The fall of Venice, result of the sinking of Venice?

To those who doubt that there can be such a thing as a temporary tax, let me remind you that there's nothing more permanent than a temporary tax.

As I am planning to spend a nice week-end in Venice, I thought I would read a bit of the city's history, which not only is an architectural marvel of our world, but also used to be one of the most advanced civilizations, and most vibrant economies of the world at some point, mainly, thanks to their openness to commerce and their gold coins.

So here's what I found on Wikipedia:

In 1604, to defray the cost of flood relief Venice introduced what could be considered the first example of what became elsewhere a 'stamp tax'. When the revenue fell short of expectations in 1608 Venice introduced paper with the superscription 'AQ' and imprinted instructions which was to be used for 'letters to officials'. Initially this was to be a temporary tax but in fact remained in effect to the fall of the Republic in 1797. Shortly after the introduction of the tax Spain produced similar paper for more general taxation purposes and the practice spread to other countries.

One must not look a lot further than a probable massive tax burden on the shoulder of the economy to see why the city state might have collapsed...