So glad to see you guys paying attention.....it's sad when a large % of fishermen claim "bluefish will hit anything".
Roddy, I have had many nights when the only way to catch them was to **** them off....aggressively working a popper to bring them into striking range....

I have documented this temperature change in (spring) bluefish behavior.....(for hitting plugs and topwater artificials at night)..... as happening at around 60 degrees......when it's below that, mid to low 50's. I have seen the topwater artificial bite turn off like a light switch...This is just my experience, yours may be different.
More about the bluefish migration here:
http://stripersandanglers.com/Forum/...fish-Migration

Have also sometimes done better with bucktails, metal and rubber...catching bluefish at the lower temps. Early season, I have found bluefish to be very picky, most notably at night......when they are not aggressively feeding on something.....I'm glad to see you noticed it as well.