According to Steve Vance—the lead paper author from NASA's Jet Propulsion Laboratory in Pasadena, California—"this is good news for Ganymede. Its ocean is huge, with enormous pressures, so it was thought that dense ice had to form at the bottom of the ocean. When we added salts to our models, we came up with liquids dense enough to sink to the sea floor."
So good news for Ganymede indeed. Even better: According to the study, this may be common to other icy moons with large oceans.
Source: gizmodo.com by Jesus Diaz