Plastic Pollution and Marine Life

Plastic pollution is taking over our oceans. We look at the impact marine plastics have on sea life

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What are marine plastics? How does plastic pollution affect our oceans? And what marine mammals are at the greatest risk of plastic pollution? We take a closer look.

Plastic is everywhere in our society. From the kitchen, to the bathroom, from the check-out line, to the take-out window, we consume millions of pounds of plastic every day.

It makes sense. Plastic is inexpensive, it’s lightweight, and it’s relatively easy to manufacture. Sadly, though, the majority of plastic we consume is used once and discarded. Just 9% of all plastic created is ever recycled, while 12 percent is incinerated.

The rest – 79% – is sent to landfills, or what’s increasingly common, it ends up in the environment, in our rivers and lakes, beaches, and our oceans.

Plastic pollution is a real threat to marine life, and the problem continues to grow each year. For example, the Great Pacific Garbage Patch, a swirling mass of plastic waste which floats off the coast of California, is now larger than the state of Texas. And every day, marine animals and wildlife ingest and become entangled in ocean plastics. An estimated 1 million seabirds and more than 100,000 marine mammals are killed every year due to ingesting or getting tangled in marine plastics. And some estimate that a dump truck load worth of plastic enters our oceans every minute.

Sadly, the problem is expected to grow. By 2050, it’s estimated the weight of all plastic in the oceans will outweigh fish!

But where does this plastic problem originate? How grave is the threat of plastic to our oceans? And which marine species are at the greatest risk to suffer? More importantly, what can we do to slow the flow of plastics into our oceans, and how can we help make a real difference?

Jump to…

Part 1: Plastic Pollution and the Ocean – A Quick Overview
Part 2: The Biggest Sources of Plastic Pollution
Part 3: How Much Plastic is in the Ocean
Part 4: How Does Plastic Pollution Harm Marine Life
Part 5: Ocean Plastic Statistics
Part 6: What Can We Do to Stop the Plastic Pollution

Plastic Pollution and the Ocean: A Quick Overview

Plastic enters the ocean in a number of ways: through rivers, drainage systems, in rain runoff, and by wind, to name a few. Some plastic washes ashore. Yet, a majority of ocean plastic gets stuck at sea. And these pieces of plastic are pulled by currents around the globe. Plastics take a beating by currents and waves, as well as the sun, and they slowly break down over time. A single plastic bottle, therefore, turns into tiny, nearly microscopic fragments of plastic called “micro-plastics.” Micro-plastics, thusly, are one of the most significant problems around the world, and these smaller bits of plastic create a number of problems for marine life, including:

  • Ingestion – Micro-plastics are consumed by hundreds of marine species. In particular, animals like albatross and whales – which hunt by skimming water – are at particular risk for ingesting these harmful plastics. In some heavily polluted areas, like the Great Pacific Garbage Patch, micro-plastics outnumber plankton by a factor of six!
  • Releasing Chemicals – Many of the most commonly used types of plastics contain harmful chemicals and artificial dyes. Animals can be exposed to these chemicals, which can cause cancer and reproductive problems. A study of Florida dolphins, for example, found that nearly all had been exposed to man-made chemicals.

Ultimately, there are five major centers of plastic pollution in the ocean, known as ocean gyres. Gyres are massive circling currents that suck in plastics of all forms – including micro-plastics, plastic debris like frisbees, bottles and flip-flops, and ghost gear (which is fishing tackle that’s lost at sea). And these gyres tend to pull debris under water, where it breaks down and tends to swirl around long-term.

In fact, 99% of all the plastic in the oceans is suspended underwater or on the seafloor. The most famous gyre is the Great Pacific Garbage Patch, which is also known as the North Pacific gyre. Other major gyres include the South Pacific, North Atlantic, South Atlantic and Indian Ocean gyres; although there are gyres in nearly every major sea and ocean in the world, including the Mediterranean and Arctic. Sadly, the plastic pollution problem has gotten dire. An estimated 5.25 trillion pieces of plastic are thought to be in our oceans, which more recently scientists have said may be a significant underestimate.

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What Are the Biggest Sources of Ocean Plastic Pollution?

Since the 1950s, when plastics became popular, worldwide production of plastics has risen significantly. In 2015, for example, an estimated  322 million tons of plastic were produced globally. And since the 1950s, the amount of plastic produced weighs as much as 1 billion elephants. Yet, of all the types of plastic that are produced, there are five common items that are most likely to end up in the ocean.

According to yearly beach clean-up statistics from the Ocean Conservancy, an organization that hosts a massive one-day cleanup event around the world, as well as The Plastics BAN List from 5Gyres, the most common items to pollute our oceans include:

  • Food Wrappers and Containers – According to 5Gyres, food wrappers account for about 31% of pollutants in the state of California. This includes items like foam take-out containers, snack bar wrappers, and plastic food bags. During the 2018 International Coastal Cleanup, food wrappers were a Top 5 item; more than 1.7 million wrappers were picked up around the world.
  • Plastic Bottle Caps – Bottles, although a source of pollution, are more likely to make it to recycling or trash bins. Caps, on the other hand, tend not to. According to International Coastal Cleanup stats, nearly 1.1 million bottle caps were picked up globally during the one-day event in 2018.
  • Plastic Bags – More than 100 billion single-use plastic bags are used each year in the U.S. On average, American families use about 1,500 bags per year. According to The Plastics Ban List, plastic bags account for about 11% of plastic waste along California coasts, and about 757,000 plastic bags were picked up during the International Coastal Cleanup in 2018.
  • Beverage Bottles – Bottles tend to be recycled more frequently than other plastic materials. According to The BAN List, bottles have recycling rates in the 70% range in California. Yet, they still often end up in our oceans. In 2018, nearly 1.6 million plastic bottles were picked up during the International Coastal Cleanup.
  • Straws/Stirrers – Plastic straws are single-use items that aren’t typically recycled. They account for a significant amount of ocean pollution; during the Coastal Cleanup nearly 650,000 straws were picked up. And they account for about 8% of plastic waste on California coasts.

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How Much Plastic Is in the Ocean? And How Did It Get There?

According to estimates, about 18 billion pounds – or 9 million U.S. tons – of plastic enter our oceans every year. That’s roughly the equivalent to 24 Empire State Buildings of plastic accumulating in our oceans.

A large majority – about 80 percent of all marine plastic – originates on land, while the other 20 percent includes items like fishing gear or boating materials that are lost at sea.

So how does all this plastic get from land into our oceans? In particular, there are four main ways that pollution enters the ocean. They include:

  • Litter/Waste – Less than 10 percent of plastic waste is recycled. Unfortunately, a percentage of non-recycled or non-incinerated plastics end up in the ocean. One source is litter; wind blows litter toward our beaches. Another is improper waste management, for example, placing a plastic bottle or bag on an overfull trash can. Ultimately, increasing recycling rates and litter cleanup projects can help limit this source of plastic pollution.
  • Rivers – A piece of litter in Ohio will eventually make it to the ocean. And often, it’s carried there by the nation’s waterways. According to the latest statistics, the world’s largest rivers carry nearly 2.5 million tons of plastic to the sea each year.
  • Down the Drain – Water drainage systems sometimes seep into the ocean, and unfortunately, many of the household products that we use – especially bath products that contain microbeads – end up in our oceans. Plastics like floss, microfibers, and synthetic cottons are also major sources of plastic pollution.
  • Ghost Gear – About 20 percent of the plastic in the oceans is created at sea. Fishing tackle, including netting, plastic fishing line, lures and bait traps, for example, are a major source, and these often create problems for seals and sea lions that tend to get caught in lines and netting. Nearly all marine mammals are prone to entanglement, though.

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How Does Plastic Pollution Harm Marine Life?

All of this plastic in the ocean has an adverse effect on marine life. It affects everyone – from the animals, to the plants, and even to us (as we’re likely to eat seafood tainted with plastic waste).

In particular, there are common ways that plastic affects marine life. For one, plastic is often mistaken for food; a floating bag, for example, looks a lot like a jellyfish to a turtle (a common source of food). When ingested, plastic can cause inflammation, cancer and digestive issues.

Another major problem is entanglement. Plastic netting, rubber bands and other plastics can get caught on seals, dolphins and other creatures, causing injuries, infections, trouble moving, etc.

Sea plastics affect a wide variety of species, about 700 species in total. Here’s a look at some of the most commonly affect types of marine life:


According to UNESCO, plastic kills roughly 1 million seabirds per year. One study found that 90% of species have ingested some form of plastic, and by 2050, nearly all, 99%, will have eaten plastic.

Many seabirds hunt by diving below the water; in the process, they scoop up and ingest lots of seawater and the micro-plastics it contains. On shore, seabirds often mistake plastics for insects and other sources of food. Ingesting plastics causes significant digestive distress; in fact, many seabirds die of starvation after ingesting plastic, because they can’t normally digest food.

Sea Turtles

The threat of plastic to turtles is two-fold. Turtles are likely to eat plastics, but they’re also at risk of entanglement. According to one study, 86% of sea turtle species are prone to entanglement and ingestion. And the World Wildlife Fund estimates that 52% of all sea turtles have ingested plastic. Further, the WWF speculates that 1,000 turtles die per year due to entanglement. Plastic on beaches and near shore can also have a significant impact on sea turtles. A study of Florida sea turtle hatchlings found that of the 27 baby turtles that died during the study, all had plastic fragments in their stomachs.

Seals and Sea Lions

Ghost gear poses a significant threat to seas and sea lions. According to one study, 28% of seals and sea lion species are affected by entanglements. Yet, it’s not just nets, and fishing tackle, according to one report, sea lions are even getting caught in bikini tops, and postal straps cause about 50% of all entanglements, according to NOAA.


Fish are often confused by plastics, thinking small fragments are plankton. Yet, they’re also prone to ingesting micro-plastics in through their gills. Numerous studies have been conducted on the prevalence of plastic ingestion in fish populations. According to one study, 70% of deep-sea fish species have ingested plastics. Another focused specifically on UK fisheries, found one-third of species – including many that end up on the dinner table like cod and black bass – had ingested plastic. The same study found that 83 percent of UK-caught scampi, a popular prawn species, contained plastic residue.

Whales and Dolphins

Whales and dolphins have also been significantly impacted by ocean debris and plastic waste. In fact, instances of whales that have washed ashore that had plastic in their stomachs are becoming more and more frequent. One recent report found a sperm whale had ingested 64 pounds of plastic.

According to the Marine Pollution Bulletin, nearly 56% of all whales and dolphins have been shown to have ingested plastics, with some specific species having ingestion rates as high as 31%.

Corals and Sponges

Corals are plastic magnets. Plastic debris gets snagged on the branches of the corals and sponges, and it often sticks there long-term. A recent study of 159 reefs found significant pollution rates in Australia, Thailand, Indonesia and Myanmar.

The researchers also examined the effect plastic has on corals and sponges. In particular, plastic tends to gash and cut into the flesh of the coral. As a result, contaminated corals have a risk of disease of 89%, compared to just 4% for non-contaminated coral. The researchers also estimated that 11.1 billion pieces of plastic are entangled on corals worldwide.

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Ocean Plastic Statistics: By the Numbers

The volume and severity of plastic pollution in our oceans is truly staggering. You can find shocking statistics about the amount of plastic that’s in our oceans, the volume that some animals are consuming, and the rates at which plastics are entering our oceans.

These are some of the most shocking stats about marine plastic pollution:
115 – Plastic drinking cups found in the stomach of one whale. In total 1,000+ pieces of plastic were found in the whale’s stomach, including two flip-flops.

329 – Pieces of plastic in the gut of one turtle found in Australia.

1763 – Pounds of plastic found in a Minke whale off the Normandy coast of France.

1000 – Turtles killed by entanglements per year.

8 Million – Pieces of plastic entering the ocean every day.

90 – Percent of waste on British beaches is plastic.

1 Million – Number of seabirds killed each year by ingesting plastic.

80,000 – Metric tons of trash in the Great Pacific Garbage Patch.

750,000 – Pieces of plastic found in 1 square kilometer of the Pacific Garbage Patch.

9.1 Billion – Tons of plastic produced since the 1950s globally.

1 – Dump truck load of plastic entering the ocean every minute.

46,000 – Pieces of plastic per every square mile of ocean.

98 – Percent of Albatross have ingested plastic.

500 – Number of dead zones in the oceans around the world.

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What Can You Do to Stop Marine Pollution? Take a Stand Against Single-Use Plastics

Plastic pollution seems overwhelming, a problem without a solution. Yet, there are many organizations working to develop tools for cleaning plastic from our oceans.

The Ocean Cleanup, for example, is an organization that’s working on building specialized boats that can clean plastic from our waterways, and others like 5Gyres advocate against plastic waste through art, science and education.

Yet, anyone can make simple choices that can help reduce plastic. A few tips for helping to keep our oceans clean include:

    • Ditch Plastic Bags – Accepting a plastic bag is second nature in the check-out line. But choosing a biodegradable option – like a paper bag – or better yet, using a reusable bag can help you reduce plastic bag waste.
    • Go with Reusables – Bring reusable items wherever you go; a reusable mug, a water bottle and shopping bag are all just a few examples.
    • Attend a Beach Cleanup – Beach cleanup events are a great way to get involved. The Ocean Conservancy’s International Coastal Cleanup day occurs all around the world. And even if you live in-land, a river or waterway cleanup can help you reduce waste that reaches the ocean.
    • Start Recycling – If you don’t recycle, start! Recycling is a quick way to reduce plastic waste.
    • Avoid Products with Microbeads – Shop for products that don’t contain microbeads. Bath gels and scrubs are some of the main culprits. Microbeads are nearly impossible to recycle; therefore, it’s best to avoid these products.
    • Buy in Bulk – Purchasing larger items can help you reduce single-serve containers and packaging.
    • Support Cleanup Organizations – Join a cleanup club or nonprofit in your area. You’ll find plenty of volunteering options. If you don’t have the time, consider a donation to a worthy cause.
    • Refuse Straws – Avoid straws at restaurants. At home, use your own reusable metal or silicone straw.
    • Pick Up Litter – If you’re out for a stroll along the beach or river trail, pick up any trash and litter you see. If you don’t, there’s a good chance it could end up in the ocean.
    • Support Bans – Nearly 350 cities in the U.S. have plastic bag bans in place. Others bans like plastic straw, single-use item and other bans are taking effect. Supporting these efforts can help reduce our reliance on single-use plastics.

Bottom Line: Plastic Is a Problem for Our Oceans. We can make a Difference

Plastic has become second-nature in our society. We use it for nearly everything. And without change, our oceans – the marine mammals and plant life – will not fare well over the long-term. Start today by reducing your reliance on plastics, and get involved. The next 25 years will matter greatly in preventing plastic pollution.

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