Science Results : Daily Update

Daily Update | Current SEA Research

July 9, 2010

By Giora Proskurowski

This morning, just after our 0430 neuston tow, we made our last major course change, turning the boat in the direction of Bermuda. We are now in the final leg of our journey, having traveled just about 3000 nautical miles, with a mere 440 nautical miles to go.

As we near the end of the expedition, our sampling scheme changes slightly to accommodate our finite schedule. We will continue doing surface neuston tows four times a day as we transit back to Bermuda, but will spend almost no more time on the wire deploying the CTD or the Tucker trawl. The reason is fairly straightforward – unless the wind changes dramatically (which the forecast suggests it won't) we don't have the station time to devote to doing the extra deployments. As things stand right now, the wind is almost directly behind us – a very slow point of sail for us. We will be doing a significant amount of motor-sailing to make the 100+ miles per day necessary to arrive on time.

Prior to this expedition, SEA's 6400 neuston net tows with plastics data were all conducted west of 57°W longitude. This evening around midnight, we will re-enter this region, after almost a month of sampling in the central Atlantic, an area infrequently studied and never visited by an SEA boat.

Over the course of this expedition we've carefully mapped more than 400,000 square miles for plastic, finding plastic in every single surface tow, sometimes in unbelievable amounts. At the eastern edge of our cruise track we found the highest concentrations of plastics ever documented in any ocean. While one of our main goals was to try to find an eastern boundary to the high concentrations of plastics in the Atlantic, it is safe to say that 40°W is not far enough east.

While we are still in an extremely remote location, this afternoon we had two large ships pass us, both bound for the Gulf of Mexico. The second, the M/V Maersk Constellation, had a friendly American mate on watch, and Captain Chris exchanged pleasantries on Channel 16. The Constellation's mate had just been checking out our Web site, and commented "oh man, you missed it, two days ago, on this watch, we went through a big section of plastic...buckets, crates, everything." Interestingly, given their speed and heading this afternoon – and those big ships rarely alter speed or course in the middle of the ocean, they would have been within several miles of where we encountered the "mother lode" of ocean plastic. It is remarkable that a mate, who has looked at millions of square miles of ocean, singled out a location that we just documented to be one of the highest concentrations of plastic debris anywhere.