A Week of the Blues in Mexico
We had a very blue week in the Sea of Cortés aboard the Safari Endeavour; blue sky, blue ocean, and many, many, many blue whales. The Gulf of California is well known for having an abundance and variety of marine mammals. In fact over 30 different species have been observed here. The largest and one of the most majestic is the blue whale. Growing to nearly 100 feet long, with a heart the size of a Volkswagen Beatle, the blue whale is the largest creature to ever live on Earth. However, despite their size, they are surprisingly graceful and elusive animals. In fact we are still learning much about their life history.
This week as we pulled away from the Puerto Escondido dock we found ourselves surrounded by towering blows. We slowly maneuvered the boat as whale after whale swam by. I have never seen so many blue whales in such a small area before. I found myself unsure of where to look as there were so many blows, backs, and fins breaking the water’s surface. We could hear the sound of powerful blows over the water; the whales' exhales sending plums of mist nearly 20 feet in the air. Several moved close enough to us so that we could see the light blue outline of their body under the surface of the water. As I watched them surface and dive I was reminded of old sailor stories of giant sea serpents. When a blue whale begins to dive it arches its back which seems to go on forever as it descends into the deep. They do not show their tail often, in fact our captain had never seen a blue whale raise its tail for a dive. That day, as we watched one whale after another, we saw two of the mighty animals lift their tail above the water as they dove.
As we watched blow after blow against the background of tall desert mountains I thought about why all of these animals were gathered here. They appeared to be feeding. As some animals surfaced you could see their relatively small pectoral fin skim the surface of the water, meaning that they had probably rolled to their side while lunging for food. When a blue whale feeds, they open their enormous mouth engulfing as much as 70 tons of water. The pleats of their throat expand like an accordion, transforming the sleek streamlined animal into what looks like a gigantic tadpole. Then, the huge tongue pushes the water through their baleen, thus filtering out any plankton. To see what was in the water, we let out a plankton tow and examined its contents under a microscope. Not surprisingly, the water was rich in plankton. The largest of creatures were feeding on some of the smallest.
We watched the whales until the sky erupted into a beautiful sunset. We continued on our way watching blows fade into the distance.