This video was filmed during December 2014 in the Sea World, San Diego, California, USA.
Review: Abdel Rahman El Gamal (Founder of the video channel)
Adaptations of walruses for aquatic environments
Walruses can stay submerged for as long as 10 minutes. The diving depth of walruses stay within 80 m which is water depth they inhabit. Walruses are physiologically adopted to conserve oxygen while diving through:
Slowing down the heart beating
Blood is shunted away from tissues tolerant of low oxygen levels toward organs where oxygen is needed, such as the heart and brain
Muscles have a high content of the oxygen-binding protein myoglobin
The heat gradient throughout the thick blubber (up to 10 cm) to the skin slows heat loss in the water during the winter and hence makes the skin warmer than the water by about 1° to 3°C.
In cold water, blood is shunted inward as blood vessels in the skin constrict, reducing heat loss to the environment. The skin appears pale, almost white. When warm, blood vessels in the skin dilate (expand), releasing heat into the environment. The skin appears pink. When air temperatures rise above 15°C, walruses often stay in the water to stay cool. It may be of interest to know that because of their gregarious nature, walruses seek out physical contact with other walruses. This helps walruses retain body heat rather than lose it to the external environment.
Threats to walrus populations
According to the 1990 population estimate, the total worldwide walrus reached about 250,000 animals; more than 200,000 of which is for the Pacific walruses while the remaining is for the Atlantic walruses.
The walrus populations -especially the Pacific walrus- have been heavily exploited in the 18th and 19th centuries due to the growing demand for their meat, skin, and ivory tusks by traders from Norway, Russia, Great Britain, Greenland, Canada, and the United States. The same is true for the Atlantic population of walrus that suffered of over-hunting by American and European sealers and whalers. In fact, many walrus populations were nearly wiped out before efforts were made to preserve them after the cycles of population depletion whereas the latest one began in 1930.
Global warming and walruses
The effect of global warming on walruses is directly related to the thickness of the pack ice that turned thinner and thinner in several recent years keeping in mind the walrus relies on this ice while giving birth and aggregating in the reproductive period as well as providing resting habitats. Therefore, as the pack ice turns thinner, the overall production performance is negatively affected especially the young.
There has been variety of protection protocols which have been adopted over years to restore the threatened walrus populations and help prevent its further declining. The conservation approaches as taken by concerned countries and/or agencies or organizations ranged from the banning of commercial hunting and sometime harassing of walrus populations to determining annual subsistence catches byindigenous Arctic peoples based on annual estimation of walrus populations. Moreover, the listing of walruses under the Convention in International Trade of Endangered Species (CITES) highlights the necessity to present the appropriate permits or certificates in order for the trade of the walruses to be legal.
Sources: Defenders of Wildlife, National Geographic, Sea World, Wikipedia