Subsistence living is an important part of culture in the Chugach region of Alaska. For many people, fishing and gathering food are part of everyday life. This lifestyle has been around for thousands of years and is especially important in remote Alaska Native communities. Along the coast, subsistence living includes collecting seafood like shrimp, clams, fish, and kelp from the ocean, as well as harvesting plants and animals on land.
With strong ties to the environment, people who gather their own food are often very aware of changes in the environment and are careful to not overharvest. Recently, people living in the Chugach region have noticed changes in the ocean environment and are concerned about how these changes might affect their way of life. If communities can no longer harvest local resources for food, the impacts would be significant both culturally and economically.
One concern in this area is ocean acidification. Scientists have found that seawater is becoming more acidic in many areas around the world. This change is linked to human activities that release large amounts of carbon dioxide into the atmosphere. While most of this carbon dioxide remains in the air, about one-third of it is absorbed by the oceans. When carbon dioxide dissolves in seawater, it reacts with water to form carbonic acid. If more and more carbon dioxide is absorbed by the ocean, the water will become increasingly acidic.
Unfortunately, even small changes in ocean acidity can harm marine life. Animals that form shells, such as molluscs, clams, shrimp, and crabs are important for marine ecosystems, but very vulnerable. Acidic water can weaken their shells, making it harder for them to grow and survive. On top of that, the minerals needed for them to build and strengthen their shells, such as aragonite, become less available in acidic water.
Based on concerns from local residents, Alutiiq Pride Marine Institute (APMI) started a community monitoring program that continues today. APMI started by finding environmental samplers in their region. These community members were trained to follow standard protocols for collecting data and water samples. Samplers go to the same site many times each year and then send the water samples to the APMI lab to be analyzed.
One variable that APMI looks at is aragonite saturation levels. When a sample has a saturation value above 1, there is aragonite available in the water for animals to build shells. When the saturation is below 0, there is not enough aragonite to build shells, and they can become very weak. Animals that build shells are most likely to survive when the saturation level is 3 or greater.
Their goal is to work together to document patterns in ocean acidification. APMI shares their results with the communities so they can have conversations about how the changing ocean will affect their lifestyle.
Featured scientists: Chugach Region Ocean Monitoring community members with Alutiiq Pride Marine Institute. Written by Melissa Kjelvik.