Animals and plants are all linked. Animals and plants living together create an ecosystem. They rely on each other to survive. Some animals hunt other animals. Others are hunted by animals. They all have a special role.
A food chain shows how animals are linked together. It shows what animals and plants eat and by what they are eaten. Each animal occupies a different trophic level. It is their position in the food chain.
Food chains are specific to each ecosystem. Let's look at a marine food chain. Algae is a plant in water. It is at the bottom of the food chain.
In fact, plants are at the bottom of every food chain. Plants are examples of producers. That is because they make their own food. Plants get food from the sun.
What eats the algae? Algae is eaten by krill. Krill are little animals that are like shrimp. They are herbivores. They do not eat meat. There is a lot of krill around.
Krill is an example of a consumer. Consumption is its method of creating energy. We call it a primary consumer because it is the first consumer in the food chain.
Krill gets eaten by small fish. One of these small fish is called cod. Cod are omnivores. That means they eat both meat and plants. It depends what they can find at the time.
Cod is also a consumer. It is a secondary consumer because it eats the primary consumer of the food chain.
Many animals like to eat cod. One animal that eats cod is the leopard seal. It is the second largest species of seal. They are carnivores. They eat meat like fish and birds.
Leopard seals are also consumers. They are tertiary consumers because they eat the primary and secondary consumers in the food chain.
What eats the leopard seal? The leopard seal only has one natural predator. It is the orca. The orca is one of the largest marine mammals.
What eats the orca? Well, nothing. The orca is an apex predator. It has no natural enemies. It is at the top of the food chain .
When an apex predator dies, its body goes back into the ecosystem. Sometimes it is eaten by scavengers. They are animals who find food to eat.
Sometimes it is left to decomposers. Decomposers complete the food chain. They break down the body of an apex predator and use it to make the soil more fertile. This allows plants to grow. Then the food chain starts again.
There are many food chains in an ecosystem. These food chains all come together to create a food web.
Food chains are very delicate. If one part of the food chain is broken, all parts are in danger. Humans often damage natural food chains. If we eat all the animals or cut down the plants, we risk ruining food chains. What will the rest of the food chain do if a part is missing?