Editor's Note: Scuba instructor and underwater videographer Drew Wheeler is traveling on board the Algalita Marine Research Foundation's 50-foot (15.2-meter) Ocean Research Vessel, Alguita, on a two-month voyage to sample and study portions of a 10-million-square-mile (25.9-million-square-kilometer) oval known as the North Subtropical Gyre (aka "Pacific garbage patch"). Wheeler and the rest of the Alguita crew left Long Beach, Calif., on June 10 with a plan to cross the International Date Line and investigate regions of reported high plastic concentrations, northwest of the Hawaiian Islands. This is his fourth blog post for Scientific American.com

July 2, 2009

Over 3,000 miles (4,828 kilometers) traveled.

After a brief three-day pit stop in Honolulu for repairs to the manta trawl [see Wheeler's June 22 entry] and the spinnaker and a little R&R, we departed Oahu around 7 P.M. Monday night (June 30) on what has turned out to be the second leg of our Journey to the Center of the Trash.

Mother Nature once again has different plans for us. The light and variable breezes left us motoring around looking for some real wind. We altered course north to split the islands of Kauai and Niihau through the Kaulakahi channel in search of a low-pressure system north of the islands. On the positive side, we continue to make the best of the situation by sampling in areas that the Alguita has never sampled before.

Our first manta trawl was performed Tuesday night just outside the Papahanaumokuakea Marine National Monument, a 50-mile (80.5-kilometer) boundary around the Northwest Hawaiian Islands. I was surprised to see a noticeable amount of plastic in the only sample we collected, from inch-long pieces to smaller bits. We keep getting plastic everywhere we trawl…even in areas not considered concentration zones. That is rather disturbing when you think about it.

We found an odd juvenile flatfish among the night surface dwellers caught in the trawl; it was the size of a quarter and white as a ghost, almost clear. We continue to find what I would consider "shore" type fish during our samplings that seem to have adapted to a deeper, open-water lifestyle in the debris fields.

On Wednesday (July 1), we were motoring through a "current line"—which occurs when two opposing currents meet and form almost a smooth line on the water's surface—when we came across a golden surface plankton bloom that could best be described as the yellow brick road from the Wizard of Oz. We decided to follow the yellow path, which stretched as far as the eye could see in both directions, to further study the hypothesized correlation between plankton blooms and plastic debris.

Immediately we started seeing debris, so Capt. Charlie [Moore] and Joel [Paschal] took position on the bow as spotters and retrievers with pole nets. [First Mate] Jeff [Ernst] and I were photo and video documenting everything we retrieved, while Nicole [Chatterson] drove the boat and Christiana [Boerger] gathered samples from the debris for later toxicology testing.

That's when I heard someone yell, "Ghost net!" A ghost net is a ball of assorted debris, mostly fishing net, left floating in the ocean that can be very dangerous to an unsuspecting ship's prop or get snagged on the centerboard (a retractable keel which pivots out of a slot in the hull of a sailboat).

During the dive to examine and document the net, I found a plastic bucket lid of some kind with two Sargassum frogfish living in it. It was quite a surprise to find frogfish out so far. But this species has adapted to surviving out in the open ocean. The strangest part of the dive, though, was the eeriness of diving under a thick yellow ceiling of plankton.

To finish off Wednesday (well, really early Thursday morning), I was just getting ready to relieve Jeff to start my watch when we suddenly felt a shudder, and the port engine quit. And then alarms started going off. We hit the "stop engines" control and began a "what-the-heck-just-happened" investigation.

Turned out that we had run over a ghost net (different from the one we removed) after all and fouled the prop. It took almost two hours of cutting for Charlie and me to free the prop, a job that left us pretty tired but also relieved that was all it was. Disaster averted!

Back on course, heading north to the Dateline to continue our Journey to the Center of the Trash…

Images © ScubaDrew VideoWorks & Algalita Marine Research Foundation