Effect of Plastic Waste on Marine Life
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The Effect of Plastic Waste on Marine Life and Life in our Oceans

Today, we commonly use a range of plastic products in everyday life. Due to their lightweight and durable qualities, we find plastics in a host of different products. Unfortunately, plastic ends up in the marine environment after having been discarded.

When you take the time to walk along just about any beach, you can find plastic debris. This is true whether it is an ocean, lake, or other body of water. It might be plastic bags, an old toy, a container for a six-pack of soda, or countless other objects.

The effect of plastic waste on marine life can now be felt across the globe.

Plastic Poses a Serious Danger to Marine Life

Sadly, the amount of marine plastic pollution in the water causes serious problems for marine life. A study from Plymouth University has found that nearly 700 species of marine animals have encountered debris from humankind8. Researchers also found evidence of more than 44,000 animals and organisms swallowing debris in the ocean or becoming entangled.

The number one debris culprit in 92% of the cases was plastic. The IUCN Red List of endangered species listed 17% of these marine animals as threatened or near-threatened.

Further, the 13 million tons of plastic waste that enter our oceans every year can transport invasive marine species. Floating plastics travel long distances, and with it, species that cause harm to the marine ecosystems in areas they don't naturally belong.

Out of nearly 700 species that have encountered debris, they found close to 400 had involvement with plastic ingested or entanglement at least once. These types of incidents happened all around the world but were in higher concentrations off the East and West Coast of North America. This occurs along the coastal areas of Europe and Australia, as well.


Fish ingest plastic waste and microplastics
Photo by Sebastian Pena Lambarri on Unsplash

Fish and other marine mammals that have gills have found their risks increased, particularly when it comes to small particles of plastic debris found in the water.

A study conducted by the University of Exeter found that it was more difficult for the fish to remove waste captured through their gills than plastic waste in the mouth. Plastics in the water can devastate fish, and because humans consume the fish, it affects us humans as well when it enters our food chain.

Sea Turtles

Sea turtle
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The sea turtle has also had a terrible time dealing with the vast amount of ocean plastic pollution in our oceans. Each year, plastic debris, including fishing nets, entangles turtles. Many turtles will also ingest plastic because they mistake it for actual food. Plastic can become lodged in their digestive system, causing them to die.

Often too, because of the plastic lodged in their guts, they can mistakenly not feel hungry. As a result, they can not seek food and die of starvation.

Six out of seven sea turtles worldwide ingest plastic debris7. Only the flatback sea turtle does not. Researchers found out that nearly 50% of sea turtles had swallowed plastic, which ultimately contributed to their deaths.

Whales and Dolphins

Whales and dolphins, as well as other marine mammals, often have the same problem. They also swallow plastic because they cannot distinguish between food and plastic. In some instances, they may be eating other marine creatures entangled in plastic. At least 26 species of cetaceans have ingested plastic debris6.

In fact, there was a case from 1993 where a male pygmy sperm whale was stranded in Texas. The beached whale died in a holding tank 11 days after rescue. Researchers discovered the first two stomach compartments were full of plastic debris. Items found in the whale include a plastic chip bag, a garbage bag, two pieces of plastic sheeting, and a bread wrapper2.

These types of plastic ingestion cases are not rare; however, it seems as though they are getting progressively worse.

Even shore crabs have had serious problems with ingesting plastic litter. It ends up retained in the body tissues of the crabs for up to 14 days after ingestion and for up to 21 days after entering into the gills5.

Related: Read more in our list of fascinating whale facts and compilation of whale quotes.

Sea Lions and Seals

Sea lions and seals are facing similar problems in regard to plastic. They have issues with plastic debris, nets, and fishing lines, as well as bags and packing bands made from plastic.

Researchers conducted an eight-year study in Southeast Alaska and British Columbia4. They found that there were 388 sea lions that were either entangled in marine debris or had eaten fishing gear. The researchers created a video that shows how sea lions become entangled. It also provides information on how people can help to deal with this problem.


Birds become entangled in plastic waste
Birds can easily become entangled in discarded fishing nets and other plastic waste.

Sea birds are not exempt from ingesting plastic debris in the marine environment either. A study found that between 1962 and 2012, eighty of 135 species had ingested plastic, and on average, 29% of the birds had plastic in their gut3. By standardizing the data, they believe that the rate of ingestion would be as high as 90% in today’s world. Again, the threat today is more severe, impacting numerous marine species, and it continues to get worse.

Related: Find out more about our feathered friends in our rundown of fascinating bird facts.

The Problem with Microplastics

It is important to realize that it is not only the larger pieces of plastic trash that are easily visible and that are causing problems in marine life.

Even if all of the large pieces of plastic were fished out of the water, we would still have to contend with the dangers of microplastics that were not removed because of their small size. These are particles that are made from non-degradable plastic that is less than 5mm long and that will not dissolve in water. They can be as small as one micrometer.

A range of different factors affects the bioavailability of microplastics in the water. Microplastics can come from a host of different sources and make their way into our water. Microbeads, for example, are small beads that are found in exfoliates, which were once made from natural ingredients.

However, today, they use small plastic beads to fill them. You find them in hand soap, conditioner and shampoo, sunscreen, cleansers, deodorants, toothpaste, and a host of other items that people will use around the house without thinking twice. Most people do not realize the amount of damage that these microplastics are doing.

Because so much sea life has already ingested these microplastics, it means that seafood for human consumption now also contains these plastics.

In fact, research in the United States and Indonesia found that about 25% of the fish in markets had small plastics in them, and this was true with about 33% of shellfish1. This means that a large number of people are already unwittingly ingesting plastic.

What Can Be Done About the Rise of Plastics in the Marine Environment?

With the massive amount of plastic in the marine environment, it is important that the world begins to take steps now to make some serious changes. The oceans, lakes, and rivers are essential to our survival as a species, as well as the survival of the species that make those locations their home.

The world needs to reduce its dependency on plastic. However, global plastic production is forecast to continue to grow, reaching 590 million metric tons by 2050.

We are already starting to see some changes in a positive direction happening in this area, as many locations have banned plastic straws, and bags and reduced disposable packaging. Further, improvements in plastic waste management are seeking to reduce ocean plastics, but we have a long way to go.

Meanwhile, as awareness of the plastic waste problem grows, many of us are now saying no to plastic water bottles, seeking our eco-friendly alternatives to plastic straws, and even shopping for zero-waste gifts. These are all steps in the right direction.

And innovative solutions are coming to bear too. Today some plastic is made from hemp, which can be used in everything from cars to packaging.

Bamboo is proving a more sustainable alternative to plastic, and as we look to reduce, reuse and recycle, different types of plastic waste are now finding their way into clothes and even roads.

As such, we have a range of solutions and alternatives. We can all do our bit to reduce plastic waste in the office, and at home and make choices to cut down on all the plastic we buy, use, and discard.

In addition, producers of products need to rethink the materials they are using, as well as their packaging. It may also be a good option to increase taxes and fees on the use of various types of polluting plastics. Improved waste management systems and recycling are essential, as well.

Additional research and studies can also help. People can learn other areas of concern, as well as new ways of dealing with our waste mountains, toxic chemicals impacting ocean health, and innovations to prevent plastic pollution.


Ultimately, there needs to be more education when it comes to plastic in the marine environment. The general public needs to understand more about the types of problems occurring and just how dangerous they can be.

Educating current and future generations and implementing meaningful changes is essential to stop plastic pollution. It may be possible to eventually eliminate or at least greatly reduce the amount of plastic in the marine environment.

1Rochman CM, Tahir A, Williams SL, Baxa DV, Lam R, Miller JT, Teh FC, Werorilagngi S, and Teh SJ, “Anthropogenic Debris in Seafood: Plastic Debris and Fibers from Textiles in Fish and Bivalves Sold for Human Consumption”, 2015
2R.J. Tarpley, S. Marwitz, “Plastic Debris Ingestion by Cetaceans along the Texas Coast: Two Case Reports”, 1993
3Chris Wilcox, Erik Van Sebille, and Britta Denise Hardesty, “Threat of Plastic Pollution to Seabirds is Global, Pervasive, and Increasing”, 2015
4Riley Woodford, Alaska Department of Fish and Game, “Entanglement of Steller Sea Lions Identifying Causes and Finding Solutions”, 2012
5Environ. Sci. Technol., “Uptake and Retention of Microplastics by the Shore Crab Carcinus Maenas”, 2014
6José G.B Derraik, The pollution of the marine environment by plastic debris: a review, Marine Pollution Bulletin, Volume 44, Issue 9, 2002, Pages 842-852, ISSN 0025-326X, https://doi.org/10.1016/S0025-326X(02)00220-5
7Qamar Schuyler, Britta Denies Hardesty, Chris Wilcox, and Kathy Townsend, Society for Conservation Biology, “Global Analysis of Anthropogenic Debris Ingestion by Sea Turtles”, 2013
8S.C. Gall, R.C. Thompson, The impact of debris on marine life, Marine Pollution Bulletin, Volume 92, Issues 1–2, 2015, Pages 170-179, ISSN 0025-326X, https://doi.org/10.1016/j.marpolbul.2014.12.041
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