The tanks may be empty but Joe Hunter and Lorraine Cupp have their hands full as they try to complete the upgrades on the Manitou Rapids sturgeon hatchery by the end of February.
Hunter said things were “still on target” to have the new water circulation and filtering system installed next month, giving them plenty of time to work out any bugs in the system before spawning season in May.
The main thing the two are waiting on is for the rest of the equipment to arrive to finish things up.
It’s hoped the new equipment will increase the hatchery’s capacity while reducing fry mortality.
“Our main water supply will be from groundwater, which is basically disease-free,” Hunter said.
“And since we’ll be using oxygen injection, we can hold our fish at a higher density," he added. "We’re still working out the logistics for having delivery options for liquid oxygen.”
A new water recirculation system also was added. Cupp said with the filters and holding tanks, about 95 percent of the water in a cycle can be reused—and should require very little fresh water.
Hunter hoped to be able to test the system on some eight-month-old fingerling sturgeon the hatchery had sent to Minneapolis before putting last spring’s fry in.
When the spawning does occur, the parent sturgeon and the eggs will be kept in river water in a separate part of the facility. Then once the fry hatch, they will be disinfected and placed into the well-water system.
The hope is these precautions will keep bacterial infections from entering the system. But for the first year, Hunter admitted they’re keeping their expectations low on the fry’s survival.
“We’re estimating a 50 percent mortality rate to a full year old, just to be safe,” he said.
“But we hope it’s nowhere near that,” added Cupp.
Both Cupp and Hunter hoped to harvest about half a million fry this year, keeping half of them in their hatchery and selling the other half.
And with recent innovations in spawning techniques, they hope to accomplish in two days what used to take two weeks.
“The cut [on the female sturgeon] is so little, the recovery is phenomenal,” Cupp said.