How I collected whale brains in Brazil – 10/26/2023 – Fundamental Science

Caravelas, a small town in the extreme south of Bahia, is one of those rare places in the world where you go for a morning walk on the beach and stumble upon a whale bone.

Between the months of August and October, the reproductive period of these cetaceans in Brazilian waters, they arrive in Caravelas and are a spectacle in itself. At the invitation of the Instituto Baleia Jubarte, I participated in scientific expeditions and stranding events that, abundant (and natural) at that time, offer us beautiful opportunities to collect biological materials. And if you read my previous text about the collection of dolphin brains, perhaps you already understood what I was going to do in that location.

It didn’t take long for me to take action. Two days after my arrival, we already received a stranding notification. The animal was on a very popular beach and there were many curious people around. I remember seeing dozens of children in uniform, as if watching that event were a school activity. In fact, although unusual, it is a great time to reinforce environmental education practices and explain the work we do.

The animal was in the sand, isolated by tape to prevent people from approaching, as it was not known what had caused its death and the risk of infection had to be avoided. It was a newborn humpback whale, about a month old. The cub was already more than four meters long, which made it impossible to perform a necropsy in the laboratory. The team, dressed in protective equipment, began taking measurements there and then collecting organ samples. When we were removing the layer of fat from the animal, one of the children pointed and shouted: “Look, it looks like chicken!”

For me, that experience was ecstatic. The anatomy of the whale skull varies between species and adequate planning is required to extract the organ efficiently. Everything needs to be aligned. After all, on the beach we deal with limiting factors such as daylight and tide tables, and it was the first time I had collected a whale brain in Brazil.

Removing the animal’s brain is one of the most complex and time-consuming tasks in a necropsy, and sometimes we have to choose between removing the brain or another large organ, such as the heart. I faced the challenge and the team joined me to complete the task on time. As I exposed the brain, I heard a voice in the background: “Look at this, such a big animal with such a small brain.”

Well, in absolute terms, we are not talking about a small brain, since humpbacks have brains that weigh almost 6kg on average, while ours weighs around 1.5kg. But in relative terms, we cannot deny that the curious man was right: in a body weighing in the order of tons, a 6kg brain does indeed seem small.

It was time to go back to the laboratory, organize the collected samples and get everything ready for the next stranding. And it happened three days later. Early in the morning a video began circulating on the team’s WhatsApp: a fisherman passes by a whale carcass on a boat and says: “It’s fresh, it just died”. The team then considered whether it was possible to locate the animal. I immediately got ready to go.

But this time the situation was more challenging. The animal was isolated on an island and we would need a boat to get to it. What’s more: there was a possibility that the animal might not be as fresh, which would make our study unfeasible. We had to evaluate the pros and cons of such extensive travel logistics.

We chose to go. We sailed for just over an hour, trying to locate the animal with the help of binoculars, but nothing. At that point, the vultures, which usually go after carcasses, were our allies and we ended up finding it. Unable to approach the beach, the vessel docked. We got into a boat, which was also unable to reach the sand and almost capsized due to the strong waves. We took our material, protected by plastic boxes, and swam – to the island. Once again, it was a baby humpback whale. We began collecting tissues from the animal.

In the condition we were in, the tide was a lurking enemy, rising more and more and pressuring us to finish the job. The physical exhaustion was obvious, but there was no time to rest. The team’s support was essential, helping me to have the strength that I lacked at times and also to remain calm. We called some locals and used a rope to move the animal away from the tide to save time.

We barely removed the brain when a wave came and took away a large part of the animal. I, who was already emotional, became even more emotional with how lucky we were. But now there was another problem: how to get back to the boat, with the brain in a container full of formaldehyde, in addition to our work boxes and all the other samples? We saw the boat in the distance, the waves were hitting hard and we didn’t know what to do.

There was no way: you had to get to the boat by walking through the sea with water up to your chest. With each wave that came, it seemed like we were going to capsize everything. We left the brain for last, counted an interval of waves and raced the organ to the boat. And finally we returned to the larger vessel. Adrenaline was pumping, everyone was exhausted and amazed by the unprecedented experience of collecting whale brains for research in Brazil.

We finally managed to collect whale brains for research in the country – and, as we know is common among Brazilian scientists, dealing with some adversities.

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Kamilla Souza is a biologist and researcher at the Physics Institute of the Federal University of Rio de Janeiro.

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