The ocean is composed of approximately 3.5% salt. This means that for every 1,000 grams of seawater, around 35 grams is salt, primarily in the form of sodium chloride.
This high salinity is due to the accumulation of minerals and salts from various sources, including river runoff, underwater volcanic eruptions, and the weathering of rocks. Over millions of years, these processes have contributed to the ocean’s saltiness, making it a unique environment that supports diverse marine life.