Here is my opinion on the air pressure: Air pressure affects a fish's swimbladder as it rises and falls.
http://www.usairnet.com/weather/conditions/?station=KADSFrom what I have come up over the years, the fish are more comfortable in a range from 29.85 to 30.10.
If the Air Pressure is 30.40, or higher, I will cancel your trip.
If the Air Pressure is 29.60, or lower, I will cancel your trip.
If the air pressure is 30.50 or higher, you are going to have a hard time even snagging a carp turd. I stay home and I won't even go fishing.
The reason I will cancel your trip sometimes are due to the air pressure, and I will give you an option to pick a new day, or go out anyways and only catch a couple. So if I call you before the trip and say: " you have an option" : that means I don't like the something about the weather, and I'd prefer we pick another day. I like to limit every trip and then possibly go limit on Sandies after crappie, or vice versa. If the pressure is out of wack, we are not going to do that.
Now, this is not by the book. This is all what I have noticed while fishing. Sometimes they will bite when the air pressure is all wacky, but 90% of the time, the air pressure, will prove itself.
I find that fish 15 ft or shallower are most affected by the rising and falling of barometric air pressure. The fish in deeper water, are already pressurized, due to the water pressure as you go deeper, so they don't seem to be as affected as the shallower fish. Again, this will only tell you why the fish have slowed down and are not biting anymore. There is nothing you can do about it, but wait it out till it stabilizes or just go home.
As an example:

This is a perfect day with the air pressure. You read it from the bottom up. The top number is current and the bottom number is hours ago. As you can see, the pressure is going up, but its rising slow and steady. That's a perfect day to fish in that scenario.

Now, the pic above is a very bad bad day to fish. We start at 29.83 and the pressure plummets all day and won't stop dropping. This really will shut the fishing down to a trickle or non at all.
My rule:
Example: If the pressure is at 29.87 and drops two points to 29.85, the fishing will slow down a bit. If it drops or rises .02 or more, your fishing trip might be a site seeing trip.
If it rises or falls .01 at time, you should be fine.
If it rises more than .02 fishing is slow.
If it falls .02 or more fishing is slow.
If its steady, or rising .01 or falling .01 every hour, fishing is good.
If the pressure rises or falls more than .05 an hour, I'll just go home.
I am pretty sure, a couple of you guys were out yesterday Crappie fishing Sandbass fishing or hybrid fishing, and that 830 in the morning the fish completely stopped biting. The air pressure had risen .02 points at a time within the hour and then it started to drop rapidly as the storm front started to roll through.
Example: We were fishing yesterday morning at Rowllet creek, as soon as we got there we started to pick up hybrids left and right every single cast. Then at about 830 the fishing completely stopped dead in its tracks. The air pressure had risen .02 points and and the fish completely stopped biting. We could see 20 to 30 hybrids sitting right in front of us but would not even budge. And again, there's nothing you can do about it, either wait it out or go home and come back when the air pressure stabilizes. I see this happen to me almost on a daily basis. I save the link in my smart phone, and refreshes every hour as I'm guiding to tell me what's going on under the waters surface.