Parasites Permeate Ecosystems

A study shows that parasites can make up three percent of an ecosystem's biomass--and even outweigh the so-called top predators. Karen Hopkin reports.

Illustration of a Bohr atom model spinning around the words Science Quickly with various science and medicine related icons around the text

Join Our Community of Science Lovers!


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.


[The following is an exact transcript of this podcast.]

When you think about an ecosystem, you usually think of the big animals that live there. The Serengeti’s ruled by lions. And estuaries are populated by fishes, birds, snails and maybe the occasional otter. But there’s more to an ecosystem than meets the eye. Because a team of scientists from the US and Mexico has found that parasites constitute a sizeable chunk of the biomass of an ecosystem.

The scientists catalogued and weighed all of the plants, animals and parasitic species living in three river estuaries. They found that in terms of sheer bulk, parasites represent about three percent of the biomass of these ecosystems. Pound for pound, one parasite—the trematode fluke that infects a certain snail—outweighs all of the estuaries’ birds, which are the ecosystem’s top predators. The results appear in the July 24 issue of Nature. That means that creatures you can’t see might be even more important to the health of an ecosystem, and to its balance of power, than the ones you can see. For example, in these estuaries, snails that are infected with trematodes outnumber those that are fluke-free. Now that’s what you call a controlling interest.

—Karen Hopkin

60-Second Science is a daily podcast. Subscribe to this Podcast: RSS | iTunes 

 

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe