TANGLED UP: Plastic netting can be deadly for sea turtles and other animals.

JORDI CHIAS/NATUREPL.COM

An Ocean of Plastic

Plastic is polluting the seas, but there’s still time to turn the tide

ESSENTIAL QUESTION: How might plastic trash affect the ocean environment?

From the ice-covered Arctic to the tropical waters of the Pacific, all of Earth’s oceans share one thing in common: plastic pollution. Discarded plastic bags, cups, and bottles make their way into the sea. Today, it seems that no part of the ocean is safe from plastic trash.

In recent years, oceanographers have searched in vain for a pristine marine environment. They’ve found plastic everywhere they’ve looked. “It’s a global problem,” says Chelsea Rochman, a marine ecologist at the University of Toronto in Canada. “We can’t point to a single habitat or location with no plastic.”

Plastic harms wildlife and introduces dangerous chemicals into marine ecosystems—communities of organisms interacting with their surroundings. Once plastic enters the environment, it lasts a long time (see Garbage Breakdown). Researchers are working to prevent plastic pollution from entering the sea.

Earth’s oceans include the ice-covered Arctic and the tropical Pacific. But they all share one thing in common: plastic pollution. After being thrown away, plastic bags, cups, and bottles make their way into the sea. Today, it seems that no part of the ocean is safe from plastic trash.

In recent years, oceanographers have failed to find a clean marine environment. They’ve spotted plastic everywhere they’ve looked. Chelsea Rochman is a marine ecologist at the University of Toronto in Canada. “It’s a global problem,” she says. “We can’t point to a single habitat or location with no plastic.”

Plastic harms wildlife. It also puts dangerous chemicals into marine ecosystems—communities of living things interacting with their surroundings. After plastic enters the environment, it lasts a long time (see Garbage Breakdown). Researchers are working to stop plastic pollution from entering the sea.

INTO THE OCEAN

When people litter, or when trash is not properly disposed of, things like plastic bags, bottles, straws, and foam beverage cups get carried to the sea by winds and waterways (see From Shore to Sea). About 80 percent of ocean plastic originates on land. The rest comes from marine industries such as shipping and fishing.

In 2015, engineer Jenna Jambeck at the University of Georgia and other researchers calculated that at least 8 million tons of plastic trash are swept into the ocean from coasts every year. That’s the equivalent of a full garbage truck of plastic being dumped into the sea every minute. If current trends in plastic production and disposal continue, that figure will double by 2025. A report published by the World Economic Forum last year predicts that by 2050, ocean plastic will outweigh all the fish in the sea.

The problem starts when people litter, or when they don’t throw trash away properly. Things like plastic bags, bottles, straws, and foam beverage cups don’t stay put. Winds and waterways carry them out to sea (see From Shore to Sea). About 80 percent of ocean plastic starts out on land. The rest comes from marine businesses like shipping and fishing.

In 2015, engineer Jenna Jambeck at the University of Georgia and other researchers did a study. They wanted to figure out how much plastic trash enters the ocean from coasts every year. The answer: at least 8 million tons. That’s as much as a full garbage truck of plastic being dumped into the sea every minute. If today’s trends in plastic production and disposal continue, that figure will double by 2025. The World Economic Forum published a report on the problem last year. It predicts that by 2050, ocean plastic will outweigh all the fish in the sea.

NOT-SO-FANTASTIC PLASTIC

In today’s world, plastic is everywhere. It’s found in shoes, clothing, household items, electronics, and more. There are different types of plastics, but one thing they all have in common is that they’re made of polymers—large molecules made up of repeating units. Their chemical structure gives them a lot of advantages: They’re cheap and easy to manufacture, lightweight, water-resistant, durable, and can be molded into nearly any shape.

Unfortunately, some of the same properties that make plastics great for consumer goods make them a problem pollutant. Plastic’s durability comes in part from the fact that unlike paper or wood, it doesn’t biodegrade, or break down naturally. “Instead it just fragments, or breaks into pieces over time,” says Jambeck. Those tiny pieces, known as microplastic, can potentially stick around for hundreds or perhaps even thousands of years.

In today’s world, plastic is everywhere. It’s in shoes, clothing, household items, electronics, and more. There are different types of plastics, but all have one thing in common. They’re made of polymers—large molecules made up of repeating units. Their chemical structure gives them many advantages. They’re cheap and easy to make, lightweight, water-resistant, and durable. They can be molded into almost any shape.

Those features make plastics great for consumer goods. But some of them also make plastics a problem pollutant. Part of the reason plastic is durable is that it’s not like paper or wood. Those materials biodegrade, or break down naturally. Plastic doesn’t. “Instead it just fragments, or breaks into pieces over time,” says Jambeck. Those tiny pieces are known as microplastic. They could stick around for hundreds or maybe even thousands of years.

Another problem with plastics is the other chemicals they contain, like dyes and flame retardants. When plastic isn’t disposed of properly, those additives end up in the environment.

Plastic also tends to absorb harmful chemicals from its surroundings. “It’s like a sponge for persistent organic pollutants,” says Jambeck. These long-lasting, toxic substances include pesticides and industrial chemicals. If plastic absorbs the chemicals, and marine organisms eat the plastic, they may be exposed to higher concentrations of these contaminants.

Another problem with plastics: They contain other chemicals, like dyes and flame retardants. When plastic isn’t thrown away properly, those chemicals end up in the environment.

Plastic can also soak up harmful chemicals from its surroundings. “It’s like a sponge for persistent organic pollutants,” says Jambeck. These are long-lasting, toxic substances. They include pesticides and industrial chemicals. Sea creatures may eat plastic that has absorbed these chemicals. That exposes them to higher amounts of the pollutants.

WILDLIFE AT RISK

One of the biggest impacts of plastic pollution is its effect on sea life. Seals, sea turtles, and even whales can become entangled in plastic netting. They can starve to death if the plastic restricts their ability to move or eat. Or the plastic can cut into the animals’ skin, causing wounds that develop severe infections.

Sea turtles eat plastic bags and soda-can rings, which resemble jellyfish, a favorite food. Seabirds eat bottle caps or chunks of foam cups. And microplastic pieces can resemble plankton, small organisms that many marine animals consume. Plastic pieces may make an animal feel full, so it doesn’t eat enough real food to get the nutrients it needs. Plastic can also block an animal’s digestive system, making it unable to eat. A 2015 study found that nearly 700 marine species have been observed entangled with or eating plastic.

One of the biggest problems of plastic pollution is its effect on sea life. Seals, sea turtles, and even whales can become entangled in plastic netting. This can make it hard for them to move or eat. If that happens, they may starve to death. The plastic can cut into the animals’ skin. It may cause wounds that develop serious infections.

Sea turtles eat plastic bags and soda-can rings. Those things look like one of their favorite foods: jellyfish. Seabirds eat bottle caps or chunks of foam cups. And microplastic pieces can look like plankton. Those are small organisms that many marine animals eat. Plastic pieces may make an animal feel full, so it doesn’t eat enough real food to get the nutrition it needs. Plastic can also block an animal’s digestive system. This stops the animal from eating. A 2015 study found that nearly 700 marine species have been seen entangled in or eating plastic.

Plastic and its associated pollutants can even make it into our own food supply. Rochman and other scientists recently examined fish and shellfish bought at markets in California and Indonesia. They found plastic in the guts of more than a quarter of samples purchased in both locations. In organisms that people eat whole, such as sardines and oysters, that means we’re eating plastic too. In larger fish, chemicals from plastic may seep into their muscles and other tissues that people consume.

Plastic and the pollutants that go with it can even make it into our own food supply. Rochman and other scientists recently looked at fish and shellfish from markets in California and Indonesia. They found plastic in the guts of more than a quarter of samples from both places. People eat some animals whole, such as sardines and oysters. That means we’re eating plastic too. In larger fish, chemicals from plastic may seep into their tissues. Then people eat those tissues.

TURNING THE TIDE

One way to keep the ocean cleaner and healthier is through cleanup efforts. A lot of plastic waste caught in ocean currents eventually washes up on beaches (see Swirling Plastic). Removing it can prevent it from blowing out to sea again. “Beach cleanup is ocean cleanup,” says Rochman.

Oregon-based artist Angela Haseltine Pozzi recently teamed up with volunteers for a project called Washed Ashore. They gathered plastic from beaches on the northwest coast of the U.S. Pozzi used it to make sculptures of marine life to help raise awareness of plastic pollution.

How can people keep the ocean healthier? One way is through cleanup. A lot of plastic caught in ocean currents washes up on beaches (see Swirling Plastic). Removing it can stop it from blowing out to sea again. “Beach cleanup is ocean cleanup,” says Rochman.

Angela Haseltine Pozzi is an artist in Oregon. She teamed up with volunteers for a project called Washed Ashore. They gathered plastic from beaches on the northwest coast of the U.S. Pozzi used it to make sculptures of marine life. She wanted to raise awareness of pollution.

Cleanup efforts can’t reach every corner of the ocean or track down every bit of microplastic. That means it’s critical to cut down on the amount of plastic that reaches the sea in the first place. Scientists are working toward new materials that are safer for the environment. For example, Jambeck and her colleagues are currently testing a new polymer that breaks down more easily in seawater.

“Individual actions make a big difference,” says Jambeck. Disposing of plastic properly for recycling or trash collection is a key step. “And simple things like reusable water bottles, mugs, and bags really cut down on waste,” she says. Skipping straws or using paper ones helps too.

Ocean pollution can seem overwhelming, but it’s something everyone can help address. “This is a problem we can really do something about,” says Rochman.

Cleanup efforts can’t reach every corner of the ocean or track down every bit of microplastic. So it’s important to decrease the amount of plastic that reaches the sea in the first place. Scientists are working toward new materials that are safer for the environment. For example, Jambeck and her co-workers are testing a new polymer. It breaks down more easily in seawater.

“Individual actions make a big difference,” says Jambeck. A key step is disposing of plastic properly for recycling or trash collection. “And simple things like reusable water bottles, mugs, and bags really cut down on waste,” she says. Skipping straws or using paper ones helps too.

Ocean pollution can seem overwhelming. But it’s something everyone can help address. “This is a problem we can really do something about,” says Rochman.

CORE QUESTION: What are some properties of plastic that make this versatile material a problem pollutant? Cite evidence from the text.

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