Connecting Green Waters to Eastern NC’s ALS Problem

On summer days in northeastern North Carolina, the water can look deceptively beautiful. Vast stretches of the Chowan River and Albemarle Sound sometimes turn a vivid shade of green, creating a scene that appears almost picturesque.

For generations, however, locals have recognized these green waters as a warning sign. Parents have told their children not to swim in them, and fishermen have learned to be cautious when the blooms appear.

While immediately harmful effects are only seen in small animals like dogs—and even then only occasionally—a suspicion has been growing amongst the area’s public health officials. These algal blooms might be the reason the area’s incidence of Amyotrophic lateral sclerosis (ALS), often called Lou Gehrig’s disease, is more than twice the national average. ALS is a devastating neurological disease that gradually destroys a person’s ability to move and communicate before ultimately leading to death.

“We have access to death certificate data in North Carolina, and it’s very clear that there is too high of a prevalence of ALS in the region,” said Ashley Stoop, the health director of Albemarle Regional Health Services, which serves eight counties in northeastern North Carolina.

“ALS is a rare disease, and out there, it’s so common that it doesn’t qualify as a rare disease anymore,” echoed Lisa Satterwhite, associate research professor of civil and environmental engineering at Duke.

The primary reason behind their suspicions is that these algal blooms are massive growths of cyanobacteria that can release neurotoxins. While these blooms are a growing environmental problem across the United States, the warm, nutrient-rich waters along North Carolina’s northeastern waterways seem to be particularly welcoming.

The connection between algae and ALS, however, is still only hypothetical. And even if a direct causal link were established, the communities wouldn’t know at what levels the blooms become dangerous nor what precautions to tell locals to take.

These are questions that researchers from Duke University are now working to help answer. Over the past few years, they have built relationships with community scientists and local ALS advocacy groups, especially the Jim “Catfish” Hunter ALS Foundation, named after the local major league baseball legend who died of the disease in 1999.

Having built these partnerships with the residents who know these waterways better than anyone, the researchers work with community members to help collect water samples, report bloom sightings and share observations about changes they have witnessed over the years. Their local knowledge, resources and time are critical to the scientific investigation.

“The neurotoxins get into the water, they might get into the food supply, they might get into your lungs—we don’t know,” Satterwhite said. “But before you go to the federal government to try to get funding to find out, you have to really have a firm idea about what you think the problem is. That’s where Duke comes in.”

The team of researchers and citizen scientists is working to understand exactly what is happening in these green waters. Scientists analyze samples to identify the species of cyanobacteria present and determine whether they are producing toxins. They also study the environmental conditions that allow blooms to thrive, including temperature, nutrient levels and weather patterns. Some researchers are even examining the genetic makeup of the algae to learn why certain blooms become toxic while others do not.

“My hope and my goal is that some of this partnership and the research that we develop gives us a more clear-cut path to actual strategies and mitigation efforts that we can take to our elected officials to ask for the funding, to ask for the mitigation efforts,” Stoop said.

“To me, the most important part of this project is that we are trying to provide the tools for the community create a lab where they can test their own water, make decisions about whether it’s safe or not, try to improve the health of the ecosystem,” Satterwhite said. “We want to give back this beautiful area to them. That’s what it’s all about.”