Creatures Of The Sea: | Orcas are clever and opportunistic feeders, taking whatever’s available. They gather near the spawning grounds of sea lions, and if a young one ventures out too far, he probably won’t make it back. Orcas will come right into shore to capture young seals, almost beaching themselves as they rush in to grab an unsuspecting youngster. Orcas are beautiful to look at, with striking black and white markings. Their tall dorsal fin is distinctive and can be used to identify individuals. They are the most widely distributed mammals on earth, found in every ocean from North Pole to South Pole. The sperm whales tend to feed on giant squid which live deep in the ocean. So sperm whales must be able to dive very deep—they regularly go 3000 feet, but sometimes as much as 10,000 feet!—and they may stay submerged for an hour or more. How they go that deep and survive, we can only imagine. Whales are fascinating and mysterious animals; there’s still so much that we don’t really know about them. How do they dive? And how do they surface quickly without suffering “the bends” as we would? They utilize air more efficiently than we do. They store oxygen in the bloodstream and the muscles rather than holding their breath. At the surface, the whale breathes in and out, rapidly taking in air which is distributed around its body. As it begins to dive, the heart rate slows and blood supply except to vital organs is decreased. The lungs collapse. After a few minutes, the muscles switch to anaerobic respiration, which produces energy without the use of oxygen. The muscles produce lactic acid which is dangerous for humans over a long period, but no problem for the whale. And whales are able to | come up rapidly, even from dives of thousands of feet, without experiencing any problems. Humans can suffer the bends when diving only about 100 feet. Blue whales are the largest animal to ever have lived on the planet, much larger than the largest dinosaur. They are regularly 100 feet long, weighing 200 tons. Its heart is huge. Although it’s proportionally the same size as our heart, it’s roughly the size of an automobile! A human baby could crawl through its arteries with room to spare. The tongue alone weighs more than an elephant, and 50 people could stand on its tongue! These are dimensions we really can’t grasp; we can only marvel at God’s creation. The smallest of the whales—only slightly larger than a dolphin—is the beluga, a white whale that lives year round near the northern ice cap. They have no dorsal fin so they can slip easily under the ice. They maintain a body temperature of 98.6 in water temperatures around 30 degrees. Their layer of blubber is about 4” thick; up to 50 percent of their body weight is fat. The relationship between man and whale has gone through many phases. The native peoples were very respectful of whales. When they hunted them they did so with reverence and admiration. They used all parts of the whale. They ate the skin, meat and blubber; they made waterproof clothing from gut; they dried and inflated the stomach and intestines as storage vessels; they used the oil for cooking, heating and light; from baleen they made thread and fishing equipment, combs, toys and traps; they used the huge bones as fences, sled runners and in the construction of houses. Cont'd on page 4 |
