Marine debris
Marine debris, also known as marine litter, is human created waste
Waste is unwanted or useless materials. In biology, waste is any of the many unwanted substances or toxins that are expelled from living organisms, metabolic waste; such as urea, sweat or feces. Litter is waste which has been disposed of improperly...

 that has deliberately or accidentally become afloat in a lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

, sea
A sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean...

, ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

 or waterway
A waterway is any navigable body of water. Waterways can include rivers, lakes, seas, oceans, and canals. In order for a waterway to be navigable, it must meet several criteria:...

. Oceanic debris tends to accumulate at the centre of gyre
A gyre in oceanography is any large system of rotating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Coriolis Effect; planetary vorticity along with horizontal and vertical friction, which determine the circulation patterns from the wind curl...

s and on coast
A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...

lines, frequently washing aground, when it is known as beach litter or tidewrack. Deliberate disposal of wastes at sea is called ocean dumping.

Some seeming forms of marine debris, such as driftwood
Driftwood is wood that has been washed onto a shore or beach of a sea or river by the action of winds, tides, waves or man. It is a form of marine debris or tidewrack....

, occur naturally, and human activities have been discharging similar material into the oceans for thousands of years. Recently however, with the increasing use of plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

, human influence has become an issue as many types of plastics do not biodegrade
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

. Waterborne plastic poses a serious threat to fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

s, marine reptile
Marine reptile
Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semi-aquatic life in a marine environment.The earliest marine reptiles arose in the Permian period during the Paleozoic era...

s, and marine mammal
Marine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...

s, as well as to boats and coastal habitations. Ocean dumping, accidental container spillages, litter washed into storm drains, and wind-blown landfill waste are all contributing to this problem.

Types of debris

Researchers classify debris as either land or ocean-based; in 1991, the United Nations Joint Group of Experts on the Scientific Aspects of Marine Pollution estimated that up to 80% of the pollution was land-based. A wide variety of anthropogenic
Anthropogeny is the study of human origins. It is not simply a synonym for human evolution, which is only a part of the processes involved in human origins...

 artifacts can become marine debris; plastic bag
Plastic bag
A plastic bag, polybag, or pouch is a type of packaging made of thin, flexible, plastic film, nonwoven fabric, or plastic textile. Plastic bags are used for containing and transporting goods such as foods, produce, powders, ice, magazines, comic books, chemicals and waste.Most plastic bags are...

s, balloon
A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

s, buoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...

s, rope
A rope is a length of fibres, twisted or braided together to improve strength for pulling and connecting. It has tensile strength but is too flexible to provide compressive strength...

, medical waste
Medical waste
Medical waste, also known as clinical waste, normally refers to waste products that cannot be considered general waste, produced from healthcare premises, such as hospitals, clinics, doctors offices, veterinary hospitals and labs.-Europe:...

, glass bottles
Glass Bottles
A glass bottle is a bottle created from glass. Glass bottles can vary in size considerably, but are most commonly found in sizes ranging between about 10ml and 5 liters....

 and plastic bottles, cigarette lighter
A lighter is a portable device used to generate a flame. It consists of a metal or plastic container filled with a flammable fluid or pressurized liquid gas, a means of ignition, and some provision for extinguishing the flame.- History :...

s, beverage can
Beverage can
A beverage can is a tin can designed to hold a specific portion of a beverage. Beverage cans are made of tin-plated steel or aluminium.- History :...

s, styrofoam
Styrofoam is a trademark of The Dow Chemical Company for closed-cell currently made for thermal insulation and craft applications. In 1941, researchers in Dow's Chemical Physics Lab found a way to make foamed polystyrene...

, lost fishing line and nets
Ghost net
Ghost nets are fishing nets that have been left or lost in the ocean by fishermen. These nets, often nearly invisible in the dim light, can be left tangled on a rocky reef or drifting in the open sea. They can entangle fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs, and...

, and various wastes from cruise ships and oil rig
Oil platform
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil and natural gas, and to temporarily store product until it can be brought to shore for refining and marketing...

s are among the items commonly found to have washed ashore. Six pack rings
Six pack rings
Six pack rings or six pack yokes are a set of connected plastic rings that are used in multi-packs of beverage, particularly six packs of beverage cans.-History:...

, in particular, are considered a poster child
Poster child
A poster child is a child afflicted by some disease or deformity whose picture is used on posters or other media as part of a campaign to raise money or enlist volunteers for a cause or organization...

 of the damage that garbage can do to the marine environment.

Studies have shown that eighty percent of marine debris is plastic – a component that has been rapidly accumulating since the end of World War II. Plastics accumulate because they don't biodegrade
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

 as many other substances do; although they will photodegrade
Photodegradation is degradation of a photodegradable molecule caused by the absorption of photons, particularly those wavelengths found in sunlight, such as infrared radiation, visible light, and ultraviolet light. However, other forms of electromagnetic radiation can cause photodegradation...

 on exposure to sunlight, they do so only under dry conditions, as water inhibits photolysis.

Ghost nets

Fishing net
Fishing net
A fishing net or fishnet is a net that is used for fishing. Fishing nets are meshes usually formed by knotting a relatively thin thread. Modern nets are usually made of artificial polyamides like nylon, although nets of organic polyamides such as wool or silk thread were common until recently and...

s left or lost in the ocean by fishermen – ghost net
Ghost net
Ghost nets are fishing nets that have been left or lost in the ocean by fishermen. These nets, often nearly invisible in the dim light, can be left tangled on a rocky reef or drifting in the open sea. They can entangle fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs, and...

s – can entangle fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...

s, sea turtle
Sea turtle
Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...

s, shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s, dugong
The dugong is a large marine mammal which, together with the manatees, is one of four living species of the order Sirenia. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow , was hunted to extinction in the 18th century...

s, crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...

s, seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

s, crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...

s, and other creatures. Acting as designed, these nets restrict movement, causing starvation, laceration and infection, and, in animals that need to return to the surface to breathe, suffocation.

Nurdles and plastics bags

Plastic particles are an increasing cause of water pollution. The particles include nurdles, microbeads from cosmetics products and the breakdown products of plastic litter. Nurdles are pre-production plastic resin pellet typically under in diameter found outside of the typical plastics...

s, also known as mermaids' tears, are plastic pellets typically under five millimetres in diameter, and are a major component of marine debris. They are used as a raw material in plastics manufacturing, and are thought to enter the natural environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

 after accidental spillages. Small plastic fragments are also created by the physical weathering of larger plastic debris. Nurdles strongly resemble fish eggs.

Plastic waste has reached all oceans around the world. This pollution harms and kills an estimated 100,000 sea turtles and marine mammals and 1,000,000 sea creatures each year. Pelagic plastic pieces in the center of our ocean’s gyres outnumber live marine plankton, and are passed up the food chain to reach all marine life. Plastic shopping bag
Plastic shopping bag
Plastic shopping bags, carrier bags or plastic grocery bags are a type of shopping bag made from various kinds of plastic, and are common worldwide. These bags are sometimes called single-use bags, referring to carrying items from a store to a home...

s may clog digestive tracts when consumed and may cause starvation through restricting the movement of food, or by filling the stomach and tricking the animal into thinking it is full. A 1994 study of the seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...

 using trawl nets in the North-Western Mediterranean around the coasts of Spain, France and Italy reported a particularly high mean concentration of debris; an average of 1,935 items per square kilometre. Plastic debris accounted for 77%, of which 93% was plastic bags.

Source of debris

It has been estimated that container ship
Container ship
Container ships are cargo ships that carry all of their load in truck-size intermodal containers, in a technique called containerization. They form a common means of commercial intermodal freight transport.-History:...

s lose over 10,000 containers
Containerization is a system of freight transport based on a range of steel intermodal containers...

 at sea each year (usually during storms). One famous spillage occurred in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 in 1992, when thousands of rubber ducks and other toys
Friendly Floatees
Friendly Floatees are plastic bath toys marketed by The First Years, Inc. and made famous by the work of Curtis Ebbesmeyer, an oceanographer who models ocean currents on the basis of flotsam movements including those of a consignment of Friendly Floatees washed into the Pacific Ocean in...

 went overboard during a storm. The toys have since been found all over the world; Curtis Ebbesmeyer
Curtis Ebbesmeyer
Curtis Charles Ebbesmeyer is an American oceanographer who, in retirement, has studied the movement of flotsam. He came to public attention through his interest in The First Years' rubber ducks a consignment of bath toys washed into the Pacific Ocean in 1992.- Life and career :Ebbesmeyer was born...

 and other scientists have used the incident to gain a better understanding of ocean current
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...

s. Similar incidents have happened before, with the same potential to track currents, such as when Hansa Carrier
Hansa Carrier
The Hansa Carrier is a container ship. On 27 May 1990, en route from Korea to the United States, the ship encountered a storm which caused the loss of twenty-one 40-foot cargo containers south of the Alaska Peninsula, near...

 dropped 21 containers (with one notably containing buoyant Nike shoes). In 2007, MSC Napoli
MSC Napoli
MSC Napoli was a United Kingdom-flagged container ship that was deliberately broken up by salvors after she ran into difficulty in the English Channel on 18 January 2007.-Early history:...

 was beached in the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...

, and dropped hundreds of containers, most of which washed up on the Jurassic Coast
Jurassic Coast
The Jurassic Coast is a World Heritage Site on the English Channel coast of southern England. The site stretches from Orcombe Point near Exmouth in East Devon to Old Harry Rocks near Swanage in East Dorset, a distance of ....

, a World Heritage Site
World Heritage Site
A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...


Though it was originally assumed that most oceanic marine waste stemmed directly from ocean dumping, it is now thought that around four fifths of the oceanic debris is from rubbish blown seaward from landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...

s, and urban runoff washed down storm drain
Storm drain
A storm drain, storm sewer , stormwater drain or drainage well system or simply a drain or drain system is designed to drain excess rain and ground water from paved streets, parking lots, sidewalks, and roofs. Storm drains vary in design from small residential dry wells to large municipal systems...

s. In the 1987 Syringe Tide
Syringe Tide
Syringe Tide refers to a period during 1987-88 in New Jersey, where significant amounts of medical waste and raw garbage washed up onto a stretch of Atlantic Ocean beaches in Jersey Shore communities in Monmouth and Ocean counties. This forced the closing of all the beaches in the two counties...

, medical waste washed ashore in New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

 after having been blown from the Fresh Kills Landfill
Fresh Kills Landfill
The Fresh Kills Landfill was a landfill covering in the New York City borough of Staten Island in the United States. The name comes from the landfill's location along the banks of the Fresh Kills estuary in western Staten Island...

. Even on the remote sub-Antarctic island of South Georgia, fishing related debris made up approximately 80% of plastics have been found washed up and are responsible for the entanglement of large numbers of Antarctic fur seals.

Legality of ocean and river dumping

Ocean dumping is controlled by international law
International law
Public international law concerns the structure and conduct of sovereign states; analogous entities, such as the Holy See; and intergovernmental organizations. To a lesser degree, international law also may affect multinational corporations and individuals, an impact increasingly evolving beyond...

  • The London Convention
    Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter
    The Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972, commonly called the "London Convention" or "LC '72555" and also barbie abbreviated as Marine Dumping, is an agreement to control pollution of the sea by dumping and to encourage regional agreements...

     (1972) – a United Nations
    United Nations
    The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...

     agreement to control ocean dumping
  • MARPOL 73/78
    MARPOL 73/78
    Marpol 73/78 is the International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of 1978....

     – an international convention designed to minimize pollution of the seas, including dumping, oil and exhaust pollution

European law

In 1972 and 1974, conventions were held in Oslo
Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality , it was established on 1 January 1838. Founded around 1048 by King Harald III of Norway, the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King...

 and Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 respectively, and resulted in the passing of the OSPAR Convention
Convention for the Protection of the Marine Environment of the North-East Atlantic
The or OSPAR Convention is the current legislative instrument regulating international cooperation on environmental protection in the North-East Atlantic. It combines and up-dates the 1972 Oslo Convention on dumping waste at sea and the 1974 Paris Convention on land-based sources of marine pollution...

, an international treaty controlling marine pollution in the north-east Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 around Europe. A similar Barcelona Convention
Barcelona Convention
The 1976 Barcelona Convention for Protection against Pollution in the Mediterranean Sea is a regional convention to prevent and abate pollution from ships, aircraft and land based sources in the Mediterranean Sea. This includes, but is not limited to, dumping, run-off and discharges...

 exists to protect the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

. The Water Framework Directive
Water framework directive
The Water Framework Directive is a European Union directive which commits European Union member states to achieve good qualitative and quantitative status of all water bodies The Water Framework Directive (more formally the Directive 2000/60/EC of the European Parliament and of the Council of 23...

 of 2000 is a European Union directive committing EU member states
Member State of the European Union
A member state of the European Union is a state that is party to treaties of the European Union and has thereby undertaken the privileges and obligations that EU membership entails. Unlike membership of an international organisation, being an EU member state places a country under binding laws in...

 to make their inland and coastal waters free from human influence. In the United Kingdom, the Marine and Coastal Access Act is designed to "ensure clean healthy, safe, productive and biologically diverse oceans and seas, by putting in place better systems for delivering sustainable development of marine and coastal environment".

United States law

In 1972, the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

 passed the Ocean Dumping Act, giving the Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

 power to monitor and regulate the dumping of sewage sludge, industrial waste, radioactive waste and biohazardous materials into the nation's territorial waters. The Act was amended sixteen years later to include medical wastes. It is illegal to dispose of any plastic in all US waters. In 2008, the California State Legislature
California State Legislature
The California State Legislature is the state legislature of the U.S. state of California. It is a bicameral body consisting of the lower house, the California State Assembly, with 80 members, and the upper house, the California State Senate, with 40 members...

 considered several bills
Bill (proposed law)
A bill is a proposed law under consideration by a legislature. A bill does not become law until it is passed by the legislature and, in most cases, approved by the executive. Once a bill has been enacted into law, it is called an act or a statute....

 aimed at reducing the sources of marine debris, following the recommendations of the California Ocean Protection Council.

Ownership of debris

Property law
Property law
Property law is the area of law that governs the various forms of ownership in real property and in personal property, within the common law legal system. In the civil law system, there is a division between movable and immovable property...

, admiralty law
Admiralty law
Admiralty law is a distinct body of law which governs maritime questions and offenses. It is a body of both domestic law governing maritime activities, and private international law governing the relationships between private entities which operate vessels on the oceans...

, and the law of the sea
United Nations Convention on the Law of the Sea
The United Nations Convention on the Law of the Sea , also called the Law of the Sea Convention or the Law of the Sea treaty, is the international agreement that resulted from the third United Nations Conference on the Law of the Sea , which took place from 1973 through 1982...

 may be of relevance when lost, mislaid, and abandoned property
Lost, mislaid, and abandoned property
Lost, mislaid, and abandoned property are categories of the common law of property which deals with personal property which has left the possession of its rightful owner without having directly entered the possession of another person...

 is found at sea. Salvage law
Marine salvage
Marine salvage is the process of rescuing a ship, its cargo, or other property from peril. Salvage encompasses rescue towing, refloating a sunken or grounded vessel, or patching or repairing a ship...

 has as a basis that a salvor should be rewarded for risking his life and property to rescue the property of another from peril. On land the distinction between deliberate and accidental loss led to the concept of a "treasure trove
Treasure trove
A treasure trove may broadly be defined as an amount of money or coin, gold, silver, plate, or bullion found hidden underground or in places such as cellars or attics, where the treasure seems old enough for it to be presumed that the true owner is dead and the heirs undiscoverable...

". In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, shipwrecked goods should be reported to a Receiver of Wreck
Receiver of Wreck
The Receiver of Wreck is an official who administers law dealing with wreck and salvage in some countries having a British administrative heritage.-Countries having a Receiver of Wreck:...

, and if identifiable, they should be returned to their rightful owner.

The Great Pacific Garbage Patch

Once waterborne, debris is far from immobile. Flotsam can be blown by the wind, or follow the flow of ocean current
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...

s, often ending up in the middle of oceanic gyres where currents are weakest. The Great Pacific Garbage Patch
Great Pacific Garbage Patch
The Great Pacific Garbage Patch, also described as the Pacific Trash Vortex, is a gyre of marine litter in the central North Pacific Ocean located roughly between 135°W to 155°W and 35°N to 42°N...

 is one such example of this, comprising a vast region of the North Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 rich with anthropogenic wastes. Estimated to be double the size of Texas, the area contains more than 3 million tons of plastic. This means that there are approximately six pounds of plastic for every pound of plankton per cubic meter of seawater. The mass of plastic in our oceans may be as high as one hundred million ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...


An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

s situated within gyres frequently have their coastlines ruined by the waste that inevitably washes ashore; prime examples are Midway
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...

  and Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

. Clean-up teams around the world patrol beaches to clean up this environmental threat.

North Atlantic Garbage Patch

The currently next biggest known marine garbage patch is the North Atlantic Garbage Patch, estimated to be some hundreds of kilometres across in size.

Environmental impact

Many animals that live on or in the sea consume
Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffix -vore from Latin vorare, meaning 'to devour', or phagy, from Greek φαγειν, meaning 'to eat'.-Evolutionary history:...

 flotsam by mistake, as it often looks similar to their natural prey. Plastic debris, when bulky or tangled, is difficult to pass, and may become permanently lodged in the digestive tracts of these animals, blocking the passage of food and causing death through starvation or infection. Tiny floating particles also resemble zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...

, which can lead filter feeder
Filter feeder
Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...

s to consume them and cause them to enter the ocean food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

. In samples taken from the North Pacific Gyre
North Pacific Gyre
The North Pacific Gyre, located in the northern Pacific Ocean, is one of the five major oceanic gyres. This gyre comprises most of the northern Pacific Ocean. It is the largest ecosystem on our planet...

 in 1999 by the Algalita Marine Research Foundation, the mass of plastic exceeded that of zooplankton by a factor of six.

Toxic additives used in the manufacture of plastic materials can leach out into their surroundings when exposed to water. Waterborne hydrophobic pollutants collect and magnify on the surface
Adsorption is the adhesion of atoms, ions, biomolecules or molecules of gas, liquid, or dissolved solids to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. It differs from absorption, in which a fluid permeates or is dissolved by a liquid or solid...

 of plastic debris, thus making plastic far more deadly in the ocean than it would be on land. Hydrophobic contaminants are also known to bioaccumulate
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...

 in fatty tissues, biomagnifying
Biomagnification, also known as bioamplification or biological magnification, is the increase in concentration of a substance that occurs in a food chain as a consequence of:* Persistence...

 up the food chain and putting great pressure on apex predator
Apex predator
Apex predators are predators that have no predators of their own, residing at the top of their food chain. Zoologists define predation as the killing and consumption of another organism...

s. Some plastic additives are known to disrupt the endocrine system
Endocrine system
In physiology, the endocrine system is a system of glands, each of which secretes a type of hormone directly into the bloodstream to regulate the body. The endocrine system is in contrast to the exocrine system, which secretes its chemicals using ducts. It derives from the Greek words "endo"...

 when consumed; others can suppress the immune system or decrease reproductive rates.

Not all anthropogenic
Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity and other resources. The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian...

 artefacts in the oceans are harmful however. Iron and concrete do little damage to the environment as they are generally immobile, and can even be used as scaffolding for the creation of artificial reef
Artificial reef
An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block ship passage, or improve surfing....

s, increasing the biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

 of a coastal region. Entire ships have been deliberately sunk in coastal waters for that purpose. Some organisms have adapted
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....

 to live on mobile plastic debris, which has allowed the inhabitants to disperse all over the world and become invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

 in remote ecosystems.

Debris removal

A variety of techniques are used to collect and remove marine (or riverine) debris by concerned jurisdictions or volunteer organizations. Besides collection by hand, some cities operate special beach-cleaning machines
Beach cleaner
A beach cleaner is a vehicle that drags a raking or sifting device over beach sand to remove rubbish and other foreign matter. Beach cleaners are either manually hand-drawn or pulled by quad-bike or tractor. Seaside cities use beach cleaning machines to combat the problems of litter left by beach...

 that collect trash deposited by the sea along the coast line. Other places (e.g. Baltimore
Baltimore is the largest independent city in the United States and the largest city and cultural center of the US state of Maryland. The city is located in central Maryland along the tidal portion of the Patapsco River, an arm of the Chesapeake Bay. Baltimore is sometimes referred to as Baltimore...

) arrange for picking debris while it is still floating; such activities are often undertaken regularly where floating debris are perceived to pose danger to navigation. For example, the US Army Corps of Engineers reports removing 90 tons of "drifting material" from San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...

 shipping lanes etc. every month. The Corps has been doing this work since 1942,
when a seaplane
A seaplane is a fixed-wing aircraft capable of taking off and landing on water. Seaplanes that can also take off and land on airfields are a subclass called amphibian aircraft...

 carrying Admiral Chester W. Nimitz collided with a piece of floating debris and sank, resulting in the death of its pilot.

Elsewhere, various kinds of "trash traps" are installed on small rivers flowing into the sea, to capture waterborne debris before it reaches the sea. For example, South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

's Adelaide
Adelaide is the capital city of South Australia and the fifth-largest city in Australia. Adelaide has an estimated population of more than 1.2 million...

 operates a number of such traps, known as "trash racks" or "gross pollutant traps" on the Torrens River, which flows (during the wet season) into Gulf St Vincent.

External links

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