Marine Mammals around the World
Who are Marine Mammals?
Dolphins, manatees, polar bears, sea otters, seals, walruses, whales, and even the unicorns of the sea, narwhals, are all marine mammals. These creatures are mammals that live in or by the sea; they breathe air, are warm-blooded, produce milk for their young, and give birth to live offspring instead of laying eggs but they depend on the oceanic environments to live a happy, healthy life. Marine mammals are typically segmented into four categories: cetaceans, pinnipeds, sirenia, and marine fissipeds.
Cetaceans represent the 70+ species of dolphins, porpoises, and whales around the world. These creatures spend their entire life underwater. They are often noticed for their playful habits of breaching, spyhopping, and tail slapping, and are known to live in family groups called pods.
Cetaceans may also be split into two smaller subgroups: baleen and toothed. Toothed cetaceans, also known as odontocetes, utilize echolocation to travel and hunt in dark, uncertain waters. Some cetaceans, such as dolphins, have such heightened senses that they can use echolocation to determine the differing size of a BB pellet versus a corn kernel up to 50 feet way. Baleen whales, or mysticetes, are some of the largest mammals on Earth and you’ve most likely seen or heard of these whales blowing streams of ocean water into the air. These massive cetaceans are known for their mighty diaphragms which they use to quickly exhale as they surface and inhale as they dip back into the waters.
The pinniped family consists of sea lions, seals, and walruses spanning across 33 species. These carnivorous creatures utilize their fin-feet to function on land and underwater. The majority of their time is spent swimming and hunting underwater or sunbathing and molting on land. They do not utilize their flippers for land travel often but do so to mate and birth their offspring. Some pinnipeds have enhanced their talents and are capable of diving for extended periods; the northern elephant seal can remain submerged for two hours as they travel 1,500 feet below sea level.
Sirenia are the manatees and dugongs of the world. The entirety of their life is lived underwater. Though most viewers don’t perceive manatees and dugongs to be the most majestic sea animals, they were named after sirens, the gorgeous Greek sea creatures that were said to have lured a large number of sailors into the depths of the sea.
Marine fissipeds are a unique group as this sector is home to polar bears and sea otters. They are classified as marine mammals because they depend on the sea for survival. Though they spend most of their time on land, marine fissipeds rely on the sea as a hunting ground. Sea otters float extremely well on water thanks to the air pocketed in their thick fur. Due to this ability they rest, mate, birth, and feed their young on the water. Polar bears have adapted least to the aquatic lifestyle though they are capable of swimming. Due to this they are at population risks as climate change continues to impact the ice floes.
Impacts on Marine Mammals
Currently, 20 to 30 percent of marine mammals are endangered or threatened. Understanding that these creatures play a vital role in the ecosystems they live in, the extinction of one species could result in detrimental impacts for another species. In 1972 the United States established the Marine Mammal Protection Act which states that no person may remove a marine mammal from their habitat without a permit. This clause further explains that people may not harass, feed, hunt, capture, collect, or kill any marine mammal. Marine mammals are also provided any and all applicable protections under the Endangered Species Act of 1973.