A tiny crab crawls on plastic retrieved from the Eastern Pacific Garbage Patch in August 2009.
The expedition easily spotted some types of plastic. But a larger problem may lurk below the surface.
The SEAPLEX team collected data on the extent of the garbage patch at the surface and the oceanographic conditions there. But no one knows how prevalent plastic may be below the surface.
What's more, this isn't the world's only vast ocean garbage patch, or even the biggest. Scripps Institution scientists hope to soon visit a massive garbage patch off South America about which even less is known.
Photograph courtesy Scripps Institution of Oceanography