Science Results : Daily Update

Daily Update | Current SEA Research

June 22, 2010

By Giora Proskurowski

Life in the lab has slowly returned to normal after what felt like a day in the trenches fighting plastic. Yesterday's morning (0930) tow, actually two tows – one on each side of the Cramer, yielded incredible amounts of plastic. In fact, yesterday's starboard tow contained nearly ten times more plastic pieces than SEA has ever observed in the subtropical gyres of the Atlantic or Pacific Oceans. I believe that the concentration of plastic we sampled yesterday to be greater than anyone has actually sampled in any ocean.

Our starboard tow contained more than 23,000 pieces, which is equivalent to more than 26 million pieces per square kilometer. Before now, 50,000 pieces per square kilometer might be considered a "high concentration" of plastic. But it is important to remember that outside of these accumulation zones in the subtropical gyres, the majority of net tows find no plastic.

The majority of pieces we collected were incredibly small, either like coarse grains of sand or one quarter-inch sections of plastic fibers. The small size made counting, rinsing, and drying of the samples a very time-intensive process. The starboard net took two lab members (rotating every hour or so) more than 14 hours of continuous work to process. The port net, which was towed for less time because a five-gallon bucket was collected, took more than 10 hours for two-person teams to process.

The tiny plastic fragments were piled on the sides of our sorting sieves like snow banks on the side of the road after plowing. It was disgusting to imagine that amount of plastic debris scattered in the ocean surface; and worse to think of these small pieces as snapshot in time of the degradation of large consumer objects to microscopic fragments.

The small patch of ocean we sampled yesterday was truly a "garbage patch", and while I typically refrain from using that phrase, I think it applies in this instance. It was a small patch, within a larger region of high concentrations of plastic, with phenomenally high accumulations of macroplastic (greater than 5 cm) and microplastic (less than 5 cm) debris. I would like to think that this is as bad as it gets, and that those waters were saturated with plastic, but the oceans will always be a mystery and it is impossible to know what the next tow will bring up.