FOR MORE THAN 130 YEARS, THE NATIONAL GEOGRAPHIC SOCIETY HAS DOCUMENTED THE MOST REMOTE AND EXTRAORDINARY PLACES ON EARTH. National Geographic-Lindblad Expeditions carries that legacy onto the water, offering voyages to all seven continents.
Last summer, Emma Cross, associate professor of the environment, geography, and marine sciences (EGMS) at Southern, joined that tradition, connecting curious travelers not just to Iceland’s dramatic fjords, but to the science unfolding beneath the water. For eight days in July, she and two graduate students — Olivia Vallejo, ’25, and Katie Wagner, ’24, both enrolled in the master’s program in integrative biological diversity — worked as visiting scientists on a National Geographic-Lindblad Expedition, a luxury cruise that carried nature-loving adventure travelers through remote coastal regions of Iceland.
While other passengers headed out for hikes and sightseeing on shore, Cross and her students loaded their gear into a small inflatable Zodiac and braved the chilly Nordic seas to collect water and zooplankton samples. Their goal: to study the impact of fish farms on local coastal ecosystems.
Since 2022, Cross has led similar research at the Skálanes Nature and Heritage Center in East Iceland, where she travels with students each summer to conduct fieldwork, supported by EGMS Professor Patrick Heidkamp’s study abroad program. The team spent an additional week in Iceland working at Skálanes after the voyage.
Cross’ ongoing research exemplifies Southern’s commitment to collaborative faculty-student research at both the undergraduate and graduate levels. In fact, Southern is nationally ranked for research, Connecticut’s first and only university to earn the prestigious Research 2 (R2) Carnegie classification.
Cross’ biodiversity research uses environmental DNA (eDNA) sampling to detect microscopic traces of DNA shed by organisms. This method allows scientists to create a snapshot of the species present in an area without resorting to more disruptive techniques, such as trawling the seafloor.
Cross combines these eDNA results with traditional water-quality measurements — including salinity, dissolved oxygen, and temperature — to monitor ecological changes over time in locations where fish farming has been introduced. The expedition provided a rare opportunity to collect baseline data in more remote waters still untouched by the industry.
THE WORK IS TIMELY. Fish farming has expanded rapidly in Iceland in recent years, raising concerns among conservationists who fear nutrient pollution and medication used to prevent the spread of disease and parasites in the pens could harm fragile fjord ecosystems. Worries intensified in 2023 when a breach released thousands of farmed salmon in the Westfjords, sparking fears that genetically modified fish might mate with wild salmon.
“It’s a complex issue,” Cross says. Aquaculture brings jobs and revenue to coastal communities that are mostly reliant on tourism. Many locals “are not very keen on these fish farms going in” because they want to keep the fjords pristine, she explains. She hopes her work will give residents and policymakers objective data.
“The work is really important because it provides information to the residents in these areas . . . so they can have a say,” says Vallejo.
Cross applied for the visiting scientist opportunity after learning about it from a National Geographic-Lindblad Expeditions science lead she met at a national marine eDNA conference in 2024. (Applications are by invitation only.)
THE RESEARCH WAS ONLY ONE PART OF THE JOB. Back on the ship, the Southern team mingled and discussed their work with cruisers, including children ages 5 to 14 in the ship’s Young Explorers club.
Explaining research on the ecological impact of fish farming in Iceland to school-age children — and holding their attention — is a tall order, especially when the specimens are mostly invisible. Luckily for Cross, the test tubes filled with zooplankton resembled miniature snow globes. The children were captivated by the tiny sea creatures floating in the sealed test tubes. “They were very much treating them like snow globes, turning them up and down,” says Cross.
The explorers’ questions followed: Are the zooplankton still alive? (No, unfortunately.) Did the researchers have a permit to collect them? (Yes!) Then, a teenage boy delivered the kicker: “So you have permits where you’re allowed to take these organisms and then kill them, all in the name of science?”
“As a scientist, I had to be honest with these kids,” Cross says, laughing now about the tricky exchange. She told the teen he was correct but quickly added context: “They’re the most abundant organism in the ocean. And we’re going to learn a great deal about our environment just by taking a small sample.”
Interacting with the tourists was a highlight of the trip, Vallejo and Wagner agree. They swapped stories with retirees, seasoned travelers, and young families, and met a renowned National Geographic Traveler photographer, Macduff Everton, whose work spans the globe. They also coincidently crossed paths with Southern alumna Marylou Blakeslee, ’78, who works as a naturalist on board. Blakeslee realized the shared connection after spotting Cross and the team decked out in Owl gear.
Vallejo says she was nervous at first about explaining her research to passengers, initially turning to Cross to speak on her behalf. But before long, she was leading discussions and answering questions with authority. “As the trip went on and I talked to more people, I gained a lot of confidence,” says Vallejo.
Conducting research in an unconventional setting posed logistical hurdles. For starters, Cross and her students couldn’t fly with the needed supplies; they spent the sleep-deprived day after their arrival trudging around Reykjavík, the capital city, searching local pharmacies for ethanol and sterile water.
The water was especially hard to come by, Cross says, since it’s typically stocked only for American tourists who use CPAP machines to treat sleep apnea. “Americans in Reykjavík are probably very unhappy with us, because we wiped out the sterile water supply,” Cross jokes.
Sampling from an inflatable boat brought challenges as well. The fieldwork is highly physical. “The beauty of the Zodiac is that they move fast, so you’re able to get to your sites very quickly,” Cross says. “But it means you have to do everything manually, as opposed to [working from] a boat with a winch on it.”
To collect the water samples for eDNA testing, the team repeatedly dropped and raised a weighted, 1.7-liter bottle (known as a Niskin bottle) to depths of 2 meters and 20 meters. The first level shows what organisms were recently present just below the surface and, the second, is just below the depth of a typical fish farm.
The team also lowered a large cone-shaped net — sometimes as many as 30 times — to collect the zooplankton, providing a visual survey to complement the eDNA results. Cross was 21-weeks pregnant, so Vallejo and Wagner did most of the heavy lifting
“We joke that Katie and Olivia definitely got their gym workouts in,” Cross says.
For Wagner and Vallejo, it was all part of the adventure. “I didn’t realize how fun it was going to be,” says Wagner. She has conducted similar research in Long Island Sound, but going abroad opened her eyes to other possibilities. “I didn’t expect that I was going to gain such a love for fieldwork.”
Read more from the Spring 2026 issue of Southern Alumni Magazine.
