“And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.”
The water pressure around a human diver increases as he goes into deeper water. As the pressure increases, his blood is able to hold more dissolved oxygen. Our blood also absorbs the nitrogen in the air around us. If a diver were to move toward the surface too quickly, the nitrogen would start to bubble out of his blood. These bubbles can block the flow of blood to muscles, organs, and even the brain, leading to death. This painful condition is called the bends.
Scientists have wondered why seals don’t get the bends. Weddell seals dive to far greater depths than human divers would consider, using even the best equipment. The fact that they are breaking every diving rule in the book means that almost every dive should lead to a fatal case of the bends.
To find the answer to this mystery, scientists outfitted four seals with scientific backpacks. These allowed scientists to record the seals’ heart rates, sample blood, and record the depths of their dives. The deeper the seals went, the more nitrogen accumulated in their blood. Just before the nitrogen reached a dangerous point, it leveled off. Scientists say that the tiny sacks in the lungs that absorb oxygen and nitrogen shut down. Then the seals’ heart, liver and blubber begin to absorb the nitrogen from the blood. The air exchange sacks in the lungs reactivate as the seal ascends to the surface.
Surely the amazing biology that allows the seal to make his living deep in the ocean could only have been designed by our Creator God.
Father, as science learns more about the wonderful things You have created, I am moved anew to glorify You. I pray that our growing knowledge of what You have made will lead others to do the same, especially those who don’t know You or the forgiveness of sins in Your Son, Jesus Christ. Amen.
“Why Seals Don’t Get the Bends.” Discover, October. 1985, pp. 10, 12. Photo: Weddell seal swimming under sea ice.