How Do Orca Dorsal Fins Grow? The powerful and distinctive dorsal fin of each Orca is made not of bone but the structural protein known as collagen. A dense connective tissue that can be vulnerable to injury in rough play with other Orca, during a hunt or on very rare occasions entanglement. During the first few days of life the dorsal fin of an Orca calf is folded over but will start to stiffen and strengthen in the weeks to follow. It will then remain small and curved until the young Orca reaches their early teens and it is at this time that the male Orca begin to “sprout” and their dorsal fin will continue to grow taller and thicker usually until their late teens reaching a maximum height of almost two meters. Orca display sexual dimorphism which means that the males and females grow to be different sizes. A female Orca will remain smaller than males once fully grown and will retain a smaller, curved dorsal fin.
Today we had dorsal fins all around as Tatty and her family along with a second family pod we are currently completing ID work for had joined together. Large males Chalky, Hookfin and Blade spent most of their time swimming alongside each other, creating an impressive sight of three enormous dorsal fins slicing through the Southern Ocean. Today they were relaxed, social and hungry! Foraging throughout the day and working together as a team, both family pods created a beautiful scene of 15+ Orca all surfacing as one. Welcomed into The Pod, it was a joy to be so close to each of these incredible apex predators and hear the powerful exhale/inhale of every breath before each deep foraging dive. Wandering Albatross, Australian Sea lions and talented Crested Terns also made for wonderful viewing on another special day with the Orca of Bremer Bay.