In a coastal marine sanctuary, human industrial and recreational activities resulted in 480,000 kilograms of synthetic polymer waste entering the waters in a single year. The graph below shows the mass of this waste (in thousands of kilograms) caused specifically by commercial fishing nets, car tyre particles, and recreational beach litter.
Calculate the mass of synthetic polymer waste, in kilograms, entering the marine sanctuary from human activities other than commercial fishing nets, car tyre particles, or recreational beach litter.
Give two conclusions that can be made from the data in the graph.
