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3. Baetis Temperature

Anyone have a bead on water temperatures associated with the first Baetis emergences?

Paul-

Assuming you are referring to Baetis tricaudatus, on this page, Jason indicates the 1st brood of the year will emerge after the water temperature reaches 40 degrees.

Yes. Thank you, Roger.

So Roger, what you are saying basically, it's over up here in Michigan then...This freakish year has it in the low 80's today...On March 19th! We fish a small pond here starting on April 1st and normally, at this time, we are wondering if there will still be ice on it! We would all bring our Neo's and long-johns...Not this time...There may actually be swimers out there this year.

Everything could really be turned around this season...

Spence

The first brood begins to emerge when the water temperature is right, but if my experience is typical, baetis continue to hatch over a period of time, sometimes lasting over a month. They are still hatching here, a month after I saw the first ones this year, and fish are very keyed in on the nymphs, and I would think will continue to be even after the duns are hatched out. So, Spence, get out there and fish.

I'm wondering about temperature at initiation -when they first appear. Any records Louis, Spence?

Paul
My records indicate (only two streams in one area, but over 15 years of data) that I have seen size 18 olives (assuming B tricaudatus, I'll try to get a photo this year) beginning at 38 degrees.
Around forty, the hatch really starts to get going and I see fish taking duns. The "peak" is around forty two.
But I don't think that temperature has as much influence as the amount of daylight present on these creeks - one is a spring creek and the other is a spring influenced freestone river. The hatch is present during the same time frame each year with a minor (one to two weeks) variation before or after that magical "date". In warmer years (like this one) they start early (late February), but the peak is always between the second and third week of March. In colder years (like last year) they started the first week of March (38 degrees)
Last year, the peak was the third week of March, (41 degrees) and I expect the same this year. When Bruce/Goose/LastChance/Feathers5 and I get back next week, I'll give an update.
Louis- are you in? Shawn?
Another variable is extreme weather such as rapid run-off, but I suspect that has more to do with actual fishing conditions and the lack of witnesses to the event...

Thanks, Tony. My waters are surface water (and snow pack) sourced and it seems the Baetis get going in April here (at the lowest elevations -5500ft). But...I've not been diligent enough to get a really good bead on them. Thanks, again. I'm around 40F now, but so far no sign of emergers. It's still all midges.

Tony, I'm in. Don't know which day yet, but Saturday or Sunday.