Sea ice is ice formed by sea water, and sea water is salty, so sea ice should also be salty, right? However, in fact, the sea ice is light, or close to light. What's going on? It turns out that not all sea ice is ice formed by sea water. It is a general term for ice bodies in sea water, including ice formed directly by sea water and ice from land.
During the process of direct freezing of sea ice, some salt juice (brine) will separate from the ice crystals and flow into the sea. As a result, the salinity of sea ice is always lower than the salinity of the seawater that formed it. If you taste sea ice with your mouth, it is not as salty and bitter as sea water. But in the ocean near the Antarctic continent, due to extremely low temperatures, the salinity of sea ice there is higher than that of sea ice elsewhere. If you try it, you will feel the salty and bitter taste.
Ice formed on land, including river ice and icebergs. River ice flows into the sea by freezing river water, and icebergs are caused by land ice and snow deposits that slide into the sea. Since they all come from fresh water and snow, their salinity is almost zero. If you taste it with your mouth, it will be naturally tasteless.