Does mono bio degrade fast???
No, not fast but it will break down (UV rays make it brittle) into much smaller pieces and eventually, though not gone, will disappear from sight and become less of hazard.
(NOTE: this is why you should store your lined reels and spools of line in the dark or at least out of direct sunlight when not in use and replace your line occasionally as the UV rays will weaken your line)
Though still obviously not good for the environment it would appear to be the lesser of 2 evils (IMO).
In a perfect world EVERYONE would take there trimmings and buggered line home with them instead of littering the banks and channels of the rivers.
I really think the environmental argument is bogus if braid is used properly.
Properly is the operative word. I'm sure you and many others are responsible and do use it properly but with the amount of line( both braided and mono) littering the rivers (mono being the lesser of the evils) there obviously is a problem with others lack of concern.
But this thread is supposed to be about floats.
I do use sliding floats and fixed floats However I generally use a stop at the bottom as well and find it easier and quicker to adjust my depth (especially with numb fingers in the winter).
I would remove the bottom stopper if I felt I had to for a deep pool but I just like the simplicity.