Friend of the blogGünter Vogt has a write-up for non-specialists about Marmorkrebs at the Atlas of Science.
If you want to talk about a success story in invasive species management, you might want to talk about the province of Alberta, Canada. Alberta like to boast that it is rat free.
But I can let you in on a little secret. I’ve seen rats in Alberta many times, when I was a student at the University of Lethbridge. Last year, the university got a government grant to build a new rat facility.
So there was a disconnect between declaring “We don’t want this invasive species!” and actually having that species in research labs. The two situations are separable.
I am not sure if that separation will exist for Marmorkrebs, though.
This year, Saskatchewan and Michigan banned Marmorkrebs. Ontario and some other US states are thinking about it. I have been thinking about what the bans might do for Marmorkrebs research. There are several issues.
First, researchers in those states and provinces might not be able to have Marmorkrebs at all. Some of the Marmorkrebs legislation does not appear to have exceptions for bona fide academic researchers.
For example, the Canadian province of Manitoba has a law against owning all crayfish species, not just Marmorkrebs. In the course of doing research, I once asked officials in Manitoba if a researcher might keep crayfish, and was told, “No.”
Second, if the laws work as intended, fewer people in general would have Marmorkrebs. It’s possible that some pet owners would stop keeping Marmorkrebs, even in jurisdictions where it is completely legal. Aquarium keepers might see “the writing on the wall” and decide not to keep Marmorkrebs any more, in case they become illegal.
This could affect researchers, too. When an animal is widely available in the pet trade, it’s easy for researchers to get them, either for a one-off study or to start a colony.
Crayfish researchers have a long history of asking for regulation of the movement and trade of crayfish. It has been hard to get those regulations, but it would be a shame if new laws were not nuanced enough to allow original research.
If there can be rats in labs in Alberta, we should be able to have crayfish in labs, too. After all, an escaped crayfish in a university building probably has a harder time getting far than an escaped rat would.
Poster from here.
Velisek J, Stara A, Zuskova E, Chabera J, Kubec J, Buric M, Kouba A. 2020. Effects of chloridazon on early life stages of marbled crayfish. Chemosphere 257: 127189. https://doi.org/10.1016/j.chemosphere.2020.127189
Last month, Saskatchewan became the first Canadian province to specifically prohibit Marmorkrebs, according to this news article. “New for this year is a regulatory change that prohibits the collection of crayfish from any Saskatchewan waterbody, as well as prohibitions related to their use as bait for angling,” (Environment Minister Dustin) Duncan said.
Rusty crayfish and marbled crayfish were added to the province’s prohibited species list in April.
17 Marbled crayfish or marmorkrebs (Procambarus virginalis). It makes clones of itself from eggs unfertilised by sperm.
As expected, Michigan has become the fourth American state (that I know of) to specifically prohibit Marmorkrebs.“It’s pretty popular in the pet trade, and the decision was not made lightly in terms of it will impact some of the pet trade industry,” said Lucas Nathan, aquatic invasive species coordinator for the Michigan Department of Natural Resources.
The (Department of Natural Resources) warns against flushing them down toilets because they may survive. What the DNR probably MEANT to say is, “that's how you get giant self-cloning crayfish roaming the sewer system.”
