Compared with the Pacific Ocean, the Arctic Ocean looks small and exquisite. It is the smallest, shallowest and coldest ocean. The water temperature of the Arctic Ocean is extremely low, mostly below 10℃ in summer, and the surface seawater temperature in most sea areas is below 0℃ in winter. Due to the high salinity of seawater, the freezing point of seawater drops to-2 ° C, so even if the water temperature is slightly below 0 ° C, the seawater in the Arctic Ocean will not freeze. In addition to the normally flowing seawater, there are also large areas of ice caps and ice floes that persist all year round on the Arctic Ocean. Set off by the deep blue sea water and blue sky, the ice and snow wonders of the Arctic Ocean are particularly gorgeous, often making photographers linger.
You might think that in such a cold ice water world, the number of fish must be pitifully small! Yes, according to common sense, who likes to live in such a cold environment for a long time? But the fact is just the opposite. Although there are not many species of fish in the Arctic Ocean, the number is so large that people even call it the "golden fishery." What's going on? It turns out that although the waters of the Arctic Ocean are very cold, there is no shortage of food here. Every spring, the North Atlantic Warm Current from south brings rich nutrients to the marginal sea of the Arctic Ocean and stimulates the vigorous growth of plankton in the seawater. These tiny plankton directly or indirectly provide a rich food for Arctic Ocean fish, allowing them to reproduce in large numbers. As a result, the Arctic Ocean marginal seas have abnormally high fish yields compared to other seas at the same latitude.
The Barents Sea, located north of Norway and Russia, is one of the marginal seas of the Arctic Ocean famous for its fish production. Its average water depth is only 230 meters, and its maximum water depth is only 450 meters. It is rich in cod, capelin and plaice. They feed on krill, ice algae, clams, crabs or other benthos. Of course, the fish themselves often become delicacy in the mouths of upper-level predators such as squid, polar bears, seals and whales. In order to combat cold waters, some species of fish have evolved "antifreeze" proteins. These special proteins prevent fish's blood from coagulating even below 0 ° C, protecting them from the freezing waters of the Arctic Ocean.