Skip to main content

Too Good to Be True: Sea Mammals, Plastic Pollution and a Modern Chimera

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


73.1% of all facts are made up.

I made that up.

Which, it seems, puts me in fairly good company. I study marine plastic pollution, it’s my thing. I’ve been at it for a year and a half now. The research and journalism I’ve perused has shined harsh, honest lights on a serious ecological problem. But it’s also raised troubling questions. For one thing, many sources recycle the same "facts" over and over. One in particular keeps cropping up, on personal blogs, nonprofit Web sites, popular scientific eZines, press releases. The words change, but the gist is always this: "100,000 sea mammals are killed by marine plastic pollution every year."


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Wow. This is a striking number. Horrifying even.

Yet something has always bothered me about that number. It’s too round. Too easy. Too "everywhere." The vanilla ice cream of heartstring-tugging environmentalism.

For some time, I didn’t give it much thought. Then, a couple weeks ago, I caught the threads of a Twitter conversation among various marine scientists & advocates. Circling around the 100k number. I decided to see if I could get to the bottom of it, once and for all. Did this number have any legs? Where did it come from? Why does it appear all over the place?

Many organizations use the 100k figure with no citation. It wouldn’t be profitable to single out one, or even a handful, of these sites. Instead, my starting point on the Quest for the Source was a tweet on September 28, 2011 by @Surfrider to a page on the 'Beachapedia' wiki.

On September 28, that page provided the "100,000" figure with one three-part citation. The most official & relevant of the three: a 2005 report by the United Nations Environment Programme called "Marine litter - trash that kills" *

Eagerly, I followed the link and thumbed through the UNEP report. And I found the figure, on p. 10. Alas, it is uncited. In fact, the 18-page document lists a dizzying array of facts and figures, yet provides no direct link for many of them, just a vague list of general references. It’s a dead end.

Still, this took the figure back to 2005, which is something. I ran a Google search, using 2004 as the latest cutoff date, to see what would crop up. Much did. The most promising was a link to a National Geographic article from May 6, 2004, "Oceans Awash in Microscopic Plastic, Scientists Say".

The bottom of the first page of the article lists the 100,000 figure, and the author says it comes from "the U.K.’s Marine Conservation Society." Ironically, the lead-in to this figure reads, "The impact of larger plastic flotsam on marine wildlife is well documented"; the article then fails to give any link to the Marine Conservation Society’s documentation.

Still, I went back to Google to look up the Marine Conservation Society. Sadly, no combination of "Marine Conservation Society", "sea mammals", "marine mammals", "100,000" (or "100000"), "plastic pollution", "plastic trash", "marine debris", "marine litter", or anything else could tie me into a relevant Web site from the right time period. Nothing.

After playing out all leads, I concluded that the "Marine Conservation Society" thread, if once useful, was now another dead end. So I dropped the term. Instead, I went back to more general searches, this time using 2000 as the latest date. Just to see.

And I hit something big. A Chicago Tribune article from March 1985, republished from the New York Times, December 25, 1984, "Deadly Tide of Plastic Waste Threatens World’s Oceans and Aqautic Life". A popular article outlining the then-new issue of marine plastics. And the 100,000 figure was there! The Times had obtained it from "The Entanglement Network," a group that had reported at the "Workshop on the Fate and Impact of Marine Debris" in Honolulu, November 26-29, 1984.

That workshop’s proceedings are available in full (pdf) on NOAA’s Marine Debris Web site. The figures for entanglement & death are on p. 269 of the report, but nowhere is the "100,000" figure given.

The New York Times article of December 1984 is the first published record of the 100,000 number.

And just like that, I had the answer. A "fact" handed down & bandied about from article to nonprofit, conservation society to international organization, over years and years. So long that it has taken a life of its own, and becomes unquestioned, and unsourced. Whether there is -- or was -- any science behind it remains in doubt.

But seeking good science misses the point. The point is, the number is now 27 years old! If it ever had real value, it doesn’t now. The world is changed. But in an age of page hits, search engine optimization, and a crowded Web, it’s a number that’s just too good to pass up. Especially when it’s been "vetted" by heavyweights like National Geographic and the United Nations. It’s an excellent warning to us all. Sometimes "facts" are built on ether.

By the way, the search for the truth took 22 minutes.

-------------------------------------------------------------------------------------

* At the end of the day on September 28, the Beachapedia link to the "100,000" figure was edited to separate the references into individual citations. As of October 9, none provides a direct reference back to the original "100,000" figure. All are dead ends.

Harold Johnson lives in Saco, Maine with his wife and young daughter. A freelance copyeditor and writer by trade, he spends his free time studying archaeology, earth sciences, and the ways the natural and manmade world have mingled across millennia. Since May 2010, he has written on marine debris and plastic pollution as The Flotsam Diaries.

More by Harold Johnson