Efforts to directly remove existing microplastics from the waters have been, however, very limited, as reflected in the extremely low quantity of related literature. This is not surprising considering the sheer volume of water in the sea (even coastal areas), making it unrealistic to install any dedicated apparatus for microplastics removal. Nevertheless, some innovative solutions utilizing watercrafts have been proposed. Wartsila Water & Waste from Finland and Grimaldi Group from Italy have collaborated to develop modified sulfur scrubber for cargo ships by adding a microplastics-capturing filter. Microplastic particles can thereby be collected while the ship travels in the ocean. The device is reportedly capable of removing 76 particles from every cubic meter of water. A similar technique was proposed by Suzuki, where a filter is placed in the cooling water return line of a boat's outboard engine to collect microplastic particles. Researchers have also taken advantage of ships' ballast water to remove microplastics. Backflushed water is filtered through devices attached to the ballast water treatment system during deballasting to remove microplastics from water discharged back to the sea. Similarly, Mitsui O.S.K Lines demonstrated a centrifugal filtration system installed on a cargo ship's ballast system. Since the device was connected to the cooling water line, it is operational throughout the entire trip, rather than just at deballasting sites.