Coral Reef

Biotic Factors

Animals                                   Plants

Caribbean Reef Squid                                   Turf Algae
Banded Coral Shrimp                                    Corralline Algae
Whitetip Reef Shark                                      Manatee Grass  
Green Sea Turtle                                            Mangroves
Giant Clam                                                       Sea Lettuce
Banded Sea Krait                                            Zooxanthellae
Glassfish                                                           Grape Algae     
Laysan Albatross                                           Cactus Algae
Brain Coral                                                       Shoal Grass
Sea Sponge                                                       Mermaid's Wineglass

Abiotic Factors

Warm Temperatures
Humid in the Summer and Dry Air in the Winter
Warm Waters
Lots of Rainfall in the Summer and Little Rainfall in the Winter
Sunlight in the Higher Layers of the Reef
Rocks/Sand in and around the Reef

Carrying Capacity

Definition: the most organisms an ecosystem can support with its resources

Many basic and essential things are needed for a population to survive such as: water, food/nutrients, air/oxygen, shelter, and space to live.

Example specific to the Coral Reef

Whitetip Reef Shark

The most obvious is without water no coral reef organism could survive. If there were no rocks or coral to hide between and under these sharks would most likely starve because they are very clumsy when preying on fish that are suspended in open water. The sharks also need these rocks and caves for shelter. The sharks do not need much space because they are very small sharks and often live on the ocean floor or in underwater caves.

The whitetip reef shark population can grow if their prey's population is thriving. If plankton and algae are abundant then the reef shark's prey will eat and thrive, this leads to more sharks eating the fish and the prey's population goes down. When the prey's population decreases then some of the sharks starve and die off and their population decreases. With less sharks the prey can again thrive. This restarts the cycle of the population change in a species.

Limiting Factors

Definition: resources or environmental conditions that limit the growth of an organism's population

Examples specific to the Coral Reef

   Many factors limit population growth on the coral reef such as proximity to land. Most coral reefs are close to land are are affected by everything that occurs on land such as: construction, coastal clearing and agriculture. Another limiting factor is over-fishing and methods of killing fish. When too many fish are removed then the algae that used to be eaten by the fish grow to much and the balance in the ecosystem is disturbed. Also, breaking off branches of coral, even just a small branch, can break off 10 years of construction. Some methods of killing the reef's fish is by dynamite or cyanide. Reef's can take many, many years to recover from a dynamite explosion. One more factor is global warming, when water temperatures rise too high the algae start to die and the corals soon become bleached. Without the algae many corals would die as well.    

Predator/Prey Relationships

Example specific to the Coral Reef

Bigeye Trevally/Cardinalfish

   The bigeye trevally form big schools to hunt prey fish such as cardinalfish. The bigeye trevally have adapted to be lightning quick and have amazing cooperation with the other fish in their school, this allows them to surround huge schools of cardinalfish and herd them to shore. When the cardinalfish get closer to shore they start to panic, then the bigeye trevallies attack.
  The cardinalfish have adaptions that allow them to sometimes stay away from predators like the bigeye trevallies. First, the cardinal fish travel in schools which allows for more protection. Also, in the schools certain fish are chosen to be "lookouts" and watch for predators. The cardinalfish also have vibration sensors so they can stay in sync with the other fish in the school.

Limiting Factors affect Predator/Prey Relationships

Global warming can affect the bigeye trevally and cardinalfish's relationship, if the water temperature rises too high then the algae that the cardinalfish feed on will die and then the cardinalfish population decreases. When there are less cardinalfish then the bigeye trevallies have less of a food source to eat and soon they start to die off as well. Many other factors also lead to the death of the algae ultimately leading to the population decrease in bigeye trevallies.

Energy Roles


Definition: producers take the radiant energy from the sun and turn it into chemical energy through photosynthesis, without producers transforming energy none of the other levels could receive energy

Examples specific to the Coral Reef

Coralline Algae
Turf Algae

Primary Consumer

Definition: primary consumers eat the producers, they are mostly herbivores but their are some omnivores

Examples specific to the Coral Reef

Sea Sponges
Green Sea Turtles
Sea Urchins

Secondary Consumers

Definition: secondary consumers eat primary consumers and can be omnivores or carnivores

Examples specific to the Coral Reef

Crown-of-thorns Sea Star
Ornate Butterfly Fish
Coral Guard Crab

Tertiary Consumers

Definition: tertiary consumers are the top consumers and eat secondary consumers, they are mostly carnivores but there are few omnivores

Examples specific to the Coral Reef

Moray Eel
Tiger Shark
Hawaiian Monk Seal
Humpback Whale

Food Chains/Webs

Food Webs over Food Chains

Food webs show more possibilities in the flow of energy while food chains only show energy flowing from one organism to the next.

Population Removal

If one population was removed then the population that consumes it would have less food and would soon decrease in population. This would cause the next population to do the same and soon the whole ecosystem is out of balance. On the other hand organisms that were once eaten by that population would increase in population and then the organisms they eat would be over-eaten and soon die off, yet again making the ecosystem go out of balance.

Energy Pyramids

Why a Pyramid?

A pyramid shows that at the base (producers) there is the most energy. As you go up the pyramid energy 90% of the energy is converted from chemical energy to mechanical energy for use for that organism, the other 10% is given to the organism that eats the lower level organism. As you move up the pyramid that 10% becomes smaller and smaller, with less energy less organisms can supported so there are less organisms at the top of the pyramid while they are plentiful at the base.


Chemical Formula for Photosynthesis

CO2 + H2O + Sunlight = C6H12O6 + O2

What this formula means is that CO2 (carbon dioxide), H2O (water), and sunlight are all taken in by a plant. During photosynthesis sunlight is captured by chloroplasts in the plant's cells. This is where the process of photosynthesis takes place. The plant goes through the photosynthesis and creates C6H12O6 (glucose) and O2 (oxygen). The plant consumes the glucose for energy and releases the oxygen into the environment.


Definition: turning/bending movement of an organism toward/away from an external stimulus such as light, heat, gravity

Examples specific to the Coral Reef

Algae and other producers grow in and around the top layer of the water because most light can be captured there.
Mangrove roots bend around corals and other things in the water
Many seagrasses grow in response to more sunlight and more water to grow in


Importance of Decomposers

Decomposers are important because they are needed to return nutrients to the environment for producers. Decomposers eat and break down dead organisms and return their nutrients to the environment. If there were no decomposers then no dead organisms would break down or decompose and no nutrients would return to the environment. When the producers in the ecosystem have no nutrients to live off of then the producers die off. When the producers die then the herbivorous consumers die by lack of food and this causes a chain reaction. This chain reaction will cause a total destruction of the ecosystem.

Examples specific to the Coral Reef

Fan Worms
Sea Cucumbers
Sea Snails
Cleaner Shrimp
Bristle Worms


Importance of Adaptations

Adaptations are very important to species in an environment. Organisms in an environment need to be able to adapt to situations like a rise/decrease in temperature. Without adaptations the organisms in an environment, as cliché as it sounds, would eventually die off because the situation in the environment would overwhelm and be too much for the species.  

Examples specific to the Coral Reef


Zooxantheallae (microscopic algae) go through photosynthesis and convert carbon dioxide and water into oxygen and carbohydrates. Coral polyps use these carbohydrates for nutrients and the oxygen for respiration.
Some fish in coral reefs are immune to jellyfish stings. The fish can take shelter in the tentacles of the jellyfish, luring a prey fish to come near. The prey fish, which is not immune to the jellyfish's sting, will die from the jellyfish sting and the predator fish and the jellyfish can share the catch.


Soft corals use toxic solutions to ward off any predators that might see them as a tasty meal. These toxins make the coral tissue taste bitter and unappetizing.
Corals often compete for room on the reef to grow and expand. The competing corals can release toxins that will ward off the other coral. Some corals have adapted to be able to digest the toxic corals and not be killed by the toxins.

Environment Change

If an organism is placed into a different environment than it is used to it will eventually die. The organism will have the wrong adaptations for the environment. A simple example for the coral reef would be any reef fish. Fish have gills and use them to take in oxygen from water and breathe. If a reef fish is put into a grassland the fish will die because they fish doesn't have lungs and can't breathe in oxygen from the atmosphere.

Natural Selection

Definition: the process in which organisms better adapted to their environment tend to survive and produce more offspring

Importance of Natural Selection

Natural Selection is important because it allows organisms to thrive and prosper. Natural selection can also rid an environment of sick and less adapted species. This in turn also lets better adapted species survive and make more adapted offspring.

Example specific to the Coral Reef

Corals have algae like zooxanthellae inside of the coral polyps. When the water that the coral is living in heats up to a certain temperature the coral ejects the algae and the coral becomes bleached (dead). The Acropora hyacinthus coral or the "table top coral" (named for its round and flat appearance), is much more heat resistant than most other corals. The coral has become more resistant to heat over several generations. Each new generation of offspring has better genes and is more tolerant to the rising water temperatures. Due to global warming, the world's oceans are heating up and this causes the corals to become bleached. This coral that has heat resistant genes can survive and help keep the coral reefs alive.

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2 years ago

Really well composed and amazing quality😄

2 years ago

nice quality pics bro 👍 👍 😄 😃

2 years ago

Thanks you guys Jacob, Matthew and Matthew, Katy, Kaylin, Alex,Jayden, and Makenna

2 years ago

Looks great!

2 years ago

thanks @dianegunnip

2 years ago

I like the detail in the in each headline, and the organization.

2 years ago

Great job wade

2 years ago

I like your descriptions for each animal

2 years ago
2 years ago

I like the pictures, information, and color.