A new project out of Ponta do Ouro is creating a baseline of data on the humpback whales that migrate north into the Indian Ocean along the of Mozambique and South Africa. On the tail end of the annual winter migration, Clare Keating Daly caught up with the project’s founder, Jenny Stromvoll.
By Clare Keating Daly
“The moment a book doesn’t satisfy my need to answer questions, I feel like I need to go find the answer out myself,” says Jenny Stromvoll of Ponta do Ouro. Jenny has lots of questions. Recently, her questions have focused on the humpback whales that migrate up and down the eastern coast of southern Africa during the winter months. What feeding grounds do they come from? How many pass through the PPMR? And what’s happening in terms of group dynamics, songs and behaviour as the whales move north and southbound?
“I read up a little bit and realised there is no on going humpback whale research happening here so that makes me feel like, well, I can do something,” she says. Jenny is Swedish born but moved to Ponta do Ouro in 2010 and is co-owner of Back to Basics Adventures, a dive charter. “I have realised that within the oceans there are so many things unknown and there are very few people that are fortunate enough to work with the ocean everyday, like myself, so I feel like I can contribute to various conservation efforts and research by simply sharing and collecting data.”
“It’s easy to write things down and store them in a box, but we want to get the information out there, in papers, on the web,” Jenny says. In a recent interview, and with follow-ups over email, Jenny shared the fundamentals and passion that form the new project:Jenny, along with researcher and fellow Ponta do Ouro resident Diana Rocha, recently started Project Humpback Whale within the Ponta do Ouro Partial Marine Reserve (PPMR) in southern Mozambique to do just that. The two are hoping to create a lasting project that contributes to the world of humpback whale research.
What is the inspiration behind Project Humpback Whale?
You know that feeling, of always wanting to know more? It started there. My friend Yara Tibiriçá [President of the Association of Coastal Conservation of Mozambiuqe and founder of the Zavora Marine Lab] was visiting, looking at the nudibranchs. We did a lot of nudibranch diving, but then we had a dwarf minke whale on our deco stop. That’s where the conversations started. Yara’s passion is nudibranchs, but she also keeps a whale catalogue because no one else does up in Zavora. She asked why I didn’t just collect data here [in the PPMR] and said I could share my data with her. So then I started thinking, what is actually done here? I started reading up, getting articles, online and from Yara. But I wanted to do it right. Yara helped me with the original proposal for the project. Very basic.
So where did the proposal go from there?
Well, I went to Miguel [the manager of the PPMR] and asked him what was going on here and how I could get involved. Then I started chatting with Diana [Rocha] over a braai and asking her about the whales because she’s done a lot with the dolphins [with Dolphin Encountours]. I said, this is that I want to do: I don’t have anything else but my drive but I can see clearly that this needs to be done here. She was really inspired and we decided to take the project on together and do the formal proposal. And you know, Miguel was really supportive of research on the area, research that’s valuable for the region. So we got the research permit and started data collection in August.
That’s great. So tell me a little about what’s already known about humpbacks. Are they endangered?
Humpback whales were one of the easiest whales to catch during the whaling years because they move close to shore and are easy to spot with their aerial surface behaviour. In the southern hemisphere, many baleen whales were driven close to extinction [during whaling years]. As far as I know, around 47,000 individual humpback whales were taken between Gabon to the west and Mozambique to the east. To put it in perspective, it is suggested that there were only 340 individual humpback whales left in the southwest Indian Ocean. In 1996, humpback whales were listed as endangered on the IUCN list but today they are listed as a least concern species. I have read in a paper that it’s estimated that the Southern Hemisphere humpback whales [population] are increasing around [the biological maximum rate of] 10% a year and this is great.
They’re cruising our coasts in winter, where are they in the summer?
Humpback whales undertake an extensive migration between their high latitude summer feeding grounds and tropical low latitude winter mating and calving grounds. So the southern hemisphere whales are feeding around 55° south, Antarctica, and winter grounds are around 20° south.
So what are the key questions of this project, in basic terms?
The main aim of this study is, on an annual or seasonal basis, to collect data on the humpback whale population that migrates to its breeding grounds north from the PPMR region. The specific questions are; one, what’s the abundance of humpback whales that pass by here during their migration and is there any rate increase; two, what is the distribution, behaviour, the sounds and group composition of the migrating population and is it different for the north and southbound journeys; three, what breeding stock do the whales passing by here come from and is there any breeding stock exchange; and four, what is the occurrence, prevalence and population distribution of a specific skin lesion observed frequently on the humpback whales passing through?
A skin lesion?
It’s not something I’ve observed myself but I’ve heard of it being seen on humpbacks in the area, kind of a scarring on their dorsal fins and always in about the same place on different individuals. One explanation is poor water quality or poor health of the individuals. We want to find out more about it.
That’s really interesting. How are you collecting the data on all of this?
We’re using land-based surveys and boat-based surveys along with ocean fix location and boat based transects. At each sighting at sea, when possible, we try to approach the individuals by boat at a steady reduced speed to obtain photo IDs and whatever detailed information we can. For all three different methodologies, the same data collection module is applied and a standard log sheet is filled in. Then once data is recorded, the boat goes back to the fixed point, or a commercial dolphin boat track or the track line of a transect and starts over. We’re keeping a photographic data catalogue with both dorsal fins, left and right sides, and flukes also.
Photographic data, does that mean that visitors in the PPMR and help with your project?
Anybody with a camera can contribute by taking photos that in turn helps us identify individual whales. The best way is to capture a photo of the whale’s fluke, their tail fin. The underside of the fluke has unique markings and what we do is build a library of the different whales passing us. It is not easy to capture a whale fluke, the best chance you have is when they dive for a longer period of time when they tend to arch their backs and show their flukes, or when they are tail slapping. And to give a good example of how citizens can help, there was a case in Madagascar where a Norwegian tourist took a photo of a whale fluke. Years later, the photo was posted on Flickr and a citizen scientist found the photo and matched the fluke to a whale that was seen off the shore of Brazil. This was an amazing discovery as it showed that one individual, thought only to migrate past Brazil, had changed his migratory route and came past east Africa. So everybody can make a difference and contribute to science and our knowledge of the ocean, humpback whales included.
Keep up with Project Humpback Whale at www.pontahumpbackwhales.com, the portal to sharing their research with the public and maintaining a meaningful and transparent project.