A study has measured the amount of plastic debris found in a region of the Atlantic Ocean over a 22-year period.US researchers, writing in Science, suggest the volume of plastic appeared to have peaked in recent years.
One reason could be tighter marine pollution rules that prevent vessels dumping their waste at sea.
The team said monitoring the free-floating plastic also provided an insight into the behaviour of ocean surface currents.
They found plastic, most pieces measuring no more than a few millimetres, in more than 60% of 6,136 samples collected by dragging fine-meshed nets along the ocean's surface.
The researchers - from the US-based Sea Education Association (Sea), Woods Hole Oceanographic Institution and the University of Hawaii - described plastic as a "major contaminant".
"Their chemically engineered durability and slow rate of biodegradation allow these synthetic polymers to withstand the ocean environment for years to decades or longer."
The impacts caused by the debris include:
- sea animals becoming entangled
- seabirds and other marine creatures eating the plastic
- the debris being used as a "life raft" by some species to reach areas outside their normal distribution range
"While high concentrations of floating plastic debris have been found in the Pacific Ocean, only limited data exist to quantify and explain the geographical range," they said.
"In the Atlantic Ocean, the subject has been all but ignored."
"In the Atlantic Ocean, the subject has been all but ignored."
