Microplastics & Megafauna

Posted Tue, 03/27/2018 - 11:00

By: Demi Fox, Northeast Regional Coordinator for the NOAA Marine Debris Program

We’re spending March talking all about marine debris and its types, sources, impacts, and solutions. Tune in throughout the month to learn more about this important topic and how we can all be part of the effort to make our lives and our ocean #DebrisFree.

Marine debris is a serious threat to marine animals. While large pieces of litter can have dramatic impacts on marine animals, less obvious are the dangers of plastics measuring less than five millimeters in size, known as “microplastics.” These small pieces of debris have quickly become a high research priority for scientists around the world. Microplastics enter the marine environment from a variety of sources: microbeads in cosmetics, microfibers washed from our clothing, and plastic fragments degraded by the sun, among many others. The threats they pose depend on their quantity, chemical composition, location in the ocean and the water column, and availability for ingestion. Despite its small size, microplastic debris is affecting some of the planet’s largest animals.

Loggerhead sea turtle hatchlings crawling on the beach.
Loggerhead sea turtle hatchlings make their way into the Gulf of Mexico. (Demi Fox/NOAA)

Every year, thousands of sea turtles come ashore to lay nests. After incubation in the sand, hatchlings make the arduous journey to the sea and take refuge in the floating algae, which provides food and shelter to many juvenile marine species. Unfortunately, this algae also collects floating debris. In a recent study by Pham et al. 2017, scientists found 83% of observed oceanic-stage loggerhead sea turtles in the North Atlantic had plastic in their gastrointestinal tracts. Plastics ranging from one to five millimeters in length were noted in 58% of individuals. This is especially bad news for sea turtles, as all seven species of sea turtles (including loggerheads) are endangered or threatened.

There is also an increasing threat to baleen whales. These animals strain thousands of gallons of water each day for plankton, small fish, or crustaceans. Not only does their filter feeding behavior enable them to consume microplastics, reportedly by the thousands per day, but because most whales have a thick blubber layer, fat-soluble chemicals leached from the plastics could be readily absorbed into their bodies.

Other marine mammals, such as dolphins, porpoises, seals, and sea lions can also be effected. If the small fish and other prey they consume have previously consumed microplastics, the debris can accumulate as it makes its way up the food chain.  

Thankfully, it’s not all bad news! There are many ways to help address this problem. Here are a few ideas to get you started:

  • Avoid single-use plastic products when you can, opting instead for reusable water bottles, utensils, grocery bags, coffee mugs, and food containers. 
  • Avoid personal care products with plastic exfoliants and opt for natural options instead. This is becoming easier now that microplastics are being phased out of production in the United States.
  • Join a cleanup! No matter where you live, removing plastic items from the environment protects the ocean.
  • Spread the word. Preventing marine debris is the ultimate solution to this problem and getting others in on the action is important!


We are learning more about the complex interactions between debris and marine species every day. As we gather more information, we can work toward more solutions. Together, we can change the course of ocean pollution for protected species, for human health, and for the long-term conservation of the marine environment upon which we all depend. 


Microplastics & Megafauna

Posted Tue, 03/27/2018 - 11:00

For citation purposes, unless otherwise noted, this article was authored by the NOAA Marine Debris Program.

The Marine Debris Blog is no longer accepting comments but continues to display past contributions.


Thu, 05/31/2018 - 08:09

why does this happen can we stop making this happen i think they should be able to live a free life like we do i think if you see trash you should pick it up we should do something like helping our community by picking up trash if you can help that would be grate


Thu, 05/31/2018 - 08:10

help the animals


Fri, 04/19/2019 - 15:39

I would like to know how micro plastics adversely affect marine mammals. What are they actually doing to the animals aside from being absorbed by their fat??

Scientists are still studying how plastics and their chemicals affect animals. Generally speaking, it is possible that ingestion of microplastics can affect growth, development, and reproduction. However, this depends on many factors, including the type of animal, the type of plastic ingested, any additives added to the plastic or chemicals that have absorbed to its surface, the amount of microplastics ingested by the animal, and the length of time microplastics are in their bodies. This is a complex issue that marine debris researchers are actively trying to understand!

If you have any other questions, please reach out to us at marinedebris.web@noaa.gov!

...The article starts as, "Marine debris is a serious threat to marine animals." There was a legit question made by someone as "I would like to know how micro plastics adversely affect marine mammals. What are they actually doing to the animals aside from being absorbed by their fat??" MDPs answer comes with "scientists are studying", "it is possible", "it depends", "researchers are actively trying to understand". Seems that there are too many doubts on this subject to start an article with such a sensationalist affirmation as the one above. I mean, it looks like a propaganda to me, not science. Specially because real science do not need to use sensationalist words, since their ASSUMPTIONS, not affirmations, are backed by provable studies and facts.
...A good example to look at are the Southern Resident Killer Whales. They have identified one of the top 3 causes of their decline includes chemical pollution with plastics being one of the vectors for that as microplastics attract harmful chemicals which then piggyback on them and are consumed up the food chain. While these chemicals are then locked away in the blubber layer, they are released into the animal's system as they starve from lack of food (Chinook salmon which is endangered too) and begin to affect their immune system and reproduction and development. It is a big conservation concern with regard to these animals and has a number of top scientists trying to address it. Thus it is a good example of microplastics causing harm to megafauna in the ocean.


Mon, 11/14/2022 - 10:37

...im scared