In 2000 Allan Williams, David Tudor and I did some research on a monitoring regime for marine litter for the MCA. Our worst grade in some harbours and in the Clyde was where the density of litter and other waste was a direct health risk and beyond counting, huge concentrations. Public health and treatment just like the worst oil spills was needed. Look at these images …. Well beyond counting

Roatan marine litter http://www.telegraph.co.uk/news/2017/10/26/shocking-photo-shows-caribbean-sea-choked-death-human-waste/