Factors Influencing Steelhead Movement

I've heard some debate lately on the factors influencing the fall run, and was wondering what everyone's personal take is, as well as if anyone has any links to scientific studies on the subject. Most can agree that it is a combination of factors including cooling lake temperatures, photoperiodism (decreasing daylight), cool stream flows, and certainly rainfall. One of my specific questions would be which is of greater importance- lake surface temperature or tributary stream temps? Last data I saw had lake Erie surface temp around 68-69 degrees with the flow gauge at Walnut reading near 61 degrees. Which of these do you feel is more influential on fish movement? Obviously in the fall, our greatest concern or obstacle is adequate rainfall to allow fish passage, but if you were to rank the other factors, where would you place them in order of importance? As a side note, I would mention moon phase, and ask if in your experiences you have noticed any measurable lunar effect on steelhead migration or feeding activity. I talked with another fisherman on Elk last year who was convinced that the slow bite on that particular day was to be blamed on the moon phase, which I believe was 3/4 full. Fishermen, hunters, and scientists have debated the moon's effect on fish and game activity for years, and will probably continue for many years to come. Just wondering what your personal experiences are and of course, if you have any cool links on the subject feel free to share.

Sweet.

We are now just a fish-handling thread away from a major run of steelhead.

ORIGINAL: Screamin Steel

I've heard some debate lately on the factors influencing the fall run, and was wondering what everyone's personal take is, as well as if anyone has any links to scientific studies on the subject. Most can agree that it is a combination of factors including cooling lake temperatures, photoperiodism (decreasing daylight), cool stream flows, and certainly rainfall. One of my specific questions would be which is of greater importance- lake surface temperature or tributary stream temps? Last data I saw had lake Erie surface temp around 68-69 degrees with the flow gauge at Walnut reading near 61 degrees. Which of these do you feel is more influential on fish movement? Obviously in the fall, our greatest concern or obstacle is adequate rainfall to allow fish passage, but if you were to rank the other factors, where would you place them in order of importance? As a side note, I would mention moon phase, and ask if in your experiences you have noticed any measurable lunar effect on steelhead migration or feeding activity. I talked with another fisherman on Elk last year who was convinced that the slow bite on that particular day was to be blamed on the moon phase, which I believe was 3/4 full. Fishermen, hunters, and scientists have debated the moon's effect on fish and game activity for years, and will probably continue for many years to come. Just wondering what your personal experiences are and of course, if you have any cool links on the subject feel free to share.

Really there are no hard and fast rules for steelhead, but many theories as to why they run at certain periods.  As noted above by Cbeagler, they come in when they are good and ready, and really nobody knows when that is.  Steelhead prefer colder water, in the lake and in the streams, so the closer it gets to steelhead operating temperature (55 to 60 degrees) they are prone to show up in bigger numbers. 

I believe that temperature regulation of the stream has a lot to do with productivity as well, more when the temperature raises closer to their optimum comfort zone.  If the stream temperature starts out at 50 degrees, and rises two degrees and steadies out during the day, it has been from my experience that the steelhead become more prone to hit during this time.  Also, in winter, the mornings are not the best time to fish, but its during the high afternoon when the temp raises and steadies out.

Although many do not like him for some reason, John Nagy's book has much detailed information and theories about Steelhead runs in Erie.

At least "noticable" numbers show up EVERY year about the same time, regardless of temperature, or rainfall. Given that it's the only constant factor year in, and year out, I would say length of daylight is the predominant factor. Followed by temperature, then rainfall.

I have to agree with Spoonchucker on this one, daylight length is the one factor that never changes year to year.  In most mammals it's photo-period / daylight length that triggers their matting season, so I'm sure it's probably the same way for fish spawning.  Bucks were long thought to go into rut based on moon phase, but I have read several recent studies online that now suggest photo-period being the predominant factor.

As for moon phases;  From personal experience I feel like the fuller the moon the slower the bite is true for all fish.  When there is a full moon and no clouds fish can see at night to feed.  However once Steelhead are up high in the creeks and in full spawning mode, I don't think they really feed much at all and bite more out of aggression.

biological clock goes off.

right after the gators go dormant and the buldged eyed wobbler starts to gaze at the stars. 2 days after that should be good. lol but seriously each year seams to be different i have never really seen a big run till the water is cold the leaves have changed and the creeks are up alittle

When they start feeling the vibrations of spoons ploppin' in the creek. Their lateral lines can detect these vibrations miles away!

Just sayin'

Photo-periods dictate when they will spawn. Local factors like weather and possibly moon phases influence migration.

If it's rainin' they're runnin'.

ORIGINAL: Cold

Sweet.

We are now just a fish-handling thread away from a major run of steelhead.

Does anyone know where I can get another pair of Boga grips? I like to hold the fish up while I run the yellow rope through its gills. I use a heavy yellow rope so I can drag it like a deer across the slate.

The run should begin any time now. You're welcome.

What we need to do now is test these theories out in July/August to see who's right . (1)So now someone plan on blocking out the sunlight earlier each day. (2)Someone intorduce a cold constant flow to the creek. (3) On cloudy nights, someone produce fake moonlight. (4) someone lower the lake temperature.
If all test are run independently, the data should show what really causes them to run. Then the theory can be proven, replicated & made into scientific fact.

Seriously, I too am interested in what triggers the run, but I really don't need to know why.

What I need to know is when they are running.

When they start running it will be all over this site, which is good. If we didn't have this site a lot of people would make wasted trips(myself included) and we would be just like the bears in AK and Canada, just standing there waiting for the fish to run. "Well, they ran at this time last year", the bears have to show up then, we don't.

But I think all of the theories hold some merit, but I think Temp & water flow are the two main reasons.
Just my $.02

Really though, as was already posted, the light intensity[ shorting of the days ] trigger the spawning urges. The rainfall is the running factor. Fish need to spawn in gravel beds and need running water for the eggs to mature and nature provides that built into the fish brain....WF

The fish are bigger thread is the first sign that the run is happening.

The early run thread should have happened in late-July or early-August if it was gonna happen. At this point, that'd be like saying "I predict Roethlisberger won't miss any regular season games." Might have been valid weeks ago. Maybe. But now it's just crazy talk.