Cool Cousins
Northern elephant seals, Mirounga angustirostris, are one of TOPP’s champion species. Over 370 e-seals have been tagged, enabling biologists at TOPP to learn an incredible amount about the mysteries of the North Pacific Ocean.

A satellite tagged Northern elephant seal swimming in the waters off Año Nuevo State Reserve. Photo: Dan Costa.
This Winter, as the E Seal Team recovers satellite tags from northern elephant seals at Año Nuevo State Reserve in Northern California, another crew will be headed south. They are going very far south, to Antarctica’s Cape Shirreff to deploy satellite tags on northern elephant seal’s relatives, the southern elephant seals.
Principle Investigator, Dan Costa, deploying a satellite tag on a southern elephant seal.
Southern elephant seals, Mirounga leonina, are fascinating, and not only for their recent debut in Happy Feet. Northern elephant seals are known to be huge, but southern elephant seals are gigantic! Large males weigh more than 4 tons. That’s a lot of seal!
Here you can see a large male southern elephant seal behind this biologist. As you can see, they are HUGE! Photo: Yann Tremblay
It takes a lot to sustain the appetite of such a large oceanic predator. Southern elephant seals are masters at locating and catching prey in the frigidly harsh Antarctic ecosystems. Northern elephant seals leave their harems and head North and West, into the Eastern North Pacific. Southern elephant seals exhibit a circumpolar distribution, or all around the South Pole and Antarctica. Furthermore, unlike northern elephant seals, southern elephant seals travel all over the Southern Ocean with a high degree of variability which indicates that they may have different foraging strategies. Satellite tagged Southern elephant seals traveled to the West Antarctic Peninsula, North, to the oceanic Front ecosystems, and some even stayed coastal near where they were tagged.
A satellite track with a dive record of a southern elephant seal tagged at the Cape. Figure: Dan Costa.
Dan Costa’s Lab at UC Santa Cruz’s Long Marine Lab has been tagging Southern elephant seals since 2005. Gitte McDonald, PhD candidate in the Costa Lab, worked on her doctorate thesis in the Antarctic Peninsula. Gitte is well known around the lab for her seasoned experience down at “The Cape.”

Gitte holding an Antarctic Fur Seal pup at the Cape. Photo: Aileen Miller
“[Southerns] are much more skittish, and they don’t get as skinny [as Northern Elephant Seals] when they fast,” Gitte said. The E-Seal team tags Northerns elephant seals based on how skinny they are, so Gitte was puzzled the first time she tagged the Southern elephant seals. “I had to learn how to work with them,” she added. “I was surprised when one stuck her tongue out when we were tagging her. It freaked me out! But soon we learned that [Southerns] like to stick their tongues out for some reason,” Gitte laughed.
A southern elephant seal sticking her tongue out! Photo: M.Goebel, U.S. AMLR
Southern and Northern elephant seals are pretty similar, except for the size, of course. Southern elephant seals don’t have warm beaches, but instead haul out on rocky shores or in muddy wallows, making for some dirty, smelly seals.
Luis Huckstadt, a PhD student in Dan Costa’s Lab at UC Santa Cruz, has been an active member in the E-Seal Crew up north. Both Luis and Gitte worked extensively with Nothern elephant seals before braving The Cape. Usually this time of year Luis would be getting ready for returning Northern elephant seals, instead he’s preparing for his next adventure: deploying satellite tags on Southern elephant seals.
Luis scanning for returning Northern elephant seals in Central California last winter. Photo: Nicole Teutschel
“They’re way cooler because they can survive in colder environments, and have deeper, longer dives. Southern elephant seals dive to over 2,100 meters, the deepest dive our lab has on record...so far.” He smiled. “[Southerns] are foraging on the ice edge, and could be using it to find prey. They forage on shelf waters on the Peninsula. That’s interesting because traditionally they’ve been thought of as active in the deep ocean food web, but they may also have a impact on an entirely different, coastal food web.” Huckstadt added.
Luis has been working hard getting all the gear ready to be shipped down to the Cape. Luis will be deploying 12 CTD tags on Southerns this winter as a part of a collaborative project. Dan Costa’s lab and TOPP have been a part of a large project with NOAA, the United States Antarctic Marine Living Resources (AMLR) Program and the Sea Mammal Research Unit at St. Andrews University (SMRU). The project uses Southern elephant seals as ocean sensors. The coveted CTD tag data (temperature, salinity, paired with depth, time, and satellite locations) collected from Southern elephant seals' tags enable biologists to learn more about the the Antarctic environment.
A southern elephant seal showing off her new CTD satellite tag. Photo: M.Goebel, U.S. AMLR
The Costa Lab then makes CTD data available to scientists all over the world. Recently physical oceanographers have discovered the value of e-seal data and how it can indicate ocean currents, front locations, and as well as monitor changes in the physical environment. There’s still a lot we can learn from Southern and Northern elephant seals alike. By utilizing the high-tech tags that collect oceanographic data, TOPP can continue to learn more about seals as predators, but also about their remote environments.
-Nicole Marie Teutschel
