Ocean waste, also called marine trash or marine debris, is any man made solid material that is disposed of on beaches, directly into the ocean itself at any depth, or in waterways that lead to the ocean. The discarded items are made primarily of plastic, paper, wood, and metal, or any other manufactured materials. Ocean waste does not include seaweed, shells, naturally occurring materials, or carcasses that wash up onto ocean beaches. Ocean waste can be the result of direct disposal, indirect disposal, or materials left behind intentionally or unintentionally.
Reports of marine life entanglement and plastic ingestion began appearing in the news and scientific literature in the 1960s and shifted to a focus on plastic pellets in the northern waters of the Atlantic Ocean in the 1970s. In the early twenty-first century, marine biologists began investigating the role of microplastics in polluting marine food sources based on reports of high concentration of plastic litter on the beaches of Pacific Rim countries. Studies have investigated the factors involved in seabird ingestion of plastic materials and entanglements of seals in netting and other marine debris in the water and on beaches in the North Pacific.
As reports of marine trash became more numerous, concerns of environmental scientists about the impact on the world's oceans also increased. These concerns led to two international conferences led by the U.S. National Marine Fisheries Service in Honolulu, Hawaii. A series of meetings on marine debris helped to establish a research agenda, and, by the end of the 1980s, the potential impact of ocean waste was understood more definitively, and the marine research community began to seek effective solutions to curbing marine litter.
As research moved forward, the discovery of dense collections of small plastic particles in the North Pacific Ocean, a mass of plastic covering approximately 600,000 square miles, prompted a redoubling of the research effort. After the Great Pacific Garbage Patch, or Pacific Trash Vortex or gyre, was found, two other patches were discovered in the Indian and Atlantic oceans, both where currents meet. Two others were subsequently found, making five patches altogether. The clockwise ocean currents tend to keep the patches of plastic debris from moving toward the coastline. Scientists estimated that the dense patches contain about 580,000 plastic pieces per square kilometer. In 1987, the Marine Plastic Research and Control Act (MARPOL) was passed, making it illegal for any U.S. vessel to dump plastics into the ocean. Countries that represent half of the world's shipping tonnage agreed to an international treaty, (Annex V) preventing pollution by trash from ships, including restriction of all manmade materials such as paper, glass, metal, and crockery, in addition to plastics. The plastics industry, represented by the Society of the Plastic Industry, was completely supportive of MARPOL Annex V and has run many public service ads promoting the ban. Nationwide coastal cleanup efforts coordinated by the Center for Marine Conservation (CMC) since 1986 were ongoing as of 2018. In 1993, 3.1 million pounds of marine trash were collected on the coasts of the United States, Canada, and Mexico.
In the twenty-first century, marine researchers and environmentalists understand that the healthiest and most socially conscious way to live is to forego disposable commodities and reverse the plastics and waste lifecycle. The MARPOL treaty has helped to reduce marine trash items such as fishing and boating supplies, galley food waste, and cruise ship debris, as evidenced in trash collected since the multinational coastal cleanup in 1993. However, because MARPOL and other laws, even though enforced by the U.S. Coast Guard, are difficult to monitor, voluntary compliance of the public through increased awareness of the problem is considered to be an essential part of the solution.
Commercial development of plastics that began in the early twentieth century ballooned into a dominant twenty-first century industry. In 2012, global plastic resin production was estimated to be 288 metric tons, up an astounding 620% compared to 1975 production levels. Packaging is the largest segment of the plastic industry and is the plastic item with the shortest life—usually disposed of immediately after one-time use. The concerns associated with plastics in the marine environment include harmful effects on the oceans, marine life, and human life. When plastic enters the ocean it threatens diverse marine life, ranging from the tiniest plankton to the largest whale. Plastics kill marine life in the cruelest ways, through entanglement, ingestion, or chemical contamination. As plastic weathers, it fragments into particles that can be ingested by even the smallest marine organisms. In addition, small plastic particles cannot be traced to their source and are more difficult to remove from the ocean or beach than larger items such as plastic beverage bottles. Experts on marine trash suggest that strategies to correct the accelerating ocean waste problem must rely on both reducing input of plastics into the marine environment and clean-up efforts.
Plastic does not biodegrade though it does break up into smaller pieces eventually, taking many years to split into macro- and micro-pieces. Micro-plastics are ingested by fish and sea mammals. Styrofoam, for example, breaks into highly toxic polystyrene components that sink lower into the ocean and spread throughout the sea column. Smaller pieces of plastic also act like sponges and soak up other toxins, which are ingested first by marine animals and then by humans in the contaminated fish. Mercury in fish has been reported for years, and, more recently, lead and cadmium have also been detected; these heavy metals are all dangerous to humans and cause cancer and nervous system disorders, among other health problems. More than 100,000 sea turtles and birds are killed each year from ingestion and entanglement. Plastic parts such as bottle caps have been found in the stomachs of turtle and in the respiratory or digestive systems of birds. Turtles and seals have been trapped in abandoned commercial fishing nets called ghost nets. Plastic waste also promotes microbial colonization by pathogenic organisms responsible for disease outbreaks in the ocean.
In 1975, the National Academy of Sciences reported that at least 14 billion pounds of trash was dumped into the ocean annually, accounting for over 1.5 million pounds per hour. Boaters and ocean-going vessels of many types on all waterways are known to dump trash directly into the sea, which in the 1970s was a major cause of ocean waste and accumulations of plastic on beaches and at various depths within the ocean itself. After such dumping was banned, 80% of ocean waste was estimated to originate on land, but this estimate was not substantiated with research.
Forty years later, in a study published by the American Association for the Advancement for Science in 2015 as part of an international collaboration of scientists at the National Center of Ecological Analysis and Synthesis (NCEAS) at the University of California, the scale, scope, and impact of marine debris on global ocean health was estimated with surveys of coastal countries worldwide. Estimates of the flow of plastic materials into the global ocean showed that of 275 million metric tons of plastic waste from 192 coastal countries around the world, 4.8 to 12.7 million metric tons went into ocean waters—10 to 100 times the amount reported in the high-concentration garbage patches.
The quality of waste management systems and the size of a country's population determine the mass of waste available from any single country to contribute to plastic marine debris. Given the rates at which populations are growing and plastic use is increasing, as many as 250 metric tons were predicted to wind up on the beaches of coastal countries by 2025. Although the dilemma involves all coastal countries and all oceans (Atlantic, Pacific, and Indian oceans, and Mediterranean and Black seas), the NCEAS study showed that 20 countries are responsible for 83% of the plastic waste entering the ocean. China, Indonesia, India, and the United States had the highest coastal populations but the greatest rate of waste generation was by Sri Lanka, followed by the United States and South Africa. The highest percentage of plastic waste was generated by the Philippines, Vietnam, Malaysia, Nigeria, Pakistan, and the United States. However, the percentage of mismanaged waste (due to lack of adequate waste management) was lowest in the United States where efficient waste management methods are employed, and highest in Burma, Pakistan, Bangladesh, Vietnam, Nigeria, and the Philippines where waste management is lacking. Authors of the study suggested that improving waste management by 50% in the top 20 countries would clean up about 40% of marine debris. They also stated that among the top 20 coastal countries that polluted, a few countries in Asia would be likely the first targets.
The Environmental Protection Agency (EPA) in the United States has directed the Ocean Dumping Management Program for more than 45 years, stopping harmful materials from being disposed of in the oceans. The Marine Pollution Control Branch within the Office of Water in Washington, DC, works with seven coastal offices of the EPA to prevent or limit dumping of any materials that would adversely affect human health and the marine environment. Several laws have been enacted to help protect beaches and reduce pollution of the ocean, in addition to the 1987 passing of MARPOL to restrict dumping of trash by boaters and ocean vessels of all kinds. Designated disposal sites are maintained and supervised by the EPA for dredged materials and fish waste, among other materials. The EPA evaluates ocean disposal issues that are presented by individuals or organizations and also works with other federal, state, and local agencies to address marine pollution issues, including those that arise in conjunction with large-scale disasters such as hurricanes and oil spills. Waste enforcement and clean-up enforcement by the EPA pertain to waste generated by manufacturers, hazardous waste sites on land (but not beaches unless it involves dumping of waste), and storage tanks or sites of any kind. The EPA finds the responsible parties and either works with them or requires them to hire third-party clean-up groups to correct the contaminate sites.
MARPOL, the law against dumping trash at sea, has been enforced by the U.S. Coast Guard since 1987. Although other laws have been enacted to protect the health of oceans and marine life, as well as human health, the U.S. Coast Guard finds that patrolling beaches is difficult at best for a seagoing military unit, largely because controlling the disposal of waste on land is not its main focus. However, its enforcement of MARPOL was indeed successful in helping to curb the purposeful disposal of waste at sea.
Ecotoxic chemicals released from plastic particles into ocean waters present a constant toxicological threat to marine life and to humans. Five major large gyres, or garbage patches, that retain webs of plastic debris are found deep in the global ocean where macro- and micro-waste causes physical and biological hazards to fish and mammals. Although this may seem remote to human health, a serious threat of disease is floating from year to year in the world's oceans. However, these dangers to the environment, marine mammals and fish, and to human health are virtually neglected by governments and public health organizations while international and local environmental organizations have conducted clean-ups with citizen volunteers.
The National Oceanic and Atmospheric Administration (NOAA), a division of the U.S. Department of Commerce, helps to protect human health by monitoring contamination of ocean fish and shellfish through a Mussel Watch Program and a FishWatch Program, looking especially for contaminants such as heavy metals and plastic components. NOAA also has conducted a Marine Debris Program since 2011. However, in 2018, the federal budget threatened to reduce NOAA support.
The Parley A.I.R. Strategy of the conservation group Parley for the Oceans stands for Avoid, Intercept, and Redesign plastics. The fast-growing global threat of ocean waste and plastic pollution must be addressed through avoiding plastic wherever possible, intercepting plastic waste (such as through beach and ocean cleanups), and redesigning the plastic economy. Parley for the Oceans expresses the belief that plastic is a design failure and if the plastic material itself can be reinvented, ocean waste can be eliminated.
The dangers of plastics for human health are derived from three main sources:
Biomonitoring of human health shows that various compounds used in the production of plastics are present in human blood and cells. The World Medical Association and World Health Organization (WHO) seem to be the most logical organizations that could play a major role in turning the ocean waste dilemma around, protecting both marine life and human health. Scientists, waste management professionals, public health officials, and federal, state, and local governments must use their combined knowledge and skills to develop strategies that will solve the problem where it begins—at the level of public responsibility.
Authors Thomas Efferth and Norbert Paul, whose article “Threats to Human Health by Great Ocean Garbage Patches,” appeared in The Lancet Planetary Health (November 2017), suggest several strategic approaches by which to address the global problem of ocean waste, including the following:
Research on various aspects of ocean waste is ongoing. In the Rochman Laboratory at the University of Toronto, Canada, for example, scientists have quantified the sources and sinks of plastic debris in freshwater and marine habitats across North America. They are examining plastic as a source of chemical contamination of aquatic habitats and evaluating the associated chemical contaminants in wildlife, birds, and fish, including that sold for human consumption. One finding was that one in every four fish purchased from fish markets in the United States and Indonesia had evidence of anthropogenic debris in their digestive systems, including plastic and microfibers. The scientists at Rochman Lab believe that scientists can help to develop policy and need to be part of the discussion, particularly so they can communicate the results of research clearly to nonscientists who make policy. Previous collaborations with nongovernment organizations such as Ocean Conservancy have shown that such exchanges of information can help to invoke positive change through effective policies.
As part of a comprehensive solution, researchers and manufacturers continue to work on photodegradable and biodegradable plastics. Although they have not yet solved the problem of ocean waste, the effort continues along with a concerted effort to make plastics recyclable. Sixteen states have passed laws requiring six-pack holders to be made of biodegrade-able materials. The voluntary cleaning of beaches has also been shown to be an effective way to prevent marine trash from being carried away by the surf and into the ocean. Plastic waste management efforts are critical in the reduction of diseases and events that threaten the health of ecosystems, marine life, and humans.
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L. Lee Culvert