“How fast can the fastest plankton move? How short-lived is the shortest-lived, and how long-lived is the longest-lived plankton?” Plankton has always captured the interest and imaginations of our students, and they are more popular than ever thanks to certain under-the-sea television characters. And well it should be, plankton is extremely important to life both in the ocean and on land. Though most plankton is microscopic, it is responsible for producing a majority of Earth’s oxygen, capturing CO2, and being the base of the oceanic food web.
The first question is, “What is plankton?” Plankton is a category of living things that live in any natural body of water and cannot move or swim against a prevailing current (although they can move). This group of drifters in incredibly diverse, including bacteria, single-celled plants, tiny animals, and even giant jellies! Because this group is so diverse, determining the life-span is difficult. Life-spans may range from a couple of days to several years, to possibly infinity (check out the “immortal jellyfish”)!
The “fastest” plankton, is actually the fastest animal on the planet! With consideration given to its size, the fastest animal is the copepod. “If it were the size of a cheetah, it would be able to run at 2,000 miles per hour” (http://www.classroomatsea.net/facts). The copepod is the model for the famous Plankton character, and our students are always excited to see it here in the San Francisco Bay.
Plankton don’t have to be racers like the copepod to move quickly. Copepods move in small bursts of speed, but like all other plankton, they also drift with the currents. The fastest currents include the Florida Current flowing into the Gulf Stream from the Carribean to the North Atlantic, and the Agulhas Current from Mozambique down the south east coast of South Africa. Both of these currents have pak speeds of about 2m/s.
These currents carry plankton quickly around the ocean. They also carry other things in the water, dispersing them far and wide. Trash, especially plastic, can move in currents just like plankton.
Stewardship action: let the plankton ride the currents, not the plastic! Reduce your plastic use, and make sure plastic ends up in the recycling, not the trash or on the ground!