The biggest chunk of garbage in the patch, 46 percent of it, is fishing nets, according to the research. Other types of commercial fishing gear, including eel traps, ropes and oyster spacers account for a majority of the rest of the trash.
Oceanographer and lead researcher with the Ocean Cleanup Foundation Laurent Lebreton told National Geographic scientists wanted to study the bigger pieces of trash in the patch.
“I knew there would be a lot of fishing gear, but 46 percent was unexpectedly high,” Lebreton said. “Initially, we thought fishing gear would be more in the 20 percent range. That is the accepted number [for marine debris] globally - 20 percent from fishing sources and 80 percent from land.”
The fishing nets that litter the world's oceans entangle whales, turtles and seals, and the plastic in the seas kills or injures 100,000 marine animals every year, National Geographic reported.
Researchers said there are still many unknowns about the garbage patch, including the level of plastic pollution in deeper waters and on the sea floor, and that more study is needed,
The findings are part of a three-year mapping effort involving Ocean Cleanup, an international team of scientists, six universities and an aerial sensor company.