North Pacific Gyre, commonly referred to as the “Pacific Garbage Patch." Photo: NOAA
This rainbow runner fish, a type of fish commonly consumed by humans, was caught in the Pacific gyre with pieces of plastic found in its gut. Photo: Algalita Marine Research Foundation

Marine debris is simply manmade trash and materials that litter our beaches and oceans. It is estimated that 80% of marine debris comes from land-based sources, while only 20% comes from the sea-based sources, such as from ships and boats.¹ (See examples of ocean and land-based marine debris here. Marine debris is widely recognized as a threat to the marine environment. Despite past efforts to control marine debris, the quantity of trash in the coastal and ocean environment is increasing dramatically world-wide.

The majority of marine debris is comprised of plastic materials. An estimated 60 to 80 percent of all marine debris (and 90 percent of floating debris) is plastic.² The most common items of trash found on beaches include Styrofoam food packaging, cigarette butts, plastic bags, lost fishing gear, plastic bottles and bottle caps, and pre-production plastic pellets, also called “nurdles”.  Plastic is so durable that it can take hundreds of years to break down at sea, and may never truly biodegrade in the ocean.  See our Marine Debris Database on the types of trash we’ve been finding on our beaches.

Marine debris is so ubiquitous, it can be found from remote arctic regions to highly populated urban beaches and inland creeks and streams. This plastic does not biodegrade in sea water; it instead breaks down into infinitely smaller pieces when exposed to sunlight (some particles as small as less than a centimeter) and persists for hundreds of years. Some of the highest concentrations of plastic pollution in the environment are found floating in an area of the Pacific Ocean called the North Pacific Gyre. Commonly referred to as the “Pacific Garbage Patch,” this area is located within a convergence zone where four ocean currents meet.  Scientists are also beginning to study the impact of plastic trash in convergence zones located in the Atlantic Ocean. (For more information please see: Bermuda Institute of Ocean Sciences Atlantic Expedition, the Plastic Ocean Blogspot, Algalita Expedition. Scripps Institution of Oceanography Expedition [Pacific]).

Research by the Algalita Marine Research Foundation shows that the mass of plastic in the North Pacific Gyre has doubled between 1999 and 2008.³ Other researchers have recently confirmed large concentrations of plastic in the Gyre.⁴

Plastic Pollution Kills marine Life and Threatens Human Health

In addition to spoiling the beauty of our beaches and coast, marine debris poses a significant threat to marine life. Marine debris has injured or killed members of at least 267 species world-wide, primarily through ingestion and entanglement.⁵ Sea life that becomes entangled in marine debris, such as lost fishing gear, often suffer from restricted mobility, which increases their susceptibility to predators, and may cause drowning.  

Marine life and seabirds can also ingest plastic fragments and other marine debris, such as lighters, bottle caps, plastic bags, polystyrene pieces and nurdles that are easily confused with their natural food.  Ingesting plastic can clog the digestive systems of these animals and make it difficult to get the proper nutrients needed for survival, often resulting in starvation.  

A study in 2008 conducted by the Algalita Marine Research Foundation in the North Pacific Gyre found plastic in the stomach contents of one-third of nocturnal surface feeding fish collected, such as myctophid fish (commonly known as “lantern fish”).⁶

During this same survey 17 plastic pieces were also found in the stomach contents of a rainbow runner fish, a species that is commonly eaten by humans.

An additional concern about plastic marine debris is its ability to adsorbs, or attach to other chemicals present in the marine environment. Researchers have found concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) present on plastic marine debris particles at nearly one million times background levels.⁷,⁸ This raises concern about whether plastic debris acts as a transporter of toxic chemicals in the marine environment.⁹ The potential for plastics to release adsorbed chemicals to wildlife that ingests them is an emerging area of concern.¹⁰ 

Scientists are expressing concern that plastic additives commonly used in consumer products may also be a source of toxic chemicals in the marine environment. Additives, called “plasticizers”, are routinely added to plastics during the manufacturing process to modify their physical characteristics.  Research has shown that many of these plasticizers, including bisphenol-A, phthalates, styrene, vinyl chloride, and perfluorooctanoate, have serious human health consequences if leached out of the plastic products and ingested.¹¹,¹² Bisphenol-A, for example, commonly found in plastic polycarbonate bottles has been linked to abnormal brain and reproductive system development in infants and children.¹³,¹⁴,¹⁵, Phthalates and bisphenol-A have also been shown to impair development in crustaceans, mollusks, and amphibians at concentration levels that are already present in some marine environments.¹⁶ While the majority of existing research documents the effects of these chemicals on human health, the effects of toxic plastic on the marine environment is an emerging area of research.