Marine debris, also known as marine litter, is human-created solid material that has deliberately or accidentally been released in seas or the ocean. 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 and drift seeds, are also present. With the increasing use of plastic, human influence has become an issue as many types of (petrochemical) plastics do not biodegrade quickly, as would natural or organic materials. The largest single type of plastic pollution (~10%) and majority of large plastic in the oceans is discarded and lost nets from the fishing industry. Waterborne plastic poses a serious threat to fish, seabirds, marine reptiles, and marine mammals, as well as to boats and coasts.
Plastic recycling is the processing of plastic waste into other products. Recycling can reduce dependence on landfill, conserve resources and protect the environment from plastic pollution and greenhouse gas emissions. Recycling rates lag behind those of other recoverable materials, such as aluminium, glass and paper. From the start of plastic production through to 2015, the world produced around 6.3 billion tonnes of plastic waste, only 9% of which has been recycled and only ~1% has been recycled more than once. Of the remaining waste, 12% was incinerated and 79% was either sent to landfills or lost to the environment as pollution.
Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although marine transportation significantly contributes as well. It is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide. Since most inputs come from land, either via the rivers, sewage or the atmosphere, it means that continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor by carrying off iron, carbonic acid, nitrogen, silicon, sulfur, pesticides or dust particles into the ocean. The pollution often comes from nonpoint sources such as agricultural runoff, wind-blown debris, and dust. These nonpoint sources are largely due to runoff that enters the ocean through rivers, but wind-blown debris and dust can also play a role, as these pollutants can settle into waterways and oceans. Pathways of pollution include direct discharge, land runoff, ship pollution, bilge pollution, atmospheric pollution and, potentially, deep sea mining.
The Great Pacific garbage patch is a garbage patch, a gyre of marine debris particles, in the central North Pacific Ocean. It is located roughly from 135°W to 155°W and 35°N to 42°N. The collection of plastic and floating trash originates from the Pacific Rim, including countries in Asia, North America, and South America.
Beach wrack or marine wrack is organic material and other debris deposited at high tide on beaches and other coastal area. This material acts as a natural input of marine resources into a terrestrial system, providing food and habitat for a variety of coastal organisms.
A garbage patch is a gyre of marine debris particles caused by the effects of ocean currents and increasing plastic pollution by human populations. These human-caused collections of plastic and other debris are responsible for ecosystem and environmental problems that affect marine life, contaminate oceans with toxic chemicals, and contribute to greenhouse gas emissions. Once waterborne, marine debris becomes mobile. Flotsam can be blown by the wind, or follow the flow of ocean currents, often ending up in the middle of oceanic gyres where currents are weakest.
Marine plastic pollution is a type of marine pollution by plastics, ranging in size from large original material such as bottles and bags, down to microplastics formed from the fragmentation of plastic material. Marine debris is mainly discarded human rubbish which floats on, or is suspended in the ocean. Eighty percent of marine debris is plastic. Microplastics and nanoplastics result from the breakdown or photodegradation of plastic waste in surface waters, rivers or oceans. Recently, scientists have uncovered nanoplastics in heavy snow, more specifically about 3,000 tons that cover Switzerland yearly.
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be molded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to their widespread use. Plastics typically are made through human industrial systems. Most modern plastics are derived from fossil fuel-based chemicals like natural gas or petroleum; however, recent industrial methods use variants made from renewable materials, such as corn or cotton derivatives.
The North Atlantic garbage patch is a garbage patch of man-made marine debris found floating within the North Atlantic Gyre, originally documented in 1972. A 22-year research study conducted by the Sea Education Association estimates the patch to be hundreds of kilometers across, with a density of more than 200,000 pieces of debris per square kilometer. The garbage originates from human-created waste traveling from rivers into the ocean and mainly consists of microplastics. The garbage patch is a large risk to wildlife through plastic consumption and entanglement.
Microplastics are fragments of any type of plastic less than 5 mm (0.20 in) in length, according to the U.S. National Oceanic and Atmospheric Administration (NOAA) and the European Chemicals Agency. They cause pollution by entering natural ecosystems from a variety of sources, including cosmetics, clothing, food packaging, and industrial processes.
Recycling can be carried out on various raw materials. Recycling is an important part of creating more sustainable economies, reducing the cost and environmental impact of raw materials. Not all materials are easily recycled, and processing recyclable into the correct waste stream requires considerable energy. Some particular manufactured goods are not easily separated, unless specially process therefore have unique product-based recycling processes.
The majority of environmental issues affecting Hawaii today are related to pressures from increasing human and animal population and urban expansion both directly on the islands as well as overseas. These include the unsustainable impacts of tourism, urbanization, implications of climate change such as sea level rise, pollution, especially marine plastic pollution, and invasive species.
Plastic pollution is the accumulation of plastic objects and particles in the Earth's environment that adversely affects humans, wildlife and their habitat. Plastics that act as pollutants are categorized by size into micro-, meso-, or macro debris. Plastics are inexpensive and durable, making them very adaptable for different uses; as a result, manufacturers choose to use plastic over other materials. However, the chemical structure of most plastics renders them resistant to many natural processes of degradation and as a result they are slow to degrade. Together, these two factors allow large volumes of plastic to enter the environment as mismanaged waste which persists in the ecosystem and travels throughout food webs.
The plastisphere is a human-made ecosystem consisting of organisms able to live on plastic waste. Plastic marine debris, most notably microplastics, accumulates in aquatic environments and serves as a habitat for various types of microorganisms, including bacteria and fungi. As of 2022, an estimated 51 trillion microplastics are floating in the surface water of the world's oceans. A single 5mm piece of plastic can host 1,000s of different microbial species. Some marine bacteria can break down plastic polymers and use the carbon as a source of energy.
John McGeehan is a Scottish research scientist and professor of structural biology. He was director of the Centre for Enzyme Innovation (CEI) at the University of Portsmouth until 2022 and is now a Principal Scientist at the National Renewable Energy Laboratory (NREL), Colorado, USA.
China's waste import ban, instated at the end of 2017, prevented foreign inflows of waste products. Starting in early 2018, the government of China, under Operation National Sword, banned the import of several types of waste, including plastics with a contamination level of above 0.05 percent. The ban has greatly affected recycling industries worldwide, as China had been the world's largest importer of waste plastics and processed hard-to-recycle plastics for other countries, especially in the West.
Roland Geyer is professor of industrial ecology at the Bren School of Environmental Science and Management, University of California at Santa Barbara. He is a specialist in the ecological impact of plastics.
Sustainable Development Goal 14 is about "Life below water" and is one of the 17 Sustainable Development Goals established by the United Nations in 2015. The official wording is to "Conserve and sustainably use the oceans, seas and marine resources for sustainable development". The Goal has ten targets to be achieved by 2030. Progress towards each target is being measured with one indicator each.
Plastic sequestration is a means of plastic waste management that secures used plastic out of industry and out of the environment into reusable building blocks made by manual compaction. Plastic sequestration is motivated by environmental protection and modeled on the Earth's process of carbon sequestration. Emerging out of the struggle of towns and communities in the Global South to deal with plastic pollution, plastic sequestration compaction methods are characterized by being locally based, non-capital, non-industrial and low-tech. Plastic sequestration is defined by the goals of securing plastic out of the environment and out of high energy/carbon industrial systems. Based on eliminating the chemical and physical and abiotic and biotic degradation pathways, plastic sequestration aims to achieve these goals, by terminally reducing the net surface area of thin film plastics. The building blocks that emerge from plastic sequestration are used in applications that further protect from degradation and permanently keep plastic out of industrial processes, thereby preventing their carbon emissions.
Plastic degradation in marine bacteria describes when certain pelagic bacteria break down polymers and use them as a primary source of carbon for energy. Polymers such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) are incredibly useful for their durability and relatively low cost of production, however it is their persistence and difficulty to be properly disposed of that is leading to pollution of the environment and disruption of natural processes. It is estimated that each year there are 9-14 million metric tons of plastic that are entering the ocean due to inefficient solutions for their disposal. The biochemical pathways that allow for certain microbes to break down these polymers into less harmful byproducts has been a topic of study to develop a suitable anti-pollutant.
