Fatter is Better for Marine Mammals

     For land mammals, we typically see weight gain as a negative thing; it slows us down, it makes us use more energy to get to the same place, and its not too attractive. However, it is found that in northern elephant seals (mirounga angustirostris), the opposite is true.

     Plumping up for the elephant seals is how they remain a better swimmer, and more buoyant. Diving down takes the mammals a considerable amount of energy, but the more buoyant they are, the easier it is for them to come up. This makes it easy for them to dive down deep and can travel far away from their breeding grounds, nearly 4000 km away. A fully plumped female takes half as many strokes per meter and have a much easier time ascending after a dive, another study has shown.
     I think this was interesting how marine mammals differ so much from land mammals even though they are both mammals. Thinned out marine mammals can't swim far, can't hunt deep down, and are overall less able to survive, which is the polar opposite of how weight gain would be detrimental to a human.