Submarine freshwater springs, intertidal zones, and melting icebergs

What do these three things tell us about "salt" water: submarine freshwater springs, intertidal zones, and melting icebergs?  To me it speaks to the salinity gradient between "salt" and "freshwater".  The tidy separation of salt and freshwater, obscures the elegant nuances of water.  Submarine springs, for instance were described by Pausanias [Greek geographer] "unmistakably fresh water rising up in the sea" ( second century AD). The Syrians developed methods to harvest freshwater welling up in the sea to supply their island city of Arvad.  

Taxonomy has played its role, in the time of Linnaeus, but now we need to be more sophisticated, and think of water as "one", with a spectrum of temperament and character.  Blue Ecology functions under the spectrum notion, not the taxonmical. 

Reference:

Kohout, F.A. 1966. Submarine Springs: a neglected phenomenon of coastal hydrology. USGS.