Sea Monkeys have helped researchers to discover biotic causes for the motion of the ocean. Water flow has always been attributed to large physical phenomena such as wind, tides and global currents, but biotic factors could also contribute to mass water movement. A new study shows that small organisms swimming in the oceans could be shifting huge amounts of water.
Researchers from Caltech University used lasers to herd brine shrimp to different areas of a tank. As the little creatures swim their waving legs push and pull the water. Sensors in the tank tracked the movement of water caused by the swimming shrimp. The water held silver-coated, hollow glass spheres which illuminated the flow. The data proved that small organisms can cause mass movement of water.
Brine shrimp live in salt lakes or salt flats and can enter a state of suspended animation when the water in their environment dries up. Because of this cryptobiosis they became a popular toy in the 1960s. They were named Sea Monkeys for marketing purposes, because shrimp eggs do not sound as fun, and they entertained children with the idea of instant life. The natural species of brine shrimp also make good test subjects for laboratory studies.
Sea Monkeys breath through their feet, are hatched with one eye but grow two more, and are very to sensitive to light and movement. One reason they entertained children was that a ripple on the surface or a flashlight shone into the water would instantly attract the shrimp. They move towards any light source. The researches rounded them up with blue and green lasers. The video of the shrimp responding to the lasers demonstrates the appeal of the minuscule sea monsters as well as provides evidence of how they move the water around them.
Although brine shrimp do not live in the oceans, the data collected from this experiment can be extrapolated and applied to krill and copepods. The idea for the research came from co-author John Dabiri, a fluid dynamicist at Caltech who observed jellyfish carrying water along as they swam.
Water in the ocean needs to be constantly mixed. Nutrients, heat and salt must be stirred and transported. The ocean does not have an even consistency. Deeper water is colder and surface water is heated by the sun. The water layers must be blended to transfer the heat. Not only is this important to marine life, but the oceans work as the earth’s central heating and cooling system and regulate the temperature of the atmosphere. Of course, density, wind, tides and currents all have the effect of stirring the oceans, but the Caltech scientists believe tiny crustaceans and plankton could also play a part in commingling ocean characteristics.
Krill, copepods and other plankton swim in vertical migration patterns. They move up and down through the ocean in dense layers of living, pulsating divers. Marine biologists once considered these tiny animals drifters; dependent on the whim of the water. More recent research indicates their short migrations are independent and purposeful. This new study goes further in theorizing that their movement has an effect on the overall motion of the ocean’s waters.
As an animal propels itself through the ocean, it pulls some of the water along for the ride. Experiments with jellyfish in 2009 showed that the water was carried along the length of the jellyfish journey, sometimes 1.600 feet. Large fish and marine mammals can push along larger amounts of liquid, but there are not nearly as many of them as there are plankton. Despite their tiny size, the sheer numbers of plankton could account for significant global mixing of the ocean layers. They do not swim across the ocean, but some organisms may ascend and descend through the layers of water hundreds of times a day. Others move en masse upward during the day to feed and sink back to the depths at night. Each organism does not move much water very far, but all together they have a powerful effect. Their movement may work like a giant blender on the ocean’s waters.
Sea Monkeys helped discover the biotic causes for the motion of the ocean. Studies in the open ocean with species that naturally reside there are the next step to supporting Dabiri’s theory. Marine organisms may be responsible for as much as one third of the ocean’s small currents. If so, their populations and locations may be essential for understanding climate.
By: Rebecca Savastio