Possible long-term effects of warm winter on fishing

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Not this year: Those who enjoy ice-fishing were shut out of the pasttime for the most part this year due to the warmer than usual winter. | File photo

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In the annals of fisher lore, this past March may be listed alongside the most legendary of lunkers. Coming on the heels of a remarkably mild winter, the month’s record-setting spate of temperatures in the 80s kickstarted the angling season. And those who could suspend their disbelief long enough to grab their gear and get to area waterways were rewarded with early-season keepers to replenish their dwindling freezer stocks.

Alas, like the best and largest of those lunkers, the weather eventually got away, snapping the line and reverting to a more normal pattern. After two weeks of heat, temperatures sank again below freezing for a few nights. Daytime averages returned to Chicago-area levels and April’s weather made March seem like a Floridian fantasy.

Like the weather itself, fishing on Lake Michigan and Indiana’s inland waterways was remarkably good in March, but returned to more normal patterns along with April’s weather, said two biologists with the Indiana Department of Natural Resources.

Fooling the fish

Brian Breidert, who specializes in Lake Michigan’s fisheries, said the lake’s warmer waters and March heating fooled spawning fish such as Chinook salmon and bass into starting their reproductive cycles early.

“Because of those three weeks (of hotter than normal temperatures), a lot of fish started moving into their spawning areas two months ahead of schedule,” Breidert said. The immediate result for those who took advantage and got their equipment out early was a much longer season for those angling from shore or boats.

“We usually have good fishing in March as soon as the ice goes out,” he said. “But this year, there was very little ice, if any at all. People could have fished all winter long if they wanted to brave the cold.”

And in March, they didn’t even have to do that. Warm temperatures brought out the fishing fans, and on Lake Michigan and its tributaries, they were rewarded by a “really good” coho salmon catch.

Over the long term, Breidert said, the early spawning followed by a return to average spring temperatures, could mean that some of those early spawning fish may have lost their eggs, and a generation of babies may not have been born this year. But Breidert said the unusual nature of winter and spring of 2012 was really unprecedented, and nobody knows what long-term effect the wacky temperatures will have on Lake Michigan fish.

“It’s yet to be seen,” he said. “Fish have a great natural ability to adapt to their environment, so I’m guessing there won’t be much of an effect at all.”

Inland lakes feel the heat

Like Lake Michigan, Indiana’s inland lakes were “on fire” in March, said fisheries biologist Tom Bacula. But then the record heat “shut off, and the fishing slowed down,” he said.

In the shallower waters of inland lakes, the fish got a head start on breeding, but so did vegetation in some lakes. In some places, weedy underwater growth began to choke out shallow areas normally used by fish such as bass and bluegill to spawn.

“For the most part, what we’re going to see in the near future is variable by the lake you’re talking about,” he said. “Some fish, like crappie, are cyclical spawners” that may not be as affected by one season’s temperature anomalies.

And in other cases, less competition could result in larger fish, he said.

Ice-fishing has meltdown

The largest factor in offsetting any damage done to fish populations by weather-related spawning problems was the loss of an entire fishing season to the warm weather, Bacula said. Even though the March warm spell caused anglers to pull fish out of Indiana lakes for a few weeks in March, there was a much shortened ice-fishing season this past winter simply because there wasn’t enough ice to support it.

Some Indiana fishing spots average about one to one-and-a-half fish per hour per angler during ice-fishing season, he said, and when you reduce the number of ice hours and anglers, that leaves a significant number of fish that weren’t pulled out of Indiana waters this winter.

So while the long-term effects of the strange winter and early spring of 2012 are still not quite known, neither of the fisheries biologists were very worried about the future of angling in Indiana.

In fact, “It’s a great time to get the kids out and get them started,” Breidert said.