Otters eat A LOT of food
So we mentioned that giant otters eat a whole lot of food. A hefty appetite isn't unique to that species. Otters in general need to eat a whole lot to satisfy speedy metabolisms. They eat between 15-25% of their body weight in food every day. To get enough to eat, they may spend as much as 5 hours a day foraging for food.
According to Defenders of Wildlife, "River otters primarily eat fish. They are also known to eat whatever is easiest to find, like crustaceans, mollusks, insects, birds, oysters, shellfish, crabs, crayfish, frogs, rodents, turtles and aquatic invertebrates."
Sea otters play a key role in the coastal ocean ecosystem. Sea otters eat a diversity of fish and crustaceans, but importantly, they eat the urchins that feed on kelp. This means sea otters are an important species in keeping kelp forests healthy. Without the sea otters, urchin populations boom and kelp disappears — and along with the kelp goes a myriad of other species that depend on the kelp forests. So a hefty appetite is a welcome attribute in a sea otter!