Rivers, hmm, beautiful. The way the water flows with the wind, in perfect harmony as if these two elements are working together...the way the water reflects mountains and pine trees so fiercy it looks like there's a world underwater (which, in fact there is) is simply stunning.
But water isn't as beautiful now, is it? Ganga and Yamuna are holy rivers. People dive in these to wash off their sins and be clean. But, is it really clean? These days, the water is like a supermarket, a dirty one. Microplastics, wrappers, dirt－you name it, it's there. And it's all our fault. People don't even have a guilty conscience because they weren't taught that water should be clean. It shouldn't be polluted.
Now, imagine taking a shower and an empty Doritos packet falls on your face. You wouldn't like that, would you? Well, neither does marine life. Fish gets stuck in different plastics and they suffer horrible deaths. 
People think that hurting people is bad. Imagine hurting an entire civilization because that's what's happening right now. Ocean water, rivers and ponds are all so polluted with chemicals, plastics and have increased levels of carbon dioxide, subsequently reducing oxygen levels which has been taking a toll on marine life. 

So don't litter. You don't want to have a guity conscience too, do you??