Consider the following statements regarding ocean currents : 1. Difference in water density is the main cause for the formation of ocean currents. 2. Density of water depends on temperature, salinity and pressure. 3. As a rule, ocean waters move from areas of higher density to areas of lower density as a current. Which of the statements given above is/are correct ?

Differences in water density (driven by temperature and salinity, i.e., thermohaline circulation) are indeed a primary cause of deep ocean currents, and density also depends on temperature, salinity and pressure — so statements 1 and 2 are correct. However, the actual movement is the opposite of what statement 3 says: denser (cold/saline) water SINKS and flows along the ocean bottom, meaning surface waters tend to move FROM areas of lower density TO areas of higher density (and dense water moves away after sinking). The blanket rule that ocean waters move from higher density to lower density areas is incorrect. Hence only statements 1 and 2 are correct.