As fresh water gradually becomes more saline (salty), growing crops to feed the human population becomes more difficult, but wild plants that can survive in sea water could be developed as crops.

Why do most plants die in sea water?  It might sound strange, but they die of dehydration!

This is because of a process called osmosis - water moves out from the plant cells into the sea water.

See a video explaining osmosis here.

If too much water is lost by osmosis, the cell will die.  But some plants, such as sea kale and samphire , have developed ways to be able to survive in brackish waters, where fresh water from rivers meet the sea and mix together.

Maybe a seafood salad of the future will include these plants as sea crops as well as the more familiar prawns and other shellfish!

See samphire recipes here!