Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a lake, sea, ocean or waterway. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing aground, when it is known as beach litter or tidewrack. Deliberate disposal of wastes at sea is called ocean dumping. Naturally occurring debris, such as driftwood, are also present.
With the increasing use of plastic, human influence has become an issue as many types of plastics do not biodegrade. Waterborne plastic poses a serious threat to fish, seabirds, marine reptiles, and marine mammals, as well as to boats and coasts. Dumping, container spillages, litter washed into storm drains and waterways and wind-blown landfill waste all contribute to this problem.
In efforts to prevent and mediate marine debris and pollutants, laws and policies have been adopted internationally. Depending on relevance to the issues and various levels of contribution, some countries have introduced more specified protection policies.
Marine debris injures and kills marine life, interferes with navigation safety, and poses a threat to human health. Our oceans and waterways are polluted with a wide variety of marine debris ranging from soda cans and plastic bags to derelict fishing gear and abandoned vessels.
Marine debris is defined as any persistent solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned into the marine environment or the Great Lakes.
Today, there is no place on Earth immune to this problem. A majority of the trash and debris that covers our beaches comes from storm drains and sewers, as well as from shoreline and recreational activities such as picnicking and beachgoing. Abandoned or discarded fishing gear is also a major problem because this trash can entangle, injure, maim, and drown marine wildlife and damage property.
More on the Problem
Marine debris is any man-made, solid material that enters waterways directly through littering or indirectly via rivers, streams and storm drains. Marine debris can be simple items such as a discarded soda can, cigarette butt, or plastic bag that ends up in the ocean potentially harming marine life. Nearly 80 percent of marine debris originates from land-based sources.
Lost or abandoned commercial and recreational fishing nets, lines, pots, and traps are another form of marine debris, categorized as derelict fishing gear (DFG). These items, whether discarded intentionally or lost accidentally, may sit on the seafloor, get caught on rocky or coral reefs, or float on the ocean surface. The majority of this lost gear does not decompose in seawater and can remain in the marine environment for many years. Often this gear continues to trap and even kill marine animals, a phenomenon known as “ghost fishing.”
With so much trash and litter entering our ocean every year, the problem of preventing and reducing marine debris is an urgent challenge that we must meet to preserve the health of our ocean. Business, government and individuals can make a difference.
Why is Marine Debris a Problem?
Marine debris can kill and injure marine wildlife through ingestion and entanglement, disperse invasive species, endanger human health, cause damage to shipping vessels, and hurt businesses and tourism by polluting our beaches and coastline. Plastic debris is especially threatening because of its ability to absorb and concentrate toxic pollutants.
Entanglement: Common items, such as fishing line or nets, strapping bands and six-pack rings, can hamper the mobility of marine animals. Once entangled, animals have trouble eating, breathing or swimming, all of which can have fatal results.
Ingestion: Birds, fish, and mammals often mistake plastics and other debris for food. Many endangered albatross birds and chicks have been found dead with stomachs full of plastic, including bottle caps and cigarette lighters. Sea turtles mistake plastic bags for jellyfish, one of their favorite foods. With debris filling their stomachs, animals have a false feeling of being full, and may die of starvation.
Disperse invasive species: Marine debris can provide suitable habitat for marine species, such as oysters, barnacles, or plants, to collect upon. As debris is carried away by the currents, so are the inhabitants. This process can potentially speed up the spread of invasive species.
Endanger human health: Beach visitors can be injured by harmful debris on beaches, such as broken glass and sharp metals. Toxic pollutants can also be transferred up the foodchain and consumed by humans.
Hurt businesses and tourism: Increased amounts of debris on popular beaches can make beaches less attractive to visitors, resulting in a decrease in visitation and loss of money to the local community.
Damage to shipping vessels: Marine debris causes damage to shipping vessels through collision, entanglement in propeller blades, and clogging of water intakes for engine cooling systems.
Concentrate toxic pollutants: Plastic debris acts as a sponge for toxic, hormone-disrupting chemicals like Polychlorinated biphenyls (PCBs) and Dichloro-Diphenyl-Trichloroethane (DDT) that reside in seawater. As contaminated plastics break down into small pieces they often resemble food, such as plankton, and are ingested by marine species, entering into the food chain. Studies connected in the North Pacific Central Gyre on fish that feed on plankton found that 35% of the fish had ingested plastic.