Seeing a lot of people talk about how the density of water is going to change with a temperature change. I don't really think that's true. Liquid water density is pretty darn inelastic and almost fully incompressible. It's one of the reasons hydraulics works. Ice on the other hand has a pretty different density.

Water density table - https://www.usgs.gov/special-topics/water-science-school/sci...

If the temperature of the ocean changed by 10°F that would result in a .1% change in overall volume. Obviously that does make a difference because the ocean is so big, but it's a lot less consequential than ice, which is above the water, melting into the water and ice.