Written by Liah McPherson
My master's thesis research with MMRP is focused on the abundance and demographics of spinner dolphins offshore west Oʻahu. It's an important project, and one that I'm excited to share more about in the coming months – but here at MMRP, I'm fortunate to be able to contribute to multiple projects within our lab and with other collaborators. This February, I had the extraordinary opportunity to travel to Antarctica with California Ocean Alliance to support their work studying whales in the Southern Ocean.
Oʻahu and Antarctica are about as different from each other as it gets. Oʻahu is hot, tropical, and jam-packed with people. Antarctica is frigid and has zero permanent residents. During fieldwork around Oʻahu, jumping in the water to cool off is an opportunity much welcomed, but in Antarctica, it would be insane. Blue, clear, calm water, vs green, turbid wind chop. One could say these two places are… polar opposites. ;)
But despite their differences, you can look across the water in either location, and count blow after blow from humpback whales.
Approaching humpback whales in the zodiac.
Humpback whales seasonally migrate thousands of miles between “feeding” and “breeding” grounds. The whales we see in the Hawaiian Islands travel north to regions such as Alaska and Russia during summer, where they feed on fish in nutrient rich subpolar waters. Like their Northern Hemisphere counterparts, the humpback whales in Antarctica travel north around April each year, but towards the warmer waters near the equator – namely those off western South and Central America, where they mate and give birth.
Humpback whale migration examples from Happy Whale. Some whales in the Northern Hemisphere migrate between Alaska, Hawaii, and even Mexico (left), and some whales in the Southern Hemisphere migrate between the West Antarctic Peninsula and Central America (right).
Last month, on two back-to-back expeditions with Hurtigruten Expeditions, I couldn’t help but to marvel at these whales as they travelled through icy channels, fed on krill, and went about their lives in the frigid waters of the Southern Ocean, so very far from the warm breeding grounds they left behind in Austral autumn. How are these animals, which undergo such costly migrations every year, affected by the ever-changing environment? How adaptable are they, and how healthy is the population? What about other species that use the same foraging habitats, such as Antarctic minke whales? These are all questions that I share with the COA team, who have been studying whales in the Antarctic for nearly 25 years.
Through numerous data streams, we are able to look at the health of whales at the level of the individual and population. A single whale can become a valuable indicator when tracked and studied over years or even decades. So when we collect data on hundreds of whales, and resample those whales over long time scales, the resulting dataset is exceptionally rich.
A mother humpback whale and her calf.
The MS Roald Amundsen was our research platform from January 28th to March 1st. Working from the ship was a great experience – we were able to give lectures to guests on board and work closely with the Amundsen’s fantastic expedition team. Whenever conditions were appropriate, and time allowed, we were given a smaller Zodiac boat to go look for whales in the straits, bays, and open waters of the West Antarctic Peninsula. For each whale we encountered in Antarctica, we tried to collect three types of data: a UAS (drone) body condition measurement, a biopsy sample, and a photograph of the whale’s tail fluke for photo-identification. Linking these data allows us to correlate the body condition of an individual whale with metrics from its biopsy sample like stress level (from cortisol), pregnancy status (if female; from progesterone) and diet (from stable isotope analysis).
Hurtigruten's MS Roald Amundsen.
As the drone pilot, my main role was to get a good body condition measurement of each whale, and communicate its behavior to my teammates so they could position us to get a good biopsy sample or fluke photo. When conditions allowed, I was able to get some biopsy sampling practice as well, thanks to the guidance of our captain and fieldwork extraordinaire, Kiirsten Flynn, from Cascadia Research Collective. COA’s Chloe Lew, an incoming PhD student in the Friedlaender lab at UC Santa Cruz, focused on collecting biopsy samples during encounters. She also deployed a hydrophone in open water at the beginning of each fieldwork day to collect ambient noise data on the Antarctic soundscape.
Chloe deploying the hydrophone (left; Photo by Leslie Hsu Oh, www.lesliehsuoh.com), and a humpback whale diving (right).
Weather conditions were variable and limited how many days we could go out and collect data. You can read more about my fieldwork and weather-related musings in my first blog post about Antarctica. Despite difficult working conditions on both voyages, we were able to collect data on both humpback whales and Antarctic minke whales. We operated the UAS over twenty whales, and collected eleven biopsy samples. On our very last day, we were finally graced with calm water and sunny skies – it was a wonderful reward after operating for many days in harsh weather.
Clear skies above the Gerlache Strait on our last day of fieldwork.
One of the most rewarding moments of the trip was collecting a UAS measurement and biopsy sample from a minke whale near Danco Island. Minke whales are notoriously elusive and don’t stay at the surface very long, making both types of data collection difficult. Needless to say, we were thrilled to get linked information on this animal.
Chloe and I (left) feeling the stoke after sampling a minke whale (right).
Working with Chloe and Kiirsten was one of the greatest aspects of the entire experience. Going into this expedition, it didn’t even occur to me that we would be a three-woman team, but with each passing day of fieldwork, I got more stoked on it. The opportunity to do research – especially operating equipment like boats, drones and crossbows – with two other accomplished women scientists in one of the harshest environments on Earth was encouraging to say the least.
Our three-woman power team launching the drone in the Gerlache Strait. Photo by Leslie Hsu Oh, www.lesliehsuoh.com.
It’s incredible to see whales in places as contrasting as Hawaiʻi and Antarctica. In particular, the adaptable humpback whales and their diverse interactions with their environments continue to fascinate me as I progress throughout my graduate career. To have seen days-old humpback whales in Maui last year, and know that calves not much older than them travel thousands of miles from Central America, across the Drake Passage, to the unforgiving waters of the Antarctic… I mean, I thought it was a long journey, and it only took me a couple days!
I couldn’t be more grateful to Ari Friedlaender and the COA team for inviting me on this expedition. I would call it the opportunity of a lifetime, except that I desperately hope to return one day, so that I may learn more, and give back. Though my feet are back in the sand on Oʻahu, my mind drifts frequently to world’s end, wandering like an albatross, southbound across the vast expanse of open ocean, towards ice, solitude, and of course, whales.
All research activities were conducted in accordance with permits NMFS 23095, ACA 2021-006, and ACA 2020-016.
