@sicamore you can get a seaplane job with way less then that, I know companies that hire with as low as 600 hours (on C206), networking is key.
The jobs listed with those TT are due to the fact that it`s very hard to keep somebody employed on a seaplane, most pilots take jobs because they need hours to get other jobs. It`s hard to find pilots that will stick around so it`s easier to just cut most of them out and go for those who maybe just do it for the lifestyle.