Researchers discover why plastic sea garbage accumulates in the same spot

THE reason why plastic dumped in the ocean accumulates in the same spot and creates floating garbage dumps three times bigger than France has been revealed.

The results could mean plastic being stopped before it can get to the huge dumps.

Large systems of circulating currents, known as gyres or vortexes, carry floating debris from the coast to the middle of the oceans, where it remains trapped, scientists have found.

Around eight million pieces of plastic are released into the ocean every day, with single use food and drink wrapping being one of the most common items.

But instead of hugging the shoreline, most of the plastic sinks or finds its way to large garbage patches located in the middle of each ocean region.

The most famous one, known as the Great Pacific Garbage Patch, has a surface area of around 618,000 sq miles or three times the size of France.

Now, researchers at the University of Miami in the United States, have mapped the currents transporting debris from the coasts to the middle of the oceans

Author Dr Philippe Miron said: “We focus on pathways from the coast to the subtropical gyres, from one gyre to another, and from the gyres to the coast.”

The researchers created a mathematical model, known as a Markov chain, using historical data from the trajectories of surface buoys.

This allowed them to calculate the probability of plastic debris floating from one region of the ocean’s surface to another.

Dr Miron said: “Surface debris is released from the coast and distributed according to their location’s share of the global landbased plastic waste entering the ocean.”

To determine where the trash was coming from and whether it would remain trapped, the researchers analysed the connections between garbage patches. The findings were published in the journal Chaos.