Daily photo by Gary Cosby Jr.|
David Barrios waits for his father, Vincent Barrios Sr., to bait his hook for him as he fishes with his dad and brother, Vincent Barrios Jr., in Flint Creek. The duckweed covers the creek like a blanket.
Flint Creek's growing problem
Still streams become haven for duckweed
By Paul Huggins
email@example.com · 340-2395
This time, the duckweed proliferation in Flint Creek is not a man-made problem.
It's another in a growing list of negative impacts caused by the record drought. Areas around North Alabama are 15 to 20 inches below normal rainfall for 2007.
"There's just no flow in the stream, so everything is just sitting there," said Brad Bole, project leader for Flint Creek Cleanup. "That duckweed is just reproducing and reproducing on the top of the water with no place to go."
Though one of the smallest plants in the world, duckweed spreads rapidly. The surface area covered by duckweed can double in less than two days. A thumb-sized planting will cover 1.2 acres in 55 days if uninhibited, according to environmentalleverage.com.
Duckweed can be an indicator that a stream is rich in nutrients, particularly nitrogen and phosphorus. Until about 10 years ago, Flint Creek wasn't just rich in nutrients, it was excessive, a result of agricultural fertilizer and animal waste runoff.
Those excessive nutrients helped the stream get listed as one of the most polluted in the state. Duckweed covered the creek like a blanket.
Cleanup efforts reduced agricultural runoff, and one of the first signs of improved water quality was the lack of duckweed.
Only regular rainfall, however, will get rid of this summer's duckweed, Bole said.
"All the tributaries to it are dry, so there's no new water coming into (Flint Creek)," he said. It's just sitting there."
At this point, the duckweed poses only a messy nuisance to boaters and anglers, as it sticks to the sides of boats and clings to fishing lines, causing reels to clog, Bole said. Aquatic wildlife shouldn't suffer.
The duckweed actually helps protect the stream during the dog days of summer, he added; it keeps the water cooler by reflecting sunlight, and its blanketing effect helps slow evaporation and inhibits the growth of oxygen-depleting algae.
Duckweed has more nutrition by weight compared to most other vascular plants and more closely resembles animal proteins. It also contains large concentrations of trace minerals.
To produce the same amount of nutrients as soybeans and corn, duckweed needs only 10 percent and 20 percent, respectively, of the area to grow those two crops.
Because of its high nutritive value, duckweed has been used for cattle and pig feed in Africa, India and Southeast Asia.
With its efficient ability to absorb nutrients, duckweed is sometimes used to convert waste water and sewage into pure water.
Duckweed is an important food for wild waterfowl and fish both directly and as a source of food for small creatures that are in turn eaten by birds and fish.
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