High salinity in a body of ocean water leads to vertical movement because it raises the water's:

1. Salinity measures how much dissolved salt the water carries. 2. Water holding more salt is heavier for its volume, so its density is higher. 3. Denser water sinks beneath lighter water around it. 4. That sinking, and the rising of lighter water to replace it, is vertical movement. 5. Salinity does not raise temperature; if anything the denser, saltier water tends to be the colder. _Source: NECTA ACSEE 2023 Geography 113/1, Question 4: Water Masses_