Dr. Stephanie Norman on Marine Mammals, Epidemiology, and Environmental Justice

Baby Island, WA – Dr. Stephanie Norman monitors a young elephant seal. (Photo credit: Dr. Stephanie Norman, taken under permit from NOAA Fisheries)


Dr. Stephanie Norman, a veterinarian and wildlife epidemiologist, studies diseases in marine species, ranging from the smallest coral polyps to large predators, like marine mammals. She embraces a “One Health” perspective in her work, where human, environmental, and animal health are inextricably linked. Her recent crowdfunding project on antibiotic resistance in the Salish Sea looked at the intersection of marine environments, aquatic organisms, and human health and wellbeing.

After reading the publication that study produced, I reached out to Dr. Norman because I was  interested in learning more about how Puget Sound local communities are both involved in and impacted by her research findings. In this interview, she talks about her work with marine mammals in Puget Sound, explains what we can learn from these charismatic megafauna about our own health, and reflects on how perceptions of her field have changed in the time of COVID-19.

Marine mammals are often referred to as sentinels of the sea. What can we learn about public health from marine mammals?

People have an intricate relationship with their aquatic environments, especially in Puget Sound. Food, medicinal compounds, jobs, recreational opportunities, and clean water are just a few ways individuals rely on this aquatic system.

Like us, marine mammals are long-lived, inhabit similar coastal ecosystems, and feed at the top of the food chain. So, similar to a canary in a coal mine, we can use marine mammals to detect early warning signals for environmental and human health. Understanding the health of organisms that live in this ecosystem can have implications for public health within the very communities that inhabit and rely on Puget Sound.

Within this context, marine mammal strandings present an opportunity to study the health of such animals. These events are quite common year-round in Puget Sound and the greater Salish Sea areas. When marine mammals who have perished wash up ashore, we can perform necropsies (autopsies for animals) on the carcasses. The information gathered can then be used to determine the cause of death and provide further insights into the health of marine mammals and their environment.

You recently led a project on antibiotic resistant bacteria in marine mammals in the Salish Sea. What was the motivation behind this work?

Almost everyone takes antibiotics at some time in their life. When a doctor prescribes you antibiotics, the purpose is to kill the bacteria. However, antibiotic resistance can occur when the bacteria develop a resistance to the medication. With antibiotic resistance becoming a global concern, we wanted to delve into its prominence in Puget Sound and the Salish Sea because it is such an urban place.

We suspect that resistant bacteria enter the waterways through wastewater, agriculture, or stormwater runoff that carries both antibiotics and resistant bacteria, or their antibiotic resistant genes. From a One Health perspective, people, their pets, and aquatic organisms can pick up these resistant bacteria and even develop further resistant bacteria if it occurs in the water.

For our study, we took samples during necropsies of freshly dead harbor seals and harbor porpoises, which are the two most common marine mammal species that strand in Washington State. They also both inhabit the same urban inland waters that people use and share a similar diet to ours, providing the opportunity to be indicators of environmental health and representations of exposure to such resistant bacteria.

Dr. Norman and team begin a necropsy on a harbor porpoise (left) and harbor seal (right). Samples taken during harbor porpoise and harbor seal necropsies contributed to Dr. Norman’s antibiotic resistance study. (Photo credit: Dr. Stephanie Norman, taken under permit from NOAA Fisheries)


How do the implications from your work affect the communities that rely on Puget Sound?

More than a third of the samples from harbor seals and harbor porpoises contained bacteria that are resistant to at least one antibiotic, suggesting Puget Sound is potentially a reservoir for these bacteria. There is a possible risk to human health since we did see bacteria in our study that can cause infections and illness in humans, such as Vibrio species that cause vibriosis. If people swim in these waters or are harvesting species that the seals or porpoises prey upon, they may be vulnerable to these bacteria.

Zoonotic diseases, those that are transmitted between animals and humans, are not particularly prevalent in marine mammals. The bigger concern is that these wild seals and porpoises were not treated with antibiotics, so they must have acquired these resistant strains from their environment—the same environment that people in the Puget Sound area use.

While porpoises and seals are relatively region-specific, both can have home ranges throughout Puget Sound. Due to the large geographical area of this study, it isn’t easy to assess the health of the specific regions. While we continue to learn the impacts humans have on the environment, we are furthering our knowledge with other antibiotic resistant studies branching off our own work to delineate areas at higher risk.

Are the local communities around Puget Sound involved in your work?

We do have some involvement, and one of the most significant ways is through the marine mammal stranding network in our state. For example, in West Seattle, residents formed a volunteer group called Seal Sitters that responds to reports of both dead and live marine mammals in the area. If a harbor seal pup comes ashore, that sets off a chain of events. Stranding volunteers respond and tape off the site, monitor the seal during daylight hours to make sure the public and their pets do not get too close. They also provide educational opportunities for passersby who want to learn more about their local marine mammals. I even have volunteers help me with necropsies, whether that be reporting a marine mammal carcass or collecting samples with me back at the lab.

We definitely rely on our coastal community’s help. People can relate to the work we do, which is a great step towards getting people to start caring. And when we care about something, we are more likely to protect it.

Shilshole Marina, Seattle – Two adult male sea lions, with boats in the background. Both marine mammals and people inhabit and use similar areas in Puget Sound. (Photo credit: Dr. Stephanie Norman, taken under permit form NOAA Fisheries)


How does your work relate to environmental justice?

I work in the realm of the applied solutions of epidemiology, where we take the results from our studies and apply them to real-world situations to help both humans and the environment. When discussing One Health and diseases, we need to think about the ecological, social, and economic conditions that can facilitate the emergence of diseases. People that rely on Puget Sound for their livelihood are the ones most vulnerable to its health and potential pollutants, like what we found from the antibiotics study. We work to understand if specific local communities are bearing disproportionate burdens because they do not have the option but to use this waterway for their food, livelihood, or general wellbeing. For Indigenous communities especially, this area has always been their resource, and they cannot be left out of this effort.

As time goes on, everything we do as humans, even as innocuous as it may seem, impacts the environment and the organisms that live there. However, we need to integrate the human dimension and social science aspects when conserving species or the environment. An essential step in epidemiological studies in Puget Sound will be to further social and educational efforts surrounding these topics.

[See this paper on work being done to incorporate Indigenous Knowledge in One Health perspectives.]

Have you seen perceptions and dialogue on epidemiology and zoonotic diseases change during the COVID-19 pandemic?

The COVID-19 pandemic has made people more aware of epidemiology. I have seen more interest in zoonotic diseases and open discussions about our relationship with wild animals and the environment. I see people becoming more aware of the risks we run by encroaching on the habitat of animals and coming into contact with them. With everyone being so cautious and clean, washing hands, and wearing masks, further discussions in at least some circles are beginning on how we can coexist with animals and prevent some of these outbreaks. I think this is where it is important to consider the social and educational aspects of zoonotic diseases. Whether that is going to change people’s behavior is yet to be seen, but I like to believe we will think about things differently.

To find out more about Dr. Norman’s current projects, visit her website.