The shrinking of fresh water table underneath islands

It bothers me to constantly hear and see from media around the world and from leading experts on this topic talking about the early signs and impact of the global concern on small islands and its people as if the island(s) are like a ship tightly tied down on both ends to a strong fixed object during low tide and when the tide rises, the water level increases and eventually pour into the ship, thereby rendering abandonment.

Such perception although it make sense is not the ultimate threat to the continued peaceable survival of innocent people and their culture on this island-countries. Before the sea level finally surpasses the ground level or shorelines of these atolls, the people of these islands-must leave behind their home country in search for a completely new home or homes. The grave concern is the shrinking of the fresh water table underneath these islands that support all life form. As the sea level rises, the salt water expanded inland under these islands thereby shrinking the existing fresh water. As the brackish water extend and freshwater shrink, edible crops that have been the source of life of these people will tie out thereby making these islands unlivable.

Hence, this process happens before one can visibly see the waves-whether small or big - pour over the islands and is declared as inundated and the first victim of the sea level rise.

Thank you