By determining the kinds of food that marine mammals eat, we can gain insight into the role that these animals play in the marine ecosystem. We can determine whether marine mammal species directly compete with commercial or sports fisheries, and this information helps in managing fisheries. Many marine mammal species are specialized for the food that they eat. For example, baleen whales use large baleen plates to sieve small food out of the water. Crabeater seals use complex teeth to sift small krill out of the water.
Sea otters have teeth with a flat, broad surface area for crushing sea urchins and shellfish.
Manatees have teeth that continually grow and move forward, because they feed entirely on aquatic vegetation and need to continually replace worn teeth. To read more about what different marine mammal species eat, check out our section about marine mammals . By determining what food marine mammals consume, we can gain insight into the role that these animals play in marine ecosystems. We can also find out if different age groups feed on different types of food. A current study focus has been concerned with how marine mammals affect commercial fisheries and whether there is direct or indirect competition between fisheries and marine mammals.