By Louie Stout

Northern Indiana fisheries biologist Tom Bacula has been a busy man.

A few weeks ago he was on Lake of the Woods near Bremen surveying the walleye population.

More recently, he examined bass populations at Koontz Lake and Fish Lake to the west of South Bend.

Here’s a preliminary look at what he saw:

Koontz: Historically, Koontz has been a good place to catch a big bass. An 8 pounder was caught there this spring and that’s huge for this part of Indiana.

But the numbers of largemouth have sagged in recent years.

“We were there in 2009 and 2010 and saw some low fish numbers,” the biologists said. “We saw a lot of nice fish but not many young ones.”

That was worrisome for his crew, so they went back this year to check again. They knew that Koontz’ reproduction (spawning) cycles were sporadic due to changing habitat conditions and the affect weather has on them when they are spawning.

“This year, the small fish numbers are up – not a lot – but that’s a good sign we’re producing a few more bass there,” Bacula said.

One of the problems is the lake has shad, stocked illegally there several years ago. While shad are high in protein, they are difficult for predators to keep in check and wind up competing with other young fish for food.

Bass growth rates aren’t off the chart, but certainly not bad. Bacula says Koontz bass reach 14 inches by age 5 which is slightly above average for natural lakes in this region.

Fish Lake: The 134-acre lake in LaPorte County has been a puzzler in that it is loaded with a lot of sub-legal fish but not many 14-inch keepers. Bacula’s crew was there in 2014 and again this year and the results were similar.

“We caught more smaller fish, an indication that 2013 was a good spawning year for bass, since we saw similar situation at Koontz in fish that size,” he said. “But we saw fewer bigger fish.”

One notable feature was the continued high number of nice bluegills and redears researchers found in the lake. These are all naturally-produced fish; the DNR doesn’t stock redear sunfish.

“It’s got to be a great lake for redear fishing, especially in lower Fish Lake,” Bacula noted. “It’s not a lake I’d go fish for big bass but one where you can catch a lot of fish. But the panfish population appears to be in excellent shape.”

Credit the abundant bass population for the high numbers of quality panfish. Because there are so many, they feed on the smaller bluegill and help keep the numbers in check.

“A good thing about abundant 12- to 14-inch bass is they do a number on the panfish,” Bacula said. “When you reduce the numbers of small bluegill, it provides more food base for the survivors to grow faster and bigger.”

Potato Creek tidbit

Although no survey is planned at Worster Lake on Potato Creek State Park, Bacula hopes to get there in the coming years to see how the hybrid striped bass are doing.

Anglers have reported catching a few of the muscle-bound fish that grow large – and hopefully – feed robustly on the abundant shad population there.

The DNR stocks tiny hybrids there every spring and those fish will grow to 7 inches by fall and 10 inches by next spring. A two-year-old hybrid (also called a “wiper” because it is a cross between white bass and striped bass) will grow to 21 inches. Wipers are usually found offshore, roaming around deeper water gobbling up schooling shad.

“We’re trying to get better (bigger) panfishing out there,” Bacula said. “If we can thin out the small bluegill and shad, those other fish will grow faster.”