons, giving oysters less time to feed and grow. While oysters in Washington might reach market size in 2 years, Alaskan oysters often take 3 years or more. Implementing modern farming techniques like intertidal tumble cages , and improved farm siting through the Aquaculture Opportunity Area identification process , can help address these challenges by sustainably accelerating growth.

Salty Lady Seafood Company and other oyster farms in Alaska sometimes experience blooms of harmful algae called Alexandrium . These blooms can produce dangerous levels of paralytic shellfish toxins, which often force farms to shut down for long periods. That's especially tough in a place where the growing season is already short. Warming ocean waters could make harmful algal blooms more intense and unpredictable. This increases the risk of toxic shellfish even during cooler seasons like spring and fall, when the ocean historically was too cold for these blooms to thrive. To support the shellfish industry and reduce the financial impact of farm closures, it's important to invest in monitoring and management. This includes finding better ways to detect toxin events early .

Charting the Future: Unlocking Oyster Farming Potential in Southeast Alaska

The study offers valuable insights that could help expand and strengthen Alaska's oyster farming industry. By better understanding local ocean conditions, scientists and farmers can work together to:

• Find the best places to site farms
• Improve farming methods
• Prepare for environmental challengesShellfish growing waters and commercial harvests are screened for toxins by the Alaska Department of Environmental Conservation before reaching the market. Continued investment in monitoring and management tools-like early warning systems for harmful algal blooms-can help reduce economic impact of farm closures, and protect farmer livelihoods.

"As the aquaculture industry adapts to various challenges, Alaska's cool coastal waters, once seen as a limitation, may prove to be one of its greatest strengths," said Cates. "By better understanding the unique ocean conditions in Southeast Alaska, we hope to help oyster farmers make smarter decisions about where and how to grow Pacific oysters, ultimately supporting a more sustainable and resilient shellfish industry."

The collaborative research was conducted by scientists from: