On a recent canoe camping trip in the Boundary Waters my friend lifted up our tent ground cloth and discovered a worm beneath it. I shouted, “Quick, grab it and kill it!” I’d like to say I’m not a regular worm killer but I have been known to drown a large number of night crawlers while attempting to catch fish with them. I prefer to drown leeches and would prefer other people use leeches as bait or make sure they never discard their crawlers on the ground.
My friend, who is very smart, did not know worms are an invasive species. I started to tell her about the damage worms can do to an ecosystem but when she asked me questions about it I began to question myself. That’s what prompted today’s topic for the blog. The bottom line is invasive earthworms can change the makeup of the forest and reduce species diversity just like other invasive plants can. There has even been evidence they have a negative impact on wildlife and birds!
I encourage you to do your best to help prevent the spread of earthworms, especially into our Boundary Waters Canoe Area Wilderness and the Gunflint Trail. Did you know worms used as bait for fishing are able to swim, survive in water for months, make it to shore and reproduce? This is why you must discard all bait into the trash and never dump crawlers into the water or onto the land, even if you think they are all dead. And believe me, it’s very difficult to find a pulse on a live night crawler so we’d rather you be safe than sorry.
PLEASE, Spread the WORD, not the WORM!
Here’s some information from the article.
Many people mistakenly believe that brown earthworms, including angleworms and night crawlers, are native. But there are no native earthworms in North America; they all were taken out during the last ice age. The only native worms are the whitish, skinny worms you might find under rocks. North American forests developed over the past 10,000 years without earthworms…
Lee Frelich, director of the University of Minnesota’s Center for Forest Ecology and an expert on mortheastern Minnesota forests said, “The non-native worms consume the duff — the decaying leaves on the forest floor — as they eat their way across the continent’s forests. The worms alter the physical and chemical properties of soils, changing the pH, nutrient and water cycles and disrupting symbiotic relationships between soil fungi and tree roots.”
Here’s some information from the Great Lakes Worm Watch.
Prevent introductions of earthworms to any site
Avoid activities that we know spread earthworms
- If you use earthworms as fishing bait, throw any unused earthworms in the trash, not in the water or on the land (it is illegal to knowingly introduce any exotic species!).
- If you use earthworms for composting (vermicomposting), before you use the compost, freeze it solid for at least 1 week (a month is better). This kills the earthworms as well as their egg cases (cocoons) which are often more tolerant of drying and freezing than the earthworms themselves. If you live in an area that gets sub-freezing temps for at least a month straight each winter, you can do this by putting a bucket of the compost in an unheated building for the winter.
- Do not transport leaves, mulch, compost or soil from one place to another unless you are confident that there are no earthworms or their cocoons present.
- If you use ATV’s or other vehicles with tread that can hold soil, be sure to wash all soil from tire treads before transporting the vehicle from one place to another.