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What to expect
10-08-2018, 06:16 PM
Post: #1
What to expect
The following was written by John Weiss and published in the Rochester Post Bulletin newspaper.

LAKE CITY — For the homecoming celebration Friday morning, Lake City High School students could have gone rollerblading or played volleyball. About 10, however, wisely chose to fish Lake Pepin from the breakwater and shore of the city’s marina.

Not that it was all the welcoming. The lake was up again. Autumn Molle noted that it also didn’t look great because it was so brown. “I wouldn’t want to swim in it,” she said.

Unfortunately, such rises in the Mississippi River, and the dirty water that goes with them, are becoming the new normal.


According to the Department of Natural Resources “the 18 years from 2000-2017 have seen nearly three times as many mega-rains as the 27 years spanning 1973-99.” That is consistent with predictions the Upper Midwest will get more precipitation, and more mega-rains of several inches.

The U.S. Environmental Protection Agency says that trend will continue. “During the next century, spring rainfall and annual precipitation are likely to increase, and severe rainstorms are likely to intensify.”

What that means to fish and anglers is a mixture of the good, the bad and the uncertain, said Dan Dieterman and Nick Schlesser, DNR fisheries officials in Lake City. But Dieterman said overall “the long-term effects of this new normal are big.”

They agreed that the summer peaks, which were once uncommon, are now the new normal. “It was getting down nice again, and boom, it went back up,” Dieterman said of the most recent rise. Heavy fall rains, also once uncommon, are becoming typical, Schlesser said.

For anglers, “there are so many more variables,” Dieterman said. When water gets into grassy lowlands, fish have even more food such as worms or seeds, and there are more nutrients in the water so they help grow more fish food. “It becomes more difficult for anglers to compete with all that food,” he said.

Because many fish are sight feeders, high, dirty water makes it harder for them to feed, he said. If fish get too much junk in their gills, they even cough, Schlesser said. “It’s a stress response,” he said.

As long as the water temperature is a minimum 40 degrees, but not too warm, “they are pretty capable of doing what they want to do,” he said. When it’s lower than 40 degrees, fish get really picky, he said.

That brings us to what might happen in winter.

High water, which we had a few winters ago, can really change things.

Heavy winter flow a few years ago affected where fish, especially bluegills, lived. They like a certain flow, not too much or too little, and like it to be near places they can rest away from current. They also are very picky about temperatures.

If water is warmer, there can be more biological responses, and more oxygen produced by plants, he said.

Sometimes, more flow means less ice, so more sunlight can penetrate — assuming less snow — and plants will give off more oxygen. Oddly, they can give off too much oxygen and fish that can’t escape an area are taking in supersaturated water. In effect, they can get the bends, Dieterman said. In some cases, that has led to fish kills for bigger fish, he said.

“There usually is a sweet spot,” where there is enough oxygen and food, but not too much oxygen, he said.

“It’s a balancing act,” Schlesser said.

In Rochester’s reservoirs, built for flood control, more flow means more oxygen and more food, so that’s good in the short run, Dieterman said. Ultimately, however, more flow means more sediment so the reservoirs fill in faster, he said.

Managing the fish and fisheries resource also changes with the high water, they said. For one thing, it means setting seines to count fish is harder if fish are in flood timber. That makes it difficult to compare data from decades past with today’s information.

That water also affects the floodplain forest, and not for the good, he said. “The whole system is connected out there,” he said.

The high water brings in more sediment, so there’s less aquatic habitat. It’s like a domino effect with the water taking dirt from one area and moving it to another.

The DNR has tried dredging some places, such as in Weaver Bottoms but that is limited.

Personally, Dieterman said he doubts we have the “societal fortitude” to make changes that will help change the trend toward more mega-rains. “We are not in the crisis mode where the evidence is overwhelming,” he said.

What it boils down to is so many more things for fish, and anglers, to grapple with. “Biology is never boring,” Schlesser said.

John Weiss, now retired, has covered the outdoors for the Post Bulletin for more than 40 years. He is the author of “Back Roads: The Best of the Best by Post-Bulletin Columnist John Weiss,” published in 2017.

The hardest thing in life is knowing which bridge to cross and which one to burn.
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Thanks given by:  Tom
10-08-2018, 07:47 PM
Post: #2
RE: What to expect
This is a great article. Lots to be learned from it.
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10-08-2018, 10:47 PM
Post: #3
RE: What to expect
After these mega rains the water carries more silt. This increases the rate at which the backwater areas are filling in. This is turn pushes more water into the channel. We are witnessing the deterioration of a lot of fish habitat. Fishing the river is changing before our eyes and it is happening very quickly.
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10-09-2018, 04:00 AM
Post: #4
RE: What to expect
Correct Pete. Another thing I found interesting and was unaware of is that there can be too much oxygen naturally produced by mother natures process. When I picture some of the backwater areas I imagined a deprivation of oxygen.

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