Daphnia in tire soup experiment

Today’s lead story in the Trib highlighted the scientific investigations of two Duluth Middle School students. These young people were way ahead of the School Board when they decided to test whether our rubber tire mulch might be toxic. It is. At least it is to water fleas otherwise known as daphnia.

Whether it is hazardous for children has yet to be established but the story certainly reinforces my decision to replace the rubber mulch in our school playgrounds.

Maybe if we dumped our tire mulch in Lake Superior we could kill off the invasive spiny waterfleas that our fish can’t eat and that so annoy anglers.

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