School Email Exchange

What is the largest concentration of plastics you have found so far?

Posted on October 29 2012

Question submitted by King Philip Regional High School

The largest concentration of plastics we have found so far has been nicknamed the “Windrow Tow”.  Just after breakfast on October 16th people on deck started noticing a lot more large and small pieces of plastic than usual.  After a short while we sailed out of the area of high concentration.  We decided to turn the Seamans around realizing we had just gone through a plastic “patch”.  Back in the patch we spent the rest of the morning collecting plastics of all sizes using dip nets, the boat hook, and the neuston net.

The plastic contents of a dip net from the windrow tow, mixed with Porpita porpita and round blue siphonophores, awaits the sharp eyes and tweezers of a plastics counter.

It was determined that the patch was in a windrow.  Using tweezers, a sieve, and a lot of patience, it took more than two days to get to the final count of plastic brought aboard.  The windrow tow had 24,217 pieces of plastic of all sizes, which is equivalent to a concentration of 12 million pieces per square kilometer.  We were excited to find such a large patch of plastic and at the same time quite discouraged because of the amount of pollution found.

The last 7,000 pieces of plastic from the windrow tow were estimated using this grid method.  Photo by Jon Waterman