How Can Plastic on the Sea Surface Affect Our Climate?

Plastic particles from packaging, personal care products, synthetic clothing, and many other applications, are a potential risk to the ocean's health. Tiny, light particles of plastic can float on the sea surface for a long time. The sea surface is a special place: it is rich in chemical compounds produced by marine organisms below. Sometimes these substances make the sea surface appear as a shining, darker or brighter layer. The sea surface also connects the ocean and the atmosphere and controls important exchanges between those two systems, including the flow of oxygen, which is an essential element for life, and the flow of carbon dioxide, one of the main gases responsible for climate change. Plastic particles can increase the amount of chemical compounds in the sea surface layer, because marine microorganisms (like bacteria) may be more productive in the presence of plastic particles than they are in plastic-free environments. This increased production and bacterial activity can reduce the oxygen content of the water. We did a simple experiment to explore this mechanism.