One of the main types of marine debris that you hear about today is plastic marine debris. In many places, it is the main type of debris that you will see as you walk along a beach, though perhaps not underwater. As common as they are on our beaches and in our homes, how much do you really know about plastics? As society has developed new uses for plastics, the variety and quantity of plastic items found in the marine environment has increased dramatically. These products range from common domestic material (bags, Styrofoam cups, bottles, balloons) to industrial products (strapping bands, plastic sheeting, hard hats) to lost or discarded fishing gear (nets, buoys, traps, lines).
Plastics can enter into the marine environment a number of ways: through ineffective or improper waste management, intentional or accidental dumping and littering on shorelines or at sea, or through storm water runoff. Eventually, larger plastics will degrade into smaller and smaller pieces.These smaller plastic pieces (smaller than 5mm in size) are termed ‘microplastics’ and also include originally manufactured products such as microbeads found in cosmetics and personal care products, industrial scrubbers used for abrasive blast cleaning, and resin pellets used in the plastic manufacturing process (for more on microplastics, check out this PBS interview with our Chief Scientist). ‘Microfibers’ are another type of microplastic that are generated from washing synthetic clothing made of polyester and nylon (petroleum-based materials).
Plastics are used in many aspects of daily life and are a big part of our waste stream. Many plastics are colorful and will float in water, which makes plastic debris a very visible part of the marine debris problem. However, an accurate estimate does not yet exist for how much debris is composed of plastic materials.