PARK RAPIDS, MINN. – The mating dance of the hex mayflies drew John Sorenson to the Straight River at sunset.
As the bugs floated like snowflakes in the fading summer light, he pulled on his waders and waited patiently for the distinct sound of trout breaking the dark water to feed.
“It’s a treasure,” he said, stepping to the edge of the grassy bank and casting his line, as he has for years.
But the Straight River is becoming warmer and more polluted as farm irrigation rigs multiply along its banks. Now Sorenson fears that the fish huddling in the cooler deep spots are a stark sign that northern Minnesota’s only naturally producing trout stream is in trouble.
“In 10 years the Straight River could be a big muddy stream good only for carp,” he said.
And the peril is flowing downstream — into the Mississippi River and across a watershed that covers almost half of Minnesota, signaling a new and rising threat to one of the state’s great natural wonders. Like many others across Minnesota, the great river is heading toward an ecological precipice.