There are hundreds of thousands of tons of plastic in the ocean, much of which exists as tiny particles. These microplastics are spread throughout the ocean which makes them excruciatingly difficult to access, find, and remove. For these reasons most ocean plastic clean-up ideas target macroplastics at singular locations which are easy to reach, such as in ports or around estuaries. Such approaches ignore microplastic in the ocean far from the coasts however. The international fleet of cargo ships criss-cross the world’s oceans and process billions of tons of seawater for ballast each year, could these vessels filter out microplastics from the open ocean?