What is Marine Debris?Whether you call it trash, garbage, or just plain litter, marine debris is a serious threat to the world’s waters.
Marine debris is any man-made solid that finds its way into the water. Floating plastic bottles, discarded fishing lines and fishing nets, used lighters, pieces of wrecked boats – marine debris can be almost anything made by man. It can also be found nearly everywhere. From the Hudson River to the middle of the Pacific Ocean, marine debris is now present all around the globe. Since marine debris is swept along by water currents, it often accumulates most noticeably along coastlines. |
Types of Marine DebrisPLASTIC: Plastic items are the most common type of marine debris. Plastic is non-biodegradable and extremely durable. Days, weeks, and even decades in the ocean will do little to break down most plastics. Studies have found that it takes a plastic water bottle nearly 450 years to dissolve at sea. Plastic grocery bags, industrial pellets, and product packaging are all flowing into our waters every day.
FISHING GEAR: Debris like nets, lures, buoys, and lines are particularly dangerous to wildlife. Broken fishing gear and discarded nets (sometimes called ghost nets) can still ensnare unsuspecting sea creatures. Hemp rope takes 3-14 months to dissolve at sea, while plastic fishing gear can remain a hazard for decades. FOOD PACKAGING: Plastic wrappers, disposable cups, and plastic utensils are frequently tossed over the side of a boat, left behind after a picnic at the beach, or simply washed out to sea from storm drains. |
GLASS: Hunting for smooth, brightly-colored sea glass can make for a great time at the beach, but sharp broken bits of bottles can be dangerous to humans and marine animals alike.
METAL: Soda cans, aerosol cans, bottle caps, fishing hooks, and coat hangers all find their way into our waters. Metals are sometimes mistaken for food by sea creatures. It takes an aluminum can 200-500 years to dissolve at sea. CIGARETTE FILTERS: Cigarette filters are a particularly insidious form of marine debris. Filters absorb cancer-causing chemicals from tobacco, and research has found that these chemicals can be deadly to small marine creatures like the Daphnia magna, a water flea crustacean at the lower end of the aquatic food chain. Ninety-five percent of cigarette filters are made of a plastic called cellulose acetate, which is thinner than sewing thread and takes many years to degrade. They are often mistaken for food by marine animals. Nearly 2.1 billion pounds of cigarette filters were discarded worldwide in 1998. |
How does Marine Debris get into the Ocean?
The National Oceanic and Atmospheric Administration has found that commercial shipping, drilling platforms, and recreational boating produced about eighteen percent of all marine debris.
Debris from ships includes food waste, pieces of wrecked vessels, fishing gear, lines, nets, and buoys. Rough seas can also cause ships to lose cargo or gear overboard. |
Beachgoers and picnickers also play a part. Many people think nothing of leaving a few plastic cups or aluminum cans behind after a day outdoors. Several bottle caps, soda tabs, plastic utensils, string, or food wrappers may not seem so bad, but cumulatively their environmental impact can be enormous. |
LAND SOURCES
Land-based items make up 49% of all marine debris according to a recent study by the National Oceanic and Atmospheric Administration. One of the most common ways that marine debris travels from land to water is by being swept through storm drains. Small pieces of trash tossed into the street are often washed into storm drains during rain storms, which deposit the water – and the trash – into the sea. Rivers and other waterways can also wash trash into our bays and oceans. Industrial and urban areas also generate marine debris. Poorly managed municipal dumps and factories can send pollution into waters near and far. |
IMPACTS OF WEATHER Extreme weather like hurricanes, tornados, tsunamis, and flooding can also produce large amounts of marine debris. During the 2005 hurricane season, nearly nine million cubic yards of debris was spread across 1,770 acres of marshlands in the Sabine National Wildlife Refuge in Louisiana. |
Marine Debris Laws
BRIEF HISTORY OF MARINE DEBRIS
People have long believed that the ocean is as an endless dumping ground for human waste.
''On Friday, a great many people put on their clothes and left the water in disgust after a few minutes, as it was so full of vegetables and grease. One woman decided to leave after a dead dog had come in contact with her face.''
– Metropolitan Sewerage Commission report on Bradley Beach, New Jersey, 1906.
People have long believed that the ocean is as an endless dumping ground for human waste.
''On Friday, a great many people put on their clothes and left the water in disgust after a few minutes, as it was so full of vegetables and grease. One woman decided to leave after a dead dog had come in contact with her face.''
– Metropolitan Sewerage Commission report on Bradley Beach, New Jersey, 1906.
Indiscriminate dumping of garbage and sewage has gone on for centuries, but it wasn’t until the early 1900’s that lawmakers in the United States began to recognize the need to do something about water pollution.
In the 1970’s, laws such as the Act to Prevent Pollution from Ships – which implemented the rules set out in the International Marine Pollution Convention – and the US Clean Water Act were passed, outlawing the discharge of oil and garbage into the water. These laws have done a great deal to help improve water quality. |
International Laws on Marine Debris
The Marine Pollution Convention (known as MARPOL), Annex V, is an international treaty that regulates the disposal of garbage aboard ships.
According to MARPOL, garbage includes “all kinds of food, domestic and operational waste, excluding fresh fish, generated during the normal operation of the vessel and liable to be disposed of continuously or periodically.”
Annex V also prohibits the discharge of plastics anywhere in the sea.
Ships, according to the treaty, must keep a garbage logbook to track all disposal and incineration aboard the ship. National governments must also provide facilities at ports and terminals to collect garbage from ships.
The Marine Pollution Convention (known as MARPOL), Annex V, is an international treaty that regulates the disposal of garbage aboard ships.
According to MARPOL, garbage includes “all kinds of food, domestic and operational waste, excluding fresh fish, generated during the normal operation of the vessel and liable to be disposed of continuously or periodically.”
Annex V also prohibits the discharge of plastics anywhere in the sea.
Ships, according to the treaty, must keep a garbage logbook to track all disposal and incineration aboard the ship. National governments must also provide facilities at ports and terminals to collect garbage from ships.
Key U.S. Laws on Marine Debris
Over the years, the United States has passed many laws regarding water pollution and marine debris. Here is a timeline of key marine debris laws:
1972
Federal Water Pollution Control Act. This act, also known as the Clean Water Act, set pollution discharge rules for US waters, established water quality criteria, and gave the EPA enforcement authority.
Coastal Zone Management Act. This law authorized NOAA to fund state programs to regulate pollution and protect environmental resources across the country.
Marine Protection, Research, and Sanctuaries Act. This act gave the US Coast Guard and the EPA authority to regulate dumping in US ocean waters.
1987
Marine Plastic Pollution Research and Control Act. This act implements the provisions of MARPOL’s Annex V into US law, making it illegal to throw plastic into waters within 200 miles of the US coastline (which constitutes the country’s Exclusive Economic Zone). It also outlawed the dumping of garbage within three miles of shore.
1994
Shore Protection Act. This law created regulations for waste transport vessels like trash barges. The act aimed to prevent accidental spills of dangerous waste into the water.
2000
Beaches Environmental Assessment and Coastal Health Act. This law amended the Clean Water Act to require water testing and public notification of unsafe water contamination.
The Coral Reef Conservation Act. This act benefits coral reefs by authorizing NOAA to “provide assistance to States in removing abandoned fishing gear, marine debris, and abandoned vessels from coral reefs to conserve living marine resources."
2006
Marine Debris Research, Prevention, and Reduction Act. This law funded NOAA’s Marine Debris Program to “identify, assess, reduce, and prevent marine debris and its effects on the marine environment.”
Over the years, the United States has passed many laws regarding water pollution and marine debris. Here is a timeline of key marine debris laws:
1972
Federal Water Pollution Control Act. This act, also known as the Clean Water Act, set pollution discharge rules for US waters, established water quality criteria, and gave the EPA enforcement authority.
Coastal Zone Management Act. This law authorized NOAA to fund state programs to regulate pollution and protect environmental resources across the country.
Marine Protection, Research, and Sanctuaries Act. This act gave the US Coast Guard and the EPA authority to regulate dumping in US ocean waters.
1987
Marine Plastic Pollution Research and Control Act. This act implements the provisions of MARPOL’s Annex V into US law, making it illegal to throw plastic into waters within 200 miles of the US coastline (which constitutes the country’s Exclusive Economic Zone). It also outlawed the dumping of garbage within three miles of shore.
1994
Shore Protection Act. This law created regulations for waste transport vessels like trash barges. The act aimed to prevent accidental spills of dangerous waste into the water.
2000
Beaches Environmental Assessment and Coastal Health Act. This law amended the Clean Water Act to require water testing and public notification of unsafe water contamination.
The Coral Reef Conservation Act. This act benefits coral reefs by authorizing NOAA to “provide assistance to States in removing abandoned fishing gear, marine debris, and abandoned vessels from coral reefs to conserve living marine resources."
2006
Marine Debris Research, Prevention, and Reduction Act. This law funded NOAA’s Marine Debris Program to “identify, assess, reduce, and prevent marine debris and its effects on the marine environment.”
IMPACT of Marine Debris ON ANIMALS
Marine animals are harmed by marine debris in two ways; ingestion and entanglement.
Small pieces of floating debris are often mistaken for food by wild animals. Birds and other creatures starve to death if their stomachs fill with plastic debris, which creates a false feeling of fullness.
Some birds have been found feeding plastic debris to their young.
Small pieces of floating debris are often mistaken for food by wild animals. Birds and other creatures starve to death if their stomachs fill with plastic debris, which creates a false feeling of fullness.
Some birds have been found feeding plastic debris to their young.
Plastic Waste Pollution
Scientists have long tracked plastic ingestion by seabirds. Plastic was found in the stomachs of fewer than five percent in 1960, but jumped to 80 percent by 1980. And a recent study published by the National Academy of Sciences found plastic trash in 90 percent of all sea birds, and the rate continues to rise as the global production of plastics continues to increase. Plastic found inside birds includes bags, bottle caps, synthetic fibers from clothing, and tiny rice-sized bits that have been broken down by the sun and waves. Plastic fragments are also frequently found in the stomachs of many marine animals, including sea turtles and whales. |
Entanglement in old fishing nets and plastic debris is another hazard.
The National Oceanic and Atmospheric's Marine Debris program reported in 2014 that entanglement can cause decreased swimming ability, disruption in feeding, life-threatening injuries, and death -- and impacts most of the marine animals on the planet. |
Marine debris can also threaten entire ecosystems. Invasive species can use marine debris to ride across the ocean to new environments, threatening local plant and animal populations. Since modern marine debris is more buoyant and durable than natural modes of transportation like driftwood, it can increase the range of wandering species. Marine debris can also damage the delicate ecosystems in coral reefs.
A phenomenon known as “ghost fishing” occurs when discarded fishing gear like nets or traps are left in the water. These items continue to trap all kinds of marine life, leading to suffocation or starvation. |
Microplastic pollution in the food chain
There is a growing awareness that tiny pieces of plastic, known as microplastics, are now widespread in the world's oceans -- but we are only just beginning to understand its impacts on marine life.
Several recent studies by scientists around the world are revealing that microplastics, defined as pieces of plastic smaller than 5 millimeters, are now present throughout the ocean food chain, and are being eaten and transferred from tiny zooplankton, to fish, and upwards to the turtles and seals that feed upon them. |
One recent study by researchers at the Plymouth Marine Laboratory analyzed scat from captive grey seals, which had been fed wild-caught Atlantic mackerel. One third of the mackerel and fully half of the scat samples from the seals contained microplastic, showing how these tiny synthetic particles move upward thought the food chain.
“Our finding that microplastic can be passed from fish to marine top predators is something we’ve long thought was the case but, until now, lacked the evidence to back our theory up," says Sarah Nelms, the study's lead author in a university news release. "We have shown that trophic transfer is an indirect, yet potentially major route of microplastic ingestion for these predators."
Microplastics have many potential sources. Larger plastic debris can degrade into smaller and smaller pieces, and synthetic fabrics like polyester fleece shed micro plastic fibers every time it is washed. Other potential sources include cigarette filters, toothbrushes, discarded fishing nets, tires, and microbeads, which are tiny pieces of manufactured polyethylene plastic that are added as exfoliants to health and beauty products, such as some cleansers and toothpastes.
"By examining scat from captive animals and the digestive tracts of fish they were fed upon," says Nelms, "we could eliminate the possibility that the seals were eating plastic directly and be sure that any microplastics we found in their scat came via the fish.”
A similar study on fur seals living in the wild by Cristóbal Galbán-Malagón, a professor in ecology and biodiversity at the Universidad Andrés Bello in Chile, also found plastic microfibers in the scat of fur seals on Guafo Island, a remote island off the Southwest coast of Chile. Galbán-Malagón, after collecting scat from wild fur seals and dissolving the organic materials using lye, found that 67% of the samples contained traces of plastic.
Of course, it's not just tiny bits of plastic that are contaminating the ocean environment. Researchers at New Zealand’s National Institute of Water and Atmospheric Research (NIWA) recently reported that they have recovered a working USB stick photos inside a chunk of seal scat that has been frozen in their lab since 2017.
Dr. Krista Hupman runs a volunteer network via LeopardSeals.org where Kiwis send in leopard seal scat for her lab to analyze. In November 2017 a local vet sent in a sample from Oreti Beach, Invercargill, which when in 2019, revealed the presence of a USB stick, which, once dried out, worked perfectly well.
Somewhat ironically, the stick contained photos of sea lions at nearby Porpoise Bay. Dr. Hupman would be happy to return the stick, should the owner come forward.
“From our work over the years we have found microplastic in nearly all the species of marine animals we have looked at," explains Dr Penelope Lindeque, a lead researcher on microplastic at Plymouth Marine Laboratory, who was involved in a 2018 study that found synthetic plastic particles present in seven different species of turtles, collected in the Atlantic, Pacific and Mediterranean. The list of impacted creatures now spans the marine food chain from tiny zooplankton at the base of the food web, to fish larvae, and upwards to include mackerels, dolphins, turtles, and seals.
“Our study demonstrates how microplastic can be transferred from prey to predator and therefore passed up through the food chain," says Dr. Lindeque. "More work is needed to understand the extent to which microplastics are ingested by wild animals and what impacts they may have upon the animals and ecosystems.”
Interested in learning more about marine debris? And if you’re reading this in New Zealand and would like to help collect leopard seal scat, you can find out how here.
“Our finding that microplastic can be passed from fish to marine top predators is something we’ve long thought was the case but, until now, lacked the evidence to back our theory up," says Sarah Nelms, the study's lead author in a university news release. "We have shown that trophic transfer is an indirect, yet potentially major route of microplastic ingestion for these predators."
Microplastics have many potential sources. Larger plastic debris can degrade into smaller and smaller pieces, and synthetic fabrics like polyester fleece shed micro plastic fibers every time it is washed. Other potential sources include cigarette filters, toothbrushes, discarded fishing nets, tires, and microbeads, which are tiny pieces of manufactured polyethylene plastic that are added as exfoliants to health and beauty products, such as some cleansers and toothpastes.
"By examining scat from captive animals and the digestive tracts of fish they were fed upon," says Nelms, "we could eliminate the possibility that the seals were eating plastic directly and be sure that any microplastics we found in their scat came via the fish.”
A similar study on fur seals living in the wild by Cristóbal Galbán-Malagón, a professor in ecology and biodiversity at the Universidad Andrés Bello in Chile, also found plastic microfibers in the scat of fur seals on Guafo Island, a remote island off the Southwest coast of Chile. Galbán-Malagón, after collecting scat from wild fur seals and dissolving the organic materials using lye, found that 67% of the samples contained traces of plastic.
Of course, it's not just tiny bits of plastic that are contaminating the ocean environment. Researchers at New Zealand’s National Institute of Water and Atmospheric Research (NIWA) recently reported that they have recovered a working USB stick photos inside a chunk of seal scat that has been frozen in their lab since 2017.
Dr. Krista Hupman runs a volunteer network via LeopardSeals.org where Kiwis send in leopard seal scat for her lab to analyze. In November 2017 a local vet sent in a sample from Oreti Beach, Invercargill, which when in 2019, revealed the presence of a USB stick, which, once dried out, worked perfectly well.
Somewhat ironically, the stick contained photos of sea lions at nearby Porpoise Bay. Dr. Hupman would be happy to return the stick, should the owner come forward.
“From our work over the years we have found microplastic in nearly all the species of marine animals we have looked at," explains Dr Penelope Lindeque, a lead researcher on microplastic at Plymouth Marine Laboratory, who was involved in a 2018 study that found synthetic plastic particles present in seven different species of turtles, collected in the Atlantic, Pacific and Mediterranean. The list of impacted creatures now spans the marine food chain from tiny zooplankton at the base of the food web, to fish larvae, and upwards to include mackerels, dolphins, turtles, and seals.
“Our study demonstrates how microplastic can be transferred from prey to predator and therefore passed up through the food chain," says Dr. Lindeque. "More work is needed to understand the extent to which microplastics are ingested by wild animals and what impacts they may have upon the animals and ecosystems.”
Interested in learning more about marine debris? And if you’re reading this in New Zealand and would like to help collect leopard seal scat, you can find out how here.
Marine Debris Prevention
Marine Debris may seem overwhelming, but there are plenty of solutions to stop the flow of trash into our oceans.
Here are a few simple things you can do to prevent marine debris.
Here are a few simple things you can do to prevent marine debris.
When on Land:
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When at Sea:
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Take Action in New Jersey
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Take Action in Massachusetts
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Marine Debris Recycling Program In Hawaii
Hawaii’s Nets to Energy Program and Partnership brings a unique solution to pollution. It turns salvaged marine debris into energy! When debris is removed from the ocean, instead of taking up space in a landfill, it is cut into small pieces and burned at an H-Power facility.
Burning debris creates steam, which generates electricity. One hundred tons of debris can power 43 homes for a year. Since the program began in 2002, more than 800 tons of debris has been collected. Instead of staying in the ocean and fouling engines or ensnaring animals, this debris is being put to great use!
Hawaii’s Nets to Energy Program and similar programs around the country are supported in part by the National Ocean and Atmospheric Administration’s Marine Debris Program, which works to conduct research, create beach clean-ups, increase public awareness, and restore habitats. This program currently supports more than 140 projects around the United States.
NOAA marine debris program's mission is to investigate and prevent the adverse impacts of marine debris.
Burning debris creates steam, which generates electricity. One hundred tons of debris can power 43 homes for a year. Since the program began in 2002, more than 800 tons of debris has been collected. Instead of staying in the ocean and fouling engines or ensnaring animals, this debris is being put to great use!
Hawaii’s Nets to Energy Program and similar programs around the country are supported in part by the National Ocean and Atmospheric Administration’s Marine Debris Program, which works to conduct research, create beach clean-ups, increase public awareness, and restore habitats. This program currently supports more than 140 projects around the United States.
NOAA marine debris program's mission is to investigate and prevent the adverse impacts of marine debris.