Students Study a Treasured Local Species

Northern elephant seals at the Piedras Blancas Rookery in San Simeon, California. Photo by Joe Johnston

RESEARCH TEAM TRACKS POPULATION TRENDS OF ONCE NEAR-EXTINCT ELEPHANT SEALS THROUGH LOCAL AND STATE PARTNERSHIPS

APRIL 2024
by Angelina Benyamin Rodriguez

Several beaches north of San Simeon serve as hotspots for elephant seals to breed, molt, nurture, fight and rest — and for Cal Poly student researchers to get real-world experience.

Graduate and undergraduate student leaders manage Team Ellie, an elephant seal research team that monitors populations on and around Piedras Blancas — a beach refuge and rookery located several miles northwest of Hearst Castle — in collaboration with California State Parks and the nonprofit Friends of the Elephant Seal (FES). FES offers opportunities for student internships, research presentation and work on the annual census of seals.

“Each breeding season, we coordinate with FES to conduct three full-colony censuses of the elephant seal population,” said biological sciences Professor Heather Liwanag, faculty mentor for Team Ellie and principal investigator of Cal Poly’s Vertebrate Integrative Physiology (VIP) Lab, to which Team Ellie belongs.

“We present regularly at the FES docent trainings, which happen twice per year, as well as at the continuing education seminars for their current docents.”

From left, Cal Poly student researchers Lauren Sprague, Isa Mattioli, Mary Keegan, Helen Hanigan and Sophia Hosmer-Hughes at Piedras Blancas Rookery to monitor northern elephant seals in spring 2024. Courtesy photo

Students monitor eight Central Coast beaches weekly. Arriving as early as 6:30 a.m., the team uses a drone to survey the elephant seals and collect data for population tracking. Experienced student team leads recruit and train volunteers, as well as earn drone certification. The philanthropic nonprofit Santa Rosa Creek Foundation provides funding to compensate student leaders for their administrative work. 

“Gaining extensive field experience with marine mammals is a rare opportunity, and I am proud to provide that opportunity to our dedicated volunteers,” said Liwanag. “As part of Team Ellie, our research students learn to work as team members.” 

Elephant seals were nearly hunted to extinction for their blubber by the early 1880s, but populations have since rebounded. The Piedras Blancas beaches alone see around 25,000 seals visit throughout the year

“What we have seen is that they are likely reaching carrying capacity, which is the maximum number of individuals that the environment can sustain in a healthy way, which is really good to see,” said Simone Goetsch (Biological Sciences, ’24).

Goetsch explained that because the species’ numbers were once so low, the variety in the gene pool was limited. This lack of genetic diversity could lead to other health issues as these seals breed. Genetic variation is important in adapting to changing environmental conditions, resisting disease, birthing and other factors that impact how the not-so-gentle giants survive and thrive over time. 

As the population of these elephant seals has grown, so has Team Ellie, which launched seven years ago. Undergraduate volunteers now total about 40 students whose majors include biological sciences, animal sciences, natural resources and environmental management, and statistics. 

The volunteers assist with surveying the elephant seals by taking weight measurements and flipper tagging the seals to help monitor the population. Students also mark the seals by applying letter-number combinations onto the fur with hair dye, to follow individual behaviors throughout the breeding season. In addition, many graduate students perform independent research for Team Ellie. 

Katie Saenger (Marine Sciences, ’21) joined Team Ellie during her third year as an undergraduate. Now a biological sciences graduate student, Saenger is spearheading a project using satellite tagging to understand the at-sea migration patterns and dive behaviors of young seals. 

She and other researchers attach satellite tags to the top of a seal’s head with a bit of glue. The satellite tags allow researchers to track animals while they’re at sea, and the locations are uploaded through the Argos satellite system, allowing the team to collect data by monitoring seal locations from transmission signals in real time. The tags may be retrieved by researchers on shore to collect the dive data stored inside, or the tag will molt off (and the seal will continue on its way untagged). Each time the elephant seal’s head emerges from the water when it takes a breath, the location is noted by the satellite and uploaded to an online portal. 

“After they’re weaned from their mom, and they go on their first at-sea migration, we’re trying to figure out where they go, and what might be influencing where they go, because it hasn’t been explored really, in the scientific community,” Saenger said. 

Adult elephant seals have distinct diving patterns that have not been compared to those of juvenile seals. Adults have been recorded diving up to a mile deep. Weaned pups less than a year old have only reached around 600 meters, less than a third of a mile. 

Additional graduate student-led research projects address topics ranging from population metrics to vocal recognition. Biological sciences graduate student Kenzie Davidson studies the movement of pregnant females, deciding which beach is best for birthing, thanks to the Kathleen A. Curtis Elephant Seal Research Graduate Fellowship Endowment. 

In addition to gaining field experience, students present their research at professional conferences and co-author peer-reviewed scientific publications. 

“My hope is that Team Ellie provides a meaningful pathway for students to advance their careers,” Liwanag said. “I will be taking several undergraduate and graduate students to the 25th Biennial Conference on the Biology of Marine Mammals in Perth, Australia, in November.”