In my world, the Straits of Gibraltar have been closed during a post-apocalyptic glacial period and the Mediterranean is isolated from the oceans. The result is similar to the Messinian salinity crisis but less extreme, with the sea level reaching equilibrium somewhere around -400m. This leaves much of the Adriatic and Aegean basins dry, and extensive new land around Sicily, Corsica, and Sardinia.
What advantages and challenges would these new lowland and/or coastal regions present to human settlers? I imagine that salt deposits, soil quality, topography, micro-climates, and exposed shipwrecks would all play a role in encouraging or deterring activity. What might these areas look like as the sea recedes, and how would the landscape change over the centuries once exposed?
Keep in mind that the overall climate of the region would be similar to that of the last glacial maximum, and the humans have no modern technology.