@ shinderhizzle84

Things to consider for drop in income.

1)Did someone declare war on you? If so you lost trade right with that faction.

2)Did you recently create a large army or fleet? Perhaps your income can't support the upkeep for it. Also, fleets are increadably expensive to maintain.

3)Did you construct an expernsive building? This can also cause a trade deficet (sp?) for a turn or two.

4)Sometimes you have bad harvests which can fluctuate your income, also trade lanes can change for example Marselle could have constructed a port redirecting trade in Genoa from Naples.

My guess is someone blocked one of your ports for one turn and thus you have lost trade rights with them. Check in the diplomacy scroll and see if your at war with anyone.