October 04, 2010
Traditionally known for walleyes and perch, Iowa's northwestern waters are harboring more crappies with each passing season. What's behind this trend, and how can you take advantage? (May 2009)
Both the number of crappies and the number of anglers pursuing them are on the rise in northwestern Iowa, and particularly on the Iowa Great Lakes.
Photo by Ron Sinfelt.
Something's awry at the Iowa Great Lakes. Old-timer anglers on this collection of northwest Iowa waters have noticed changes in the species and numbers of fish they catch, and long-term creel and netting surveys by the Iowa Department of Natural Resources support the bait shop talk: Fish populations are changing in the Iowa Great Lakes.
In the 1950s and '60s, the Iowa Great Lakes -- collectively, West Okoboji, East Okoboji and Big Spirit lakes, along with a handful of smaller waters -- were predominantly walleye and yellow perch fisheries. Largemouth bass, smallmouth bass, bluegills and crappies were present, but only as secondary species. In the past decade, however, anglers and fisheries biologists have noticed that warm-water species, such as bass, bluegills and crappies, have shown up more and more frequently in surveys.
"On West Okoboji, we've definitely seen a notable shift away from (yellow) perch populations and toward more of a bluegill, bass and crappie fishery," said fisheries management biologist Mike Hawkins. "We've got long-term data from both anglers' creel surveys and from bag seine nets that we've set for decades in the same locations, in the same lakes, at the same times of year. The data indicate that changing conditions may favor warmer-water species."
Hawkins can tick off several possibilities for why fish populations are changing in northwest Iowa. A warming climate is a possible factor, but he also cites work undertaken by municipalities that has improved water quality in the Iowa Great Lakes.
"During the same time that we've recorded warming in the climate, we've also had significant changes in water quality in those lakes," he said. "A sanitary sewer system was installed so houses around the lakes don't (need) septic systems that can leach into the lakes, so we aren't seeing as many algae blooms due to excess nutrients.
There have also been major improvements in farming practices in the watersheds that supply the lakes. The improved water quality from those changes has made life a lot easier for sight feeders like crappies. So to say that a climatic warming trend is the only cause of changes in crappie populations at the Iowa Great Lakes ignores other factors."
Hawkins acknowledged data gathered by state climatologist Elwynn Taylor that indicates a trend toward milder winters in Iowa over the past decades. "(Iowa's winters have been) an average of 4 degrees warmer between 1970 through 2005," said Taylor. "To a climatologist, that's significant. Maybe it's significant to crappies too."
Whatever the reasons, bluegill, bass and crappie populations over the past decade have held steady or increased in the Iowa Great Lakes, while perch and walleye populations have been merely stable.
"Yellow perch and walleyes are cool-water species," said Hawkins. "Largemouth bass and bluegills favor warmer waters. Crappies are sort of in the middle. In the past, the Iowa-Minnesota border was toward the northern end of (the crappie) range, but for the past decade they've been doing pretty well in this area. The slight climatic warming probably isn't the only cause, but it's a factor."
NORTHWEST IOWA'S 'STEALTH' FISH?
Some anglers may be surprised to hear that crappie catching is on an upswing at the Iowa Great Lakes because crappies are often overlooked in those lakes. Most of the year they roam the basins of West Okoboji, Big Spirit and other lakes in the region, feeding easily on the abundant forage fish available in those lakes. Ice-out and the annual spawn during May are often the only opportunities many anglers have to catch crappies while they're concentrated and easy to find.
"Right after ice-out, when the water is still cold, guys find crappies clustering in any areas where the water is a little warmer, or where warmer water is flowing into the lake," said Steve Pflueger, manager of Shucks Bait Shop south of West Lake Okoboji. "In West Okoboji, they catch them pretty good that time of year in the canals along the west side of the lake and up towards the north end at the harbor. Upper Gar (Lake) is a good spot too, because they leave the docks in that lake all winter, and the crappies like that woody structure in shallow water."
As waters warm, crappies move slightly deeper in the pre-spawn period, then move to shallow spawning areas in early to mid-May. "On West Okoboji, they spawn around the docks in the canals, in the backs of the shallow bays, maybe in some of the sloughs," said Hawkins.
Local anglers have learned that the canals carved into Gull Point are prime places from which to pull spawning crappies. The same shallow-water strategy pinpoints crappies spawning in the harbor area at the lake's northwest corner.
On Big Spirit Lake, most spawning crappies come from natural habitat.
"On Big Spirit, you can really cash in on crappies during the spawn by fishing in and around the hard-stem bulrush beds," said Hawkins. "Those bulrushes are absolutely loaded with crappies during the first two weeks of May."
Anglers can also find spawning crappies at Big Spirit around the pilings of the big handicap-accessible fishing pier in the bay on the northwest corner of the lake, as well as associated with the gentle current that flows through the narrowed mouth of that bay. The same applies to the shallow weedbeds of Angler's Bay and Little Angler's Bay on the lake's northeast corner.
AND THE SURVEYS SAY . . .
IDNR surveys indicate crappies at the Iowa Great Lakes, specifically in West Okoboji, enjoyed above-average spawns and recruitment (the scientific term fisheries biologists use to describe the transition from fry to fingerlings to yearlings) in 2004 and again in 2007.
"They had a tremendous spawn and recruitment in 2004," said Hawkins. "We've seen excellent crappie fishing every year since that year-class reached catchable size. That year-class is starting to reach the end of its life cycle, but there's still a strong population of 10- to 12-inch fish from that group in the lake. They got off another good year-class in 2007, and we'll start to see those 7- to 9-inch fish this year. Crappies have been strong at the Iowa Great Lakes for the past decade, and there's no reason they shouldn't stay strong."
Crappies in other natural lakes scattered across northwest and north-central Iowa are often local secrets. Trumbull Lake, Ingham Lake, Lost Island and Little Wall Lake won't attract anglers from Des Moines or southern Iowa to fish for crappies. But local anglers know when and where crappies are biting in those lakes and take advantage of the bonanza.
"The guys in the bibbed overalls certainly know exactly how to take crappies out of those lakes," chuckled Hawkins. "I heard of good catches of crappies during the spawn at Trumbull Lake last year, so there's every reason to expect that those crappies will be back and maybe a size larger this year. We also saw a strong population of nice crappies at Lost Island Lake last year. Those are two lakes that would definitely be worth checking out during the spawn this year."
In north-central Iowa, IDNR fisheries biologist Scott Grummer hasn't seen a measurable uptick in crappie numbers in any of his lakes, but he hasn't seen a decrease, either.
"They're pretty consistent, year to year," he said. "One place where anglers might see a noticeable improvement in crappie fishing this year is at Little Wall Lake, near Jewell. Those crappies are going to be in the 8-inch range this year. They still won't be big, but there's the potential for catching a lot of them."
Anglers at Little Wall Lake can focus during the spawn on the large area of artificial fish habitat installed in the big bay on the lake's eastern shore. Stakebeds and pallet piles concentrate fish year 'round in that area but especially during the spawn.
Elsewhere in north-central Iowa, Grummer cited Briggs Woods Lake near Webster City, Beeds Lake near Hampton and Rice Lake near Lake Mills as potential places to catch crappies this year.
"Briggs Woods is a consistent crappie fishery," said Grummer. "They're not big and there aren't huge numbers, but they're always there. Same with Beeds Lake. Rice Lake actually has a big population of good-sized crappies that we see in our surveys, but they're really hard to catch. There's a huge population of fathead minnows in that lake, and the crappies simply aren't interested in what anglers offer."
Who knows? Things have changed at the Iowa Great Lakes and crappie fishing has improved as a result. Maybe similar changes at Rice Lake and other lakes in northern Iowa will turn them into some of Iowa's best crappie lakes in the next decade.