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 third blog post for ScientificAmerican.com.

June 23, 2009

Day 14—We Found Plastic!!!

Currently, we are sailing wing and wing downwind on a direct heading to Oahu, Hawaii. Yesterday was a good day despite all that happened with the Manta Trawl because we achieved one of the objectives of our voyage—we found some plastic.

One aspect of the danger of plastic floating in the ocean that fish eat it and then we eat the fish. I don't think I need to say much more about the negative impact of that food chain. So while we sail from test area to test area, we set fishing lines out to see if we can catch some food for the crew—and get some fish to sample for plastic.

Well, yesterday we hooked two Mahi Mahi, and while Christiana [Boerger] was doing her dissection and collection of tissue samples for toxin testing, she also inspected the digestive tract of each fish. In the smaller one (five pounds, or 2.3 kilograms) she found some suspect material that was later confirmed by microscopic inspection to be a piece of plastic.

Now, we can't tell whether the plastic was ingested directly by the fish or through some smaller fish it ate, but there were no obvious remains of a previous meal. The discovery was documented on video so we are pretty pleased with ourselves today.

Image © Drew Wheeler