"The whale encounters made had been memorable"
Pietro Vermicelli, from Italy
The atmosphere was relaxed and laid back in a very South African fashion, and the office always bustling with activity. There are so many projects going on. Tess and Simon are knowledgeable and passionate about what they do, as everyone else I met there at Sea Search.
Definitely a stimulating and fun environment in which to work. The first three weeks were dedicated to catching up with the latest research on the study species of my two projects as an intern: photo identification of humpback whales and study of humpback dolphins’ vocal repertoire, especially whistle. They were followed by three weeks in the field, in Paternoster, to study the so called ‘suspended migration’ of large groups of humpback whales. There, depending on the fierce west coast weather, we spent our time surveying the whales from land, which allows one to collect precious behavioural data, or recording/taking ID-shot of them on dedicated boat days, and, it goes without saying, the whale encounters made had been memorable. The remaining two weeks (+1 of conference) had been mostly devoted to preparations for the upcoming 1st African Bio-acoustic conference that Sea Search organised and which had been a great success! Meantime I also had the chance to travel a bit and enjoy the spectacular South African landscape and wildlife.
"Humpback whales are known as the best singers in the ocean"
Ilka Beith, from Germany
During my internship with Sea Search Africa I worked on a set of photographic and acoustic data on humpback whales (Megaptera novaeangliae) collected late last year. The goal of the study was to collect sounds of animals known to be feeding in the large aggregations of whales, which occur off the west coast in late winter and early summer. This data will then be used to help us identify sounds made on moored hydrophones as part of the E3C project. The data was collected around Hout Bay in November 2015 over 6 days in collaboration with Steve Benjamin of Animal Ocean who took us out to sea when we didn’t have our own boat.
Photo-identification is the practice of identifying animals from their natural marks (fin shapes, scars, injuries, colouration etc) from photographs of them. Important for photo-ID of whales and dolphins are shots of the dorsal fin from both left and right sides and for humpback whales, the underside of tail fluke, which has individually distinctive black and white patterning.
My task was identifying all the individuals photographed over the 6 days by pulling out all the left dorsal fins (LD), the right dorsal fins (RD) and the tail flukes (TF). I identified every single individual and gave everyone a number and identified the ‘best’ image each side (and tail) of each whale for each day, essentially making three catalogues a LD, RD and TF catalogue. I drew the different dorsal fins and tail flukes of the whales on paper and I also named a few of them to remember them better, which is pretty helpful during the identifying process. On the basis of the best pictures I matched the left and right dorsal fin together to one whale where possible.
Some of the pictures I turned into black and white, because it is easier to see marks and it also highlights the shape.
Matching the tail fluke to the right and left dorsal fin was the hardest part. The main identifying feature used is the under-side but by using the many different angles photographed it is often possible to match a ‘side shot’ as below to both a dorsal fin and a good underside.
Humpback whales are known as the best singers in the ocean, but only the male whales sing. Most of the time they sing during mating season to attract female whales. But there are also social vocalizations produced by both male and female humpback whales which are heard on the feeding and breeding grounds and even surface-generated percussive sounds as breaches, pectoral flipper slaps and tail slaps (Dunlop R. A. et al., 2007).
During my internship, I did the first part of the acoustic analysis Adobe Audition. I converted the spectrograms to the right settings for viewing, noted the start and end time of each noise and quantified, classified and categorized the noises (mostly following the categories defined by Rebecca Dunlop and colleagues in Australia – Dunlop et al. 2007). All in all I found over 1500 sounds in the acoustic data of the first three days of research. Most of the sounds are between 100 Hz and 4 kHz and can be divided into low-, mid- and high-frequency sounds. Low frequency sounds are the most common, especially the “wop”, “grumbles” and “barks”. The most common mid-frequency sound is the “modulated cry” and the common high-frequency sound is the “shriek”.
"I’ve never seen so many passionate researchers in one place"
Nicole Buss, joined the project for 7 weeks
Doing this 7 week marine mammal research internship with the Sea Search Team based in Muizenberg, Cape Town was the best experience I’ve ever had! I’ve never seen so many passionate researchers in one place, always happy, helpful and full of knowledge about cetaceans to share! Drs Gridley and Elwen are a great and ambitious couple of marine mammal scientists, that created a pleasant working environment by always have a smile on their face and a friendly attitude. During my time I worked on a small research project on the prevalence of skin diseases, ecto-parasites, shark bites, entanglement and deformities of Indo-Pacific bottlenose dolphins around the South African coast. This provided me with an opportunity to improving my knowledge on the theoretical background and my data analysis skills in MS Excel. Drs Gridley and Elwen provided me with project relevant papers to read, involved me in field relevant talks of other local researchers from other institutes and provided me with the opportunity to participate in a stranding course. Besides data analysis, I also had the opportunity to experience marine field work out at sea, which was an experience I will never forget.
My best experience was assisting in data collection of humpback whales, attempting to collect photographs of their dorsal fins and tail flukes, as these parts are the best to use for photo-identification to identify individual animals. During my time quite a lot of humpback whales – so called super-groups – were around and there was nothing better being on the ocean surrounded by a hundred animals that were lung feeding, tail slapping, diving and breaching. Collecting behavioural data of so many animals was often quite a challenge! I also helped with setting up to record the acoustic behaviour of these humpback whales during their feeding events and it was such a great feeling coming home and listening to the noises these animals would make. But no matter if in the office, with the best crew one can imagine or doing field work on the water, every day was a surprise of learning something new and having great experiences. During my free time I tried to explore Cape Town and the area and I must say I fall head over heels in love with this beautiful country and with the always smiling people that live here. Cape Town is a city with a special vibe, full of different cultures, history, events and sights so that you’ll never get bored and I definitely have to return as it is impossible to see it all during such a short period of time. From diving, snorkelling, bike riding, hiking no name but a few, Cape Town has so much to offer.
Muizenberg, where the office is based, is a lovely little suburb of Cape Town with a nice beach where I started my first little baby steps into surfing, as the waves there are perfect for beginners but also for advanced surfers to enjoy. I learned so much here about how cetacean research is done and collecting the best experiences of my life being out there on the water. I really enjoyed and appreciate my time in South Africa making the most amazing friends and meeting loads of wonderful people within the Sea Search Team, knowing for sure that I definitely have to come back!
"I learned a lot about acoustics, dolphins and scientific writing"
Julia Heiler, joined Sea Search to write her master thesis
I came to Sea Search to write my master thesis on the acoustic behaviour of common bottlenose dolphins (Tursiops truncatus). As I had only 5 months, I could not collect my own data for my project but Dr Gridley let me analyse an existing long-term acoustic dataset on bottlenose dolphins in Namibia. Through her professional guidance I learned a lot about acoustics, dolphins and scientific writing. She taught me how to use necessary software and always helped, when I was stuck at any point during my thesis. The same applies to everybody in the Sea Search team where I always got advice when I needed it. I also had the chance to spend 3 weeks in Namibia and experience how my data was collected in the previous years, as I participated in the current surveys of the Namibian Dolphin Project. This was a great help to write the material/methods part of my thesis and a wonderful opportunity to see another beautiful African country.
Apart from my work at Sea Search, I was living in the shared student/intern accommodation right across the road which is nice and close to work, but also just a few meters from the ocean. A great opportunity to spend lunch breaks and spare time surfing. All in all, I had a wonderful stay and a successful outcome of my thesis and I would love to come back one day!