Fish spawns

[Thorny]

I am curious about fish spawn timing. I know time of year and water temperature are the biggest triggers.  I guess my question is how tied to temperature are the spawn cycles?  For example, the bass spawn starts earlier in southern Utah then central Utah as the water warms up sooner.  That said, is it as simple as saying that fish will start spawning when the water hits X temperature range with only rare exceptions?  Is that the case for most kinds of fish?

[TubeDude]

Yes.  And a majority of our "warm water" species seem to get most spawningly active at around 65 degrees.  Some will start earlier...or later. 

Another factor is the hours of daylight.  But there are others.  HERE IS A LINK .

[castnshoot]

Here are a few observations on the subject from a southern Utah lake just over a week ago.

Rainbows were still spawning, so much so the eggs were washing up all along the shore after the afternoon winds.




The small Mouth seemed to be schooling up close to shore but I did not see any nests.



Both Bass and Wipers were feeding on the trout eggs and catchable sight fishing. Fun to watch a bigger Bass following a pair of spawning bows, when the hen would turn on her side to release eggs the Bass would rush in and the big hookjawed male bow following behind would rush in and try to chase the Bass off.



Sorry can’t tell you what the temp was. When the Right temp and a full moon intersect,, that will trigger A spawn in a lot of fish.

[Anglinarcher]

I suppose a wild card or two is that not all fish spawn when they are suppose to.  

For years and years fisheries managers worked on genetic selection to make rainbow spawn at different times to allow them to get bigger fish for stalking at specific times.  I seem to remember that the fish would revert back to normal in a couple of generations if they spawned in the wild.  I don't think that they still use this method.

Still, "nature finds a way".  I have caught Browns in the snake river that were spawning in the Spring, and Cutties in central Idaho that were spawning in the fall.  Most of the fish were not spawning at this time, but enough that a viable population could have sustained themselves.

Last, Salmon and Steelhead "always" spawn at the place of their birth, Except when they don't.  LOL  Riddle me this Bat Man.  Mount St. Helens blew it's top and destroyed the spawning rivers (massive mud flows for years).  It was declared a study area so no trees could be replanted and no animals or fish could be stocked inside the boundaries.  Yet, today, Salmon and Steelhead are slowing making a comeback. The prior lineage was wiped out due to the long time it took the rivers to fix themselves.  Soooooo, somehow Salmon and Steelhead from other rivers got lost and "always" meant not always.

I know this does not help on planning a trip during the spawn, but it does show how variable the rules of the Spawn can be.