Why does water need conservation even though large oceans surround the land masses?

Explanation

Salt water of seas and oceans is unfit for consumption by humans, animals land plants or industries. Therefore, trerrestrial biota and human beings have to depend upon fresh-water resources available on land (such as water present in rain, snow, springs, river, lakes, ponds and other fresswhater bodies (only about 0.5% of the total water on earth). As a result freshwater needs its conservation.