anthropic, this is something we look at-among other things-to help decide when to start fall test netting.
When length of day gets close to 12hrs (sunrise to sunset) this seems to trigger many species to start their movements and step up the process of, dare I say-feeding more aggressively. Obviously water temps, weather, etc, all play into this but we've pinned it down to a good reference if nothing else.
As you well know, photo period affects/triggers many instinctive actions to kick in on many creatures, fish included.
I also oversimplified my statement above about length of day in my post above. Water temps do not drop just because of cooler nights but also less solar input (energy transfer). Interestingly, when night time temps start dropping well below water temps, there can be "almost" as much evaporation as there is in hot summer weather. Now, this may not be the case in east TX, but here in the central parts we can have water in the 60's and nights dropping to near freezing..It flat sucks the warmer water into vapor. That was FYI, not really on topic there :-)))
