A visitor from North America appears to be doing wonders for the Waikato River.

Tiny zooplankton could be helping reduce the amount of harmful algae in the water.

Waikato Regional Council water scientist Bill Vant says the North American zooplankton arrived out of the blue. 

“There’s actually more grazing of algae in the river now that this North American species has arrived than there may have been in the past and that may also be bringing down the algae.”

How long the zooplankton will stay is unknown.

– Newstalk ZB