Each night, a migration takes place in the waters around Bermuda that
rivals any in the animal kingdom. By studying this migration, scientists at the Bermuda Biological Station for Research (BBSR), are advancing the work of
early deep-sea biologists such as William Beebe, whose dives in the 1930s first put Bermuda at the forefront of deep-sea exploration.
Perhaps unknown to Beebe, however, was that some of the deep-sea
creatures he found often leave the deep. Each evening as the sun sets over the Sargasso Sea, millions of these sea creatures migrate up from the depths to feast on microscopic plants growing in sunlit surface waters. At dawn,
these animals reverse course, sinking or swimming down to spend another day in the darkness. By almost any measure, this daily migration rivals the great seasonal movements of caribou on land or arctic terns in the air. Yet its
magnitude was virtually unknown to science until the 1940s, and many of its mysteries remain.
Scientists are studying deep-ocean mysteries by collecting these migrating
animals in special nets towed behind BBSR's oceanographic vessel, the R/V Weatherbird II. The research team does much of their work at night, when the animals are nearer to the surface and easier to catch. Many of the
animals are invisible to the naked eye. A glance under the microscope, however, reveals a startling and beautiful world filled with animals stranger than any imagined in science fiction!
For animals of this size, swimming upward as far as 1,500 feet each
evening, then returning in the morning, takes a lot of energy and requires traveling tens of thousands of body lengths every day. It would be like a person walking 25 miles each way to get to and from breakfast.
Some of the largest migrators include euphausiids, or "krill," shrimp-like animals that reach a few centimeters in length and are best known for
their importance as food for whales. Other important migrators include the smaller copepods. These "insects of the sea" are the most common and abundant
animals on earth. On average, one copepod inhabits about every single liter of sea water.
Not all of the creatures you see on this page are migrators. Some of them
are true deep-sea fish. Deep-sea dwellers are unlike anything else in the sea. They have adapted to the low light environment in which they live. Some are bioluminecent, meaning they can actually produce their own light!
Others, like the angler fish and viper fish, attract prey to them using bait, and then use their huge jaws and massive teeth to catch and eat the smaller fish.
