The ocean is salty mainly because of minerals and salts washed into it from the Earth’s land by rivers and streams. Over millions of years, rainwater dissolves minerals from rocks, which then flow into the ocean. The most common salt is sodium chloride, the same as table salt, which gives seawater its salty taste.
The salt stays in the ocean because water evaporates but the salt does not, causing the salt concentration to increase. This salinity is important for marine life, influencing water density, circulation, and the health of ocean ecosystems. Understanding why oceans are salty helps scientists study Earth's water cycle and climate. Shutdown123