Below is an article written by John Weiss.
The good and the bad in backwater Shangri-La
WEAVER — As I waited Monday morning to see how Weaver Bottoms fared this year, a time of near-record low flows, I thought of all the changes I’ve seen in it and wondered: which Weaver would I see today or would I see an all new one?
How would this year’s low flows affect the Mississippi River backwater south of Kellogg and, for that matter, scores of other backwaters? The condition of Weaver is shared by backwaters from Wabasha down into Iowa because they share a common history and usually act alike, so what I would see wouldn’t be unique.
Would the Weaver I was about to see be like the one 45 years ago when I first saw it? It would be miraculous to see it in its once abundant splendor, thick with vegetation, when I stood agape as thousands of canvasbacks and other ducks undulated across the sky.
Would it be the one from maybe 35 years ago, after it began deteriorate because of sedimentation and less vegetation. Around then, there were also low flows and I hoped light would penetrate deep to key a flush of vegetation. Instead, it triggered an algal bloom that blocked light. The entire backwater system had a massive dieback of some of the key plants, such as water celery, needed by migrating waterfowl.
How about 15 years ago, after a drawdown when arrowhead (another key food source), water celery and other key plants began to bounce back?
And perhaps most importantly, will it be a place of vital food and rest this fall for tens of thousands of migrating waterfowl?
All I knew for certain is that nothing I think or know is for certain on the Mississippi because it’s such as maddeningly complex system, especially now with so many changes in the past century. This summer’s drought just added to my perplexity.
A quick history of how the backwaters came to be will help explain my uncertainty.
Before Europeans came, the Mississippi flowed unimpeded, rising in spring floods and dropping low in summer. It was an old river, but forever young because it renewed itself by changing courses, opening up new channels and closing others. When it got lower in summer, it exposed big mud flats or allowed light to penetrate deeper, keying magnificent vegetation.
Europeans, however, were not satisfied with the river. They needed it for commerce in the early to mid 1800s and it got too low in summer and froze over in winter. Along came the railroads in the mid-19th century and took over commercially. They also became monopolies, so Upper Midwest commercial eventually forced Congress to approve a series of locks and dams. They would turn the Mississippi into a series of pools, the main channel at least 9 feet deep so the river would be deep enough for barges and towboats.
The dams, mostly finished in the 1930s, also created the incredible backwaters by flooding lowland that once was pasture or got wet now and then. They soon became phenomenal places for fish and game.
But the dams also stopped the river from renewing itself and the backwaters began to age as they began to fill in and never rejuvenated.
Right now, natural resources agencies are trying to hold back time by selective dredging and drawing down the pools now and then just enough to keep commerce moving but enough for more green growth. Weaver has had one drawdown.
Would this year’s drought create a de facto drawdown? I wondered.
Mary Stefanski, Winona District of the US Fish and Wildlife Service, drove up with a john boat and answers. We chatted before heading out and what she told me reminded me just how complex it is to try to manage a massive river.
She said we would see a little bit of filamentous algae that covers wanted plant “but it’s not horrible.” Fortunately, the backwaters aren’t getting much blue-green algae that is toxic to pets and humans.
Many people see green on the water and think it’s all algae. Instead, it’s often duck weed, that is great for mature ducks and it holds bugs for young waterfowl, she said.
After the drawdown, Weaver was covered with arrowhead,”she said. Now, there’s more wild rice. “We would like to have the arrowhead because they are perennial plants; wild the rice is a grass so it’s an annual,” she said. But arrowhead needs low water to renew itself and, for several years later in the past decade, the Mississippi was very high.
Again, one of those wicked curveballs the river throws at us. We might manage the river but we never really control it.
Still, rice is good duck food.
More importantly, submerged plants, such as water celery and sago pondweed, are doing well, she said. Canvasbacks and swans love the tubers of those plants.
People seem to think the river is low this year, Stefanski said. “We are about normal but people got used to the river being at flood stage which it was beginning in 2015,” she said.
With that, we were off into Weaver.
A small flock of red-winged blackbirds skittered around the rice and then we were more into the open where we saw narrow-leaf and broad-leaf arrowhead. “This is what we’d like to see, more arrowhead,” she said.
Nearby was pickerelweed. They have seen monarch butterflies on the purple flower, which seemed to be unusual. We saw none Monday, but two bumblebees were busy harvesting nectar there.
Water was quite clear and we saw little algae. We did see water celery, coontail and elodea, all great for the resource and ducks.
In the north, we could see a large flock of non-nesting pelicans and double-crested cormorants along with gulls. Stefanski hoped to see some black terns, a species of special concern. They were seen at Weaver in the 1990s and a few pairs nested there this year, she said.
Then a pair of sandhill cranes flew in their gangly flight. Cranes weren’t around maybe 20 or more years ago but are getting common. Again, there was change for some reason, and I love seeing them and hearing their guttural calls.
Toward shore was phragmites, a tall strong plant that once dominated Weaver and other backwaters. Hunters loved it because they could push their boats back into it and have great cover.
Fisheries resource managers, however, aren’t as enthralled with it.
There is also an invasive species of phragmites but analysis has found it’s not in Weaver, she said.
There are a few really nasty invasive that are found there such as flowering rush, with a pretty flower but a horrible tendency to take over from native plants. It has to be killed chemically, not by pulling, she said. The service has a $188,000 grant to try to stop it. Purple loosestrife was controlled by beetles, a biological control, but the high water may have wiped them out, she it might be time to restock the beetles.
Overall, she believes vegetation is going well and diversifying, she said. It’s even being bettered by deltas forming such as where the Whitewater River enters Weaver. Fisheries people hate the deltas because they wipe out fish habitat but it’s good for plants and animals, she said. Again, what the Mississippi hits us with is often a mixed bag, at least for humans.
Tree swallows zigzagged across the plants, seeking bugs to eat. They, like wood ducks, are cavity nesters so the service has been concentrating on keeping and adding trees in the floodplain, Stefanski said. They have planted tens of thousands of mast-bearing trees such as oaks and hickory and might even try the Kentucky coffee tree because with climate change, the system might need a tree found now more to the south.
Toward the Whitewater River delta, we finally saw a flock of mallards. The service doesn’t monitor production but from what they’ve seen doing other work, there were a lot of Canada goose broods, and wood ducks, too. Minnesota will have an early-teal season for the first time Sept. 4-8, and the small ducks should be here by then because they tend to migrate by the calendar, not by weather, she said.
How about conditions for waterfowl hunters at Weaver and other river backwaters this fall? If the potholes of the Dakotas into Canada produced ducks (the count is going on now), then there will be food for them around here, Stefanski said. “The wild rice, I would say, is medium-high for value so there is plenty to eat,” she said.
One interesting observation she made was that the backwaters around here, while showing their age in some ways, are still magnificent, at least from Wabasha down into northeast Iowa. Those who work on resources further south are jealous because they have so few plants. An Iowa resource person said “you work in Shangri-La,” she said.
She was right. I had feared for years Weaver, my favorite backwater, would be wretched by this time, after seeing it faring so badly a few decades ago. But it still is looking good. Different, but good.