Managing the Eco-System For Kids: Krill Predators

The eco-system is a word that describes the world around us and our environment. Every animal within the eco-system plays a very important role in the overall function of the earth. Predators and prey are the two major components of the eco-system, and each is equally important. Predators are animals that eat other animals in order to survive. Prey can be defined as the animals that are actually being eaten by the predator. For example, a tiger is a predator, and an elk would be its prey. A tiny little animal called Krill is essential to many marine animals and their survival. This form of prey is a microscopic shrimp-like crustacean that can be found in all of the oceans in the world. These little shrimp make great food for many animals including whales, seals, squid, and other marine life. Although tiny, they are essential foods that help the other animals survive and thrive. Without these millions of small Krill in the ocean, a great deal of species would not survive and it would greatly affect the food chain.


Whales are the world’s largest mammal. These mammals are fully adapted to living in water, but they do come up for air occasionally, using large blowholes located at the top of their heads. There are many different species of whales including the sperm whale, beluga, humpback, orca or killer whale, and the narwhal, to name a few. Whales can be massive in size, and the baleen whales eat Krill exclusively, but some toothed whales like the orca and beluga also prey on other mammals like seals. Whales are high in the food chain and have little to no predators. Because of their size, it is almost impossible for other animals to prey on them. Whales can weight several tons and be larger than a full sized boat.

  • Whale Species – Check out the many different species of whales that live in the waters.
  • Beluga Whales – Learn more about these amazing white colored whales.
  • Whales: Voices in the Sea – An amazing whale-themed website with videos, pictures, sounds and much more.
  • How Did Whales Evolve? – Check out these huge animals have evolved throughout time.
  • Humpback Whales – Discover more about the beloved humpback whale.

Manta Rays

A manta ray is a huge fish, and is the largest of all the rays. This intriguing creature can be found in many different oceans and can dive down deep as far as 500 meters into cold water. Manta rays have interesting shapes that make them look like they can fly. Their large pectorals appear to be wings, and these wings allow them to swim fast and smooth under water. Although quite large, manta rays are usually very gentle towards humans and feed on small fish, plankton, and even sharks. The people of Peru once worshipped the manta ray, and many pieces of Peruvian artwork depict the animal as a regal being.


Seals are amazing marine mammals that live on land but can swim underwater to find their prey. Seals can be large or small, and can live in both cold and warm waters, depending on the species. Most seals eat a variety of fish and are often prey to sharks and some species of whales. Seals have unusual fins that look like flappers, and these help to propel them through the water as they glide gracefully below the sea. Many seals eat Krill and this is an integral part of their diet. Seals serve as both predator and prey, making them an important part of the eco-system.

  • Gray Seal Facts – Learn some amazing facts about the gray seal.
  • Arctic Seals – Check out the beautiful arctic seal and learn more about their home.
  • Harbor Seals – These amazing seals can be found in many places including California.
  • All About Seals – Learn all about these interesting marine mammals.
  • Fun Seal Facts – Discover some fun seal facts here.


Penguins are known as flightless birds, meaning they do not have the ability to fly like many other birds. Most penguins are easily recognizable by their “tuxedo” colored feathers, with a white belly and head and black wings and body. Penguins are excellent swimmers, and can dive deep down into the ocean to seek out Krill and fish for their diet. Penguins are also predators, and are often eaten by sharks or whales if they venture too far off into the deep. Most penguins like cold climates, and some species live in warmer places like Africa. Some birds like eagles actually prey on penguins, so they are an essential part of the food chain.


Squid are cephalopods, a unique subspecies of mollusk. These interesting animals have a very unique shape with a protruding head, tentacles, and an elongated body. They are very strong swimmers and can leap out of the water for brief periods during feeding. Many species of squid, like their cousin the octopus, can shoot ink out to divert predators away from them. Some predators of squid include various sea birds, sharks, and other large fish, and even humans. In some countries, the squid is considered a delicacy to humans.

  • Squids in the US – Discover some of the types of squid that live in the US in places like Washington state.
  • The Glowing Squid – Check out this video that explores the mysterious glowing squid.
  • The Giant Squid – Learn more about the amazing giant squid here.
  • Mollusks, Squid, Octopus – Read about the family that the squid comes from.
  • Squid Facts – Read some quick yet interesting facts about squid here.