On the morning of Saturday the 4th of August, I had my heart set on a quiet day. There’d be a few late nights recently and I never really sleep well over here so I was loving the idea of a day of laziness. By around 3:30pm that day, this is where I was at. Needless to say my day didn’t go as planned….
We got notified a bit before midday that a mother and calf cetacean had washed up dead at Kleinbrak, fifteen minutes from Mossel Bay. By midday we were deciding to take the interns over to see it. Things got more interesting when we learnt the species. It was a True’s Beaked Whale, a species so rarely that my reference guide prefaced every section on it with “Little is known…”.
True’s Beaked Whale
These species are super rare because they live in the open ocean. They’re only rarely spotted when they surface to breathe or strand on a beach. They’ve been observed of the east coast of North America, off the coast on the United Kingdom, off the coast of Northern and Southern Africa and off the south coast of Australia but we have no idea if thee are isolated populations or part of a larger group. They’re known to dive to depths of around 3000 meters. Little is known about their population numbers or home range. The guide I read about them says of their diet, “they are presumed to eat squid”.
What did I Learn?
Seeing Cetaceans at a distance or on a documentary doesn’t prepare you for the reality. It was somewhat surreal being able to see one up close and touch it. It was incredible to see how evolution has designed these animals.
When the first cuts were made into the animal, I first noticed the thick while layer of blubber. This layer several centimetres thick and covered the entire body. Clearly it’s adapted for life in extremely cold water, Once we cut past the blubber we could see first hand how powerful these animals are.
Cutting through to the chest cavity meant going through dense red muscle tissue that was in some places was as thick as my hand is long. This means it had the power to dive deep and swim through the open ocean. There was one surprising aspect of its biology however, it had strangely small lungs for an animal that spends long periods of time underwater
As I learnt later its lungs aren’t so much for holding air as for moving oxygen into their muscles for storage. Their muscle tissue is dark red, almost black because they have extremely high levels of myoglobin, a molecule responsible for storing oxygen.
The Whales store as much oxygen as they can in their huge muscular body while breathing at the surface and then dive for long periods of time where oxygen is released from their muscles slowly. This actually makes a lot of sense for deep dives. Under the crushing pressure of a deep water dive, a gas filled space like a lung would be compressed and potentially damaged, So having smaller lungs that don’t need to be filled to capacity is a massive bonus to these mysterious animals.
So why did it die?
Well I wish I could give you a definitive answer on that one. On the day, we removed its lungs, digestive system and numerous other samples for analysis. The first stomach (cetacea have four) looked extremely full. Later analysis showed that what we thought was a large full stomach was all due to inflammation of the inner lining. There were a few squid beaks in there and some parasites but it was clear this animal hadn’t fed in a long time. I may do a follow up post to this if and when I learn more…