National Geographic : 1954 Mar
Night Life in the Gulf Stream 391 A Marine "Pied Piper" Lures Queer Creatures with a Light Bulb in Nocturnal Studies of Humble Dwellers in Warm Seas BY PAUL A. ZAHL With Illustrations from Photographs by the Author T HE night was dark and windless, and a blanket of warm air lay heavily on the sea. Knifing us along at 16 knots, the propeller churned up a wake of silver white phosphorescence that dimly illumined the boat and its passengers. There were four of us: my wife, myself, and two Negro Bahamian crewmen. We had set out from the Bimini Islands an hour earlier, crept through the mouth of North Bimini's harbor to the shoal-free waters of the open sea, and then opened the throttle to full speed ahead on a due westward course. If continued, this course would have taken us across the Gulf Stream.* But it was not our purpose to cross the Gulf Stream. We planned to stop squarely upon it, beyond the submarine wall that de fines its eastern edge. This wall forms one side of a half-mile-deep, 50-mile-wide gorge through which one of the mightiest of earth's sea rivers flows northward (see the National Geographic Society's new map, "West In dies," a supplement to this issue). At my signal, the wheelman flipped off the switches. Our bow nosed down abruptly, and after the wake's wash had flattened, a great black quiet settled over our world. The sea was a millpond this night-no swells to lift and drop the little 20-foot open-decker, not even the lapping of waves at its sides. Night Draws Life to Surface We had purposely chosen a moonless night. Only on such nights do some of the Gulf Stream's strangest creatures leave the depths and swim upward toward the surface. These were the objects of our search-a search that was to lay useful groundwork for later studies of deep-sea species in the turbulent waters of Italy's Strait of Messina.t Our lure was neither baited hook nor tow net, but an electric light. Primitive fisher men had discovered the principle for us-that on a dark night many species of marine life will rise to a light or gather around it, like moths around a flame (pages 393 and 400). Here now in the Gulf Stream we would apply this ancient knowledge in an attempt to explore, and to extend if possible, what has been called man's last earthly horizon-the sea, with its enormously diverse and mysteri ous population of living things. Pictures accompanying this article depict some of the weird and bizarre creatures at tracted by our lure. They also show some equally strange forms that we collected near the shores and reefs of the Bimini Islands during daylight hours. We hooked up our storage batteries, and immediately the darkness fell back before the bright glow of a 50-watt bulb encased in a glass-walled watertight lantern (page 404). Downward Look into a Watery Void I picked up the lantern and, using its heavy rubber-sheathed current-carrying cord as a suspension rope, lowered it into the sea to a depth of about a foot. Then I secured the cord to the end of a narrow slab of wood screwed onto the starboard gunwale and projecting over the water about two feet. Now a new and rather scary world un folded. We were floating upon an insub stantial watery firmament. The eerie penetra tion of light into the sea gave us the feeling of looking into a starless astronomical void. These Gulf Stream waters near the Great Bahama Bank are among the world's clear est; we could see down perhaps 50 feet before darkness and the unknown again took over. But gradually, as our four pairs of eyes searched the ebony depths, they seemed to become sprinkled with stars, as if someone at * Popularly, the Gulf Stream may be thought of as a great ocean river, drawing on Caribbean and trop ical Atlantic waters. Between the Straits of Florida and Cape Hatteras, though technically known as the Florida Current, it is widely called (as here) the Gulf Stream. The Antilles Current, an offshoot of the North Equatorial Current, joins it north of the Ba hamas. Oceanographers give the name Gulf Stream only to the combined system between Cape Hatteras and the Grand Banks.-The Editor. t See "Fishing in the Whirlpool of Charybdis," by Paul A. Zahl, NATIONAL GEOGRAPHIC MAGAZINE, No vember, 1953.