Lets discuss how food chains work!

Every animal provides energy for the animal that eats it. For example: 1 fish may need to eat 50 plankton in one day to have enough energy to preform daily functions. 1 octopus may need to eat 15 fish to preform its daily functions. Finally 1 whale may need to eat 5 octopus to preform its daily functions.

This means that 1 whale eats 5 octopus, which survive by eating 75 fish, which need to eat 3,750 plankton. The further down an animal is on the food chain, the less energy they provide for the animal that consumes it. You need to have 50 times as many plankton as you have fish, you need to have 15 times as many fish as you have octopus, and you need 5 times as many octopus as you have whales.  This is how a normal food chain works, there is a perfect number of producers and consumers.

In overpopulation there are so many plankton that there is not enough resources for them all to feed on. They are over crowded. Once the fish begin to eat them, there will be to many fish for the octopus to eat, making the fish overcrowded and competing for recources. The same thing can happen to any oceanic creatures.

In underpopulation there are not enough plankton for the fish to eat, this mean that the fish will starve because they aren’t getting enough to eat. After the fish starve, there won’t be enough fish for the octopus to survive. After the octopus have eaten all of the octopus then they will no longer have any food source.

(All animals have multiple food sources, in our examples we will pretend that each animal can only eat the one specified in this webquest.)


Evaluate the world that each plankton lives in.


He lives in a world of over population, that means that there are not enough wales to eat all the plankton in Coconut Ocean. He doesn't have enough room to grow and there isn't enough bacteria for him to eat because he has to share with all of his friends.

Get Eaten By Get Eaten By Gets Eaten By

A more common way to read this food web is as follows:

                                             Killer Whale    <------- Click to learn more!

                                                 Blue Ringed Octopus     <------- Click to learn more!

                                                     Forage Fish      <-------- Click to learn more!

                                                      Plankton        <------- Click to learn more!

In the case of overpopulation of the plankton, there are not enough wales to eat all the octopus, not enough octopus to eat all of the fish and not enough fish to eat all of the plankton. There will eventually be more plankton living in an area that can be properly supported by that area's resources. Click on the picture of Boardton to learn more about overpopulation.



He lives in a world that has the perfect population of plankton, whales, and every animal in between. In Pineapple Sea the food chain would look something like this:


It is important to see what part of the food chain each animal is (consumers or producers), you will need to know this for your final project. 

When there is the perfect number of plankton to sustain the fish, octopus, and whale life then the food cycle will continue and all the sea animals will be fed. To learn more about how a normal food chain works, click on the picture of Plankton! 



He lives in a world of under population. This means that there are to many whales and not enough plankton! Him and all of his friends are in constant danger of being eaten! He is very scared that he will get eaten too!! In Crabby-Patty Sea, the food chain might look something like this: 

Under population is simply not having enough primary consumers to feed all of the upper level consumers. In the food chain above, there are not enough plankton to feed all of the fish, then there are not enough fish for the sharks to all eat. If nothing is changed in this population, all of the plankton will get eaten, leaving the fish with nothing to eat so they will be eaten or starve, once all of the fish are gone there will be no more food for the sharks which will leave them to starve. 


Parts of the Food Chain

There are many organisms involved in a food chain and each of them plays an important role in it. Both small and big organisms are important in the food chain and without one of them the food chain could fail. As I mentioned before, there are all kids of organisms involved in the food chain and each of these organisms falls under one of two categories; producer or consumer.


Plants are the producers in the food chain. Plants are called producers because they produce their own food. They do so in a process called Photosynthesis.  

Plants use sunlight, carbon dioxide and water to produce sugar and oxygen.

Click on the picture above to learn more about photosynthesis.

Producers are an important part of the food cycle since they are the first stage of the food cycle. Plankton also go through photosynthesis to create their own food and so they are the producers of our food chain. We will use Boardton's food chain as an example. 

 Producer: Plankton known as Boardton



Every other organism that doesn't create their own food through photosynthesis is a consumer. Consumers are organisms that have to eat other organisms for food. The Forage fish, Blue Ringed Octopus, and the Killer Whale in our food chain are consumers since they must consume other organisms. 

 Consumers :

Forage Fish 


Blue Ringed Octopus 


Killer Whale



Our food web is now broken up into producers and consumers. 





Since the food web has so many consumers it is broken down further in the food chain as shown below. 




   Primary Consumer 


    Secondary Consumer 


      Tertiary Consumer 


Consumer Levels

Primary Consumer

The primary Consumer is the organism or animal that ate the producer. They are the first consumer in the food chain.

 Forage Fish are Primary Consumers



Secondary Consumer 

The Secondary Consumer is the animal that ate the Primary Consumer. They are the second consumer in the food chain.

The Blue Ring Octopus is the Secondary Consumer since they eat the Forage Fish.



Tertiary Consumer 

The  Tertiary Consumer is the animal that ate the Secondary Consumer. They are the third consumer in the food chain.

The Killer Whale is the Tertiary Consumer.


The levels go on and on according to the place they are in. 

Consumers can then be broken down further according to what they eat. 

Herbivores, Carnivores, and Omnivores. 

As I mentioned before consumers can be broken down even further according to what they eat. They are either herbivores, carnivores or omnivores. 


These are animals that eat only plants. These animals may eat leaves, grass, flowers, seeds, roots, and fruits. These animals eat non-living matter. 

Plankton that eat bacteria or produce food through photosynthesis would be considered herbivores. 

Many primary consumers are herbivores but not all the time. Some of them may be omnivores. 


These are animals that eat both plants and other animals. Primary Consumers can be omnivores since they eat producers and they may also eat meat.  A good example of a omnivore would be humans or You! We are omnivores because we eat both meat and vegetables. 


These are the animals that only eat meat. Secondary and Tertiary Consumers usually fall under this categories since they eat other animals but there are instances where they may be considered omnivores. Secondary and Tertiary Consumers are never herbivores. Both the Blue Ringed Octopus and the Killer Whale are carnivores. 



Flashcard study game:

Click on the picture to visit this website to help you practice your new vocabulary.