History

• Blue whales are the largest living animal on the planet and can reach lengths of 100 or more feet. There is no natural predator to an adult blue whale. Humans began hunting blue whales in the 19th century for the oil derived from their blubber and for their baleen, which was used to make corsets and parasols. Despite its size, the blue whale's diet is very simple, relying on a small marine invertebrate.
  
  

Types

• Blue Whales feed upon krill, a small marine animal similar to a shrimp. They catch krill by opening their mouths to scoop up large volumes of water. They then push that water back out, sifting it through their baleen (wiry, brush-like teeth) which allows the water to pass through but capturing the krill. An adult Blue Whale can eat up to four tons of krill in a single day. Blue Whales are constantly on the move and are present in every ocean in the world in search of new sources of krill.
  
  

Size

• Krill, in turn, feed upon phytoplankton, a microscopic plant. The phytoplankton synthesize carbohydrates by drawing water and carbon dioxide from the ocean. The whole process is powered by sunlight in a process called photosynthesis. This energy is used to produce more phytoplankton and their numbers can grow rapidly. Because of their dependence upon sunlight, phytoplankton remain close tot he surface of the ocean.
  
  

Geography

• Different types of krill feed on specific types of phytoplankton. If there is a disturbance in the reproductive process or photosynthesis of food for phytoplanktons, krill will starve to death because of their inability to eat a different food. This in turn determines whether blue whales will find food in a particular region.
  
  

Time Frame

• Blue whales migrate almost constantly in search of food. Their lifecycle is tied to this migration as well. Calves will be born in warmer waters, for example blue whales in the Pacific may migrate from Alaska to Mexico in order to give birth in the spring and return along the same route in the fall. The calves, like all other mammals, drink milk from their mother instead of eating krill. The milk of the blue whale is extremely rich in fat and most young blue whales gain 8 pounds an hour or 200 pounds a day.
  
  

Prevention/Solution

• Once weaned, juvenile blue whales learn to hunt krill with their pod. The older whales often round up and concentrate the krill in a fixed area and allow the young whales to take turns in practicing scooping techniques. As the whales grow older, they will move further and further out of the center of the pack until they reach full adulthood and autonomy.
  
  

Warning

• Shifts in environmental conditions, from temperature to pollutants can easily affect the growth of the vital phytoplankton. Without these small plants, the krill necessary to sustain the blue whale population will be endangered. Loss of krill can affect blue whales, fish, squid, penguin and some seal populations as well.