Spawning Northern U.s. Natives

Do the nothern species have to go through "seasons" to spawn in captivity?

I think your question is too general. Many (most?) species spawn in a set season, triggered by water temperature, day length, etc. This is even true for some tropicals (e.g., water change/rainy season to trigger corydoras spawn). BUT, as to whether this is required, and for which species, I do not know. It probably depends on the species.

Well I was wondering if I could "force" my fish to spawn by controlling the water conditions (water changes, heating up water, etc.) like with cichlids. Many times a water change with them can "induce" a female or two to want to spawn.

If you make the effort, you could probably get most species to spawn out of season. I am reasonably sure you could get sunfish to spawn year 'round. Darters might be a bit more difficult.

Sunfish don't seem to be real paticular, as long as the temperature is up and the day length is long they will spawn reliably every 12-20 days if they are in a good healthy condition.

Other species such as darters and other very seasonal spawners (species that spawn once and only once a year) often do need a wintering perior to enduce spawning but if you have a chiller and a room with no windows you can cause this to be much shorter than normal and have some success. I personally have not done this but I know other NANFA members have.

One of NANFA's most successful bigtime breeders has his basement set up to serve as a cold room just for the purpose of spawning fish whenever he wants them to spawn.
I am SO jealous. We don't have basements down here, ya know, and you'd be hard pressed to find anyone who'd ever even been in one.

Anyway, yeah, it's a long and well known fact that manipulation of temperature and photoperiod and water hardness can fool a fish into spawning well outside of spawning season. In many cases it's pretty much essential.

I back up that up. Sunfish like cichlids will just keep on spawning if fed well and kept warm and "well lit". The same goes for killifish. I don't have much experience with other types, but know that pickerel and mudminnows have to be chilled. However, that doesn't mean it will never happen without a cool down. I would think certain minnows might not need to be chilled. I have kept golden shiners on and off for controlling duckweed and algae ( and I just like how they look), and they seem to spawn for no reason other than that they are ready to go. These indoor spawns were very rarely successful, but goldens kept indoors all winter, then dumped in the pond early summer spawned successfully. Putting them into the pond can give them some kind of seasonal conditioning, if there is a cool spell and water temps drop, or heavy rains can drop pond temps.