Eighty percent of marine pollution comes from land. The biggest source is called nonpoint source pollution. Nonpoint pollution means that the pollution comes from many smaller sources like septic tanks or cars. 

Most plastics enter the ocean through littering or improper recycling. Every year, around 8 million tons of plastic ends up in the ocean. Ocean Gyres are slow moving circular ocean currents that are formed by Earth’s wind patterns. The ocean gyres tend to collect and trap plastics forming garbage patches. The great garbage patch in the pacific ocean contains 1.8 trillion pieces of plastic and is twice the size of texas. It weighs 7 million tons, is up to 9 feet deep.

The garbage patch is filled with billions of microplastics. Microplastics are plastic pieces less than 5mm. Microplastics come from larger plastic debris which degrades into smaller pieces. They’re dangerous to aquatic life such as fish since they may accidentally swallow them.