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Earth Rangers, You Squashed the Gross Out Challenge!

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Congratulations, Earth Rangers! You’ve successfully out-slimed and out-grimed the Gross Out Challenge! Together, you’ve logged over 120,000 climate-friendly habits, and to celebrate, we’re going to introduce you to someone who knows a LOT about slimy creatures: earthworm researcher Stephen Paterson!

Meet researcher Stephen Paterson, sampling for earthworms in northern Saskatchewan. Photo Credit: Aaron Bell

The Mysterious Earthworm

It might surprise you to find out that we don’t know a whole lot about many species of earthworm. We know they come in different colors. Some live in trees, some live in lakes, and one type of Australian earthworm can grow to be up to three meters long! We know that the roles earthworms play in their ecosystems are complex. (They’re sometimes called ‘ecosystem engineers.’) That’s why it’s important to understand HOW earthworms are distributed and what effect they’re having on the ecosystems they’re in.

This is Stephen Paterson recording habitat data at a sampling site in the Yukon. He records lots of information about the habitat and soil properties to understand where earthworms like to live. Photo credit: Samantha Bennett

Invasion of the Earthworms

First, let’s talk about how earthworms came to Canada. There were almost NO earthworms in Canada after the last ice age. People brought them here from Asia and Europe because earthworms are often great for gardens and agriculture – they aerate the soil and they make nutrients more available to plants. But it’s not all good news. When non-native species are brought to a new place, there can be consequences.

Meet field assistant Samantha Bennett, in a northern Saskatchewan forest, sampling for earthworms. Photo credit: Stephen Paterson

Into the Woods

Earthworms can become a problem when they end up in our forests. They decompose leaf litter, a thick layer of decaying leaves that native plants and animals rely on. Earthworms do it much faster than native decomposers. This can cause biodiversity loss and the release of greenhouse gases – two things we definitely DON’T want.

This is Dendrobaena octaedra, a common non-native earthworm species in the Canadian boreal forest. Photo credit: Stephen Paterson

But HOW do earthworms end up where they’re not supposed to be? Blame it on people. Earthworms are often spread when people use them as fishing bait, put them into their gardens, or move soil or plants around.

Earthworms collected as samples. Did you know that scientists have found over 7000 different species of earthworm…and they think there are probably about 20,000 more species to be discovered! Photo credit: Stephen Paterson

We can appreciate the good work worms do in our gardens, but make every effort to keep them out of the forests where they can do harm. Avoid moving soil or wood into forests because worms can hide in even the smallest amounts of both. And, if you’re going fishing, definitely do not leave your bait behind.

A New Friend!

Everyone who logged a habit during the Gross Out Challenge will unlock a special Worm Buddy for your avatar in the Earth Rangers App! Visit the Community Rewards section of the Challenge to learn more. We’re proud to support the work Stephen Paterson is doing, so in honor of our Gross-Out Challenge, we’re making a donation to contribute to his important research.