Latest Expedition Journal
October 8: Day 6
Our Plastic Quarry and the Nets We Carry
Three days and almost 400 miles west of California, the rail is now free of slumped crew feeding the fish. From my aft berth, I can hear the deck being scrubbed above. Even though we've passed beyond the shallow edge of the continental shelf, we're still amid cold, northern currents. With the exception of today's afternoon calm, deck workers are dressed in sweaters and wind gear.
We've left the shallow waters and upwellings from the continental shelf along the coast. In place of those productive and opaque waters, we've entered the vivid and clear blue zone of mariners' dreams. Shafts of sunlight penetrate these pellucid waters and glow with the fierce beauty of limitless sapphire.
We're now regularly seeing larger bits of plastic floating on the surface, even though we have not yet reached the gyre—approximately 800 miles offshore. There, amid the eye of this enormous, clockwise swirling Pacific, tiny plastic particles will routinely fill our nets.
No one can yet say with accuracy exactly where the various types of plastic exist within the ocean. We think, for starters, that the majority of this plastic comes from land. And it is widely believed that the tiny plastic particles we'll find near the surface represents a small fraction of the denser and more common plastic that falls toward Davy Jones' Locker. Much of this single-use plastic—such as disposable water bottles—are probably lying on the ocean floor. It's also speculated that plastic particles are suspended in deeper layers below the surface. And potentially toxic plastic is ingested by every species from copepods to whales. Even humans may not be exempt.
This new ecological phenomenon reshaping and (along with acidification) possibly destroying our oceans was created by a manufacturing revolution after World War II. Susan Freinkel (author of Plastic: A Toxic Love Affair) called it, "Plasticville." By the end of the 20th century, our world was drawn into the convenience, economy and availability of new lightweight combs, toothbrushes, and bags—to name only a few of the plethora of plastic that surrounds us in our daily lives. Inherent in the manufacturer-consumer cycle is that we're conditioned to throw plastic away almost immediately. Since the substance is easily manufactured, it can be resold as rapidly as it is thrown away.
Along with every imaginable shape and size, there are thousands of different plastic forms. From the most common polyethylene (bottles, bags, toys), to polystyrene (Styrofoam), to the lesser used acrylics (airplane windows, tail-lights, shower doors). Our quarry is those few plastic "species" that float.
The Robert C. Seamans is equipped with four different nets that will be used for our plastic hunt. Long-handled dip nets will allow us to reach over the rails and scoop up visible pieces of plastic. The neuston net and manta nets both sit on the surface of the water while being towed. Each of them has a cod end that concentrates the sample (ironically enough) into a plastic bottle. They are both towed at 2 knots for 30 minutes to determine the volume of water sampled so that the concentration of plastics can be calculated. Finally, the state-of-the-art MOCNESS net samples below the surface with preprogrammed opening and closing nets. Unlike our other nets, this cable-deployed device—lifted out away from the ship's hull by a hydraulic J-frame, then lowered into the sea—will allow researchers on board to determine if plastics are forced downward by the effects of wind mixing in the ocean.
Although there are many parts to this research and other science projects that we will be learning about in weeks to come, plastic (and resident organisms) are the main quarry, while the nets are the tools that we carry. Welcome to our hunt.