Once river walleyes spawn, they typically disperse from spawning sites to current break locations to rest and recuperate. If the flow is high, they often seek refuge in flooded wood and slough backwaters, where they may remain until water levels subside.
‘EYE GOTTA SPAWN
In spring, river walleyes seek out classic spawning locations — hard bottom, rock-rubble, or riprap areas swept by current; mussel beds mixed with gravel; or small tributary creeks with gravel washout bottoms. During years of high flow, walleyes may spawn on vegetation, like reed canary grass.
They typically start spawning when the water reaches 40F to 45F. Males generally arrive at spawning sites about a week or two before females and remain about two weeks longer. Females often hold a short distance away from spawning sites, in slower current, until their eggs ripen. Once water temperatures reach the proper level, spawning begins and is usually staggered over a 14- to 20-day period.
“Every spring, walleyes come out of their wintering habitat and move into warmer backwater locations,” says John Pitlo, Iowa Natural Resource biologist, who has spent many hours studying the prespawn and postspawn movements of river walleyes. “Mud bottoms in backwater lakes and shallow sloughs absorb the sun, which can raise water temperatures 2 to 6 degrees warmer than the main channel.
“Female walleyes seek out warmer water during the prespawn period to help their eggs mature,” Pitlo says, “often staying in warmer backwaters until their eggs are ripe, before moving to the spawning ground where males await their arrival. Females generally don’t spend much time at the spawning site. In fact, a female may be on the spawning bed for only about half a day, long enough to dump her eggs, and then she’s out of there,” Pitlo explains. “She may return to the same backwater spots she came from if the water level remains the same.
“During the postspawn period, we’ve observed interesting walleye behavior during studies where we radio tagged fish to track their movements. The fish are scattered during this period and may set up in the same spot for several weeks, say behind a tree or in a small clearing in the trees.
“When I started these studies, we returned to the same spots day after day and found radio-tagged walleyes in the exact same spots. Just to see if they were dead or alive, we positioned right over them and banged on the side of the boat. Still no signs of life. We finally lowered a paddle into the water to touch them,” Pitlo explains, “and sure enough, they moved.”
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