Positive Effects!
There are believed to be 46,000 pieces of plastic in every square mile of ocean. Every single plastic bag picked up can save an animals life. ("Plastic Statistics." Ocean Crusaders)
Enviromentalist have created objects that suck up trash directly from ocean.
Images:
1. https://40ddd.wordpress.com/2011/05/16/blog-a-day-15-an-la-day-t-46/
2. http://www.theguardian.com/environment/2012/may/09/pacific-garbage-patch-insect-habits
3. http://www.businessinsider.com/floating-garbage-can-cleans-ocean-2015-12