I know! I know its a little aud to bring home a piece of litter plucked from The Colorado River!! But I was fascinated by the travertine deposits on this plastic Gatorade bottle and I wondered if I could find out how long it had been in the canyon’s system.
Travertine is a deposit in the Grand Canyon that looks like icing dripping from the limestone cliffs. When water percolates through the limestone layer it picks up high concentrations of carbon dioxide. This can dissolve carbonate rocks in the groundwater. Once out of the ground and the water is no longer under pressure, the carbon dioxide is released into the atmosphere, allowing the dissolved calcium carbonate to precipitate and form striking travertine drips. It takes thousands of years to form this surface texture so how long did it take to cover a plastic Gatorade bottle? And was the Gatorade bottle left by humans on the land and eventually washed into the river? Or had it traveled a very long time in the river system itself?
My research didn’t exactly answer my questions. Or, at least, not the research I could understand! But I learned a lot about plastic and our waterways.
According to Global Industry Analysts, plastic consumption will reach 297.5 million tons by 2015. Plastic is versatile, lightweight, flexible, moisture resistant, strong, and relatively inexpensive. These attractive qualities have created a voracious over-consumption of plastic goods. Our tremendous attraction to plastic and our behavior of over-consuming, discarding, littering and polluting, has become a combination with a lethal nature. http://www.strategyr.com
Plastic is thought of as a long-lasting pollutant that does not fully break down. Because it is a combination of elements extracted from crude oil then re-mixed in man made combinations unknown to nature, there is no natural system to break them down. The enzymes and the micro organisms responsible for breaking down organic materials don’t recognize plastic. Dr. Katsuhiko Saido, a chemist at Nihon University in Chiba, Japan spoke at a meeting of the American Chemical Society in Washington, D.C. and was the first one to look at what actually happens over time to the tons of plastic waste floating in the oceans. The study presents an alarming fact: plastic waste reputed to be virtually indestructible decomposes with surprising speed, at lower temperatures than previously thought, and as it breaks down it releases toxic substances into the seawater, namely bisphenol A (BPA) and PS oligomer. Since the resin pellets that make plastic are round, shiny, tiny, oily and greasy (basically plastics are solid oil) they can easily absorb hydrophobic contaminants like PCB’s and DDE from the surrounding seawater. The pellets suck up these dangerous toxins with a concentration factor that’s almost 1 million times greater compared to the overall concentration of the chemicals in seawater. All sea creatures, from the largest to the microscopic are swallowing the seawater soup instilled with toxic chemicals from plastic decomposition. We are eating fish that have eaten other fish, which have eaten toxin-saturated plastics. It makes plastic far more deadly in the ocean than it would be on land.
I did find a report from The Marine Conservancy http://www.oceanconservancy.org/our-work/marine-debris that states estimated decomposition rates of most plastic debris found on coasts:
- Foamed plastic cups: 50 years
- Plastic beverage holder: 400 years
- Disposable diapers: 450 year
- Plastic bottle: 450
- Fishing line: 600 years.
These images are saddening but they certainly do express how the buoyancy of our plastic waste is capable of accumulating in our waterways. These and a lot more photos are on the CoastCare site. http://www.coastcare.com.au
Ways you can help:
- Reduce the purchases of single use containers and packaging
- Become diligent about discarding and recycling plastics correctly
- Participate in a beach clean up www.cleanbeaches.com
Until next week,