By: Katie Todoroff

Circulation Sub-tropical Convergence Zone

Concentration of Plastics Sewage, tourism, fishing, waste from ships and boats 9,064 tons of plastic debris Gyre has surface area of 3,625,753 km^2 25,000 pieces of plastic/km^2 Highest concentrations observed in the Sargasso Sea

Garbage Patches located beneath High Pressure Systems Weak winds

Estimation and Modeling Use trajectories of drifting buoys to estimate the rate and location of aggregation Consistent with observations of garbage and defragmented plastic Neuston nets used to collect samples Bottom Trawling Nets also used on the seafloor

Entanglement and Ingestion

Microplastics Undergo photo-oxidative degradation Happens faster on land and ocean surface, extremely slow process at abyssal depths due to lack of UV-rays and colder temperatures Most are not visible to the naked-eye Once surface is degraded, further broken down by stresses in the ocean such as turbulence

Microplastics Persistent Organic Pollutants (POPs)- occur universally in the oceans via runoff POPs are hydrophobic, dissolved in the microplastics and concentrated there Become bioavailable to organisms

Implications to the Marine Food Web Can deliver toxins across trophic levels All types of plankton susceptible- foundation of the marine food web No significant studies yet that quantify the outcomes 1-L plastic water bottle will photo-degrade into enough small pieces to pout once piece on every mile of beach in the world