Articles & Reports – Microplastics and Waterways

Topic Key

Biological Consequences

Marine Debris Concepts


Sources of Marine Debris

Strategies for Mitigation

The Adopt-A-Catch Basin logo. (Source: City of New Orleans)

City of New Orleans - 2018

With this resource, community members in New Orleans are invited to take part in stewardship by adopting a loca catch basin.

"The City of New Orleans is working closely with residents and business owners to Adopt A Catch Basin on their block and help improve drainage conditions throughout the City. Eighty five percent of the City's clogged catch basins are full of leaves and grass clippings that can be easily and safely removed by residents like you!"

An overfilled waste container. (Source: RitaE, Pixabay)

National Geographic - Jun 2019

"The world is waking up to a crisis of ocean plastic—and we're tracking the developments and solutions as they happen.

The world has a plastic pollution problem and it’s snowballing—but so is public awareness and action. National Geographic magazine devoted a special cover package to plastic in June 2018. Here, we continue to track some of the developments around this important issue. We will update this article periodically as news develops."

Formosa Plastics plant in Point Comfort, TX (Source: Duy Vu)

National Geographic - Jun 2019

"The plastics industry has long styled itself as a constructive force in battling plastic pollution, while blaming the problem on messy consumers and weak trash disposal and recycling programs. Whatever the weight of that argument, it falls apart when it comes to plastic pellets. More insidious than visible eyesores like discarded bottles and takeout containers, the tiny pellets have escaped into waterways by the countless billions as a result of failures by industry, not consumers."

Map showing volunteer sample sites. (Source: Adventure Scientists)

Adventure Scientists - Ongoing

"After four years of collecting water samples, we are confident that our dataset represents the most diverse and one of the largest datasets exposing the extent of microplastic pollution around the globe. With this in hand, we have transitioned to data analysis as we seek a deeper understanding of microplastic pollution, and importantly, how our work can contribute to positive change. This data has already inspired businesses to reduce their plastic consumption, is being used by governments towards conservation decision making, and has motivated over 80% of our project volunteers into taking action towards reducing plastic pollution."

Ocean Conservancy - Jun 2020

"Every time you wash your clothes, thousands of tiny microfibers shed from the fabric into wastewaters. As 60% of all clothing is now produced from synthetic fibers (such as polyester and nylon), many of these microfibers are microplastics. Because of their small size, microfibers often pass through wastewater treatment systems, flowing into our waterways and oceans, where they can be ingested by wildlife.

A new study from researchers at Northumbria University and Procter & Gamble estimates that European countries alone release almost 13,000 tons of microfibers to marine environments every year. This is equal to the mass of dumping two garbage trucks worth of waste every day."

Ferreira created a method to remove plastics from the ocean. (Source: Fionn Ferreira)

EcoWatch - Aug 2019

"Ferreira's project used a novel, but effective methodology for removing ocean plastics. He used magnets to attract microplastics from water. The project found that a magnetic liquid called ferrofluid attracted the tiny plastic particles and removed them from the water. After nearly a thousand tests, his device successfully removed about 88 percent of the microplastics from water samples, according to The Irish Times."

Ferreira's Google science fair video can be viewed here.

Microplastic sample. (Source: USGS)

United States Geological Survey - 2016

"Microplastics are the miniscule plastic fragments (smaller than 0.04 inch) that fall off of decomposing plastic bottles and bags, and are intentionally manufactured into some toothpastes and lotions. Scientists have found microplastics nearly everywhere, particularly in lakes, rivers, and aquatic animals...

U.S. Geological Survey and State University of New York Fredonia scientists sampled rivers flowing into the Great Lakes3 to find out which kinds of microplastics are most commonly found in rivers, and which rivers contain the most microplastics particles. These scientists found that rivers carry many different kinds of microplastics, and were surprised to learn that plastic microbeads make up only a small fraction of all microplastics."

Nurdles washed up along the Missippi River. (Source: Tristan Baurick)

Tristan Baurick ( - Sep 2020

"Outrage over last month’s sprawling Mississippi River nurdle spill in New Orleans and the lax government response to it has inspired a bill in Congress to prevent similar incidents.

Sen. Tom Udall, D-N.M., had already introduced a wide-ranging bill to reduce plastic pollution, and last week he drafted a new one aimed specifically at prohibiting the discharge of plastic pellets, called nurdles, into rivers and oceans."

Plastic debris in Norway (Source: Ashley Cooper/Corbis)

Environmental Health Perspectives - Feb 2015

"In recent years plastic pollution in the ocean has become a significant environmental concern for governments, scientists, nongovernmental organizations, and members of the public worldwide. A December 2014 study derived from six years of research by the 5 Gyres Institute estimated that 5.25 trillion plastic particles weighing some 269,000 tons are floating on the surface of the sea. At the same time, plastics in consumer products have become subject to increasing scrutiny regarding their potential effects on human health."

A water filled with plastic fragments. (Source: Eric Gaillard/Reuters)

The New York Times - APR 2019

"Researchers in France said this week that they found thousands and thousands of microplastic particles raining down on a secluded spot in the Pyrenees, 75 miles from the nearest city.

Their study, published in the journal Nature Geoscience, suggests that microplastics — long known as a source of water pollution — may also travel by air, spreading their ill effects far from dense population centers."

National Geographic Logo

National Geographic - AUG 2017

"Anchovies are known more as a pickled pizza topping than for their crucial place in the marine food chain. Now scientists have confirmed a disturbing new behavior by these tiny forage fish that could have larger implications for human health: anchovies are eating tiny pieces of ocean plastic, and because they, in turn, are eaten by larger fish, the toxins in those microplastics could be transferred to fish consumed by humans."

Biopolymer for clothing (Source: Chris Joyce/NPR)

NPR - JUN 2019

"If civilizations are remembered for what they leave behind, our time might be labeled the Plastic Age. Plastic can endure for centuries. It's everywhere, even in our clothes, from polyester leisure suits to fleece jackets.

A Silicon Valley startup is trying to get the plastic out of clothing and put something else in: biopolymers."

The transportation of microplastics (Source: U of Manchester)

CBS News - May 2020

"Researchers have uncovered the highest-ever concentration of microplastics on the seafloor. According to a new study in the journal Science, scientists recently found 1.9 million pieces in an area of about 11 square feet in the Mediterranean Sea.

Over 10 million tons of plastic waste enter oceans each year — but the visible floating plastic that has led to anti-straw and anti-plastic bag movements accounts for less than 1% of the ocean's total plastic.

The other 99% is thought to live in the deep ocean — and the new study helps to explain how it ends up there."

Brown pelicans in the San Francisco Bay (Source: Eric Risberg)

Los Angeles Times - Oct 2019

"Driving is not just an air pollution and climate change problem — turns out, it just might be the largest contributor of microplastics in California coastal waters.

That is one of many new findings, released Wednesday, from the most comprehensive study to date on microplastics in California. Rainfall washes more than 7 trillion pieces of microplastics, much of it tire particles left behind on streets, into San Francisco Bay each year — an amount 300 times greater than what comes from microfibers washing off polyester clothes, microbeads from beauty products and the many other plastics washing down our sinks and sewers."

A sample of trash in South Padre Island, Texas. (Source: NRDC)

Natural Resource Defense Council - Jun 2018

"A 10-year-old girl walks to the edge of the Kansas River in Topeka, Kansas, rolls up a note, and slips it into a plastic bottle before sending it downstream. Sixteen years, hundreds of miles, and two rivers later, Michael Coyne-Logan, an educational facilitator for Living Lands and Waters, hoists it from the Mississippi River in St. Louis. That is one bottle among the millions of pounds of trash that he and his cleanup crew have collected in recent years as they try to make a dent in the enormous amount of garbage floating down the Mississippi."

A handfull of recycled blue "nurdles" (Source: Ryan McGinnis/Getty Images)

The Atlantic - 2019

"Last September, Jace Tunnell discovered a layer of tiny, round plastic pellets covering a beach on Padre Island off the southern coast of Texas. There were “millions of them,” he recalled, “and it went on for miles.” Tunnell, a marine biologist, knew exactly what the pellets were, but says he had never actually seen them before.

They’re called nurdles, and they’re the preproduction building blocks for nearly all plastic goods, from soft-drink bottles to oil pipelines. But as essential as they are for consumer products, nurdles that become lost during transit or manufacturing are also an environmental hazard. In the ocean and along coastal waterways, they absorb toxic chemicals and are often mistaken for food by animals. They also wash up by the millions on beaches, leaving coastal communities to deal with the ramifications."

Microplastics in sand. (Source: NOAA)

NOAA - 2020

"Microplastics come from a variety of sources, including from larger plastic debris that degrades into smaller and smaller pieces. In addition, microbeads, a type of microplastic, are very tiny pieces of manufactured polyethylene plastic that are added as exfoliants to health and beauty products, such as some cleansers and toothpastes. These tiny particles easily pass through water filtration systems and end up in the ocean and Great Lakes, posing a potential threat to aquatic life."

Scholarly Research

Examples of microplastic (Source: Di Mauro et al.)

Di Mauro et al. (Environmental pollution) - 2017

"Accumulation of marine debris is a global problem that affects the oceans on multiple scales. The majority of floating marine debris is composed of microplastics: plastic particles up to 5 mm in diameter. With similar sizes and appearances to natural food items, these small fragments pose potential risks to many marine organisms including zooplankton and zooplanktivores... Our study documented and characterized microplastics in continental shelf waters off the Louisiana coast in the northern Gulf of Mexico, using bongo nets, neuston nets, and Niskin bottles."

A pyramid of microplastics. (Source: Cox et al.)

Cox et al. (Environmental Science & Technology) - 2019

"Microplastics are ubiquitous across ecosystems, yet the exposure risk to humans is unresolved. Focusing on the American diet, we evaluated the number of microplastic particles in commonly consumed foods in relation to their recommended daily intake. The potential for microplastic inhalation and how the source of drinking water may affect microplastic consumption were also explored. ... Evaluating approximately 15% of Americans’ caloric intake, we estimate that annual microplastics consumption ranges from 39000 to 52000 particles depending on age and sex. These estimates increase to 74000 and 121000 when inhalation is considered."

Microplastic sampling and analysis (Source: Thompson et al.)

Thompson et al. (Science) - May 2004

"Millions of metric tons of plastic are produced annually. Countless large items of plastic debris are accumulating in marine habitats worldwide and may persist for centuries (1-4). Here we show that microscopic plastic fragments and fibers (Fig. 1A) are also accumulated in the pelagic zone and sedimentary habitats. The fragments appear to have resulted from degradation of larger items. Plastics of this size are ingested by marine organisms, but the environmental consequences of this contamination are still unknown."

Global plastic production trends. (Source: Gallo et al.)

Gallo et al. (Environmental Sciences Europe - Apr 2018

"Persistent plastics, with an estimated lifetime for degradation of hundreds of years in marine conditions, can break up into micro- and nanoplastics over shorter timescales, thus facilitating their uptake by marine biota throughout the food chain. These polymers may contain chemical additives and contaminants, including some known endocrine disruptors that may be harmful at extremely low concentrations for marine biota, thus posing potential risks to marine ecosystems, biodiversity and food availability."

Microplastic concentrations (Source: Koelmans et al.)

Koelmans et al. (Water Research) - May 2019

"Microplastics have recently been detected in drinking water as well as in drinking water sources. This presence has triggered discussions on possible implications for human health. However, there have been questions regarding the quality of these occurrence studies since there are no standard sampling, extraction and identification methods for microplastics. Accordingly, we assessed the quality of fifty studies researching microplastics in drinking water and in its major freshwater sources. This includes an assessment of microplastic occurrence data from river and lake water, groundwater, tap water and bottled drinking water."

Plastics along shoreline of Hawaii (Source: Anna-Marie Cook)

Burgess et al. (Environ. Toxicol. Chem) - Aug 2017

"As microplastics continue to be released and distributed throughout the aquatic environment, they leave a trail of questions: How much and what types of microplastics are most commonly found in the water column, in sediments, and in organisms? ... Do microplastics cause adverse ecological or human health effects? Do the chemicals they contain cause adverse ecological or human health effects? ... Here, we bring together 4 perspectives on these questions and othersindustry, government, academia, and a nongovernmental organizationto continue the ongoing dialogue regarding the risks associated with microplastics in aquatic environments."

Pathways of plastic pollution. (Source: Ritchie & Roser)

Ritchie & Roser (Our World in Data) - Sep 2018

"To understand the magnitude of input of plastics to the natural environment and the world’s oceans, we must understand various elements of the plastic production, distribution and waste management chain. This is crucial, not only in understanding the scale of the problem but in implementing the most effective interventions for reduction...

Plastic waste generated in coastal regions is most at risk of entering the oceans; in 2010 coastal plastic waste – generated within 50 kilometres of the coastline – amounted to 99.5 million tonnes."

A sample collected using the Ice Cream Scoop. (Source: CLEAR)

Fauziah Shahul Hamid et al. - Aug 2018

"The widespread occurrence of microplastic has invaded the environment to an extent that it appears to be present throughout the globe. This review investigated the global abundance and distribution of microplastics in marine and freshwater ecosystems. Furthermore, the issues and challenges have been addressed for better findings in microplastics studies. Findings revealed that the accumulation of microplastics varies geographically, with locations, hydrodynamic conditions, environmental pressure, and time. From this review, it is crucial that proper regulations are proposed and implemented in order to reduce the occurrence of microplastics in the aquatic environment. Without appropriate law and regulations, microplastic pollution will eventually threaten human livelihood."


Cover artwork: Microplastics mixed in sand. (Gothenburg University)

Gothenburg University - 2018

"The Swedish Environmental Protection Agency has been tasked with identifying important sources of microplastics (MPs) in the environment and suggesting actions to mitigate their emissions into the environment... The major focus of this report is aquatic ecosystems (marine and freshwater), although we also review the prevalence and potential impacts of MPs in terrestrial ecosystems. However, the latter ecosystems are much less studied than the former."

A microplastics sample (Source: NOAA Marine Debris Program)

United Nations Environment Programme - 2020

"Microplastics are tiny plastic particles up to 5mm in diameter. In the last four decades, concentrations of these particles appear to have increased significantly in the surface waters of the ocean. Concern about the potential impact of microplastics in the marine environment has gathered momentum during the past few years. The number of scientific investigations has increased, along with public interest and pressure on decision- makers to respond."

An example of a microplastic. (Source: NOAA)

United Nations Environment Programme - 2020

"Microplastics are tiny plastic particles up to 5mm in diameter. In the last four decades, concentrations of these particles appear to have increased significantly in the surface waters of the ocean. Concern about the potential impact of microplastics in the marine environment has gathered momentum during the past few years. The number of scientific investigations has increased, along with public interest and pressure on decision- makers to respond."

Guidebook cover photo. (Source: MSU)

Mississippi State University - 2018

"Microplastics have been found all over the ocean—from the surface water to deep-sea benthic zones (lowest level of the ocean). Tere are even reports of microplastics being found frozen in Arctic ice! Tese small plastic pieces are often mistaken as food and can be ingested by small organisms like plankton to larger organisms like whale sharks. Not only are plastics indigestible, but they may also be toxic to the animals that consume them. Plastic is absorbent, like a sponge, so it absorbs hydrophobic chemicals from the water it foats in. There are all kinds of chemicals in seawater—from pesticides to steroids to BPA—that can be very harmful to humans and wildlife. Plastic can absorb these chemicals."