Erin Ross-Marsh (34) is doing a PhD in zoology at Stellenbosch University. Erin, who will submit her thesis – researching humpback whale bioacoustics – in October, is one of only a few people in South Africa to have ever studied whale song, and how whales communicate with one another. She hopes that her research will help to fill knowledge gaps about these mammals, and put Africa on the map for bioacoustic knowledge.
Erin Ross-Marsh is one of only a few marine bio-acquisitionists studying humpback whale song in South Africa. The Stellenbosch University PhD student has always had a deep love of the sea, and dreams of putting Africa on the map for bioacoustic research. PHOTO: Britannie Hohls
The door swings open at exactly three o’clock, and Erin Ross-Marsh’s headphones are still on her head. She is not listening to a Spotify track. Erin (34) is doing her PhD in song evolution and transmission in humpback whales in Southern Africa, and so, she is listening to the sound waves of whale song.
“Basically, I am looking at data from 2016 to 2023: What is the song doing? How is it changing? And are the changes between the two different coasts of Southern Africa the same or different?” She hangs up her headphones, and settles in for the next hour and a half to do one of her favourite pastimes: Talk about whales, and the songs they like to sing.
Growing
The whale tail necklace hanging around her neck might be the first clue to what Erin spends most of her time doing. That, and the crocheted humpback sitting on her shelf.
Erin was raised in Pretoria.
“I always think of it as quite hilarious that this girl who hates the smell of fish, who gets so seasick, who grew up, and studied hours and hours away from the ocean, has found herself to be a marine biologist,” she says.
With her parents originally being from KwaZulu-Natal, Erin’s family spent many holidays by the ocean.
“I fell in love with it,” she says. They went regularly to a familiar beach cottage, and Erin remembers being intrigued by the rock pools, seeing whales and watching the sardine run from the stoep.
“I remember just being in awe of the beauty and power of the ocean,” she says.
Stellenbosch University PhD student Erin Ross-Marsh’s headphones are used for listening to the humpback whale song that is recorded by hydrophones. The hydrophones are placed in various places in the ocean along the coastline of South Africa. They are then extracted from the sea, cleaned, and then Erin, a marine biologist, can begin analyzing the song. PHOTO: Britannie Hohls
Marion Island
Marion Island is 19 kms long and sits in the southern part of the Indian Ocean. Between South Africa and Antarctica, its exclusivity is what makes it unique, says Erin. The island is used for research purposes, and it is a lengthy process to make sure that they are the type of person who can handle the isolation and cold. The journey to get there involves a trip on the SA Agulhas, and then a helicopter ride before arriving.
It’s a trip that Erin has been on. During Erin’s masters year, she was studying elephant seals, and was selected to go.
“It was a really rare and special opportunity that I got to see that island. It was one of the most beautiful places I had ever seen,” she says, reflecting on her six weeks working in Marion Island.
“I was kind of like a skivvy. I was just there to help.”
The island is located in what is called the ‘roaring 40’s’, a really wild part of the ocean, she says. It’s given the name because of the fact that it is located 40° south of the equator.
“I seem to remember that I was busy all of the time,” she says. She had to help stock up research huts around the island with food and supplies. This, Erin says, was one of her most memorable experiences in a wild, wondrous place.
In South Africa, there are two different populations of humpback whales, referred to as breeding stock B and C. Once Erin Ross-Marsh, a PhD student in zoology at Stellenbosch, has listened to the whale song, she begins to analyse what is different or the same between the songs that the two different groups of humpbacks are singing. PHOTO: Britannie Hohls
Sea Search
Erin smiles when she speaks about the people who she has met in her career so far. They are colleagues, but have also become firm friends.
Rachel Probert, a close friend of Erin’s, is currently a postdoctorate fellow at the University of Cape Town (UCT), and is working on behavioral cues for rabies in Cape fur seals. Their friendship started at Sea Search, where Erin was doing her internship in 2018. Sea Search is a non-governmental organisation (NGO) that does research on marine mammals, with a large acoustic component, says Rachel.
Erin’s work on humpback whales “gives us insight into population connectivity, cultural exchange, migration pathways, and the ecological processes that shape whale communication”, says Rachel. “It can help us to understand how often whales from different breeding stocks interact and exchange information.”
“We worked well together within the team and hit it off from the beginning,” says Rachel about her friendship with Erin.
Sea Search, Erin says, is the reason her research went into humpback whales.
Dr Tess Gridley, one of the co-founders of Sea Search, reached out to Erin when she was looking for an internship.
“She was like: ‘Hey, listen, we saw that you want to be a marine biologist and we’ve got a lot of data with humpback whale vocalisations’,” says Erin.
This was the point where she got even more excited and passionate about the work she was wanting to do. When Erin got the offer from Tess, she “literally saw the word ‘humpback whale’ and was, like: ‘Done, immediate, 100%’.”
At this point, Tess mentioned that Sea Search wanted to do some bioacoustics work.
“I didn’t even know what that was,” says Erin.
Erin Ross-Marsh’s ‘phrase catalogue’ consists of printed-out soundwaves of actual whale song. This is song that Erin collects from the hydrophones. From there, she can listen to them, and record similarities and differences between them.“In total, to get this PhD done, I boxed 74818 different sounds,” says Erin, who will submit her PhD thesis in zoology in October. PHOTO: Britannie Hohls
What you need to know about bioacoustics in Africa
Dr Courteney Gardiner is a friend of Erin’s, who does work with fish in the Mozambique Channel.
“Erin’s research is incredibly important. It reveals the hidden complexity of Humpback whale acoustic behaviour, particularly in the southern African region,” says Courtney. “The humpback whales along our coastline have displayed some really unique behaviour such as ‘supergroups’ where tens to hundreds of whales are congregating in tightly packed groups.”
“Erin’s research is making a significant contribution towards understanding phenomena like this, and it provides insights that can be directly applied to the conservation of this species,” says Courtney.
‘Boxing’ is the process Erin goes through to analyse the sound waves that she listens to. Boxing, she explains, involves listening to the sound, and highlighting certain nuances in it. Once she has boxed the sound, all of the information needed to conduct research is within it.
After having boxed 74 818 different songs, she says, she doesn’t need to even listen to them anymore. Erin can tell what a whale song sounds like, just by looking at the soundwaves.
Bioacoustics is not a widely studied field in Africa, Erin says.
“The really interesting thing about Africa is that we have one of the highest biodiversities in the world,” Erin says. “A lot of African animals are being researched in bioacoustics. It’s just that researchers in Africa can’t get the skills, funding, or equipment to do that kind of research.”
“That’s changing now, rapidly,” says Erin. “There is this massive gap [in research about bioacoustics] in Africa. My goal is to close that gap, but also to invest in the bioacoustics knowledge that is coming out.”
Stellenbosch University PhD student Erin Ross-Marsh explains how to read the humpback whale song, and how she ‘boxes’ the sound, in order to analyze it. Since the age of 10, Erin’s dream was to become a marine biologist. At the time, her mother gave her a book on whales which she now referenced in her PhD. “That started me on this path so I feel I need to acknowledge it.” PHOTO: Britannie Hohls