Managing Microplastics in Our Oceans

As after school specials have told us time and time again, the plastic rings around packs of soda shouldn’t be thrown directly in the trash. So we cut them up before throwing them away and feel a glowing sense of environmental gratification. However, sea turtle entanglement is only a very small part of the plastics problem in the sea.

Plastic bags, bottles, packaging, and other knickknacks frequently end up in the ocean, whether they were dumped there intentionally or not. Here, these plastics are broken down into smaller and smaller pieces. This can happen through photodegradation, physical degradation by water movement, and digestion by marine animals. Tiny bits of plastic are havens for bacteria, which use them as private yachts to move around the ocean and collect nutrients. When covered in bacteria, these bits of plastic become especially appetizing to hungry fish. Our plastic consumption has turned into the world’s biggest cruise line, and it offers an all-you-can-eat buffet for marine life.

Making a Dent in the Plastic Patch

Despite this widespread consumption, plastic is not food, and even when broken into smaller pieces it largely remains inedible. Plastic in the oceans is a major issue, and the Great Pacific Garbage Patch is a key example. Here, plastic outweighs zooplankton by a factor of 36:1. Plastic has an astounding impact on the marine food chain. Aside from the harm done by plastic itself, small pieces can attract bacteria, nutrients, and oily chemicals, concentrating these harmful contaminants in the bellies of fish.

Recently, there have been several developments to remediate this problem. Clean Oceans International, based in Santa Cruz, California, aims to skim floating plastics off the surface of the ocean with a specially designed catamaran. The project is targeting the four most common types of plastic: #2HDPE, #4LDPE, #5PP, and #6PS. The catamaran uses a one-fourth inch mesh to skim for plastics, so while current microplastics are not captured, the system does prevent the future breakdown of larger pieces. The Ocean Cleanup project, founded by brainchild Boyan Slat, aims to use the ocean’s currents to collect plastic waste on large, floating booms. These booms catch floating plastic while marine life passes freely underneath. According to the organization, a 62-mile boom would remove 42% of the Great Pacific Garbage Patch in the next 10 years at a cost of only $2.30 a pound. This project will be launched at a pilot scale in the Korea Strait in the second quarter of 2016.

Are these efforts enough to avert our oceans’ plastic problem, or are more efforts needed to target the root of our plastic addiction? With scientists recently doubling the estimates on predicted sea level rise due to climate change, we may find out sooner than we thought.