6 ms·Perhaps larger pieces of plastic contain trapped air that increases their bouyancy.by bagacrap 7y agoPerhaps larger pieces of plastic contain trapped air that increases their bouyancy.carapace 7y agoI'm pretty sure "microplasitcs (sic) tend to sink" is bogus nonsense.hanniabu 7y agoThey also float, it really depends on the buoyancy. I think I heard that most of the microplastics are suspending within 5 meters of the surface.