CoralsCorals

Landlords of the ReefsLandlords of the Reefs

What is a coral reef?What is a coral reef?    A reef is a coral community consisting of several A reef is a coral community consisting of several thousand organisms living together. thousand organisms living together.

Reefs grow very slowly over time. In fact, an inch Reefs grow very slowly over time. In fact, an inch of coral reef takes nearly 100 years to grow! of coral reef takes nearly 100 years to grow!

Where are Coral Reefs?Where are Coral Reefs?

World wide, coral reefs cover World wide, coral reefs cover 600,000 square miles and are 600,000 square miles and are home to over 500,000 species!home to over 500,000 species!

So many fish live near coral So many fish live near coral reefs…reefs…

What’s a Polyp?What’s a Polyp?

The actual animal The actual animal that makes up the that makes up the physical coral is physical coral is called a polyp. called a polyp.

Thousands of Thousands of individual polyps individual polyps form a colony, which form a colony, which in turn forms a reef. in turn forms a reef.

Plants live inside of Plants live inside of themthem

What makes the reef What makes the reef hard?hard?

Each individual polyp is responsible for each bump Each individual polyp is responsible for each bump in the reef. in the reef.

Each polyp creates its own skeleton, usually made Each polyp creates its own skeleton, usually made up of calcium carbonate (chalk), which it lives in. up of calcium carbonate (chalk), which it lives in.

Polyps are active at night. During the daytime, they Polyps are active at night. During the daytime, they retreat into their skeleton, so divers usually only retreat into their skeleton, so divers usually only see their skeletons. see their skeletons.

Zoo-what!?! Zoo-what!?! Algae, Coral Polyps’ Algae, Coral Polyps’

TenantsTenants

Inside polyps live zooxanthellae, Inside polyps live zooxanthellae, which are algae.which are algae.

Zooxanthellae give corals their Zooxanthellae give corals their color.color.

Since algae are plants, they use Since algae are plants, they use sunlight and COsunlight and CO22 to make food (the to make food (the process known as photosynthesis).process known as photosynthesis).

Zooxanthellae

Tiny plant cells called zooxanthellae live within most types of coral polyps. They provide the coral

with foods resulting from photosynthesis.

Symbiosis:Symbiosis:So Happy TogetherSo Happy Together

Two organisms living together and Two organisms living together and helping each other is called helping each other is called symbiosissymbiosis.. Zooxanthellae make oxygen, remove the Zooxanthellae make oxygen, remove the

polyp’s wastes, and make food for the polyp’s wastes, and make food for the polyp from photosynthesis.polyp from photosynthesis.

Coral polyps protect the zooxanthellae, Coral polyps protect the zooxanthellae, release COrelease CO22, and provide it with , and provide it with necessary nutrients from their own waste.necessary nutrients from their own waste.

Mutually Beneficial Mutually Beneficial SymbiosisSymbiosis

A Win-Win SituationA Win-Win Situation

Egyptian Plover bird and crocodileEgyptian Plover bird and crocodile Bumblebee and flowersBumblebee and flowers Lichens (fungi and algae)Lichens (fungi and algae) Your intestine and bacteriaYour intestine and bacteria

Zooxanthellae cells provide corals with pigmentation. On the left is a healthy stony coral. On the right is a stony coral that has lost its zooxanthellae cells and has taken on a bleached appearance. If a coral polyp is without zooxanthellae cells for a long period of time, it will most likely die.

Threats to Coral ReefsThreats to Coral Reefs

Human ContactHuman Contact Runoff WaterRunoff Water SewageSewage Cyanide FishingCyanide Fishing Fertilizers and PollutionFertilizers and Pollution Blast FishingBlast Fishing

Algae GrowthAlgae Growth

Blast FishingBlast Fishing

Bahamian Reef SurveyBahamian Reef Survey

EarthWatch: San SalvadorEarthWatch: San Salvador

Hard CoralsHard Corals

Soft CoralsSoft Corals

Parasitic Symbiosis Parasitic Symbiosis A Win-Lose SituationA Win-Lose Situation

Tapeworms and intestinesTapeworms and intestines Ticks and dogsTicks and dogs Mistletoe and treesMistletoe and trees

How are these mutually How are these mutually symbiotic?symbiotic?

Drivers and passengers in a Drivers and passengers in a carpoolcarpool

Tenants and landlordsTenants and landlords