NewsNational News


Parasites disappearing and it's not all good news for humans

Posted at 3:28 PM, Feb 02, 2023

As temperatures rise around the world, there is an increase in disease-spreading parasites like ticks. While there might be an increase in the parasites that harm humans, parasites that don’t cause us much harm can help us by keeping the ecosystems around us in check.

These types of parasites are at risk due to climate change.

A recent study from researchers at the University of Washington found 52 of these species are disappearing at a rate of 11 percent per decade.

“Which is a scary amount of biodiversity loss even for things that are icky and gross like parasites,” said Chelsea Wood, a University of Washington professor.

She says parasites can be compared to predators in many ways and uses the example of gray wolves being driven out of Yellowstone in the 1920s.

That shook up the food web before they were reintroduced in the 1990s, and balance was restored.

“Just like gray wolves keep a cap on things like elk that would otherwise overgraze an ecosystem, parasites can keep a cap on the abundance of their hosts and prevent those hosts from becoming overabundant pests that are going to bother us or destroy human livelihoods,” Wood said.

Parasites also help us with predator conservation efforts.

They make their prey weak, slow, reckless and less fearful of their predators, and as a result, they make those prey likelier to be eaten by predators. They're essentially knitting together the food web by pushing energy from prey into predators.

Wood says research into the role parasites play in ecosystems is still pretty new. But all this indicates that we may miss them when they’re gone.

If climate change slows down, so will the decline of parasites.