Origin of Plastic Found on the Shores of the Galapagos Islands

Abstract

Around 8 million tons of plastic end up in the ocean every year. Wind and ocean currents disperse plastic as far as the Arctic and even into deep oceans. Most of the floating plastic is gathered within the gyres, while a significant fraction of it ends up on the ocean surface outside the gyres. The Galapagos Marine Reserve is one of the largest pristine ecosystems in the world and is therefore heavily protected from the excesses of human influence. With around 97% of the islands being off limits to humans, one would expect to find an uncontaminated environment. However, the islands are no strangers to plastic pollution, with even the most isolated ones containing high levels of plastic. In this research we attempt to look into the origin of this plastic. In order to tackle plastic pollution on the shores of Galapagos, we need to find out where all this plastic is coming from and thus enable its removal from the marine environment before it ever reaches the islands. We use Parcels to simulate the trajectories of virtual pieces of plastic originating from North and South America and flowing in the ocean under the effect of geostrofic currents. The results show that most of the plastic debris that ends up within the Galapagos Marine Reserve originates from countries on the west coast of America that are close to the Equator.