After 20 days and 3,000 miles on the high seas, SEAPLEX (Scripps Environmental Accumulation of Plastic Expedition) returned to La Jolla from the North Pacific Ocean Gyre (aka the Pacific Ocean Garbage Patch) with enough material to occupy them for at least six months with sample analysis and subsequent data reporting.
At a press conference on Thursday at Scripps Institution of Oceanography at UCSD, displays of plastic bottles, buckets, ropes, and tangled nets collected in a 1,700-mile area provided graphic evidence of an open-ocean environmental problem a thousand miles from land.
They found plastic debris in each of 100 consecutive net tows of the water surface during the voyage.
"It's shocking to find what you're looking for over and over again," said Miriam Goldstein, chief scientist of the SEAPLEX expedition.
Goldstein was quick to point out that the vast majority of pieces observed and collected were fragments less than a quarter inch in diameter (size of a thumbnail). Larger objects provide an unnatural home remote from land for organisms such as barnacles and crabs. This, in turn, attracts fish and birds.
The SEAPLEX science team, many of them graduate students, will perform a wide range of analytical studies on the collected samples including assessments of debris density, type, and size in high-plastic areas as well as conducting toxicology tests of tissue samples and gut contents of fish and birds to determine the ecological impacts of ingested plastics.
The North Pacific Ocean Gyre is one of five major areas in the world's oceans where large-scale trade winds create a whirlpool of currents which can drive and accumulate water-borne debris.
Since the announcement earlier this month of the SEAPLEX voyage the national news media and public have followed the expedition via a daily ship-board blog.
"This is an unusual news conference," said Tony Haymet, SIO director. "But the public interest in this cruise has been so high.(We want) to acknowledge our wonderful students and our partners who have really taken up the burden of explaining this international problem."
The SEAPLEX expedition received financial support from the UC Ship Funds, National Science Foundation, and Project Kaisei (www.projectkaisei.org).
"This is the first collaborative voyage to understand where efforts, knowledge, and funds may need to be deployed to speed the world's ability to fix the issues of marine debris and pollution which have long been neglected," said Doug Woodring, Project Kaisei co-founder.
"The work is ahead of us," said Haymet, who announced that Scripps would mount another expedition, this time to the Southern Pacific Gyre a seldom visited part of the world with a water surface area four times the size of France. That voyage is expected to take place in late 2010 or early 2011.