Teacher Background Material

In oceans, as on land, there is a natural interconnection of creatures that forms a kind of food chain.

Diatoms are microscopic plants that make their own food from sunlight.

Zooplankton are tiny sea animals, such as krill, copepods, medusa jellyfish, and crab larvae.

Small fish might include mackerel, herring, and basking sharks, as well as crustaceans (crab, shrimp, lobster), mollusks (clams, scallops) and squid.

Large fish might include swordfish, tuna, octopus, and shark.

Killer whales eat other whales and seals, as well as fish.

Diatoms < Zooplankton < Small Fish < Large Fish < Killer Whales

Some scientists describe the ocean ecosystem more as a web than a chain because many sea creatures eat more than one kind of creature, and some creatures eat others from their own group.