What is the importance of the sea in providing food for humans?

Many Asian countries rely on fish, etc., from the sea (part of their diet) as well as other countries. If we don't stop raping our oceans of every living thing by netting and throwing back other creatures of the sea that one doesn't want (some already dead) then there will be no more food. Seafood is good for people and high in protein and use to be cheap at one time, but not so today.