This has been a point of concern since day one and many have voiced questions and heard occasional complaints. Considering we have been riding there for almost ten years, I wouldn't worry too much.
Things can obviously change, and sometimes do, but it's not like we went un-noticed until just recently.
I would be more concerned riding over by MacDill.
If you are actually interested in salt marsh mosquitos (which I doubt), they can indeed mature in salty water. Eggs are laid on the marsh in lower lying areas before the water appears, unlike many species of freshwater blood suckers which search out standing (and still) water.
http://www.rci.rutgers.edu/~insects/sp10.htm