The waters of Isabela and Fernandina Islands
Could we ask for more? An incredible day exploring the western side of the Galapagos archipelago started with bottle-nosed dolphins bow-riding the M.S. Polaris around Roca Redonda. This impressive piece of an eroded volcano lies 18 nautical miles north of Isabela Island where ocean currents collide and upwell. Just four miles off the rock we found ourselves in 10,000 feet of water. A logical location for finding a solitary male sperm whale, Physeter macrocephalus, lolling on the surface. It was obviously resting, hardly moving, breathing deeply, the blows coming from the end of the snout, displaced to the left, and forward facing, a feature unique to these leviathans.
After their deep dives, typically as deep as 2,000 feet, and thought to possibly go as deep as 9,000 feet, they must surface to re-oxygenate. Sperm whales are known to spend up to two hours underwater, and in a particularly deep dive, which older males are known to do more frequently than others, their lungs collapse and they depend on the oxygen in their muscles and blood for that time. The individual we were watching stayed on the surface for a good 15-20 minutes, allowing us an excellent view of the head that makes up about 1/3 of the body length, and contains a huge cavity called the spermaceti organ. The exact function of this is still a matter of debate, but is thought to be used in buoyancy control and to focus sonar clicks.
Despite the fact that over 2,000 animals are known individually here in Galapagos from photographs, they are rarely seen except in the western part of the archipelago, and then only seldom. It has been a few years since I last saw a sperm whale while cruising here, and then not so well and in such detail as this morning. The moment arrived, however, when the whale decided it was time once again to dive (for giant squid?), and with a magnificent arching of the tail, the flukes poured water as they were lifted smoothly out of the ocean, and slid gracefully into the deep.
