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To survive living in frigid Antarctic waters some species of fishes, the Notothenioids, have developed proteins that act as antifreeze. These antifreeze proteins are a group of unique macromolecules that help some polar and subpolar marine bony fishes avoid freezing in their icy habitats.

Waters of the southern oceans are so cold that temperate and tropical fish would freeze if they were placed in this environment. The presence of salt in sea water allows it to remain liquid to about -1.9 °C. The antifreeze proteins, along with normal body salts, depress the freezing point of blood and body fluids to - 2.5 °C, slightly below the freezing point of sea water. These proteins bind to and inhibit growth of ice crystals within the body. The proteins attach to small ice crystals stemming their growth.

There may be several commercial applications of these antifreeze proteins. These compounds are about 300 times more effective in preventing freezing than conventional chemical antifreezes at the same concentrations. The effectiveness of fish antifreeze proteins in inhibiting ice growth suggests that they could be used to prevent freezing of food and freezing injury in several applications. The Food and Drug Administration has approved the use of the antifreeze proteins in 100 products and they have been added to ice cream and yogurt products. The addition of the proteins allows the production of very creamy, dense, reduced fat ice cream with fewer additives. The proteins used in food products are isolated from fish and replicated on a larger scale in yeast.