03-14-2016, 07:43 PM
[#0000ff]I had previously thought that the shad spawned in a very narrow window...usually about mid June. But in communicating with Chris Penne...DWR biologist...I learned that some will spawn as early as late April, depending on water temps and other factors. And their window extends at least 6 weeks. See the except attached from my recent CD/book on Willard.
Some years, when storms and water temps prolong the spawn there are some late arrivals that do not survive into winter. The water cools down too fast in the fall and the zooplankton numbers drop. The late arrivals are unable to switch to the detritus diet on the bottom and starve to death. Not unusual to see large numbers of tiny emaciated shadlets dieing and floating to the top in November. The terns are mopping them up fast in the early morning after a night dieoff. You would think there was a wiper boil going on. But nooooooo.
The small fish you observed being "recycled" at Hyrum are doubtless last year's perchlets. They only reach a little over an inch their first year. That is what makes them such a big forage item not only for perch, but for smallies and trout too. A lot of the trout caught through the ice are stuffed with them. That is if the perch population is large enough to produce sufficient fry for predator forage.
Perch spawn first. Usually just after iceout. In some lakes that are icebound longer they can even spawn beneath the ice. Seldom in Utah.
Then walleye...where walleye are present. Smallies don't spawn until water temps are over 60...usually after about mid May. But their yearling young are voracious feeders on baby perch...both the survivors from last year and the new sac fry from this year.
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Some years, when storms and water temps prolong the spawn there are some late arrivals that do not survive into winter. The water cools down too fast in the fall and the zooplankton numbers drop. The late arrivals are unable to switch to the detritus diet on the bottom and starve to death. Not unusual to see large numbers of tiny emaciated shadlets dieing and floating to the top in November. The terns are mopping them up fast in the early morning after a night dieoff. You would think there was a wiper boil going on. But nooooooo.
The small fish you observed being "recycled" at Hyrum are doubtless last year's perchlets. They only reach a little over an inch their first year. That is what makes them such a big forage item not only for perch, but for smallies and trout too. A lot of the trout caught through the ice are stuffed with them. That is if the perch population is large enough to produce sufficient fry for predator forage.
Perch spawn first. Usually just after iceout. In some lakes that are icebound longer they can even spawn beneath the ice. Seldom in Utah.
Then walleye...where walleye are present. Smallies don't spawn until water temps are over 60...usually after about mid May. But their yearling young are voracious feeders on baby perch...both the survivors from last year and the new sac fry from this year.
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