Diet Secrets of the Deep

There are innumerable creatures that reside in the oceans’ deep waters, from whales to viperfish, sea lions and anglers to gulper eels. Regardless of size, all creatures have their own survival strategies, and must eat in order to survive in their environment, even massive-sized whales. One may think that whales eat anything and everything that swims underwater from phytoplankton to zooplankton and shrimp. However, the main dietary staple is a tiny zooplankton called krill.

The krill is a member of the shrimp family. Krills are a cold water marine organism that lives in both the Arctic and Antarctic oceans. They are considered to be highly nutritious, because they contain high levels of protein, amino acids and unsaturated fatty acids, such as Omega 3. They live in swarms at a depth of 350 feet beneath the ocean surface. This tiny, bioluminescent creature is food for penguins and seals, as well as whales. Krills are also consumed by people, because of their nutritional value and ability to reduce diseases and improve health in humans, making it the “little big friend” of the human health world. Krill is recognized by the World Health Organization and the United Nation’s Food and Agriculture Organization as a nutritious food source.

There are a variety of whales alive today: baleen, humpback, right, blue, and killer whales to name a few. One thing whales have in common is that they eat krill, but how much krill whales eat depends upon their bodyweight. For instance, a blue whale consumes 8,000 pounds of krill daily during their 120 day feeding season. However, a grey whale will consume 340,000 pounds of krill daily during their 130-140 day feeding season. For whales, the blubber gained while eating krill during feeding season sustains the mammal during the winter months and mating seasons, in which they eat less.

Different whales have divergent eating habits. Right whales swim near the surface to feed, or they will swim in a group, forming a V-shape to capture their sustenance. Rorqual whales engage in both surface and depth feeding, and like to eat on their sides. Humpback whales feed while blowing bubbles, while the grey whale feeds on the ocean floor. Fin whales target schools of fish at high speeds, and overtake their prey by tossing them around, then turn onto their side, and devour their catch. Killer whales either encircle their prey as a team or hunt alone. Killer whales are known to hit icebergs from below, in an effort to knock their prey off of the iceberg and into the water, and frequently use this tactic to capture sea lions. Whales do not chew their prey, they either swallow it whole or tear it into chunks.

Cruising and filtering are the terms used for when whales feed on the ocean floor, swimming slowly through swarms of Krill. They pass by their target with their mouths agape. The krill become trapped in the whales mouth, and are swallowed whole.

Climate change not only affects the human ecosystem, it also affects the animal kingdom and alters survival strategies. Where krill was once protected from predators like the humpback whale by oceanic ice formations, these formations have melted, thus exposing krill to their predators. According to a scientist from Duke University, the dwindling ice caps, and melting snow and ice have provided over 300 humpback whales the opportunity to feed on the largest swarm of krill observed in the Antarctic. And while climate change affords whales plenty of krill to feast on, it causes other problems for whales by altering their mating cycle and its locations. This alteration occurs because whales will not return to their breeding grounds if there is a viable food supply. Whales are dwindling in numbers due to altered mating schedules because they generally do not eat during mating season and vice versa.

For more information on whales and krill, please see the following websites:

  • Marine Life – An excellent website that explains marine life. This website has a video, and information on marine biology, including types of plants and vertebra.
  • Diet and Eating of Baleen Whales – The information found here comes from Sea World. It has information on baleen whales, how they eat, live, and their habitat.
  • Humpback Whales – This is a thorough website covering the biology and natural history of the humpback whale. Information includes biological classification and factors threatening their population.
  • Right Whales – This website answers questions about the right whale, their anatomy and why they are hunted.
  • Killer Whales – A website that gives a general description of the orcas (or killer whales). Included is information on their migration, breeding, habitat and how they communicate.
  • All About the Killer Whale – Information gathered on this site includes the killer whale’s hunting habits, appearance, giving birth, and how people can protect killer whales.
  • Types of Whales – An excellent website that lists different type of whales, giving their scientific names and a brief explanation of what they eat and where they live. Photos of the different whales named on the site appear.
  • The Marine Food Web – This website describes the food chain of marine life in detail.
  • The Blue Whale and Krill – An interesting article all about the blue whale that explains how they breathe.
  • Whale Mob: All You Can Eat Krill -A very informative site that includes a video on the eating frenzy of whales.
  • The Blue Whale and Krill – A very informative article describing the largest animal of the ocean, included are photos of blue whales in action.
  • Krill Stories – Information on this page is all about krill. It includes pictures.
  • Climate Change and Krill – A brief article that summarizes information on how climate change is affecting whale lifestyles.
  • Fishing for Facts: Fin Whale -Information on this website is all about fin whales.
  • The Blue Whale Food Chain -This page has cool facts about blue whales, covers their history and conservation.
  • Whalers Myths and the Reality – This informative page uncovers truths and myths about whales.
  • Whales Are Not the Cause of Dwindling Fish Stock – National Oceanic & Atmospheric Administration US Department of Commerce. It has a food chart and a video about whales.
  • Krill Count – Information found on this website is from the Krill Conservation Project. It talks about Antarctica as a great wilderness in danger.