It is easy to freeze in icy water but not for sea animals like fish as it can even survive in icy waters. It is surprising how fish can survive underwater even when the land above is almost frozen. The explanation behind this is simply because heat does not easily pass through the ice. This slows down the process of freezing the waters.
Fish body fluids can easily solidify when the water temperature drops below minus 5 degrees Celsius. Bodies of water in the arctic can look frozen on top, but temperatures at a depth of 30 meters can still be stable allowing the fish to live without getting frozen. While the temperature below freezing water is cold, these creatures have learned to adjust to their surroundings making it the least of their concern. The scarcity of food is another problem.
Scientists at the International Space Station (ISS) conducted microgravity experiments and found out the reason why fish can survive freezing water, as per Science Daily. The study showed the antifreeze glycoproteins found in frozen waters oscillates and accelerates the growth rate of the ice crystals. Such results may be contradictory but it explained the mystery the antifreeze characteristics of fishes.
Researchers concluded that the growth of the ice crystals in the water slows down when it combines with glycoproteins in the fish blood. Lead researcher Yoshinori Furukawa of Hokkaido University sought to get a correct measurement of the actual growth rate of the ice crystals using the microgravity conditions of space. The University's Institute of Low Temperature Science and JAXA developed a device that will measure the speed of this growth in space. The device is called Ice Crystal Cell 2.
The device that will determine why fish survive in freezing water was installed in the KIBO experiment module and researchers controlled the device using ground signals, according to Phys.org. A total of 124 experiments were conducted and 22 were able to measure the growth rates of the ice crystals accurately. The experiment showed that the glycoproteins hastened by up to five times faster the growth of ice crystals in waters with glycoprotein compared to pure water.
"Our results suggest that the prevention of freezing in living organisms cannot be solely explained by the growth depression effect of glycoproteins. In other words, the novel mechanism we observed is essential for preventing living organisms from freezing,"researcher Ken Nagashima said
The freezing temperature of the Antarctic Ocean that can reach up to minus 1.8 degrees Celsius is much lower than the minus 0.9 degrees Celsius freeing point of the fish blood and this could easily keep all those dishes frozen. This has remained a mystery for years, but finally, scientists found the anti-freezing glycoproteins contained in fish blood, and how these actually worked to help fish survive even when swimming below frozen waters.
