24 April 2020

Canadian Marmorkrebs: The North American invasion has begun

Update, 24 April 2020: The CBC news article was wrong. There are no Marmorkrebs in the wild in Canada. See this follow-up post.

I have been wondering for years when I would hear the first confirmed reports of marbled crayfish in the wild in North American, and today is the day.

The Canadian Broadcasting Company (CBC) is reporting not only that Marmorkrebs are in the province of Alberta, but they have apparently been there for some time.

In the last 10 to 20 years however, the marbled crayfish — a crustacean not native to the Bow River — has begun spreading to rivers and lakes throughout Alberta.

It's a problem that Nicole Kimmel, aquatic invasive species specialist for Alberta Environment and Parks, is trying to tackle.

Historically, the crustaceans are normally found in between Wainwright and Ryley in the Beaver River watershed south of Edmonton, Kimmel told The Calgary Eyeopener.

But now they’ve been showing up in water bodies anywhere from the Edmonton area, down to Calgary and Medicine Hat, as well as in the Milk River region.

I’m gobsmacked that marbled crayfish have apparently been out in Alberta for years in multiple locations but that this information apparently never made it out of Alberta, never mind into the scientific literature.

And yet again, people put out origin stories for Marmorkrebs that are not supported by evidence.

Kimmel calls the marbled crayfish a kind of “freak accident” of two crayfish species that may have been imported from Florida into Germany in the ‘90s and were able to mate.

There is no evidence that Marmorkrebs were created by hybridization.

I’ll be following up with the province and seeing if I can discover more. I have not updated the map of Marmorkrebs introductions, but should do soon.

Update: The map of Marmorkrebs introductions now contains general Alberta locations.

Update: False alarm! See follow-up post.

External links

This self-cloning crayfish is scuttling into rivers and streams throughout Alberta

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