In a state where walleye fever runs unchecked, sunfish and crappies thrill anglers ages 8 to 80 and a trout or muskie in hand still inspires awe, it's no surprise fish are a top attraction at the Minnesota State Fair.

And we're not talking fish on a stick.

Starting Thursday, upward of a half-million people will gawk at live fish in the Department of Natural Resource's outdoor fish pond and wander through the DNR's historic log building to view fish in aquariums.

This year, they'll find a big change.

The DNR has replaced the 17 small, almost-ancient indoor aquariums with five much larger tanks — one stretching 18 feet and two measuring 14 feet. Each will show fish in their simulated native habitat: trout in a southeastern Minnesota stream, fish from the St. Croix River, and fish from central, southern and northern Minnesota lakes.

"Rather than just seeing individual fish species in a tank, they'll see fish living together in their habitat," said T.J. DeBates, DNR east metro fisheries supervisor. "It's awesome."

The St. Croix River tank, for example, will display a variety of habitats, from sand and muck to rock and woody debris. It will have game fish such as walleyes, catfish, sauger, muskies and bass, as well as nongame species such as suckers, gizzard shad and various minnows.

DeBates said he hopes the aquariums will help fair visitors understand the need to conserve fish habitat.

The state-of-the-art tanks were built lower to the ground, so youngsters will get a better view. The major makeover wasn't cheap: It cost $460,000, taxpayer money that came from a bonding bill appropriated by the Legislature for the DNR to maintain facilities.

The old tanks had been around since the 1960s and were scratched and yellowed.

DeBates said each of the five new tanks will house at least 10 species. They hold a total of more than 5,000 gallons of water.

Meanwhile, the popular 50,000-gallon outdoor pond will display about 45 species of Minnesota fish — the largest being a 50-inch lake sturgeon.

The DNR's building is open from 9 a.m. to 9 p.m. daily during the 12-day fair.

Invasive species

A revamped invasive species exhibit in the DNR building will allow visitors to look for emerald ash borers, purple loosestrife, zebra mussels and Eurasian water milfoil as they walk along a recreated prairie trail, conduct a watercraft inspection or visit an imaginary state forest campsite. The goal is to teach people how to prevent their spread.

Wall of shame

Fairgoers also will find a major change outside the DNR building: The former DNR Nature Store near the outdoor fish pond has been discontinued, and that building now will house the Turn in Poachers "Wall of Shame" — a display of trophy antlers seized from poachers.

Doug Smith • dsmith@startribune.com