Go with the Flow

Friendly Floatees, the Global Ocean Conveyor and Our Part in All of It

Lessons Learned from Rubber Duckies

Oceanographer Curtis Ebbesmeyer tracked the trajectory of the “Friendly Floatees” to monitor ocean currents.

The First Years Inc. always expected its line of plastic bath toys to end up in water, but it never dreamed they would ride ocean currents 17,000 miles around the world. In January 1992, a shipment of 29,000 plastic yellow ducks, blue turtles, red beavers and green frogs washed into the Pacific Ocean on the way from Hong Kong, China, to Washington, USA. The container broke open, and the packaging quickly deteriorated, sending the toys on a journey that would teach us what we know today about our oceans’ currents.

Scientists had tracked the routes of previous flotsam, but this shipment was particularly helpful due to its size. With a 2 percent recovery rate, experts estimated that approximately 600 of these “Friendly Floatees” would be recovered. This compares to the 10 or so bottles they expected to recover from the planned release of 500 to 1,000 drift bottles.

Newspaper articles and ads alerted beachcombers of the bath toys’ impending arrival, and The First Years offered a $100 savings bond for their recovery. Eventually, beachcombers started discovering Friendly Floatees on the shores of Hawaii, Alaska, South America, Australia and the Pacific Northwest. Fifteen years after the spill—some of which were spent trapped in Arctic ice—the bath toys appeared in England. Others traveled as far as Scotland and Newfoundland.

Using computer simulation of ocean currents to map the toys’ journey, experts were able to determine the speed of these currents and how long it takes objects to complete a full circuit around the North Pacific Gyre. Today, around 2,000 of the bath toys are still bobbing in the currents of the North Pacific Gyre, where they’re most likely trapped in the Great Pacific Garbage Patch, a dense mass of marine debris.

Understanding the Global Ocean Conveyor Belt

Deep underwater currents are powered by a process called thermohaline circulation, which distributes heat and moisture throughout our oceans. Also known as the global ocean conveyor belt, this system of deep-ocean circulation is generated by temperature and salinity.

Though its force is 16 times stronger than all of the world’s rivers combined, the conveyor belt churns at a much slower speed than wind-driven or tidal currents, taking nearly 1,000 years to complete a single cycle.

To understand how it works, it’s important to know that water density depends on temperature and salinity. The colder and saltier the water, the denser it is. So when water reaches the poles, it freezes, but all of the salt doesn’t freeze with it, so the cold, salty water that’s left behind sinks to the bottom of the ocean. More water rushes in to take its place, creating a current. This new water continues the cycle as it gets cold and sinks.

Powered by this system, the ocean’s water travels south, between Africa and South America, around the edge of Antarctica and then splits into two sections: One travels into the Indian Ocean, while the other moves into the Pacific Ocean. Both move northward toward the equator, and then loop back southward and westward to the South Atlantic, eventually meeting again in the North Atlantic, where the cycle repeats.

The conveyor belt plays an essential role in our oceans’ ecosystems, distributing nutrients throughout our planet’s waters and helping support the world’s food chain.

Your Role

Research suggests that climate change may pose a serious threat to our global ocean conveyor belt. Global warming has the potential to cause an influx of warm freshwater onto the sea surface due to increased rainfall in the North Atlantic and the melting of glaciers and sea ice. This unusual influx of warm freshwater into the North Atlantic could prevent sea ice from forming, potentially disrupting the thermohaline cycle.

Without the heat delivered by our ocean currents, NASA estimates that the average temperature in Europe could plummet 9 to 18 degrees Fahrenheit, with North America experiencing slightly less of a temperature drop.

The science isn’t conclusive about when this might happen—it could be in a couple of decades, or it may never happen at all. But considering the number of problems already associated with climate change, it’s worth making an effort to reduce your carbon footprint. To make an impact in your own life, try these tips:

  • Be more energy-efficient. Swap out your old light bulbs for compact fluorescents or LEDs.
  • Leave the car at home. Walk, bike or take publication transportation to work whenever possible.
  • Eat locally and sustainably. Bonus: You’re supporting your local economy.
  • Compost kitchen scraps and garden trimmings.
  • Recycle paper, plastic, metal and glass to prevent the buildup of garbage in landfills, which produces methane.

Visit 48DaysofBlue.com to learn more simple ways to change your lifestyle for the good of the planet. http://48daysofblue.com/

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